Commit graph

903 commits

Author SHA1 Message Date
Wei Liu
3019270282 Revert "Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer"
This reverts commit a8c3209998.

It is reported that the said commit caused regression in netvsc.

Reported-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-15 10:49:11 +00:00
Wei Liu
7e279d7866 Drivers: hv: vmbus: skip VMBus initialization if Linux is root
There is no VMBus and the other infrastructures initialized in
hv_acpi_init when Linux is running as the root partition.

Signed-off-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-4-wei.liu@kernel.org
2021-02-11 08:47:06 +00:00
Andrea Parri (Microsoft)
7ef4b2f0d9 Drivers: hv: vmbus: Enforce 'VMBus version >= 5.2' on isolated guests
Restrict the protocol version(s) that will be negotiated with the host
to be 5.2 or greater if the guest is running isolated.  This reduces the
footprint of the code that will be exercised by Confidential VMs and
hence the exposure to bugs and vulnerabilities.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210201144814.2701-4-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11 08:47:05 +00:00
Andrea Parri (Microsoft)
21a4e356d3 Drivers: hv: vmbus: Restrict vmbus_devices on isolated guests
Only the VSCs or ICs that have been hardened and that are critical for
the successful adoption of Confidential VMs should be allowed if the
guest is running isolated.  This change reduces the footprint of the
code that will be exercised by Confidential VMs and hence the exposure
to bugs and vulnerabilities.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210201144814.2701-3-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11 08:47:05 +00:00
Colin Ian King
bdb49526d2 hv_utils: Fix spelling mistake "Hearbeat" -> "Heartbeat"
There is a spelling mistake in an error message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20210127233136.623465-1-colin.king@canonical.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11 08:47:05 +00:00
Dexuan Cui
c068e3f484 Drivers: hv: vmbus: Add /sys/bus/vmbus/hibernation
When a Linux VM runs on Hyper-V, if the host toolstack doesn't support
hibernation for the VM (this happens on old Hyper-V hosts like Windows
Server 2016, or new Hyper-V hosts if the admin or user doesn't declare
the hibernation intent for the VM), the VM is discouraged from trying
hibernation (because the host doesn't guarantee that the VM's virtual
hardware configuration will remain exactly the same across hibernation),
i.e. the VM should not try to set up the swap partition/file for
hibernation, etc.

x86 Hyper-V uses the presence of the virtual ACPI S4 state as the
indication of the host toolstack support for a VM. Currently there is
no easy and reliable way for the userspace to detect the presence of
the state (see https://lkml.org/lkml/2020/12/11/1097).  Add
/sys/bus/vmbus/hibernation for this purpose.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210107014552.14234-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11 08:47:05 +00:00
Andrea Parri (Microsoft)
e4d221b423 Drivers: hv: vmbus: Resolve race condition in vmbus_onoffer_rescind()
An erroneous or malicious host could send multiple rescind messages for
a same channel.  In vmbus_onoffer_rescind(), the guest maps the channel
ID to obtain a pointer to the channel object and it eventually releases
such object and associated data.  The host could time rescind messages
and lead to an use-after-free.  Add a new flag to the channel structure
to make sure that only one instance of vmbus_onoffer_rescind() can get
the reference to the channel object.

Reported-by: Juan Vazquez <juvazq@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-6-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Andrea Parri (Microsoft)
e3fa4b747f Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind()
When channel->device_obj is non-NULL, vmbus_onoffer_rescind() could
invoke put_device(), that will eventually release the device and free
the channel object (cf. vmbus_device_release()).  However, a pointer
to the object is dereferenced again later to load the primary_channel.
The use-after-free can be avoided by noticing that this load/check is
redundant if device_obj is non-NULL: primary_channel must be NULL if
device_obj is non-NULL, cf. vmbus_add_channel_work().

Fixes: 54a66265d6 ("Drivers: hv: vmbus: Fix rescind handling")
Reported-by: Juan Vazquez <juvazq@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-5-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Andrea Parri (Microsoft)
fe8c1b18a2 Drivers: hv: vmbus: Copy the hv_message in vmbus_on_msg_dpc()
Since the message is in memory shared with the host, an erroneous or a
malicious Hyper-V could 'corrupt' the message while vmbus_on_msg_dpc()
or individual message handlers are executing.  To prevent it, copy the
message into private memory.

Reported-by: Juan Vazquez <juvazq@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-4-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Andrea Parri (Microsoft)
9c400d3548 Drivers: hv: vmbus: Reduce number of references to message in vmbus_on_msg_dpc()
Simplify the function by removing various references to the hv_message
'msg', introduce local variables 'msgtype' and 'payload_size'.

Suggested-by: Juan Vazquez <juvazq@microsoft.com>
Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-3-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Andrea Parri (Microsoft)
e99c4afbee Drivers: hv: vmbus: Initialize memory to be sent to the host
__vmbus_open() and vmbus_teardown_gpadl() do not inizialite the memory
for the vmbus_channel_open_channel and the vmbus_channel_gpadl_teardown
objects they allocate respectively.  These objects contain padding bytes
and fields that are left uninitialized and that are later sent to the
host, potentially leaking guest data.  Zero initialize such fields to
avoid leaking sensitive information to the host.

Reported-by: Juan Vazquez <juvazq@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201209070827.29335-2-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Andres Beltran
06caa778d8 hv_utils: Add validation for untrusted Hyper-V values
For additional robustness in the face of Hyper-V errors or malicious
behavior, validate all values that originate from packets that Hyper-V
has sent to the guest in the host-to-guest ring buffer. Ensure that
invalid values cannot cause indexing off the end of the icversion_data
array in vmbus_prep_negotiate_resp().

Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by:  Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201109100704.9152-1-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Andres Beltran
a8c3209998 Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer
Pointers to ring-buffer packets sent by Hyper-V are used within the
guest VM. Hyper-V can send packets with erroneous values or modify
packet fields after they are processed by the guest. To defend
against these scenarios, return a copy of the incoming VMBus packet
after validating its length and offset fields in hv_pkt_iter_first().
In this way, the packet can no longer be modified by the host.

Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: netdev@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201208045311.10244-1-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-05 09:55:42 +00:00
Dexuan Cui
dfe94d4086 x86/hyperv: Fix kexec panic/hang issues
Currently the kexec kernel can panic or hang due to 2 causes:

1) hv_cpu_die() is not called upon kexec, so the hypervisor corrupts the
old VP Assist Pages when the kexec kernel runs. The same issue is fixed
for hibernation in commit 421f090c81 ("x86/hyperv: Suspend/resume the
VP assist page for hibernation"). Now fix it for kexec.

2) hyperv_cleanup() is called too early. In the kexec path, the other CPUs
are stopped in hv_machine_shutdown() -> native_machine_shutdown(), so
between hv_kexec_handler() and native_machine_shutdown(), the other CPUs
can still try to access the hypercall page and cause panic. The workaround
"hv_hypercall_pg = NULL;" in hyperv_cleanup() is unreliabe. Move
hyperv_cleanup() to a better place.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201222065541.24312-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-01-05 17:52:04 +00:00
Linus Torvalds
571b12dd1a hyperv-next for 5.11
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Merge tag 'hyperv-next-signed-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Wei Liu:

 - harden VMBus (Andres Beltran)

 - clean up VMBus driver (Matheus Castello)

 - fix hv_balloon reporting (Vitaly Kuznetsov)

 - fix a potential OOB issue (Andrea Parri)

 - remove an obsolete TODO item (Stefan Eschenbacher)

* tag 'hyperv-next-signed-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv_balloon: do adjust_managed_page_count() when ballooning/un-ballooning
  hv_balloon: simplify math in alloc_balloon_pages()
  drivers/hv: remove obsolete TODO and fix misleading typo in comment
  drivers: hv: vmbus: Fix checkpatch SPLIT_STRING
  hv_netvsc: Validate number of allocated sub-channels
  drivers: hv: vmbus: Fix call msleep using < 20ms
  drivers: hv: vmbus: Fix checkpatch LINE_SPACING
  drivers: hv: vmbus: Replace symbolic permissions by octal permissions
  drivers: hv: Fix hyperv_record_panic_msg path on comment
  hv_netvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening
  scsi: storvsc: Use vmbus_requestor to generate transaction IDs for VMBus hardening
  Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening
2020-12-16 11:49:46 -08:00
Vitaly Kuznetsov
d1df458cbf hv_balloon: do adjust_managed_page_count() when ballooning/un-ballooning
Unlike virtio_balloon/virtio_mem/xen balloon drivers, Hyper-V balloon driver
does not adjust managed pages count when ballooning/un-ballooning and this leads
to incorrect stats being reported, e.g. unexpected 'free' output.

Note, the calculation in post_status() seems to remain correct: ballooned out
pages are never 'available' and we manually add dm->num_pages_ballooned to
'commited'.

Suggested-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201202161245.2406143-3-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-13 15:06:10 +00:00
Vitaly Kuznetsov
7f3f227b41 hv_balloon: simplify math in alloc_balloon_pages()
'alloc_unit' in alloc_balloon_pages() is either '512' for 2M allocations or
'1' for 4k allocations. So

1 << get_order(alloc_unit << PAGE_SHIFT)

equals to 'alloc_unit' and the for loop basically sets all them offline.
Simplify the math to improve the readability.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201202161245.2406143-2-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-13 15:06:05 +00:00
Stefan Eschenbacher
5c641fee4c drivers/hv: remove obsolete TODO and fix misleading typo in comment
Removes an obsolete TODO in the VMBus module and fixes a misleading typo
in the comment for the macro MAX_NUM_CHANNELS, where two digits have been
twisted.

Signed-off-by: Stefan Eschenbacher <stefan.eschenbacher@fau.de>
Co-developed-by: Max Stolze <max.stolze@fau.de>
Signed-off-by: Max Stolze <max.stolze@fau.de>
Link: https://lore.kernel.org/r/20201206104850.24843-1-stefan.eschenbacher@fau.de
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-07 11:24:08 +00:00
Matheus Castello
b0c03eff79 drivers: hv: vmbus: Fix checkpatch SPLIT_STRING
Checkpatch emits WARNING: quoted string split across lines.
To keep the code clean and with the 80 column length indentation the
check and registration code for kmsg_dump_register has been transferred
to a new function hv_kmsg_dump_register.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201125032926.17002-1-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-12-02 11:54:19 +00:00
Matheus Castello
14c685d9eb drivers: hv: vmbus: Fix call msleep using < 20ms
Fixed checkpatch warning: MSLEEP: msleep < 20ms can sleep for up to
20ms; see Documentation/timers/timers-howto.rst

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-7-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:56:48 +00:00
Matheus Castello
e4f2212e53 drivers: hv: vmbus: Fix checkpatch LINE_SPACING
Fixed checkpatch warning: Missing a blank line after declarations
checkpatch(LINE_SPACING)

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-4-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:56:44 +00:00
Matheus Castello
f0434de41a drivers: hv: vmbus: Replace symbolic permissions by octal permissions
This fixed the below checkpatch issue:
WARNING: Symbolic permissions 'S_IRUGO' are not preferred.
Consider using octal permissions '0444'.

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-3-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:56:39 +00:00
Matheus Castello
b18e358972 drivers: hv: Fix hyperv_record_panic_msg path on comment
Fix the kernel parameter path in the comment, in the documentation the
parameter is correct but if someone who is studying the code and see
this first can get confused and try to access the wrong path/parameter

Signed-off-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201115195734.8338-2-matheus@castello.eng.br
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:56:24 +00:00
Andres Beltran
e8b7db3844 Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening
Currently, VMbus drivers use pointers into guest memory as request IDs
for interactions with Hyper-V. To be more robust in the face of errors
or malicious behavior from a compromised Hyper-V, avoid exposing
guest memory addresses to Hyper-V. Also avoid Hyper-V giving back a
bad request ID that is then treated as the address of a guest data
structure with no validation. Instead, encapsulate these memory
addresses and provide small integers as request IDs.

Signed-off-by: Andres Beltran <lkmlabelt@gmail.com>
Co-developed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20201109100402.8946-2-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-17 10:51:06 +00:00
Linus Torvalds
a5698b3835 hyperv-fixes for 5.10-rc5
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Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V fix from Wei Liu:
 "One patch from Chris to fix kexec on Hyper-V"

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Allow cleanup of VMBUS_CONNECT_CPU if disconnected
2020-11-16 15:02:33 -08:00
Chris Co
92e4dc8b05 Drivers: hv: vmbus: Allow cleanup of VMBUS_CONNECT_CPU if disconnected
When invoking kexec() on a Linux guest running on a Hyper-V host, the
kernel panics.

    RIP: 0010:cpuhp_issue_call+0x137/0x140
    Call Trace:
    __cpuhp_remove_state_cpuslocked+0x99/0x100
    __cpuhp_remove_state+0x1c/0x30
    hv_kexec_handler+0x23/0x30 [hv_vmbus]
    hv_machine_shutdown+0x1e/0x30
    machine_shutdown+0x10/0x20
    kernel_kexec+0x6d/0x96
    __do_sys_reboot+0x1ef/0x230
    __x64_sys_reboot+0x1d/0x20
    do_syscall_64+0x6b/0x3d8
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

This was due to hv_synic_cleanup() callback returning -EBUSY to
cpuhp_issue_call() when tearing down the VMBUS_CONNECT_CPU, even
if the vmbus_connection.conn_state = DISCONNECTED. hv_synic_cleanup()
should succeed in the case where vmbus_connection.conn_state
is DISCONNECTED.

Fix is to add an extra condition to test for
vmbus_connection.conn_state == CONNECTED on the VMBUS_CONNECT_CPU and
only return early if true. This way the kexec() path can still shut
everything down while preserving the initial behavior of preventing
CPU offlining on the VMBUS_CONNECT_CPU while the VM is running.

Fixes: 8a857c5542 ("Drivers: hv: vmbus: Always handle the VMBus messages on CPU0")
Signed-off-by: Chris Co <chrco@microsoft.com>
Reviewed-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201110190118.15596-1-chrco@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-11-11 10:58:09 +00:00
Linus Torvalds
6732b35485 hyperv-fixes for 5.10-rc3
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Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - clarify a comment (Michael Kelley)

 - change a pr_warn() to pr_info() (Olaf Hering)

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Clarify comment on x2apic mode
  hv_balloon: disable warning when floor reached
2020-11-05 11:32:03 -08:00
Olaf Hering
2c3bd2a5c8 hv_balloon: disable warning when floor reached
It is not an error if the host requests to balloon down, but the VM
refuses to do so. Without this change a warning is logged in dmesg
every five minutes.

Fixes:  b3bb97b8a4 ("Drivers: hv: balloon: Add logging for dynamic memory operations")

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20201008071216.16554-1-olaf@aepfle.de
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-19 13:39:20 +00:00
Linus Torvalds
c4cf498dc0 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
 "155 patches.

  Subsystems affected by this patch series: mm (dax, debug, thp,
  readahead, page-poison, util, memory-hotplug, zram, cleanups), misc,
  core-kernel, get_maintainer, MAINTAINERS, lib, bitops, checkpatch,
  binfmt, ramfs, autofs, nilfs, rapidio, panic, relay, kgdb, ubsan,
  romfs, and fault-injection"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (155 commits)
  lib, uaccess: add failure injection to usercopy functions
  lib, include/linux: add usercopy failure capability
  ROMFS: support inode blocks calculation
  ubsan: introduce CONFIG_UBSAN_LOCAL_BOUNDS for Clang
  sched.h: drop in_ubsan field when UBSAN is in trap mode
  scripts/gdb/tasks: add headers and improve spacing format
  scripts/gdb/proc: add struct mount & struct super_block addr in lx-mounts command
  kernel/relay.c: drop unneeded initialization
  panic: dump registers on panic_on_warn
  rapidio: fix the missed put_device() for rio_mport_add_riodev
  rapidio: fix error handling path
  nilfs2: fix some kernel-doc warnings for nilfs2
  autofs: harden ioctl table
  ramfs: fix nommu mmap with gaps in the page cache
  mm: remove the now-unnecessary mmget_still_valid() hack
  mm/gup: take mmap_lock in get_dump_page()
  binfmt_elf, binfmt_elf_fdpic: use a VMA list snapshot
  coredump: rework elf/elf_fdpic vma_dump_size() into common helper
  coredump: refactor page range dumping into common helper
  coredump: let dump_emit() bail out on short writes
  ...
2020-10-16 11:31:55 -07:00
David Hildenbrand
2c76e7f6c4 hv_balloon: try to merge system ram resources
Let's try to merge system ram resources we add, to minimize the number of
resources in /proc/iomem.  We don't care about the boundaries of
individual chunks we added.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Julien Grall <julien@xen.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Leonardo Bras <leobras.c@gmail.com>
Cc: Libor Pechacek <lpechacek@suse.cz>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lkml.kernel.org/r/20200911103459.10306-9-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:18 -07:00
David Hildenbrand
b611719978 mm/memory_hotplug: prepare passing flags to add_memory() and friends
We soon want to pass flags, e.g., to mark added System RAM resources.
mergeable.  Prepare for that.

This patch is based on a similar patch by Oscar Salvador:

https://lkml.kernel.org/r/20190625075227.15193-3-osalvador@suse.de

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Juergen Gross <jgross@suse.com> # Xen related part
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Pingfan Liu <kernelfans@gmail.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Libor Pechacek <lpechacek@suse.cz>
Cc: Anton Blanchard <anton@ozlabs.org>
Cc: Leonardo Bras <leobras.c@gmail.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Julien Grall <julien@xen.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Link: https://lkml.kernel.org/r/20200911103459.10306-5-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:18 -07:00
Linus Torvalds
2d0f6b0aab hyperv-next for 5.10, part 2
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull another Hyper-V update from Wei Liu:
 "One patch from Michael to get VMbus interrupt from ACPI DSDT"

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT
2020-10-15 15:48:06 -07:00
Michael Kelley
626b901f60 Drivers: hv: vmbus: Add parsing of VMbus interrupt in ACPI DSDT
On ARM64, Hyper-V now specifies the interrupt to be used by VMbus
in the ACPI DSDT.  This information is not used on x86 because the
interrupt vector must be hardcoded.  But update the generic
VMbus driver to do the parsing and pass the information to the
architecture specific code that sets up the Linux IRQ.  Update
consumers of the interrupt to get it from an architecture specific
function.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1597434304-40631-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-10-14 19:14:51 +00:00
Linus Torvalds
4907a43da8 hyperv-next for 5.10
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Wei Liu:

 - a series from Boqun Feng to support page size larger than 4K

 - a few miscellaneous clean-ups

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv: clocksource: Add notrace attribute to read_hv_sched_clock_*() functions
  x86/hyperv: Remove aliases with X64 in their name
  PCI: hv: Document missing hv_pci_protocol_negotiation() parameter
  scsi: storvsc: Support PAGE_SIZE larger than 4K
  Driver: hv: util: Use VMBUS_RING_SIZE() for ringbuffer sizes
  HID: hyperv: Use VMBUS_RING_SIZE() for ringbuffer sizes
  Input: hyperv-keyboard: Use VMBUS_RING_SIZE() for ringbuffer sizes
  hv_netvsc: Use HV_HYP_PAGE_SIZE for Hyper-V communication
  hv: hyperv.h: Introduce some hvpfn helper functions
  Drivers: hv: vmbus: Move virt_to_hvpfn() to hyperv header
  Drivers: hv: Use HV_HYP_PAGE in hv_synic_enable_regs()
  Drivers: hv: vmbus: Introduce types of GPADL
  Drivers: hv: vmbus: Move __vmbus_open()
  Drivers: hv: vmbus: Always use HV_HYP_PAGE_SIZE for gpadl
  drivers: hv: remove cast from hyperv_die_event
2020-10-14 10:32:10 -07:00
Boqun Feng
061dc93ef6 Driver: hv: util: Use VMBUS_RING_SIZE() for ringbuffer sizes
For a Hyper-V vmbus, the size of the ringbuffer has two requirements:

1) it has to take one PAGE_SIZE for the header

2) it has to be PAGE_SIZE aligned so that double-mapping can work

VMBUS_RING_SIZE() could calculate a correct ringbuffer size which
fulfills both requirements, therefore use it to make sure vmbus work
when PAGE_SIZE != HV_HYP_PAGE_SIZE (4K).

Note that since the argument for VMBUS_RING_SIZE() is the size of
payload (data part), so it will be minus 4k (the size of header when
PAGE_SIZE = 4k) than the original value to keep the ringbuffer total
size unchanged when PAGE_SIZE = 4k.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Cc: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-11-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-28 08:57:28 +00:00
Boqun Feng
bca6b91dfd Drivers: hv: vmbus: Move virt_to_hvpfn() to hyperv header
There will be more places other than vmbus where we need to calculate
the Hyper-V page PFN from a virtual address, so move virt_to_hvpfn() to
hyperv generic header.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-6-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-28 08:55:13 +00:00
Boqun Feng
ef514d3e38 Drivers: hv: Use HV_HYP_PAGE in hv_synic_enable_regs()
Both the base_*_gpa should use the guest page number in Hyper-V page, so
use HV_HYP_PAGE instead of PAGE.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-5-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-28 08:55:12 +00:00
Boqun Feng
c1135c7fd0 Drivers: hv: vmbus: Introduce types of GPADL
This patch introduces two types of GPADL: HV_GPADL_{BUFFER, RING}. The
types of GPADL are purely the concept in the guest, IOW the hypervisor
treat them as the same.

The reason of introducing the types for GPADL is to support guests whose
page size is not 4k (the page size of Hyper-V hypervisor). In these
guests, both the headers and the data parts of the ringbuffers need to
be aligned to the PAGE_SIZE, because 1) some of the ringbuffers will be
mapped into userspace and 2) we use "double mapping" mechanism to
support fast wrap-around, and "double mapping" relies on ringbuffers
being page-aligned. However, the Hyper-V hypervisor only uses 4k
(HV_HYP_PAGE_SIZE) headers. Our solution to this is that we always make
the headers of ringbuffers take one guest page and when GPADL is
established between the guest and hypervisor, the only first 4k of
header is used. To handle this special case, we need the types of GPADL
to differ different guest memory usage for GPADL.

Type enum is introduced along with several general interfaces to
describe the differences between normal buffer GPADL and ringbuffer
GPADL.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-4-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-28 08:55:12 +00:00
Boqun Feng
edd9bbc1d9 Drivers: hv: vmbus: Move __vmbus_open()
Pure function movement, no functional changes. The move is made, because
in a later change, __vmbus_open() will rely on some static functions
afterwards, so we separate the move and the modification of
__vmbus_open() in two patches to make it easy to review.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-3-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-28 08:55:12 +00:00
Boqun Feng
a5dda201a0 Drivers: hv: vmbus: Always use HV_HYP_PAGE_SIZE for gpadl
Since the hypervisor always uses 4K as its page size, the size of PFNs
used for gpadl should be HV_HYP_PAGE_SIZE rather than PAGE_SIZE, so
adjust this accordingly as the preparation for supporting 16K/64K page
size guests. No functional changes on x86, since PAGE_SIZE is always 4k
(equals to HV_HYP_PAGE_SIZE).

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200916034817.30282-2-boqun.feng@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-28 08:55:12 +00:00
Linus Torvalds
00acc50506 hyperv-fixes for 5.9-rc6
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Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:
 "Two patches from Michael and Dexuan to fix vmbus hanging issues"

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload
  Drivers: hv: vmbus: hibernation: do not hang forever in vmbus_bus_resume()
2020-09-15 16:20:43 -07:00
Michael Kelley
911e1987ef Drivers: hv: vmbus: Add timeout to vmbus_wait_for_unload
vmbus_wait_for_unload() looks for a CHANNELMSG_UNLOAD_RESPONSE message
coming from Hyper-V.  But if the message isn't found for some reason,
the panic path gets hung forever.  Add a timeout of 10 seconds to prevent
this.

Fixes: 415719160d ("Drivers: hv: vmbus: avoid scheduling in interrupt context in vmbus_initiate_unload()")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/1600026449-23651-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-14 11:42:33 +00:00
Dexuan Cui
19873eec7e Drivers: hv: vmbus: hibernation: do not hang forever in vmbus_bus_resume()
After we Stop and later Start a VM that uses Accelerated Networking (NIC
SR-IOV), currently the VF vmbus device's Instance GUID can change, so after
vmbus_bus_resume() -> vmbus_request_offers(), vmbus_onoffer() can not find
the original vmbus channel of the VF, and hence we can't complete()
vmbus_connection.ready_for_resume_event in check_ready_for_resume_event(),
and the VM hangs in vmbus_bus_resume() forever.

Fix the issue by adding a timeout, so the resuming can still succeed, and
the saved state is not lost, and according to my test, the user can disable
Accelerated Networking and then will be able to SSH into the VM for
further recovery. Also prevent the VM in question from suspending again.

The host will be fixed so in future the Instance GUID will stay the same
across hibernation.

Fixes: d8bd2d442b ("Drivers: hv: vmbus: Resume after fixing up old primary channels")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200905025555.45614-1-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-09-09 11:37:19 +00:00
Linus Torvalds
51c4518ab7 hyperv-fixes for 5.9-rc3
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Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:
 "Two patches from Vineeth to improve Hyper-V timesync facility"

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv_utils: drain the timesync packets on onchannelcallback
  hv_utils: return error if host timesysnc update is stale
2020-08-26 10:44:15 -07:00
Vineeth Pillai
b46b4a8a57 hv_utils: drain the timesync packets on onchannelcallback
There could be instances where a system stall prevents the timesync
packets to be consumed. And this might lead to more than one packet
pending in the ring buffer. Current code empties one packet per callback
and it might be a stale one. So drain all the packets from ring buffer
on each callback.

Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200821152849.99517-1-viremana@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-24 14:49:04 +00:00
Vineeth Pillai
90b125f4cd hv_utils: return error if host timesysnc update is stale
If for any reason, host timesync messages were not processed by
the guest, hv_ptp_gettime() returns a stale value and the
caller (clock_gettime, PTP ioctl etc) has no means to know this
now. Return an error so that the caller knows about this.

Signed-off-by: Vineeth Pillai <viremana@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200821152523.99364-1-viremana@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-24 14:48:37 +00:00
Gustavo A. R. Silva
df561f6688 treewide: Use fallthrough pseudo-keyword
Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23 17:36:59 -05:00
Olaf Hering
49971e6bad drivers: hv: remove cast from hyperv_die_event
No need to cast a void pointer.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Link: https://lore.kernel.org/r/20200819090510.28995-1-olaf@aepfle.de
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-19 11:28:54 +00:00
Linus Torvalds
cd94257d7a hyperv-fixes for 5.9-rc
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Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyper-v fixes from Wei Liu:

 - fix oops reporting on Hyper-V

 - make objtool happy

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/hyperv: Make hv_setup_sched_clock inline
  Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops
2020-08-14 13:31:25 -07:00
Michael Kelley
608a973bd5 Drivers: hv: vmbus: Only notify Hyper-V for die events that are oops
Hyper-V currently may be notified of a panic for any die event. But
this results in false panic notifications for various user space traps
that are die events. Fix this by ignoring die events that aren't oops.

Fixes: 510f7aef65 ("Drivers: hv: vmbus: prefer 'die' notification chain to 'panic'")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/1596730935-11564-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-08-07 13:49:37 +00:00
Linus Torvalds
9ab9bc5115 hyperv-next for 5.9
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - A patch series from Andrea to improve vmbus code

 - Two clean-up patches from Alexander and Randy

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hyperv: hyperv.h: drop a duplicated word
  tools: hv: change http to https in hv_kvp_daemon.c
  Drivers: hv: vmbus: Remove the lock field from the vmbus_channel struct
  scsi: storvsc: Introduce the per-storvsc_device spinlock
  Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list updaters)
  Drivers: hv: vmbus: Use channel_mutex in channel_vp_mapping_show()
  Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list readers)
  Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with cpu_online()
  Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel struct
  Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel struct
2020-08-06 09:26:10 -07:00
Joseph Salisbury
77b48bea2f Drivers: hv: Change flag to write log level in panic msg to false
When the kernel panics, one page of kmsg data may be collected and sent to
Hyper-V to aid in diagnosing the failure.  The collected kmsg data typically
 contains 50 to 100 lines, each of which has a log level prefix that isn't
very useful from a diagnostic standpoint.  So tell kmsg_dump_get_buffer()
to not include the log level, enabling more information that *is* useful to
fit in the page.

Requesting in stable kernels, since many kernels running in production are
stable releases.

Cc: stable@vger.kernel.org
Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1593210497-114310-1-git-send-email-joseph.salisbury@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-29 10:30:35 +00:00
Andrea Parri (Microsoft)
775f43facf Drivers: hv: vmbus: Remove the lock field from the vmbus_channel struct
The spinlock is (now) *not used to protect test-and-set accesses
to attributes of the structure or sc_list operations.

There is, AFAICT, a distinct lack of {WRITE,READ}_ONCE()s in the
handling of channel->state, but the changes below do not seem to
make things "worse".  ;-)

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-9-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-20 09:16:19 +00:00
Andrea Parri (Microsoft)
8a99e50134 Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list updaters)
None of the readers/updaters of sc_list rely on channel->lock for
synchronization.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-7-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19 15:38:30 +00:00
Andrea Parri (Microsoft)
3eb0ac869c Drivers: hv: vmbus: Use channel_mutex in channel_vp_mapping_show()
The primitive currently uses channel->lock to protect the loop over
sc_list w.r.t. list additions/deletions but it doesn't protect the
target_cpu(s) loads w.r.t. a concurrent target_cpu_store(): while the
data races on target_cpu are hardly of any concern here, replace the
channel->lock critical section with a channel_mutex critical section
and extend the latter to include the loads of target_cpu; this same
pattern is also used in hv_synic_cleanup().

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-6-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19 15:38:26 +00:00
Andrea Parri (Microsoft)
12d0dd8e72 Drivers: hv: vmbus: Remove unnecessary channel->lock critical sections (sc_list readers)
Additions/deletions to/from sc_list (as well as modifications of
target_cpu(s)) are protected by channel_mutex, which hv_synic_cleanup()
and vmbus_bus_suspend() own for the duration of the channel->lock
critical section in question.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-5-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19 15:38:23 +00:00
Andrea Parri (Microsoft)
0a96820929 Drivers: hv: vmbus: Replace cpumask_test_cpu(, cpu_online_mask) with cpu_online()
A slight improvement in readability, and this does also remove one
memory access when NR_CPUS == 1!  ;-)

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-4-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19 15:38:19 +00:00
Andrea Parri (Microsoft)
458d090fba Drivers: hv: vmbus: Remove the numa_node field from the vmbus_channel struct
The field is read only in numa_node_show() and it is already stored twice
(after a call to cpu_to_node()) in target_cpu_store() and init_vp_index();
there is no need to "cache" its value in the channel data structure.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-3-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19 15:38:15 +00:00
Andrea Parri (Microsoft)
5bf7468211 Drivers: hv: vmbus: Remove the target_vp field from the vmbus_channel struct
The field is read only in __vmbus_open() and it is already stored twice
(after a call to hv_cpu_number_to_vp_number()) in target_cpu_store() and
init_vp_index(); there is no need to "cache" its value in the channel
data structure.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200617164642.37393-2-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-06-19 15:38:10 +00:00
Linus Torvalds
6b2591c212 hyperv-next for 5.8
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyper-v updates from Wei Liu:

 - a series from Andrea to support channel reassignment

 - a series from Vitaly to clean up Vmbus message handling

 - a series from Michael to clean up and augment hyperv-tlfs.h

 - patches from Andy to clean up GUID usage in Hyper-V code

 - a few other misc patches

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (29 commits)
  Drivers: hv: vmbus: Resolve more races involving init_vp_index()
  Drivers: hv: vmbus: Resolve race between init_vp_index() and CPU hotplug
  vmbus: Replace zero-length array with flexible-array
  Driver: hv: vmbus: drop a no long applicable comment
  hyper-v: Switch to use UUID types directly
  hyper-v: Replace open-coded variant of %*phN specifier
  hyper-v: Supply GUID pointer to printf() like functions
  hyper-v: Use UUID API for exporting the GUID (part 2)
  asm-generic/hyperv: Add definitions for Get/SetVpRegister hypercalls
  x86/hyperv: Split hyperv-tlfs.h into arch dependent and independent files
  x86/hyperv: Remove HV_PROCESSOR_POWER_STATE #defines
  KVM: x86: hyperv: Remove duplicate definitions of Reference TSC Page
  drivers: hv: remove redundant assignment to pointer primary_channel
  scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assigned
  Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type
  Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug
  Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity logic
  PCI: hv: Prepare hv_compose_msi_msg() for the VMBus-channel-interrupt-to-vCPU reassignment functionality
  Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. channel removal
  hv_utils: Always execute the fcopy and vss callbacks in a tasklet
  ...
2020-06-03 15:00:05 -07:00
Andrea Parri (Microsoft)
afaa33da08 Drivers: hv: vmbus: Resolve more races involving init_vp_index()
init_vp_index() uses the (per-node) hv_numa_map[] masks to record the
CPUs allocated for channel interrupts at a given time, and distribute
the performance-critical channels across the available CPUs: in part.,
the mask of "candidate" target CPUs in a given NUMA node, for a newly
offered channel, is determined by XOR-ing the node's CPU mask and the
node's hv_numa_map.  This operation/mechanism assumes that no offline
CPUs is set in the hv_numa_map mask, an assumption that does not hold
since such mask is currently not updated when a channel is removed or
assigned to a different CPU.

To address the issues described above, this adds hooks in the channel
removal path (hv_process_channel_removal()) and in target_cpu_store()
in order to clear, resp. to update, the hv_numa_map[] masks as needed.
This also adds a (missed) update of the masks in init_vp_index() (cf.,
e.g., the memory-allocation failure path in this function).

Like in the case of init_vp_index(), such hooks require to determine
if the given channel is performance critical.  init_vp_index() does
this by parsing the channel's offer, it can not rely on the device
data structure (device_obj) to retrieve such information because the
device data structure has not been allocated/linked with the channel
by the time that init_vp_index() executes.  A similar situation may
hold in hv_is_alloced_cpu() (defined below); the adopted approach is
to "cache" the device type of the channel, as computed by parsing the
channel's offer, in the channel structure itself.

Fixes: 7527810573 ("Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type")
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200522171901.204127-3-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-23 09:07:00 +00:00
Andrea Parri (Microsoft)
a949e86c0d Drivers: hv: vmbus: Resolve race between init_vp_index() and CPU hotplug
vmbus_process_offer() does two things (among others):

 1) first, it sets the channel's target CPU with cpu_hotplug_lock;
 2) it then adds the channel to the channel list(s) with channel_mutex.

Since cpu_hotplug_lock is released before (2), the channel's target CPU
(as designated in (1)) can be deemed "free" by hv_synic_cleanup() and go
offline before the channel is added to the list.

Fix the race condition by "extending" the cpu_hotplug_lock critical
section to include (2) (and (1)), nesting the channel_mutex critical
section within the cpu_hotplug_lock critical section as done elsewhere
(hv_synic_cleanup(), target_cpu_store()) in the hyperv drivers code.

Move even further by extending the channel_mutex critical section to
include (1) (and (2)): this change allows to remove (the now redundant)
bind_channel_to_cpu_lock, and generally simplifies the handling of the
target CPUs (that are now always modified with channel_mutex held).

Fixes: d570aec0f2 ("Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug")
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200522171901.204127-2-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-23 09:06:42 +00:00
Wei Liu
723c425f29 Driver: hv: vmbus: drop a no long applicable comment
None of the things mentioned in the comment is initialized in hv_init.
They've been moved elsewhere.

Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20200506160806.118965-1-wei.liu@kernel.org
Reviewed-by:  Michael Kelley <mikelley@microsoft.com>
2020-05-20 09:13:59 +00:00
Andy Shevchenko
0027e3fd6d hyper-v: Replace open-coded variant of %*phN specifier
printf() like functions in the kernel have extensions, such as
%*phN to dump small pieces of memory as hex values.

Replace print_alias_name() with the direct use of %*phN.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200423134505.78221-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20 09:13:59 +00:00
Andy Shevchenko
458c4475be hyper-v: Supply GUID pointer to printf() like functions
Drop dereference when printing the GUID with printf() like functions.
This allows to hide the uuid_t internals.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200423134505.78221-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20 09:13:59 +00:00
Andy Shevchenko
69f57058ba hyper-v: Use UUID API for exporting the GUID (part 2)
This is a follow up to the commit 1d3c9c0754
  ("hyper-v: Use UUID API for exporting the GUID")
which starts the conversion.

There is export_guid() function which exports guid_t to the u8 array.
Use it instead of open coding variant.

This allows to hide the uuid_t internals.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200423134505.78221-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20 09:13:58 +00:00
Colin Ian King
677b0ce5d6 drivers: hv: remove redundant assignment to pointer primary_channel
The pointer primary_channel is being assigned with a value that is never
used. The assignment is redundant and can be removed.  Move the
definition of primary_channel to a narrower scope.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200414152343.243166-1-colin.king@canonical.com
[ wei: move primary_channel and update commit message ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20 09:13:58 +00:00
Andrea Parri (Microsoft)
7769e18c20 scsi: storvsc: Re-init stor_chns when a channel interrupt is re-assigned
For each storvsc_device, storvsc keeps track of the channel target CPUs
associated to the device (alloced_cpus) and it uses this information to
fill a "cache" (stor_chns) mapping CPU->channel according to a certain
heuristic.  Update the alloced_cpus mask and the stor_chns array when a
channel of the storvsc device is re-assigned to a different CPU.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: <linux-scsi@vger.kernel.org>
Link: https://lore.kernel.org/r/20200406001514.19876-12-parri.andrea@gmail.com
Reviewed-by; Long Li <longli@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
[ wei: fix a small issue reported by kbuild test robot <lkp@intel.com> ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-05-20 09:13:19 +00:00
Linus Torvalds
869997be0e hyperv-fixes for 5.7-rc4
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Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V fixes from Wei Liu:

 - Two patches from Dexuan fixing suspension bugs

 - Three cleanup patches from Andy and Michael

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hyper-v: Remove internal types from UAPI header
  hyper-v: Use UUID API for exporting the GUID
  x86/hyperv: Suspend/resume the VP assist page for hibernation
  Drivers: hv: Move AEOI determination to architecture dependent code
  Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VM
2020-04-27 13:28:27 -07:00
Andrea Parri (Microsoft)
7527810573 Drivers: hv: vmbus: Introduce the CHANNELMSG_MODIFYCHANNEL message type
VMBus version 4.1 and later support the CHANNELMSG_MODIFYCHANNEL(22)
message type which can be used to request Hyper-V to change the vCPU
that a channel will interrupt.

Introduce the CHANNELMSG_MODIFYCHANNEL message type, and define the
vmbus_send_modifychannel() function to send CHANNELMSG_MODIFYCHANNEL
requests to the host via a hypercall.  The function is then used to
define a sysfs "store" operation, which allows to change the (v)CPU
the channel will interrupt by using the sysfs interface.  The feature
can be used for load balancing or other purposes.

One interesting catch here is that Hyper-V can *not* currently ACK
CHANNELMSG_MODIFYCHANNEL messages with the promise that (after the ACK
is sent) the channel won't send any more interrupts to the "old" CPU.

The peculiarity of the CHANNELMSG_MODIFYCHANNEL messages is problematic
if the user want to take a CPU offline, since we don't want to take a
CPU offline (and, potentially, "lose" channel interrupts on such CPU)
if the host is still processing a CHANNELMSG_MODIFYCHANNEL message
associated to that CPU.

It is worth mentioning, however, that we have been unable to observe
the above mentioned "race": in all our tests, CHANNELMSG_MODIFYCHANNEL
requests appeared *as if* they were processed synchronously by the host.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-11-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
[ wei: fix conflict in channel_mgmt.c ]
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:12 +00:00
Andrea Parri (Microsoft)
d570aec0f2 Drivers: hv: vmbus: Synchronize init_vp_index() vs. CPU hotplug
init_vp_index() may access the cpu_online_mask mask via its calls of
cpumask_of_node().  Make sure to protect these accesses with a
cpus_read_lock() critical section.

Also, remove some (hardcoded) instances of CPU(0) from init_vp_index()
and replace them with VMBUS_CONNECT_CPU.  The connect CPU can not go
offline, since Hyper-V does not provide a way to change it.

Finally, order the accesses of target_cpu from init_vp_index() and
hv_synic_cleanup() by relying on the channel_mutex; this is achieved
by moving the call of init_vp_index() into vmbus_process_offer().

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-10-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:12 +00:00
Andrea Parri (Microsoft)
8ef4c4abbb Drivers: hv: vmbus: Remove the unused HV_LOCALIZED channel affinity logic
The logic is unused since commit 509879bdb3 ("Drivers: hv: Introduce
a policy for controlling channel affinity").

This logic assumes that a channel target_cpu doesn't change during the
lifetime of a channel, but this assumption is incompatible with the new
functionality that allows changing the vCPU a channel will interrupt.

Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-9-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:12 +00:00
Andrea Parri (Microsoft)
9403b66e61 Drivers: hv: vmbus: Use a spin lock for synchronizing channel scheduling vs. channel removal
Since vmbus_chan_sched() dereferences the ring buffer pointer, we have
to make sure that the ring buffer data structures don't get freed while
such dereferencing is happening.  Current code does this by sending an
IPI to the CPU that is allowed to access that ring buffer from interrupt
level, cf., vmbus_reset_channel_cb().  But with the new functionality
to allow changing the CPU that a channel will interrupt, we can't be
sure what CPU will be running the vmbus_chan_sched() function for a
particular channel, so the current IPI mechanism is infeasible.

Instead synchronize vmbus_chan_sched() and vmbus_reset_channel_cb() by
using the (newly introduced) per-channel spin lock "sched_lock".  Move
the test for onchannel_callback being NULL before the "switch" control
statement in vmbus_chan_sched(), in order to not access the ring buffer
if the vmbus_reset_channel_cb() has been completed on the channel.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-7-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:12 +00:00
Andrea Parri (Microsoft)
238d2ed8f7 hv_utils: Always execute the fcopy and vss callbacks in a tasklet
The fcopy and vss callback functions could be running in a tasklet
at the same time they are called in hv_poll_channel().  Current code
serializes the invocations of these functions, and their accesses to
the channel ring buffer, by sending an IPI to the CPU that is allowed
to access the ring buffer, cf. hv_poll_channel().  This IPI mechanism
becomes infeasible if we allow changing the CPU that a channel will
interrupt.  Instead modify the callback wrappers to always execute
the fcopy and vss callbacks in a tasklet, thus mirroring the solution
for the kvp callback functions adopted since commit a3ade8cc47
("HV: properly delay KVP packets when negotiation is in progress").
This will ensure that the callback function can't run on two CPUs at
the same time.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-6-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:11 +00:00
Andrea Parri (Microsoft)
ac50476717 hv_netvsc: Disable NAPI before closing the VMBus channel
vmbus_chan_sched() might call the netvsc driver callback function that
ends up scheduling NAPI work.  This "work" can access the channel ring
buffer, so we must ensure that any such work is completed and that the
ring buffer is no longer being accessed before freeing the ring buffer
data structure in the channel closure path.  To this end, disable NAPI
before calling vmbus_close() in netvsc_device_remove().

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: <netdev@vger.kernel.org>
Link: https://lore.kernel.org/r/20200406001514.19876-5-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:11 +00:00
Andrea Parri (Microsoft)
8b6a877c06 Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels
When Hyper-V sends an interrupt to the guest, the guest has to figure
out which channel the interrupt is associated with.  Hyper-V sets a bit
in a memory page that is shared with the guest, indicating a particular
"relid" that the interrupt is associated with.  The current Linux code
then uses a set of per-CPU linked lists to map a given "relid" to a
pointer to a channel structure.

This design introduces a synchronization problem if the CPU that Hyper-V
will interrupt for a certain channel is changed.  If the interrupt comes
on the "old CPU" and the channel was already moved to the per-CPU list
of the "new CPU", then the relid -> channel mapping will fail and the
interrupt is dropped.  Similarly, if the interrupt comes on the new CPU
but the channel was not moved to the per-CPU list of the new CPU, then
the mapping will fail and the interrupt is dropped.

Relids are integers ranging from 0 to 2047.  The mapping from relids to
channel structures can be done by setting up an array with 2048 entries,
each entry being a pointer to a channel structure (hence total size ~16K
bytes, which is not a problem).  The array is global, so there are no
per-CPU linked lists to update.  The array can be searched and updated
by loading from/storing to the array at the specified index.  With no
per-CPU data structures, the above mentioned synchronization problem is
avoided and the relid2channel() function gets simpler.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-4-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:11 +00:00
Andrea Parri (Microsoft)
b9fa1b8797 Drivers: hv: vmbus: Don't bind the offer&rescind works to a specific CPU
The offer and rescind works are currently scheduled on the so called
"connect CPU".  However, this is not really needed: we can synchronize
the works by relying on the usage of the offer_in_progress counter and
of the channel_mutex mutex.  This synchronization is already in place.
So, remove this unnecessary "bind to the connect CPU" constraint and
update the inline comments accordingly.

Suggested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20200406001514.19876-3-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:11 +00:00
Andrea Parri (Microsoft)
8a857c5542 Drivers: hv: vmbus: Always handle the VMBus messages on CPU0
A Linux guest have to pick a "connect CPU" to communicate with the
Hyper-V host.  This CPU can not be taken offline because Hyper-V does
not provide a way to change that CPU assignment.

Current code sets the connect CPU to whatever CPU ends up running the
function vmbus_negotiate_version(), and this will generate problems if
that CPU is taken offine.

Establish CPU0 as the connect CPU, and add logics to prevents the
connect CPU from being taken offline.   We could pick some other CPU,
and we could pick that "other CPU" dynamically if there was a reason to
do so at some point in the future.  But for now, #defining the connect
CPU to 0 is the most straightforward and least complex solution.

While on this, add inline comments explaining "why" offer and rescind
messages should not be handled by a same serialized work queue.

Suggested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20200406001514.19876-2-parri.andrea@gmail.com
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:11 +00:00
Vitaly Kuznetsov
52c7803f9b Drivers: hv: check VMBus messages lengths
VMBus message handlers (channel_message_table) receive a pointer to
'struct vmbus_channel_message_header' and cast it to a structure of their
choice, which is sometimes longer than the header. We, however, don't check
that the message is long enough so in case hypervisor screws up we'll be
accessing memory beyond what was allocated for temporary buffer.

Previously, we used to always allocate and copy 256 bytes from message page
to temporary buffer but this is hardly better: in case the message is
shorter than we expect we'll be trying to consume garbage as some real
data and no memory guarding technique will be able to identify an issue.

Introduce 'min_payload_len' to 'struct vmbus_channel_message_table_entry'
and check against it in vmbus_on_msg_dpc(). Note, we can't require the
exact length as new hypervisor versions may add extra fields to messages,
we only check that the message is not shorter than we expect.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104326.45361-1-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:11 +00:00
Vitaly Kuznetsov
b0a284dc65 Drivers: hv: make sure that 'struct vmbus_channel_message_header' compiles correctly
Strictly speaking, compiler is free to use something different from 'u32'
for 'enum vmbus_channel_message_type' (e.g. char) but it doesn't happen in
real life, just add a BUILD_BUG_ON() guardian.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104316.45303-1-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:11 +00:00
Vitaly Kuznetsov
5cc415001b Drivers: hv: avoid passing opaque pointer to vmbus_onmessage()
vmbus_onmessage() doesn't need the header of the message, it only
uses it to get to the payload, we can pass the pointer to the
payload directly.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104154.45010-4-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:11 +00:00
Vitaly Kuznetsov
a276463b7a Drivers: hv: allocate the exact needed memory for messages
When we need to pass a buffer with Hyper-V message we don't need to always
allocate 256 bytes for the message: the real message length is known from
the header. Change 'struct onmessage_work_context' to make it possible to
not over-allocate.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104154.45010-3-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:10 +00:00
Vitaly Kuznetsov
ac0f7d4258 Drivers: hv: copy from message page only what's needed
Hyper-V Interrupt Message Page (SIMP) has 16 256-byte slots for
messages. Each message comes with a header (16 bytes) which specifies the
payload length (up to 240 bytes). vmbus_on_msg_dpc(), however, doesn't
look at the real message length and copies the whole slot to a temporary
buffer before passing it to message handlers. This is potentially dangerous
as hypervisor doesn't have to clean the whole slot when putting a new
message there and a message handler can get access to some data which
belongs to a previous message.

Note, this is not currently a problem because all message handlers are
in-kernel but eventually we may e.g. get this exported to userspace.

Note also, that this is not a performance critical path: messages (unlike
events) represent rare events so it doesn't really matter (from performance
point of view) if we copy too much.

Fix the issue by taking into account the real message length. The temporary
buffer allocated by vmbus_on_msg_dpc() remains fixed size for now. Also,
check that the supplied payload length is valid (<= 240 bytes).

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406104154.45010-2-vkuznets@redhat.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-23 13:17:10 +00:00
Andy Shevchenko
1d3c9c0754 hyper-v: Use UUID API for exporting the GUID
There is export_guid() function which exports guid_t to the u8 array.
Use it instead of open coding variant.

This allows to hide the uuid_t internals.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200422125937.38355-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-22 14:40:02 +01:00
Michael Kelley
2ddddd0b4e Drivers: hv: Move AEOI determination to architecture dependent code
Hyper-V on ARM64 doesn't provide a flag for the AEOI recommendation
in ms_hyperv.hints, so having the test in architecture independent
code doesn't work. Resolve this by moving the check of the flag
to an architecture dependent helper function. No functionality is
changed.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200420164926.24471-1-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-21 10:02:38 +01:00
Dexuan Cui
1a06d017fb Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VM
Before the hibernation patchset (e.g. f53335e328), in a Generation-2
Linux VM on Hyper-V, the user can run "echo freeze > /sys/power/state" to
freeze the system, i.e. Suspend-to-Idle. The user can press the keyboard
or move the mouse to wake up the VM.

With the hibernation patchset, Linux VM on Hyper-V can hibernate to disk,
but Suspend-to-Idle is broken: when the synthetic keyboard/mouse are
suspended, there is no way to wake up the VM.

Fix the issue by not suspending and resuming the vmbus devices upon
Suspend-to-Idle.

Fixes: f53335e328 ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation")
Cc: stable@vger.kernel.org
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/1586663435-36243-1-git-send-email-decui@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-14 21:16:35 +01:00
Linus Torvalds
8632e9b564 hyperv-fixes for 5.7-rc1
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Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - a series from Tianyu Lan to fix crash reporting on Hyper-V

 - three miscellaneous cleanup patches

* tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  x86/Hyper-V: Report crash data in die() when panic_on_oops is set
  x86/Hyper-V: Report crash register data when sysctl_record_panic_msg is not set
  x86/Hyper-V: Report crash register data or kmsg before running crash kernel
  x86/Hyper-V: Trigger crash enlightenment only once during system crash.
  x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump
  x86/Hyper-V: Unload vmbus channel in hv panic callback
  x86: hyperv: report value of misc_features
  hv_debugfs: Make hv_debug_root static
  hv: hyperv_vmbus.h: Replace zero-length array with flexible-array member
2020-04-14 11:58:04 -07:00
Tianyu Lan
f3a99e761e x86/Hyper-V: Report crash data in die() when panic_on_oops is set
When oops happens with panic_on_oops unset, the oops
thread is killed by die() and system continues to run.
In such case, guest should not report crash register
data to host since system still runs. Check panic_on_oops
and return directly in hyperv_report_panic() when the function
is called in the die() and panic_on_oops is unset. Fix it.

Fixes: 7ed4325a44 ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-7-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-11 17:19:07 +01:00
Tianyu Lan
040026df70 x86/Hyper-V: Report crash register data when sysctl_record_panic_msg is not set
When sysctl_record_panic_msg is not set, the panic will
not be reported to Hyper-V via hyperv_report_panic_msg().
So the crash should be reported via hyperv_report_panic().

Fixes: 81b18bce48 ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-6-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-11 17:19:06 +01:00
Tianyu Lan
73f26e526f x86/Hyper-V: Trigger crash enlightenment only once during system crash.
When a guest VM panics, Hyper-V should be notified only once via the
crash synthetic MSRs.  Current Linux code might write these crash MSRs
twice during a system panic:
1) hyperv_panic/die_event() calling hyperv_report_panic()
2) hv_kmsg_dump() calling hyperv_report_panic_msg()

Fix this by not calling hyperv_report_panic() if a kmsg dump has been
successfully registered.  The notification will happen later via
hyperv_report_panic_msg().

Fixes: 7ed4325a44 ("Drivers: hv: vmbus: Make panic reporting to be more useful")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-4-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-11 17:18:22 +01:00
Tianyu Lan
7f11a2cc10 x86/Hyper-V: Free hv_panic_page when fail to register kmsg dump
If kmsg_dump_register() fails, hv_panic_page will not be used
anywhere.  So free and reset it.

Fixes: 81b18bce48 ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-3-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-10 15:29:00 +01:00
Tianyu Lan
74347a99e7 x86/Hyper-V: Unload vmbus channel in hv panic callback
When kdump is not configured, a Hyper-V VM might still respond to
network traffic after a kernel panic when kernel parameter panic=0.
The panic CPU goes into an infinite loop with interrupts enabled,
and the VMbus driver interrupt handler still works because the
VMbus connection is unloaded only in the kdump path.  The network
responses make the other end of the connection think the VM is
still functional even though it has panic'ed, which could affect any
failover actions that should be taken.

Fix this by unloading the VMbus connection during the panic process.
vmbus_initiate_unload() could then be called twice (e.g., by
hyperv_panic_event() and hv_crash_handler(), so reset the connection
state in vmbus_initiate_unload() to ensure the unload is done only
once.

Fixes: 81b18bce48 ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-2-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-10 15:29:00 +01:00
David Hildenbrand
bc58ebd506 hv_balloon: don't check for memhp_auto_online manually
We get the MEM_ONLINE notifier call if memory is added right from the
kernel via add_memory() or later from user space.

Let's get rid of the "ha_waiting" flag - the wait event has an inbuilt
mechanism (->done) for that.  Initialize the wait event only once and
reinitialize before adding memory.  Unconditionally call complete() and
wait_for_completion_timeout().

If there are no waiters, complete() will only increment ->done - which
will be reset by reinit_completion().  If complete() has already been
called, wait_for_completion_timeout() will not wait.

There is still the chance for a small race between concurrent
reinit_completion() and complete().  If complete() wins, we would not wait
- which is tolerable (and the race exists in current code as well).

Note: We only wait for "some" memory to get onlined, which seems to be
      good enough for now.

[akpm@linux-foundation.org: register_memory_notifier() after init_completion(), per David]
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Yumei Huang <yuhuang@redhat.com>
Link: http://lkml.kernel.org/r/20200317104942.11178-6-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07 10:43:40 -07:00
YueHaibing
3e0d377650 hv_debugfs: Make hv_debug_root static
Fix sparse warning:

drivers/hv/hv_debugfs.c:14:15: warning: symbol 'hv_debug_root' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by:  Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20200403082845.22740-1-yuehaibing@huawei.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-04-04 17:47:43 +01:00
Gustavo A. R. Silva
032d4a4802 hv: hyperv_vmbus.h: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2020-03-21 16:26:12 +00:00
Linus Torvalds
d0fa925031 - Most of the commits here are work to enable host-initiated hibernation
support by Dexuan Cui.
 - Fix for a warning shown when host sends non-aligned balloon requests
 by Tianyu Lan.
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Sasha Levin:

 - Most of the commits here are work to enable host-initiated
   hibernation support by Dexuan Cui.

 - Fix for a warning shown when host sends non-aligned balloon requests
   by Tianyu Lan.

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv_utils: Add the support of hibernation
  hv_utils: Support host-initiated hibernation request
  hv_utils: Support host-initiated restart request
  Tools: hv: Reopen the devices if read() or write() returns errors
  video: hyperv: hyperv_fb: Use physical memory for fb on HyperV Gen 1 VMs.
  Drivers: hv: vmbus: Ignore CHANNELMSG_TL_CONNECT_RESULT(23)
  video: hyperv_fb: Fix hibernation for the deferred IO feature
  Input: hyperv-keyboard: Add the support of hibernation
  hv_balloon: Balloon up according to request page number
2020-02-03 14:42:03 +00:00
Dexuan Cui
54e19d3401 hv_utils: Add the support of hibernation
Add util_pre_suspend() and util_pre_resume() for some hv_utils devices
(e.g. kvp/vss/fcopy), because they need special handling before
util_suspend() calls vmbus_close().

For kvp, all the possible pending work items should be cancelled.

For vss and fcopy, some extra clean-up needs to be done, i.e. fake a
THAW message for hv_vss_daemon and fake a CANCEL_FCOPY message for
hv_fcopy_daemon, otherwise when the VM resums back, the daemons
can end up in an inconsistent state (i.e. the file systems are
frozen but will never be thawed; the file transmitted via fcopy
may not be complete). Note: there is an extra patch for the daemons:
"Tools: hv: Reopen the devices if read() or write() returns errors",
because the hv_utils driver can not guarantee the whole transaction
finishes completely once util_suspend() starts to run (at this time,
all the userspace processes are frozen).

util_probe() disables channel->callback_event to avoid the race with
the channel callback.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-26 22:10:17 -05:00
Dexuan Cui
ffd1d4a493 hv_utils: Support host-initiated hibernation request
Update the Shutdown IC version to 3.2, which is required for the host to
send the hibernation request.

The user is expected to create the below udev rule file, which is applied
upon the host-initiated hibernation request:

root@localhost:~# cat /usr/lib/udev/rules.d/40-vm-hibernation.rules
SUBSYSTEM=="vmbus", ACTION=="change", DRIVER=="hv_utils", ENV{EVENT}=="hibernate", RUN+="/usr/bin/systemctl hibernate"

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-26 22:10:16 -05:00
Dexuan Cui
3e9c72056e hv_utils: Support host-initiated restart request
The hv_utils driver currently supports a "shutdown" operation initiated
from the Hyper-V host. Newer versions of Hyper-V also support a "restart"
operation. So add support for the updated protocol version that has
"restart" support, and perform a clean reboot when such a message is
received from Hyper-V.

To test the restart functionality, run this PowerShell command on the
Hyper-V host:

Restart-VM  <vmname>  -Type Reboot

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-26 22:10:16 -05:00
Dexuan Cui
ddc9d357b9 Drivers: hv: vmbus: Ignore CHANNELMSG_TL_CONNECT_RESULT(23)
When a Linux hv_sock app tries to connect to a Service GUID on which no
host app is listening, a recent host (RS3+) sends a
CHANNELMSG_TL_CONNECT_RESULT (23) message to Linux and this triggers such
a warning:

unknown msgtype=23
WARNING: CPU: 2 PID: 0 at drivers/hv/vmbus_drv.c:1031 vmbus_on_msg_dpc

Actually Linux can safely ignore the message because the Linux app's
connect() will time out in 2 seconds: see VSOCK_DEFAULT_CONNECT_TIMEOUT
and vsock_stream_connect(). We don't bother to make use of the message
because: 1) it's only supported on recent hosts; 2) a non-trivial effort
is required to use the message in Linux, but the benefit is small.

So, let's not see the warning by silently ignoring the message.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-25 16:52:11 -05:00
Tianyu Lan
d33c240d47 hv_balloon: Balloon up according to request page number
Current code has assumption that balloon request memory size aligns
with 2MB. But actually Hyper-V doesn't guarantee such alignment. When
balloon driver receives non-aligned balloon request, it produces warning
and balloon up more memory than requested in order to keep 2MB alignment.
Remove the warning and balloon up memory according to actual requested
memory size.

Fixes: f671223847 ("hv: hv_balloon: avoid memory leak on alloc_error of 2MB memory block")
Cc: stable@vger.kernel.org
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-25 16:51:49 -05:00
Andrea Parri
0af3e137c1 clocksource/drivers/hyper-v: Untangle stimers and timesync from clocksources
hyperv_timer.c exports hyperv_cs, which is used by stimers and the
timesync mechanism.  However, the clocksource dependency is not
needed: these mechanisms only depend on the partition reference
counter (which can be read via a MSR or via the TSC Reference Page).

Introduce the (function) pointer hv_read_reference_counter, as an
embodiment of the partition reference counter read, and export it
in place of the hyperv_cs pointer.  The latter can be removed.

This should clarify that there's no relationship between Hyper-V
stimers & timesync and the Linux clocksource abstractions.  No
functional or semantic change.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200109160650.16150-2-parri.andrea@gmail.com
2020-01-16 19:09:02 +01:00
Linus Torvalds
596cf45cbf Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:
 "Incoming:

   - a small number of updates to scripts/, ocfs2 and fs/buffer.c

   - most of MM

  I still have quite a lot of material (mostly not MM) staged after
  linux-next due to -next dependencies. I'll send those across next week
  as the preprequisites get merged up"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (135 commits)
  mm/page_io.c: annotate refault stalls from swap_readpage
  mm/Kconfig: fix trivial help text punctuation
  mm/Kconfig: fix indentation
  mm/memory_hotplug.c: remove __online_page_set_limits()
  mm: fix typos in comments when calling __SetPageUptodate()
  mm: fix struct member name in function comments
  mm/shmem.c: cast the type of unmap_start to u64
  mm: shmem: use proper gfp flags for shmem_writepage()
  mm/shmem.c: make array 'values' static const, makes object smaller
  userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK
  fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register()
  userfaultfd: wrap the common dst_vma check into an inlined function
  userfaultfd: remove unnecessary WARN_ON() in __mcopy_atomic_hugetlb()
  userfaultfd: use vma_pagesize for all huge page size calculation
  mm/madvise.c: use PAGE_ALIGN[ED] for range checking
  mm/madvise.c: replace with page_size() in madvise_inject_error()
  mm/mmap.c: make vma_merge() comment more easy to understand
  mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops
  autonuma: reduce cache footprint when scanning page tables
  autonuma: fix watermark checking in migrate_balanced_pgdat()
  ...
2019-12-01 20:36:41 -08:00
Souptick Joarder
12cc1c7345 mm/memory_hotplug.c: remove __online_page_set_limits()
__online_page_set_limits() is a dummy function - remove it and all
callers.

Link: http://lkml.kernel.org/r/8e1bc9d3b492f6bde16e95ebc1dee11d6aefabd7.1567889743.git.jrdr.linux@gmail.com
Link: http://lkml.kernel.org/r/854db2cf8145d9635249c95584d9a91fd774a229.1567889743.git.jrdr.linux@gmail.com
Link: http://lkml.kernel.org/r/9afe6c5a18158f3884a6b302ac2c772f3da49ccc.1567889743.git.jrdr.linux@gmail.com
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01 12:59:10 -08:00
David Hildenbrand
30a9c246b9 hv_balloon: use generic_online_page()
Let's use the generic onlining function - which will now also take care
of calling kernel_map_pages().

Link: http://lkml.kernel.org/r/20190909114830.662-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-12-01 12:59:04 -08:00
Linus Torvalds
0dd0c8f7db - Support for new VMBus protocols (Andrea Parri).
- Hibernation support (Dexuan Cui).
 - Latency testing framework (Branden Bonaby).
 - Decoupling Hyper-V page size from guest page size (Himadri Pandya).
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Sasha Levin:

 - support for new VMBus protocols (Andrea Parri)

 - hibernation support (Dexuan Cui)

 - latency testing framework (Branden Bonaby)

 - decoupling Hyper-V page size from guest page size (Himadri Pandya)

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (22 commits)
  Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic
  drivers/hv: Replace binary semaphore with mutex
  drivers: iommu: hyperv: Make HYPERV_IOMMU only available on x86
  HID: hyperv: Add the support of hibernation
  hv_balloon: Add the support of hibernation
  x86/hyperv: Implement hv_is_hibernation_supported()
  Drivers: hv: balloon: Remove dependencies on guest page size
  Drivers: hv: vmbus: Remove dependencies on guest page size
  x86: hv: Add function to allocate zeroed page for Hyper-V
  Drivers: hv: util: Specify ring buffer size using Hyper-V page size
  Drivers: hv: Specify receive buffer size using Hyper-V page size
  tools: hv: add vmbus testing tool
  drivers: hv: vmbus: Introduce latency testing
  video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver
  video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host
  hv_netvsc: Add the support of hibernation
  hv_sock: Add the support of hibernation
  video: hyperv_fb: Add the support of hibernation
  scsi: storvsc: Add the support of hibernation
  Drivers: hv: vmbus: Add module parameter to cap the VMBus version
  ...
2019-11-30 14:50:51 -08:00
Michael Kelley
7a1323b5df Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic
The crash handler calls hv_synic_cleanup() to shutdown the
Hyper-V synthetic interrupt controller.  But if the CPU
that calls hv_synic_cleanup() has a VMbus channel interrupt
assigned to it (which is likely the case in smaller VM sizes),
hv_synic_cleanup() returns an error and the synthetic
interrupt controller isn't shutdown.  While the lack of
being shutdown hasn't caused a known problem, it still
should be fixed for highest reliability.

So directly call hv_synic_disable_regs() instead of
hv_synic_cleanup(), which ensures that the synic is always
shutdown.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:46 -05:00
Davidlohr Bueso
8aea7f8215 drivers/hv: Replace binary semaphore with mutex
At a slight footprint cost (24 vs 32 bytes), mutexes are more optimal
than semaphores; it's also a nicer interface for mutual exclusion,
which is why they are encouraged over binary semaphores, when possible.

Replace the hyperv_mmio_lock, its semantics implies traditional lock
ownership; that is, the lock owner is the same for both lock/unlock
operations. Therefore it is safe to convert.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:45 -05:00
Dexuan Cui
25bd2b2f1f hv_balloon: Add the support of hibernation
When hibernation is enabled, we must ignore the balloon up/down and
hot-add requests from the host, if any.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:45 -05:00
Himadri Pandya
2af5e7b7b2 Drivers: hv: balloon: Remove dependencies on guest page size
Hyper-V assumes page size to be 4K. This might not be the case for
ARM64 architecture. Hence use hyper-v specific page size and page
shift definitions to avoid conflicts between different host and guest
page sizes on ARM64.

Also, remove some old and incorrect comments and redefine ballooning
granularities to handle larger page sizes correctly.

Signed-off-by: Himadri Pandya <himadri18.07@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:45 -05:00
Himadri Pandya
53edce00ce Drivers: hv: vmbus: Remove dependencies on guest page size
Hyper-V assumes page size to be 4K. This might not be the case for ARM64
architecture. Hence use hyper-v page size and page allocation function
to avoid conflicts between different host and guest page size on ARM64.

Signed-off-by: Himadri Pandya <himadri18.07@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:45 -05:00
Himadri Pandya
0541a22594 Drivers: hv: util: Specify ring buffer size using Hyper-V page size
VMbus ring buffers are sized based on the 4K page size used by
Hyper-V. The Linux guest page size may not be 4K on all architectures
so use the Hyper-V page size to specify the ring buffer size.

Signed-off-by: Himadri Pandya <himadri18.07@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:45 -05:00
Himadri Pandya
b14d749ac5 Drivers: hv: Specify receive buffer size using Hyper-V page size
The recv_buffer is used to retrieve data from the VMbus ring buffer.
VMbus ring buffers are sized based on the guest page size which
Hyper-V assumes to be 4KB. But it may be different on some
architectures. So use the Hyper-V page size to allocate the
recv_buffer and set the maximum size to receive.

Signed-off-by: Himadri Pandya <himadri18.07@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:45 -05:00
Branden Bonaby
af9ca6f9bb drivers: hv: vmbus: Introduce latency testing
Introduce user specified latency in the packet reception path
By exposing the test parameters as part of the debugfs channel
attributes. We will control the testing state via these attributes.

Signed-off-by: Branden Bonaby <brandonbonaby94@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:44 -05:00
Andrea Parri
931cccc967 Drivers: hv: vmbus: Add module parameter to cap the VMBus version
Currently, Linux guests negotiate the VMBus version with Hyper-V
and use the highest available VMBus version they can connect to.
This has some drawbacks: by using the highest available version,
certain code paths are never executed and can not be tested when
the guest runs on the newest host.

Add the module parameter "max_version", to upper-bound the VMBus
versions guests can negotiate.

Suggested-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:44 -05:00
Andrea Parri
2d4f49b3e1 Drivers: hv: vmbus: Enable VMBus protocol versions 4.1, 5.1 and 5.2
Hyper-V has added VMBus protocol versions 5.1 and 5.2 in recent release
versions.  Allow Linux guests to negotiate these new protocol versions
on versions of Hyper-V that support them.  While on this, also allow
guests to negotiate the VMBus protocol version 4.1 (which was missing).

Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:43 -05:00
Andrea Parri
bedc61a922 Drivers: hv: vmbus: Introduce table of VMBus protocol versions
The technique used to get the next VMBus version seems increasisly
clumsy as the number of VMBus versions increases.  Performance is
not a concern since this is only done once during system boot; it's
just that we'll end up with more lines of code than is really needed.

As an alternative, introduce a table with the version numbers listed
in order (from the most recent to the oldest).  vmbus_connect() loops
through the versions listed in the table until it gets an accepted
connection or gets to the end of the table (invalid version).

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-21 20:10:43 -05:00
Michael Kelley
4df4cb9e99 x86/hyperv: Initialize clockevents earlier in CPU onlining
Hyper-V has historically initialized stimer-based clockevents late in the
process of onlining a CPU because clockevents depend on stimer
interrupts. In the original Hyper-V design, stimer interrupts generate a
VMbus message, so the VMbus machinery must be running first, and VMbus
can't be initialized until relatively late. On x86/64, LAPIC timer based
clockevents are used during early initialization before VMbus and
stimer-based clockevents are ready, and again during CPU offlining after
the stimer clockevents have been shut down.

Unfortunately, this design creates problems when offlining CPUs for
hibernation or other purposes. stimer-based clockevents are shut down
relatively early in the offlining process, so clockevents_unbind_device()
must be used to fallback to the LAPIC-based clockevents for the remainder
of the offlining process.  Furthermore, the late initialization and early
shutdown of stimer-based clockevents doesn't work well on ARM64 since there
is no other timer like the LAPIC to fallback to. So CPU onlining and
offlining doesn't work properly.

Fix this by recognizing that stimer Direct Mode is the normal path for
newer versions of Hyper-V on x86/64, and the only path on other
architectures. With stimer Direct Mode, stimer interrupts don't require any
VMbus machinery. stimer clockevents can be initialized and shut down
consistent with how it is done for other clockevent devices. While the old
VMbus-based stimer interrupts must still be supported for backward
compatibility on x86, that mode of operation can be treated as legacy.

So add a new Hyper-V stimer entry in the CPU hotplug state list, and use
that new state when in Direct Mode. Update the Hyper-V clocksource driver
to allocate and initialize stimer clockevents earlier during boot. Update
Hyper-V initialization and the VMbus driver to use this new design. As a
result, the LAPIC timer is no longer used during boot or CPU
onlining/offlining and clockevents_unbind_device() is not called.  But
retain the old design as a legacy implementation for older versions of
Hyper-V that don't support Direct Mode.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Link: https://lkml.kernel.org/r/1573607467-9456-1-git-send-email-mikelley@microsoft.com
2019-11-15 10:33:49 +01:00
Dexuan Cui
83b50f83a9 Drivers: hv: vmbus: Fix harmless building warnings without CONFIG_PM_SLEEP
If CONFIG_PM_SLEEP is not set, we can comment out these functions to avoid
the below warnings:

drivers/hv/vmbus_drv.c:2208:12: warning: ‘vmbus_bus_resume’ defined but not used [-Wunused-function]
drivers/hv/vmbus_drv.c:2128:12: warning: ‘vmbus_bus_suspend’ defined but not used [-Wunused-function]
drivers/hv/vmbus_drv.c:937:12: warning: ‘vmbus_resume’ defined but not used [-Wunused-function]
drivers/hv/vmbus_drv.c:918:12: warning: ‘vmbus_suspend’ defined but not used [-Wunused-function]

Fixes: 271b2224d4 ("Drivers: hv: vmbus: Implement suspend/resume for VSC drivers for hibernation")
Fixes: f53335e328 ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by:  Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-01 14:49:45 -04:00
Linus Torvalds
af5a7e99cc - First round of vmbus hibernation support from Dexuan Cui.
- Removal of dependencies on PAGE_SIZE by Maya Nakamura.
 - Moving the hyper-v tools/ code into the tools build system by Andy
 Shevchenko.
 - hyper-v balloon cleanups by Dexuan Cui.
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull Hyper-V updates from Sasha Levin:

 - first round of vmbus hibernation support (Dexuan Cui)

 - remove dependencies on PAGE_SIZE (Maya Nakamura)

 - move the hyper-v tools/ code into the tools build system (Andy
   Shevchenko)

 - hyper-v balloon cleanups (Dexuan Cui)

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Resume after fixing up old primary channels
  Drivers: hv: vmbus: Suspend after cleaning up hv_sock and sub channels
  Drivers: hv: vmbus: Clean up hv_sock channels by force upon suspend
  Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation
  Drivers: hv: vmbus: Ignore the offers when resuming from hibernation
  Drivers: hv: vmbus: Implement suspend/resume for VSC drivers for hibernation
  Drivers: hv: vmbus: Add a helper function is_sub_channel()
  Drivers: hv: vmbus: Suspend/resume the synic for hibernation
  Drivers: hv: vmbus: Break out synic enable and disable operations
  HID: hv: Remove dependencies on PAGE_SIZE for ring buffer
  Tools: hv: move to tools buildsystem
  hv_balloon: Reorganize the probe function
  hv_balloon: Use a static page for the balloon_up send buffer
2019-09-24 12:36:31 -07:00
Linus Torvalds
7f2444d38f Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core timer updates from Thomas Gleixner:
 "Timers and timekeeping updates:

   - A large overhaul of the posix CPU timer code which is a preparation
     for moving the CPU timer expiry out into task work so it can be
     properly accounted on the task/process.

     An update to the bogus permission checks will come later during the
     merge window as feedback was not complete before heading of for
     travel.

   - Switch the timerqueue code to use cached rbtrees and get rid of the
     homebrewn caching of the leftmost node.

   - Consolidate hrtimer_init() + hrtimer_init_sleeper() calls into a
     single function

   - Implement the separation of hrtimers to be forced to expire in hard
     interrupt context even when PREEMPT_RT is enabled and mark the
     affected timers accordingly.

   - Implement a mechanism for hrtimers and the timer wheel to protect
     RT against priority inversion and live lock issues when a (hr)timer
     which should be canceled is currently executing the callback.
     Instead of infinitely spinning, the task which tries to cancel the
     timer blocks on a per cpu base expiry lock which is held and
     released by the (hr)timer expiry code.

   - Enable the Hyper-V TSC page based sched_clock for Hyper-V guests
     resulting in faster access to timekeeping functions.

   - Updates to various clocksource/clockevent drivers and their device
     tree bindings.

   - The usual small improvements all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
  posix-cpu-timers: Fix permission check regression
  posix-cpu-timers: Always clear head pointer on dequeue
  hrtimer: Add a missing bracket and hide `migration_base' on !SMP
  posix-cpu-timers: Make expiry_active check actually work correctly
  posix-timers: Unbreak CONFIG_POSIX_TIMERS=n build
  tick: Mark sched_timer to expire in hard interrupt context
  hrtimer: Add kernel doc annotation for HRTIMER_MODE_HARD
  x86/hyperv: Hide pv_ops access for CONFIG_PARAVIRT=n
  posix-cpu-timers: Utilize timerqueue for storage
  posix-cpu-timers: Move state tracking to struct posix_cputimers
  posix-cpu-timers: Deduplicate rlimit handling
  posix-cpu-timers: Remove pointless comparisons
  posix-cpu-timers: Get rid of 64bit divisions
  posix-cpu-timers: Consolidate timer expiry further
  posix-cpu-timers: Get rid of zero checks
  rlimit: Rewrite non-sensical RLIMIT_CPU comment
  posix-cpu-timers: Respect INFINITY for hard RTTIME limit
  posix-cpu-timers: Switch thread group sampling to array
  posix-cpu-timers: Restructure expiry array
  posix-cpu-timers: Remove cputime_expires
  ...
2019-09-17 12:35:15 -07:00
Linus Torvalds
e2bddc20b5 Merge branch 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 hyperv updates from Ingo Molnar:
 "Misc updates related to page size abstractions within the HyperV code,
  in preparation for future features"

* 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  drivers: hv: vmbus: Replace page definition with Hyper-V specific one
  x86/hyperv: Add functions to allocate/deallocate page for Hyper-V
  x86/hyperv: Create and use Hyper-V page definitions
2019-09-16 19:39:00 -07:00
Dexuan Cui
d8bd2d442b Drivers: hv: vmbus: Resume after fixing up old primary channels
When the host re-offers the primary channels upon resume, the host only
guarantees the Instance GUID  doesn't change, so vmbus_bus_suspend()
should invalidate channel->offermsg.child_relid and figure out the
number of primary channels that need to be fixed up upon resume.

Upon resume, vmbus_onoffer() finds the old channel structs, and maps
the new offers to the old channels, and fixes up the old structs,
and finally the resume callbacks of the VSC drivers will re-open
the channels.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06 14:52:44 -04:00
Dexuan Cui
b307b38962 Drivers: hv: vmbus: Suspend after cleaning up hv_sock and sub channels
Before suspend, Linux must make sure all the hv_sock channels have been
properly cleaned up, because a hv_sock connection can not persist across
hibernation, and the user-space app must be properly notified of the
state change of the connection.

Before suspend, Linux also must make sure all the sub-channels have been
destroyed, i.e. the related channel structs of the sub-channels must be
properly removed, otherwise they would cause a conflict when the
sub-channels are recreated upon resume.

Add a counter to track such channels, and vmbus_bus_suspend() should wait
for the counter to drop to zero.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06 14:52:44 -04:00
Dexuan Cui
1f48dcf180 Drivers: hv: vmbus: Clean up hv_sock channels by force upon suspend
Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
hibernation. There is no better method to clean up the channels since
some of the channels may still be referenced by the userspace apps when
hibernation is triggered: in this case, with this patch, the "rescind"
fields of the channels are set, and the apps will thoroughly destroy
the channels after hibernation.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06 14:52:44 -04:00
Dexuan Cui
f53335e328 Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation
Before Linux enters hibernation, it sends the CHANNELMSG_UNLOAD message to
the host so all the offers are gone. After hibernation, Linux needs to
re-negotiate with the host using the same vmbus protocol version (which
was in use before hibernation), and ask the host to re-offer the vmbus
devices.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06 14:52:44 -04:00
Dexuan Cui
e3ede02add Drivers: hv: vmbus: Ignore the offers when resuming from hibernation
When the VM resumes, the host re-sends the offers. We should not add the
offers to the global vmbus_connection.chn_list again.

This patch assumes the RELIDs of the channels don't change across
hibernation. Actually this is not always true, especially in the case of
NIC SR-IOV the VF vmbus device's RELID sometimes can change. A later patch
will address this issue by mapping the new offers to the old channels and
fixing up the old channels, if necessary.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06 14:52:44 -04:00
Dexuan Cui
271b2224d4 Drivers: hv: vmbus: Implement suspend/resume for VSC drivers for hibernation
The high-level VSC drivers will implement device-specific callbacks.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06 14:52:44 -04:00
Dexuan Cui
63ecc6d22c Drivers: hv: vmbus: Suspend/resume the synic for hibernation
This is needed when we resume the old kernel from the "current" kernel.

Note: when hv_synic_suspend() and hv_synic_resume() run, all the
non-boot CPUs have been offlined, and interrupts are disabled on CPU0.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06 14:52:44 -04:00
Dexuan Cui
dba61cda30 Drivers: hv: vmbus: Break out synic enable and disable operations
Break out synic enable and disable operations into separate
hv_synic_disable_regs() and hv_synic_enable_regs() functions for use by a
later patch to support hibernation.

There is no functional change except the unnecessary check
"if (sctrl.enable != 1) return -EFAULT;" which is removed, because when
we're in hv_synic_cleanup(), we're absolutely sure sctrl.enable must be 1.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-06 14:52:44 -04:00
Vitaly Kuznetsov
3e2d94535a clocksource/drivers/hyperv: Enable TSC page clocksource on 32bit
There is no particular reason to not enable TSC page clocksource on
32-bit. mul_u64_u64_shr() is available and despite the increased
computational complexity (compared to 64bit) TSC page is still a huge win
compared to MSR-based clocksource.

In-kernel reads:
  MSR based clocksource: 3361 cycles
  TSC page clocksource: 49 cycles

Reads from userspace (utilizing vDSO in case of TSC page):
  MSR based clocksource: 5664 cycles
  TSC page clocksource: 131 cycles

Enabling TSC page on 32bits allows to get rid of CONFIG_HYPERV_TSCPAGE as
it is now not any different from CONFIG_HYPERV_TIMER.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lkml.kernel.org/r/20190822083630.17059-1-vkuznets@redhat.com
2019-08-23 16:59:54 +02:00
Dexuan Cui
a9fc4340ae Drivers: hv: vmbus: Fix virt_to_hvpfn() for X86_PAE
In the case of X86_PAE, unsigned long is u32, but the physical address type
should be u64. Due to the bug here, the netvsc driver can not load
successfully, and sometimes the VM can panic due to memory corruption (the
hypervisor writes data to the wrong location).

Fixes: 6ba34171bc ("Drivers: hv: vmbus: Remove use of slow_virt_to_phys()")
Cc: stable@vger.kernel.org
Cc: Michael Kelley <mikelley@microsoft.com>
Reported-and-tested-by: Juliana Rodrigueiro <juliana.rodrigueiro@intra2net.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by:  Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-20 12:49:57 -04:00
Dexuan Cui
16c7596372 Drivers: hv: vmbus: Remove the unused "tsc_page" from struct hv_context
This field is no longer used after the commit
63ed4e0c67 ("Drivers: hv: vmbus: Consolidate all Hyper-V specific clocksource code")
, because it's replaced by the global variable
"struct ms_hyperv_tsc_page *tsc_pg;" (now, the variable is in
drivers/clocksource/hyperv_timer.c).

Fixes: 63ed4e0c67 ("Drivers: hv: vmbus: Consolidate all Hyper-V specific clocksource code")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-20 11:25:57 -04:00
Nishad Kamdar
61e0f39105 tools: hv: Use the correct style for SPDX License Identifier
This patch corrects the SPDX License Identifier style
in the trace header file related to Microsoft Hyper-V
client drivers.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used)

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-17 15:29:34 -04:00
Dexuan Cui
221f6df008 hv_balloon: Reorganize the probe function
Move the code that negotiates with the host to a new function
balloon_connect_vsp() and improve the error handling.

This makes the code more readable and paves the way for the
support of hibernation in future.

Makes no real logic change here.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-30 18:35:56 -04:00
Dexuan Cui
1fed17df7e hv_balloon: Use a static page for the balloon_up send buffer
It's unnecessary to dynamically allocate the buffer.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-30 18:35:30 -04:00
Maya Nakamura
83527ef7ab drivers: hv: vmbus: Replace page definition with Hyper-V specific one
Replace PAGE_SIZE with HV_HYP_PAGE_SIZE because the guest page size may not
be 4096 on all architectures and Hyper-V always runs with a page size of
4096.

Signed-off-by: Maya Nakamura <m.maya.nakamura@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Sasha Levin <sashal@kernel.org>
Link: https://lkml.kernel.org/r/0d9e80ecabcc950dc279fdd2e39bea4060123ba4.1562916939.git.m.maya.nakamura@gmail.com
2019-07-22 11:06:45 +02:00
Matteo Croce
eec4844fae proc/sysctl: add shared variables for range check
In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range.  This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.

On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.

The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:

    $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
    248

Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.

This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:

    # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
    add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
    Data                                         old     new   delta
    sysctl_vals                                    -      12     +12
    __kstrtab_sysctl_vals                          -      12     +12
    max                                           14      10      -4
    int_max                                       16       -     -16
    one                                           68       -     -68
    zero                                         128      28    -100
    Total: Before=20583249, After=20583085, chg -0.00%

[mcroce@redhat.com: tipc: remove two unused variables]
  Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
  Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-07-18 17:08:07 -07:00
Linus Torvalds
16c97650a5 - Add a module description to the Hyper-V vmbus module.
- Rework some vmbus code to separate architecture specifics out to
 arch/x86/. This is part of the work of adding arm64 support to Hyper-V.
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Merge tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyper-v updates from Sasha Levin:

 - Add a module description to the Hyper-V vmbus module.

 - Rework some vmbus code to separate architecture specifics out to
   arch/x86/. This is part of the work of adding arm64 support to
   Hyper-V.

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Break out ISA independent parts of mshyperv.h
  drivers: hv: Add a module description line to the hv_vmbus driver
2019-07-12 15:28:38 -07:00
Linus Torvalds
8faef7125d Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 platform updayes from Ingo Molnar:
 "Most of the commits add ACRN hypervisor guest support, plus two
  cleanups"

* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/jailhouse: Mark jailhouse_x2apic_available() as __init
  x86/platform/geode: Drop <linux/gpio.h> includes
  x86/acrn: Use HYPERVISOR_CALLBACK_VECTOR for ACRN guest upcall vector
  x86: Add support for Linux guests on an ACRN hypervisor
  x86/Kconfig: Add new X86_HV_CALLBACK_VECTOR config symbol
2019-07-08 17:49:45 -07:00
Michael Kelley
dd2cb34861 clocksource/drivers: Continue making Hyper-V clocksource ISA agnostic
Continue consolidating Hyper-V clock and timer code into an ISA
independent Hyper-V clocksource driver.

Move the existing clocksource code under drivers/hv and arch/x86 to the new
clocksource driver while separating out the ISA dependencies. Update
Hyper-V initialization to call initialization and cleanup routines since
the Hyper-V synthetic clock is not independently enumerated in ACPI.

Update Hyper-V clocksource users in KVM and VDSO to get definitions from
the new include file.

No behavior is changed and no new functionality is added.

Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: "bp@alien8.de" <bp@alien8.de>
Cc: "will.deacon@arm.com" <will.deacon@arm.com>
Cc: "catalin.marinas@arm.com" <catalin.marinas@arm.com>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>
Cc: "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>
Cc: "olaf@aepfle.de" <olaf@aepfle.de>
Cc: "apw@canonical.com" <apw@canonical.com>
Cc: "jasowang@redhat.com" <jasowang@redhat.com>
Cc: "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com>
Cc: Sunil Muthuswamy <sunilmut@microsoft.com>
Cc: KY Srinivasan <kys@microsoft.com>
Cc: "sashal@kernel.org" <sashal@kernel.org>
Cc: "vincenzo.frascino@arm.com" <vincenzo.frascino@arm.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>
Cc: "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>
Cc: "arnd@arndb.de" <arnd@arndb.de>
Cc: "linux@armlinux.org.uk" <linux@armlinux.org.uk>
Cc: "ralf@linux-mips.org" <ralf@linux-mips.org>
Cc: "paul.burton@mips.com" <paul.burton@mips.com>
Cc: "daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>
Cc: "salyzyn@android.com" <salyzyn@android.com>
Cc: "pcc@google.com" <pcc@google.com>
Cc: "shuah@kernel.org" <shuah@kernel.org>
Cc: "0x7f454c46@gmail.com" <0x7f454c46@gmail.com>
Cc: "linux@rasmusvillemoes.dk" <linux@rasmusvillemoes.dk>
Cc: "huw@codeweavers.com" <huw@codeweavers.com>
Cc: "sfr@canb.auug.org.au" <sfr@canb.auug.org.au>
Cc: "pbonzini@redhat.com" <pbonzini@redhat.com>
Cc: "rkrcmar@redhat.com" <rkrcmar@redhat.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Link: https://lkml.kernel.org/r/1561955054-1838-3-git-send-email-mikelley@microsoft.com
2019-07-03 11:00:59 +02:00
Michael Kelley
fd1fea6834 clocksource/drivers: Make Hyper-V clocksource ISA agnostic
Hyper-V clock/timer code and data structures are currently mixed
in with other code in the ISA independent drivers/hv directory as
well as the ISA dependent Hyper-V code under arch/x86.

Consolidate this code and data structures into a Hyper-V clocksource driver
to better follow the Linux model. In doing so, separate out the ISA
dependent portions so the new clocksource driver works for x86 and for the
in-process Hyper-V on ARM64 code.

To start, move the existing clockevents code to create the new clocksource
driver. Update the VMbus driver to call initialization and cleanup routines
since the Hyper-V synthetic timers are not independently enumerated in
ACPI.

No behavior is changed and no new functionality is added.

Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: "bp@alien8.de" <bp@alien8.de>
Cc: "will.deacon@arm.com" <will.deacon@arm.com>
Cc: "catalin.marinas@arm.com" <catalin.marinas@arm.com>
Cc: "mark.rutland@arm.com" <mark.rutland@arm.com>
Cc: "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>
Cc: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>
Cc: "olaf@aepfle.de" <olaf@aepfle.de>
Cc: "apw@canonical.com" <apw@canonical.com>
Cc: "jasowang@redhat.com" <jasowang@redhat.com>
Cc: "marcelo.cerri@canonical.com" <marcelo.cerri@canonical.com>
Cc: Sunil Muthuswamy <sunilmut@microsoft.com>
Cc: KY Srinivasan <kys@microsoft.com>
Cc: "sashal@kernel.org" <sashal@kernel.org>
Cc: "vincenzo.frascino@arm.com" <vincenzo.frascino@arm.com>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>
Cc: "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>
Cc: "linux-kselftest@vger.kernel.org" <linux-kselftest@vger.kernel.org>
Cc: "arnd@arndb.de" <arnd@arndb.de>
Cc: "linux@armlinux.org.uk" <linux@armlinux.org.uk>
Cc: "ralf@linux-mips.org" <ralf@linux-mips.org>
Cc: "paul.burton@mips.com" <paul.burton@mips.com>
Cc: "daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>
Cc: "salyzyn@android.com" <salyzyn@android.com>
Cc: "pcc@google.com" <pcc@google.com>
Cc: "shuah@kernel.org" <shuah@kernel.org>
Cc: "0x7f454c46@gmail.com" <0x7f454c46@gmail.com>
Cc: "linux@rasmusvillemoes.dk" <linux@rasmusvillemoes.dk>
Cc: "huw@codeweavers.com" <huw@codeweavers.com>
Cc: "sfr@canb.auug.org.au" <sfr@canb.auug.org.au>
Cc: "pbonzini@redhat.com" <pbonzini@redhat.com>
Cc: "rkrcmar@redhat.com" <rkrcmar@redhat.com>
Cc: "kvm@vger.kernel.org" <kvm@vger.kernel.org>
Link: https://lkml.kernel.org/r/1561955054-1838-2-git-send-email-mikelley@microsoft.com
2019-07-03 11:00:59 +02:00
Joseph Salisbury
674eecb3d3 drivers: hv: Add a module description line to the hv_vmbus driver
This patch only adds a MODULE_DESCRIPTION statement to the driver.
This change is only cosmetic, so there should be no runtime impact.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-23 20:20:02 -04:00
Zhao Yakui
ecca250294 x86/Kconfig: Add new X86_HV_CALLBACK_VECTOR config symbol
Add a special Kconfig symbol X86_HV_CALLBACK_VECTOR so that the guests
using the hypervisor interrupt callback counter can select and thus
enable that counter. Select it when xen or hyperv support is enabled. No
functional changes.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: linux-hyperv@vger.kernel.org
Cc: Nicolai Stange <nstange@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: xen-devel@lists.xenproject.org
Link: https://lkml.kernel.org/r/1559108037-18813-2-git-send-email-yakui.zhao@intel.com
2019-06-11 21:21:11 +02:00
Thomas Gleixner
3b20eb2372 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 320
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not write to the free
  software foundation inc 59 temple place suite 330 boston ma 02111
  1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 33 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190530000435.254582722@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:05 +02:00
Thomas Gleixner
43aa31327b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 280
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose good title or non infringement see
  the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 9 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.459653302@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:36 +02:00
Dexuan Cui
a0033bd1ea Drivers: hv: vmbus: Remove the undesired put_cpu_ptr() in hv_synic_cleanup()
With CONFIG_DEBUG_PREEMPT=y, the put_cpu_ptr() triggers an underflow
warning in preempt_count_sub().

Fixes: 37cdd991fa ("vmbus: put related per-cpu variable together")
Cc: stable@vger.kernel.org
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
2019-04-13 09:36:35 -04:00
Kimberly Brown
14948e3944 Drivers: hv: vmbus: Fix race condition with new ring_buffer_info mutex
Fix a race condition that can result in a ring buffer pointer being set
to null while a "_show" function is reading the ring buffer's data. This
problem was discussed here: https://lkml.org/lkml/2018/10/18/779

To fix the race condition, add a new mutex lock to the
"hv_ring_buffer_info" struct. Add a new function,
"hv_ringbuffer_pre_init()", where a channel's inbound and outbound
ring_buffer_info mutex locks are initialized.

Acquire/release the locks in the "hv_ringbuffer_cleanup()" function,
which is where the ring buffer pointers are set to null.

Acquire/release the locks in the four channel-level "_show" functions
that access ring buffer data. Remove the "const" qualifier from the
"vmbus_channel" parameter and the "rbi" variable of the channel-level
"_show" functions so that the locks can be acquired/released in these
functions.

Acquire/release the locks in hv_ringbuffer_get_debuginfo(). Remove the
"const" qualifier from the "hv_ring_buffer_info" parameter so that the
locks can be acquired/released in this function.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-10 18:58:56 -04:00
Kimberly Brown
4713eb7b58 Drivers: hv: vmbus: Set ring_info field to 0 and remove memset
Set "ring_info->priv_read_index" to 0. Now, all of ring_info's fields
are explicitly set in this function. The memset() call is no longer
necessary, so remove it.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-10 18:58:56 -04:00
Kimberly Brown
fcedbb293e Drivers: hv: vmbus: Refactor chan->state if statement
The chan->state "if statement" was introduced in commit 6712cc9c22
("vmbus: don't return values for uninitalized channels"). That commit
states that the purpose of the chan->state "if statement" is to prevent
returning garbage or causing a kernel OOPS when the channel ring buffer
is not initialized. The changes in this patch provide the same
protection.

Refactor the chan->state “if statement” in vmbus_chan_attr_show():
 - Instead of checking the channel state in the "if statement", check
   whether the channel ring buffer pointer is NULL. Checking the
   ring buffer pointer makes this code consistent with
   hv_ringbuffer_get_debuginfo().

 - Move the "if statement" to the four "_show" functions that access a
   channel ring buffer. Only four of the channel-level "_show" functions
   access a ring buffer. The ring buffer pointer does not need to be
   checked before calling the other "_show" functions, and moving the
   ring buffer pointer "if statement" to the "_show" functions that
   access a ring buffer makes the purpose of the "if statement" clear.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-04-10 18:58:56 -04:00