Commit Graph

2111 Commits

Author SHA1 Message Date
Juergen Gross cfbb3abadc xen/events: increment refcnt only if event channel is refcounted
[ Upstream commit d277f9d828 ]

In bind_evtchn_to_irq_chip() don't increment the refcnt of the event
channel blindly. In case the event channel is NOT refcounted, issue a
warning instead.

Add an additional safety net by doing the refcnt increment only if the
caller has specified IRQF_SHARED in the irqflags parameter.

Fixes: 9e90e58c11 ("xen: evtchn: Allow shared registration of IRQ handers")
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/20240313071409.25913-3-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:20:09 -04:00
Juergen Gross 99e425032c xen/evtchn: avoid WARN() when unbinding an event channel
[ Upstream commit 51c23bd691 ]

When unbinding a user event channel, the related handler might be
called a last time in case the kernel was built with
CONFIG_DEBUG_SHIRQ. This might cause a WARN() in the handler.

Avoid that by adding an "unbinding" flag to struct user_event which
will short circuit the handler.

Fixes: 9e90e58c11 ("xen: evtchn: Allow shared registration of IRQ handers")
Reported-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Tested-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/20240313071409.25913-2-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26 18:20:09 -04:00
Dan Carpenter 980278aca1 xen/events: fix error code in xen_bind_pirq_msi_to_irq()
commit 7f3da4b698 upstream.

Return -ENOMEM if xen_irq_init() fails.  currently the code returns an
uninitialized variable or zero.

Fixes: 5dd9ad32d7 ("xen/events: drop xen_allocate_irqs_dynamic()")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Juergen Gross <jgross@ssue.com>
Link: https://lore.kernel.org/r/3b9ab040-a92e-4e35-b687-3a95890a9ace@moroto.mountain
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-03-01 13:35:04 +01:00
Maximilian Heyne 20980195ec xen/events: close evtchn after mapping cleanup
[ Upstream commit fa765c4b4a ]

shutdown_pirq and startup_pirq are not taking the
irq_mapping_update_lock because they can't due to lock inversion. Both
are called with the irq_desc->lock being taking. The lock order,
however, is first irq_mapping_update_lock and then irq_desc->lock.

This opens multiple races:
- shutdown_pirq can be interrupted by a function that allocates an event
  channel:

  CPU0                        CPU1
  shutdown_pirq {
    xen_evtchn_close(e)
                              __startup_pirq {
                                EVTCHNOP_bind_pirq
                                  -> returns just freed evtchn e
                                set_evtchn_to_irq(e, irq)
                              }
    xen_irq_info_cleanup() {
      set_evtchn_to_irq(e, -1)
    }
  }

  Assume here event channel e refers here to the same event channel
  number.
  After this race the evtchn_to_irq mapping for e is invalid (-1).

- __startup_pirq races with __unbind_from_irq in a similar way. Because
  __startup_pirq doesn't take irq_mapping_update_lock it can grab the
  evtchn that __unbind_from_irq is currently freeing and cleaning up. In
  this case even though the event channel is allocated, its mapping can
  be unset in evtchn_to_irq.

The fix is to first cleanup the mappings and then close the event
channel. In this way, when an event channel gets allocated it's
potential previous evtchn_to_irq mappings are guaranteed to be unset already.
This is also the reverse order of the allocation where first the event
channel is allocated and then the mappings are setup.

On a 5.10 kernel prior to commit 3fcdaf3d76 ("xen/events: modify internal
[un]bind interfaces"), we hit a BUG like the following during probing of NVMe
devices. The issue is that during nvme_setup_io_queues, pci_free_irq
is called for every device which results in a call to shutdown_pirq.
With many nvme devices it's therefore likely to hit this race during
boot because there will be multiple calls to shutdown_pirq and
startup_pirq are running potentially in parallel.

  ------------[ cut here ]------------
  blkfront: xvda: barrier or flush: disabled; persistent grants: enabled; indirect descriptors: enabled; bounce buffer: enabled
  kernel BUG at drivers/xen/events/events_base.c:499!
  invalid opcode: 0000 [#1] SMP PTI
  CPU: 44 PID: 375 Comm: kworker/u257:23 Not tainted 5.10.201-191.748.amzn2.x86_64 #1
  Hardware name: Xen HVM domU, BIOS 4.11.amazon 08/24/2006
  Workqueue: nvme-reset-wq nvme_reset_work
  RIP: 0010:bind_evtchn_to_cpu+0xdf/0xf0
  Code: 5d 41 5e c3 cc cc cc cc 44 89 f7 e8 2b 55 ad ff 49 89 c5 48 85 c0 0f 84 64 ff ff ff 4c 8b 68 30 41 83 fe ff 0f 85 60 ff ff ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 00 00
  RSP: 0000:ffffc9000d533b08 EFLAGS: 00010046
  RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006
  RDX: 0000000000000028 RSI: 00000000ffffffff RDI: 00000000ffffffff
  RBP: ffff888107419680 R08: 0000000000000000 R09: ffffffff82d72b00
  R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000001ed
  R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000002
  FS:  0000000000000000(0000) GS:ffff88bc8b500000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 0000000002610001 CR4: 00000000001706e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  Call Trace:
   ? show_trace_log_lvl+0x1c1/0x2d9
   ? show_trace_log_lvl+0x1c1/0x2d9
   ? set_affinity_irq+0xdc/0x1c0
   ? __die_body.cold+0x8/0xd
   ? die+0x2b/0x50
   ? do_trap+0x90/0x110
   ? bind_evtchn_to_cpu+0xdf/0xf0
   ? do_error_trap+0x65/0x80
   ? bind_evtchn_to_cpu+0xdf/0xf0
   ? exc_invalid_op+0x4e/0x70
   ? bind_evtchn_to_cpu+0xdf/0xf0
   ? asm_exc_invalid_op+0x12/0x20
   ? bind_evtchn_to_cpu+0xdf/0xf0
   ? bind_evtchn_to_cpu+0xc5/0xf0
   set_affinity_irq+0xdc/0x1c0
   irq_do_set_affinity+0x1d7/0x1f0
   irq_setup_affinity+0xd6/0x1a0
   irq_startup+0x8a/0xf0
   __setup_irq+0x639/0x6d0
   ? nvme_suspend+0x150/0x150
   request_threaded_irq+0x10c/0x180
   ? nvme_suspend+0x150/0x150
   pci_request_irq+0xa8/0xf0
   ? __blk_mq_free_request+0x74/0xa0
   queue_request_irq+0x6f/0x80
   nvme_create_queue+0x1af/0x200
   nvme_create_io_queues+0xbd/0xf0
   nvme_setup_io_queues+0x246/0x320
   ? nvme_irq_check+0x30/0x30
   nvme_reset_work+0x1c8/0x400
   process_one_work+0x1b0/0x350
   worker_thread+0x49/0x310
   ? process_one_work+0x350/0x350
   kthread+0x11b/0x140
   ? __kthread_bind_mask+0x60/0x60
   ret_from_fork+0x22/0x30
  Modules linked in:
  ---[ end trace a11715de1eee1873 ]---

Fixes: d46a78b05c ("xen: implement pirq type event channels")
Cc: stable@vger.kernel.org
Co-debugged-by: Andrew Panyakin <apanyaki@amazon.com>
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20240124163130.31324-1-mheyne@amazon.de
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:34:58 +01:00
Juergen Gross 636ac94cee xen/events: modify internal [un]bind interfaces
[ Upstream commit 3fcdaf3d76 ]

Modify the internal bind- and unbind-interfaces to take a struct
irq_info parameter. When allocating a new IRQ pass the pointer from
the allocating function further up.

This will reduce the number of info_for_irq() calls and make the code
more efficient.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Stable-dep-of: fa765c4b4a ("xen/events: close evtchn after mapping cleanup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:34:58 +01:00
Juergen Gross 40f14760da xen/events: drop xen_allocate_irqs_dynamic()
[ Upstream commit 5dd9ad32d7 ]

Instead of having a common function for allocating a single IRQ or a
consecutive number of IRQs, split up the functionality into the callers
of xen_allocate_irqs_dynamic().

This allows to handle any allocation error in xen_irq_init() gracefully
instead of panicing the system. Let xen_irq_init() return the irq_info
pointer or NULL in case of an allocation error.

Additionally set the IRQ into irq_info already at allocation time, as
otherwise the IRQ would be '0' (which is a valid IRQ number) until
being set.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Stable-dep-of: fa765c4b4a ("xen/events: close evtchn after mapping cleanup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:34:57 +01:00
Juergen Gross 666860d56d xen/events: remove some simple helpers from events_base.c
[ Upstream commit 3bdb0ac350 ]

The helper functions type_from_irq() and cpu_from_irq() are just one
line functions used only internally.

Open code them where needed. At the same time modify and rename
get_evtchn_to_irq() to return a struct irq_info instead of the IRQ
number.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Stable-dep-of: fa765c4b4a ("xen/events: close evtchn after mapping cleanup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:34:57 +01:00
Juergen Gross b79345efd0 xen/events: reduce externally visible helper functions
[ Upstream commit 686464514f ]

get_evtchn_to_irq() has only one external user while irq_from_evtchn()
provides the same functionality and is exported for a wider user base.
Modify the only external user of get_evtchn_to_irq() to use
irq_from_evtchn() instead and make get_evtchn_to_irq() static.

evtchn_from_irq() and irq_from_virq() have a single external user and
can easily be combined to a new helper irq_evtchn_from_virq() allowing
to drop irq_from_virq() and to make evtchn_from_irq() static.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Stable-dep-of: fa765c4b4a ("xen/events: close evtchn after mapping cleanup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:34:57 +01:00
Viresh Kumar 3c8f5965a9 xen: evtchn: Allow shared registration of IRQ handers
[ Upstream commit 9e90e58c11 ]

Currently the handling of events is supported either in the kernel or
userspace, but not both.

In order to support fast delivery of interrupts from the guest to the
backend, we need to handle the Queue notify part of Virtio protocol in
kernel and the rest in userspace.

Update the interrupt handler registration flag to IRQF_SHARED for event
channels, which would allow multiple entities to bind their interrupt
handler for the same event channel port.

Also increment the reference count of irq_info when multiple entities
try to bind event channel to irqchip, so the unbinding happens only
after all the users are gone.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/99b1edfd3147c6b5d22a5139dab5861e767dc34a.1697439990.git.viresh.kumar@linaro.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Stable-dep-of: fa765c4b4a ("xen/events: close evtchn after mapping cleanup")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-01 13:34:57 +01:00
Oleksandr Tyshchenko 9744be5e89 xen/gntdev: Fix the abuse of underlying struct page in DMA-buf import
[ Upstream commit 2d2db7d402 ]

DO NOT access the underlying struct page of an sg table exported
by DMA-buf in dmabuf_imp_to_refs(), this is not allowed.
Please see drivers/dma-buf/dma-buf.c:mangle_sg_table() for details.

Fortunately, here (for special Xen device) we can avoid using
pages and calculate gfns directly from dma addresses provided by
the sg table.

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Link: https://lore.kernel.org/r/20240107103426.2038075-1-olekstysh@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-02-05 20:14:31 +00:00
Keith Busch fe5b55bcfe swiotlb-xen: provide the "max_mapping_size" method
commit bff2a2d453 upstream.

There's a bug that when using the XEN hypervisor with bios with large
multi-page bio vectors on NVMe, the kernel deadlocks [1].

The deadlocks are caused by inability to map a large bio vector -
dma_map_sgtable always returns an error, this gets propagated to the block
layer as BLK_STS_RESOURCE and the block layer retries the request
indefinitely.

XEN uses the swiotlb framework to map discontiguous pages into contiguous
runs that are submitted to the PCIe device. The swiotlb framework has a
limitation on the length of a mapping - this needs to be announced with
the max_mapping_size method to make sure that the hardware drivers do not
create larger mappings.

Without max_mapping_size, the NVMe block driver would create large
mappings that overrun the maximum mapping size.

Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Link: https://lore.kernel.org/stable/ZTNH0qtmint%2FzLJZ@mail-itl/ [1]
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Suggested-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/151bef41-e817-aea9-675-a35fdac4ed@redhat.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-03 07:33:07 +01:00
Roger Pau Monne 32ca78deed acpi/processor: sanitize _OSC/_PDC capabilities for Xen dom0
commit bfa993b355 upstream.

The Processor capability bits notify ACPI of the OS capabilities, and
so ACPI can adjust the return of other Processor methods taking the OS
capabilities into account.

When Linux is running as a Xen dom0, the hypervisor is the entity
in charge of processor power management, and hence Xen needs to make
sure the capabilities reported by _OSC/_PDC match the capabilities of
the driver in Xen.

Introduce a small helper to sanitize the buffer when running as Xen
dom0.

When Xen supports HWP, this serves as the equivalent of commit
a21211672c ("ACPI / processor: Request native thermal interrupt
handling via _OSC") to avoid SMM crashes.  Xen will set bit
ACPI_PROC_CAP_COLLAB_PROC_PERF (bit 12) in the capability bits and the
_OSC/_PDC call will apply it.

[ jandryuk: Mention Xen HWP's need.  Support _OSC & _PDC ]
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
Reviewed-by: Michal Wilczynski <michal.wilczynski@intel.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20231108212517.72279-1-jandryuk@gmail.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-11-28 17:19:57 +00:00
Juergen Gross a7762cb290 xen/events: fix delayed eoi list handling
[ Upstream commit 47d9702040 ]

When delaying eoi handling of events, the related elements are queued
into the percpu lateeoi list. In case the list isn't empty, the
elements should be sorted by the time when eoi handling is to happen.

Unfortunately a new element will never be queued at the start of the
list, even if it has a handling time lower than all other list
elements.

Fix that by handling that case the same way as for an empty list.

Fixes: e99502f762 ("xen/events: defer eoi in case of excessive number of events")
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 17:19:51 +00:00
Juergen Gross 1be00f8364 xen/events: avoid using info_for_irq() in xen_send_IPI_one()
[ Upstream commit e64e7c74b9 ]

xen_send_IPI_one() is being used by cpuhp_report_idle_dead() after
it calls rcu_report_dead(), meaning that any RCU usage by
xen_send_IPI_one() is a bad idea.

Unfortunately xen_send_IPI_one() is using notify_remote_via_irq()
today, which is using irq_get_chip_data() via info_for_irq(). And
irq_get_chip_data() in turn is using a maple-tree lookup requiring
RCU.

Avoid this problem by caching the ipi event channels in another
percpu variable, allowing the use notify_remote_via_evtchn() in
xen_send_IPI_one().

Fixes: 721255b982 ("genirq: Use a maple tree for interrupt descriptor management")
Reported-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Juergen Gross <jgross@suse.com>
Tested-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 17:19:50 +00:00
Marek Marczykowski-Górecki 90e8b74931 xen-pciback: Consider INTx disabled when MSI/MSI-X is enabled
[ Upstream commit 2c269f42d0 ]

Linux enables MSI-X before disabling INTx, but keeps MSI-X masked until
the table is filled. Then it disables INTx just before clearing MASKALL
bit. Currently this approach is rejected by xen-pciback.
According to the PCIe spec, device cannot use INTx when MSI/MSI-X is
enabled (in other words: enabling MSI/MSI-X implicitly disables INTx).

Change the logic to consider INTx disabled if MSI/MSI-X is enabled. This
applies to three places:
 - checking currently enabled interrupts type,
 - transition to MSI/MSI-X - where INTx would be implicitly disabled,
 - clearing INTx disable bit - which can be allowed even if MSI/MSI-X is
   enabled, as device should consider INTx disabled anyway in that case

Fixes: 5e29500eba ("xen-pciback: Allow setting PCI_MSIX_FLAGS_MASKALL too")
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Acked-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20231016131348.1734721-1-marmarek@invisiblethingslab.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:12 +01:00
Viresh Kumar 0d99e8c816 xen: Make struct privcmd_irqfd's layout architecture independent
[ Upstream commit 8dd765a5d7 ]

Using indirect pointers in an ioctl command argument means that the
layout is architecture specific, in particular we can't use the same one
from 32-bit compat tasks. The general recommendation is to have __u64
members and use u64_to_user_ptr() to access it from the kernel if we are
unable to avoid the pointers altogether.

Fixes: f8941e6c4c ("xen: privcmd: Add support for irqfd")
Reported-by: Arnd Bergmann <arnd@kernel.org>
Closes: https://lore.kernel.org/all/268a2031-63b8-4c7d-b1e5-8ab83ca80b4a@app.fastmail.com/
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/a4ef0d4a68fc858b34a81fd3f9877d9b6898eb77.1697439990.git.viresh.kumar@linaro.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:12 +01:00
Juergen Gross da9de139a1 xenbus: fix error exit in xenbus_init()
[ Upstream commit 44961b81a9 ]

In case an error occurs in xenbus_init(), xen_store_domain_type should
be set to XS_UNKNOWN.

Fix one instance where this action is missing.

Fixes: 5b3353949e ("xen: add support for initializing xenstore later as HVM domain")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202304200845.w7m4kXZr-lkp@intel.com/
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/20230822091138.4765-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 11:59:12 +01:00
Juergen Gross 87797fad6c xen/events: replace evtchn_rwlock with RCU
In unprivileged Xen guests event handling can cause a deadlock with
Xen console handling. The evtchn_rwlock and the hvc_lock are taken in
opposite sequence in __hvc_poll() and in Xen console IRQ handling.
Normally this is no problem, as the evtchn_rwlock is taken as a reader
in both paths, but as soon as an event channel is being closed, the
lock will be taken as a writer, which will cause read_lock() to block:

CPU0                     CPU1                CPU2
(IRQ handling)           (__hvc_poll())      (closing event channel)

read_lock(evtchn_rwlock)
                         spin_lock(hvc_lock)
                                             write_lock(evtchn_rwlock)
                                                 [blocks]
spin_lock(hvc_lock)
    [blocks]
                        read_lock(evtchn_rwlock)
                            [blocks due to writer waiting,
                             and not in_interrupt()]

This issue can be avoided by replacing evtchn_rwlock with RCU in
xen_free_irq(). Note that RCU is used only to delay freeing of the
irq_info memory. There is no RCU based dereferencing or replacement of
pointers involved.

In order to avoid potential races between removing the irq_info
reference and handling of interrupts, set the irq_info pointer to NULL
only when freeing its memory. The IRQ itself must be freed at that
time, too, as otherwise the same IRQ number could be allocated again
before handling of the old instance would have been finished.

This is XSA-441 / CVE-2023-34324.

Fixes: 54c9de8989 ("xen/events: add a new "late EOI" evtchn framework")
Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-10-09 09:21:16 +02:00
Juergen Gross 37510dd566 xen: simplify evtchn_do_upcall() call maze
There are several functions involved for performing the functionality
of evtchn_do_upcall():

- __xen_evtchn_do_upcall() doing the real work
- xen_hvm_evtchn_do_upcall() just being a wrapper for
  __xen_evtchn_do_upcall(), exposed for external callers
- xen_evtchn_do_upcall() calling __xen_evtchn_do_upcall(), too, but
  without any user

Simplify this maze by:

- removing the unused xen_evtchn_do_upcall()
- removing xen_hvm_evtchn_do_upcall() as the only left caller of
  __xen_evtchn_do_upcall(), while renaming __xen_evtchn_do_upcall() to
  xen_evtchn_do_upcall()

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-09-19 07:04:49 +02:00
Linus Torvalds 6c1b980a7e dma-maping updates for Linux 6.6
- allow dynamic sizing of the swiotlb buffer, to cater for secure
    virtualization workloads that require all I/O to be bounce buffered
    (Petr Tesarik)
  - move a declaration to a header (Arnd Bergmann)
  - check for memory region overlap in dma-contiguous (Binglei Wang)
  - remove the somewhat dangerous runtime swiotlb-xen enablement and
    unexport is_swiotlb_active (Christoph Hellwig, Juergen Gross)
  - per-node CMA improvements (Yajun Deng)
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Merge tag 'dma-mapping-6.6-2023-08-29' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-maping updates from Christoph Hellwig:

 - allow dynamic sizing of the swiotlb buffer, to cater for secure
   virtualization workloads that require all I/O to be bounce buffered
   (Petr Tesarik)

 - move a declaration to a header (Arnd Bergmann)

 - check for memory region overlap in dma-contiguous (Binglei Wang)

 - remove the somewhat dangerous runtime swiotlb-xen enablement and
   unexport is_swiotlb_active (Christoph Hellwig, Juergen Gross)

 - per-node CMA improvements (Yajun Deng)

* tag 'dma-mapping-6.6-2023-08-29' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: optimize get_max_slots()
  swiotlb: move slot allocation explanation comment where it belongs
  swiotlb: search the software IO TLB only if the device makes use of it
  swiotlb: allocate a new memory pool when existing pools are full
  swiotlb: determine potential physical address limit
  swiotlb: if swiotlb is full, fall back to a transient memory pool
  swiotlb: add a flag whether SWIOTLB is allowed to grow
  swiotlb: separate memory pool data from other allocator data
  swiotlb: add documentation and rename swiotlb_do_find_slots()
  swiotlb: make io_tlb_default_mem local to swiotlb.c
  swiotlb: bail out of swiotlb_init_late() if swiotlb is already allocated
  dma-contiguous: check for memory region overlap
  dma-contiguous: support numa CMA for specified node
  dma-contiguous: support per-numa CMA for all architectures
  dma-mapping: move arch_dma_set_mask() declaration to header
  swiotlb: unexport is_swiotlb_active
  x86: always initialize xen-swiotlb when xen-pcifront is enabling
  xen/pci: add flag for PCI passthrough being possible
2023-08-29 20:32:10 -07:00
Viresh Kumar f8941e6c4c xen: privcmd: Add support for irqfd
Xen provides support for injecting interrupts to the guests via the
HYPERVISOR_dm_op() hypercall. The same is used by the Virtio based
device backend implementations, in an inefficient manner currently.

Generally, the Virtio backends are implemented to work with the Eventfd
based mechanism. In order to make such backends work with Xen, another
software layer needs to poll the Eventfds and raise an interrupt to the
guest using the Xen based mechanism. This results in an extra context
switch.

This is not a new problem in Linux though. It is present with other
hypervisors like KVM, etc. as well. The generic solution implemented in
the kernel for them is to provide an IOCTL call to pass the interrupt
details and eventfd, which lets the kernel take care of polling the
eventfd and raising of the interrupt, instead of handling this in user
space (which involves an extra context switch).

This patch adds support to inject a specific interrupt to guest using
the eventfd mechanism, by preventing the extra context switch.

Inspired by existing implementations for KVM, etc..

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/8e724ac1f50c2bc1eb8da9b3ff6166f1372570aa.1692697321.git.viresh.kumar@linaro.org
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-22 12:12:50 +02:00
Petr Pavlu 442466e04f xen/xenbus: Avoid a lockdep warning when adding a watch
The following lockdep warning appears during boot on a Xen dom0 system:

[   96.388794] ======================================================
[   96.388797] WARNING: possible circular locking dependency detected
[   96.388799] 6.4.0-rc5-default+ #8 Tainted: G            EL
[   96.388803] ------------------------------------------------------
[   96.388804] xenconsoled/1330 is trying to acquire lock:
[   96.388808] ffffffff82acdd10 (xs_watch_rwsem){++++}-{3:3}, at: register_xenbus_watch+0x45/0x140
[   96.388847]
               but task is already holding lock:
[   96.388849] ffff888100c92068 (&u->msgbuffer_mutex){+.+.}-{3:3}, at: xenbus_file_write+0x2c/0x600
[   96.388862]
               which lock already depends on the new lock.

[   96.388864]
               the existing dependency chain (in reverse order) is:
[   96.388866]
               -> #2 (&u->msgbuffer_mutex){+.+.}-{3:3}:
[   96.388874]        __mutex_lock+0x85/0xb30
[   96.388885]        xenbus_dev_queue_reply+0x48/0x2b0
[   96.388890]        xenbus_thread+0x1d7/0x950
[   96.388897]        kthread+0xe7/0x120
[   96.388905]        ret_from_fork+0x2c/0x50
[   96.388914]
               -> #1 (xs_response_mutex){+.+.}-{3:3}:
[   96.388923]        __mutex_lock+0x85/0xb30
[   96.388930]        xenbus_backend_ioctl+0x56/0x1c0
[   96.388935]        __x64_sys_ioctl+0x90/0xd0
[   96.388942]        do_syscall_64+0x5c/0x90
[   96.388950]        entry_SYSCALL_64_after_hwframe+0x72/0xdc
[   96.388957]
               -> #0 (xs_watch_rwsem){++++}-{3:3}:
[   96.388965]        __lock_acquire+0x1538/0x2260
[   96.388972]        lock_acquire+0xc6/0x2b0
[   96.388976]        down_read+0x2d/0x160
[   96.388983]        register_xenbus_watch+0x45/0x140
[   96.388990]        xenbus_file_write+0x53d/0x600
[   96.388994]        vfs_write+0xe4/0x490
[   96.389003]        ksys_write+0xb8/0xf0
[   96.389011]        do_syscall_64+0x5c/0x90
[   96.389017]        entry_SYSCALL_64_after_hwframe+0x72/0xdc
[   96.389023]
               other info that might help us debug this:

[   96.389025] Chain exists of:
                 xs_watch_rwsem --> xs_response_mutex --> &u->msgbuffer_mutex

[   96.413429]  Possible unsafe locking scenario:

[   96.413430]        CPU0                    CPU1
[   96.413430]        ----                    ----
[   96.413431]   lock(&u->msgbuffer_mutex);
[   96.413432]                                lock(xs_response_mutex);
[   96.413433]                                lock(&u->msgbuffer_mutex);
[   96.413434]   rlock(xs_watch_rwsem);
[   96.413436]
                *** DEADLOCK ***

[   96.413436] 1 lock held by xenconsoled/1330:
[   96.413438]  #0: ffff888100c92068 (&u->msgbuffer_mutex){+.+.}-{3:3}, at: xenbus_file_write+0x2c/0x600
[   96.413446]

An ioctl call IOCTL_XENBUS_BACKEND_SETUP (record #1 in the report)
results in calling xenbus_alloc() -> xs_suspend() which introduces
ordering xs_watch_rwsem --> xs_response_mutex. The xenbus_thread()
operation (record #2) creates xs_response_mutex --> &u->msgbuffer_mutex.
An XS_WATCH write to the xenbus file then results in a complain about
the opposite lock order &u->msgbuffer_mutex --> xs_watch_rwsem.

The dependency xs_watch_rwsem --> xs_response_mutex is spurious. Avoid
it and the warning by changing the ordering in xs_suspend(), first
acquire xs_response_mutex and then xs_watch_rwsem. Reverse also the
unlocking order in xs_suspend_cancel() for consistency, but keep
xs_resume() as is because it needs to have xs_watch_rwsem unlocked only
after exiting xs suspend and re-adding all watches.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230607123624.15739-1-petr.pavlu@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-22 08:04:59 +02:00
Yang Li 187b4c0d34 xen: Fix one kernel-doc comment
Use colon to separate parameter name from their specific meaning.
silence the warning:

drivers/xen/grant-table.c:1051: warning: Function parameter or member 'nr_pages' not described in 'gnttab_free_pages'

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=6030
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230731030037.123946-1-yang.lee@linux.alibaba.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-21 15:58:57 +02:00
Li Zetao 035a69586f xen: xenbus: Use helper function IS_ERR_OR_NULL()
Use IS_ERR_OR_NULL() to detect an error pointer or a null pointer
open-coding to simplify the code.

Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230817014736.3094289-1-lizetao1@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-21 09:55:11 +02:00
Ruan Jinjie 71281ec9c8 xen: Switch to use kmemdup() helper
Use kmemdup() helper instead of open-coding to
simplify the code.

Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Chen Jiahao <chenjiahao16@huawei.com>
Link: https://lore.kernel.org/r/20230815092434.1206386-1-ruanjinjie@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-21 09:54:05 +02:00
Yue Haibing 3e0d473dcb xen-pciback: Remove unused function declarations
Commit a92336a117 ("xen/pciback: Drop two backends, squash and cleanup some code.")
declared but never implemented these functions.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230808150912.43416-1-yuehaibing@huawei.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-08-21 09:53:22 +02:00
Petr Tesarik 05ee774122 swiotlb: make io_tlb_default_mem local to swiotlb.c
SWIOTLB implementation details should not be exposed to the rest of the
kernel. This will allow to make changes to the implementation without
modifying non-swiotlb code.

To avoid breaking existing users, provide helper functions for the few
required fields.

As a bonus, using a helper function to initialize struct device allows to
get rid of an #ifdef in driver core.

Signed-off-by: Petr Tesarik <petr.tesarik.ext@huawei.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-08-01 18:02:09 +02:00
Demi Marie Obenour c04e989484 xen: speed up grant-table reclaim
When a grant entry is still in use by the remote domain, Linux must put
it on a deferred list.  Normally, this list is very short, because
the PV network and block protocols expect the backend to unmap the grant
first.  However, Qubes OS's GUI protocol is subject to the constraints
of the X Window System, and as such winds up with the frontend unmapping
the window first.  As a result, the list can grow very large, resulting
in a massive memory leak and eventual VM freeze.

To partially solve this problem, make the number of entries that the VM
will attempt to free at each iteration tunable.  The default is still
10, but it can be overridden via a module parameter.

This is Cc: stable because (when combined with appropriate userspace
changes) it fixes a severe performance and stability problem for Qubes
OS users.

Cc: stable@vger.kernel.org
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230726165354.1252-1-demi@invisiblethingslab.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-07-27 07:53:12 +02:00
Rahul Singh 58f6259b7a xen/evtchn: Introduce new IOCTL to bind static evtchn
Xen 4.17 supports the creation of static evtchns. To allow user space
application to bind static evtchns introduce new ioctl
"IOCTL_EVTCHN_BIND_STATIC". Existing IOCTL doing more than binding
that’s why we need to introduce the new IOCTL to only bind the static
event channels.

Static evtchns to be available for use during the lifetime of the
guest. When the application exits, __unbind_from_irq() ends up being
called from release() file operations because of that static evtchns
are getting closed. To avoid closing the static event channel, add the
new bool variable "is_static" in "struct irq_info" to mark the event
channel static when creating the event channel to avoid closing the
static evtchn.

Also, take this opportunity to remove the open-coded version of the
evtchn close in drivers/xen/evtchn.c file and use xen_evtchn_close().

Signed-off-by: Rahul Singh <rahul.singh@arm.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/ae7329bf1713f83e4aad4f3fa0f316258c40a3e9.1689677042.git.rahul.singh@arm.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-07-26 08:42:34 +02:00
Stefano Stabellini 0d8f7cc805 xenbus: check xen_domain in xenbus_probe_initcall
The same way we already do in xenbus_init.
Fixes the following warning:

[  352.175563] Trying to free already-free IRQ 0
[  352.177355] WARNING: CPU: 1 PID: 88 at kernel/irq/manage.c:1893 free_irq+0xbf/0x350
[...]
[  352.213951] Call Trace:
[  352.214390]  <TASK>
[  352.214717]  ? __warn+0x81/0x170
[  352.215436]  ? free_irq+0xbf/0x350
[  352.215906]  ? report_bug+0x10b/0x200
[  352.216408]  ? prb_read_valid+0x17/0x20
[  352.216926]  ? handle_bug+0x44/0x80
[  352.217409]  ? exc_invalid_op+0x13/0x60
[  352.217932]  ? asm_exc_invalid_op+0x16/0x20
[  352.218497]  ? free_irq+0xbf/0x350
[  352.218979]  ? __pfx_xenbus_probe_thread+0x10/0x10
[  352.219600]  xenbus_probe+0x7a/0x80
[  352.221030]  xenbus_probe_thread+0x76/0xc0

Fixes: 5b3353949e ("xen: add support for initializing xenstore later as HVM domain")
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Tested-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>

Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2307211609140.3118466@ubuntu-linux-20-04-desktop
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-07-25 17:36:36 +02:00
Linus Torvalds 1599932894 xen: branch for v6.5-rc2
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Merge tag 'for-linus-6.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - a cleanup of the Xen related ELF-notes

 - a fix for virtio handling in Xen dom0 when running Xen in a VM

* tag 'for-linus-6.5-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/virtio: Fix NULL deref when a bridge of PCI root bus has no parent
  x86/Xen: tidy xen-head.S
2023-07-13 13:39:36 -07:00
Petr Pavlu 21a235bce1 xen/virtio: Fix NULL deref when a bridge of PCI root bus has no parent
When attempting to run Xen on a QEMU/KVM virtual machine with virtio
devices (all x86_64), function xen_dt_get_node() crashes on accessing
bus->bridge->parent->of_node because a bridge of the PCI root bus has no
parent set:

[    1.694192][    T1] BUG: kernel NULL pointer dereference, address: 0000000000000288
[    1.695688][    T1] #PF: supervisor read access in kernel mode
[    1.696297][    T1] #PF: error_code(0x0000) - not-present page
[    1.696297][    T1] PGD 0 P4D 0
[    1.696297][    T1] Oops: 0000 [#1] PREEMPT SMP NOPTI
[    1.696297][    T1] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.3.7-1-default #1 openSUSE Tumbleweed a577eae57964bb7e83477b5a5645a1781df990f0
[    1.696297][    T1] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[    1.696297][    T1] RIP: e030:xen_virtio_restricted_mem_acc+0xd9/0x1c0
[    1.696297][    T1] Code: 45 0c 83 e8 c9 a3 ea ff 31 c0 eb d7 48 8b 87 40 ff ff ff 48 89 c2 48 8b 40 10 48 85 c0 75 f4 48 8b 82 10 01 00 00 48 8b 40 40 <48> 83 b8 88 02 00 00 00 0f 84 45 ff ff ff 66 90 31 c0 eb a5 48 89
[    1.696297][    T1] RSP: e02b:ffffc90040013cc8 EFLAGS: 00010246
[    1.696297][    T1] RAX: 0000000000000000 RBX: ffff888006c75000 RCX: 0000000000000029
[    1.696297][    T1] RDX: ffff888005ed1000 RSI: ffffc900400f100c RDI: ffff888005ee30d0
[    1.696297][    T1] RBP: ffff888006c75010 R08: 0000000000000001 R09: 0000000330000006
[    1.696297][    T1] R10: ffff888005850028 R11: 0000000000000002 R12: ffffffff830439a0
[    1.696297][    T1] R13: 0000000000000000 R14: ffff888005657900 R15: ffff888006e3e1e8
[    1.696297][    T1] FS:  0000000000000000(0000) GS:ffff88804a000000(0000) knlGS:0000000000000000
[    1.696297][    T1] CS:  e030 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.696297][    T1] CR2: 0000000000000288 CR3: 0000000002e36000 CR4: 0000000000050660
[    1.696297][    T1] Call Trace:
[    1.696297][    T1]  <TASK>
[    1.696297][    T1]  virtio_features_ok+0x1b/0xd0
[    1.696297][    T1]  virtio_dev_probe+0x19c/0x270
[    1.696297][    T1]  really_probe+0x19b/0x3e0
[    1.696297][    T1]  __driver_probe_device+0x78/0x160
[    1.696297][    T1]  driver_probe_device+0x1f/0x90
[    1.696297][    T1]  __driver_attach+0xd2/0x1c0
[    1.696297][    T1]  bus_for_each_dev+0x74/0xc0
[    1.696297][    T1]  bus_add_driver+0x116/0x220
[    1.696297][    T1]  driver_register+0x59/0x100
[    1.696297][    T1]  virtio_console_init+0x7f/0x110
[    1.696297][    T1]  do_one_initcall+0x47/0x220
[    1.696297][    T1]  kernel_init_freeable+0x328/0x480
[    1.696297][    T1]  kernel_init+0x1a/0x1c0
[    1.696297][    T1]  ret_from_fork+0x29/0x50
[    1.696297][    T1]  </TASK>
[    1.696297][    T1] Modules linked in:
[    1.696297][    T1] CR2: 0000000000000288
[    1.696297][    T1] ---[ end trace 0000000000000000 ]---

The PCI root bus is in this case created from ACPI description via
acpi_pci_root_add() -> pci_acpi_scan_root() -> acpi_pci_root_create() ->
pci_create_root_bus() where the last function is called with
parent=NULL. It indicates that no parent is present and then
bus->bridge->parent is NULL too.

Fix the problem by checking bus->bridge->parent in xen_dt_get_node() for
NULL first.

Fixes: ef8ae384b4 ("xen/virtio: Handle PCI devices which Host controller is described in DT")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20230621131214.9398-2-petr.pavlu@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-07-04 08:18:21 +02:00
Linus Torvalds 6e17c6de3d - Yosry Ahmed brought back some cgroup v1 stats in OOM logs.
- Yosry has also eliminated cgroup's atomic rstat flushing.
 
 - Nhat Pham adds the new cachestat() syscall.  It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability.
 
 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning.
 
 - Lorenzo Stoakes has done some maintanance work on the get_user_pages()
   interface.
 
 - Liam Howlett continues with cleanups and maintenance work to the maple
   tree code.  Peng Zhang also does some work on maple tree.
 
 - Johannes Weiner has done some cleanup work on the compaction code.
 
 - David Hildenbrand has contributed additional selftests for
   get_user_pages().
 
 - Thomas Gleixner has contributed some maintenance and optimization work
   for the vmalloc code.
 
 - Baolin Wang has provided some compaction cleanups,
 
 - SeongJae Park continues maintenance work on the DAMON code.
 
 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting.
 
 - Christoph Hellwig has some cleanups for the filemap/directio code.
 
 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the provided
   APIs rather than open-coding accesses.
 
 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings.
 
 - John Hubbard has a series of fixes to the MM selftesting code.
 
 - ZhangPeng continues the folio conversion campaign.
 
 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock.
 
 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from
   128 to 8.
 
 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management.
 
 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code.
 
 - Vishal Moola also has done some folio conversion work.
 
 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch.
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Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull mm updates from Andrew Morton:

 - Yosry Ahmed brought back some cgroup v1 stats in OOM logs

 - Yosry has also eliminated cgroup's atomic rstat flushing

 - Nhat Pham adds the new cachestat() syscall. It provides userspace
   with the ability to query pagecache status - a similar concept to
   mincore() but more powerful and with improved usability

 - Mel Gorman provides more optimizations for compaction, reducing the
   prevalence of page rescanning

 - Lorenzo Stoakes has done some maintanance work on the
   get_user_pages() interface

 - Liam Howlett continues with cleanups and maintenance work to the
   maple tree code. Peng Zhang also does some work on maple tree

 - Johannes Weiner has done some cleanup work on the compaction code

 - David Hildenbrand has contributed additional selftests for
   get_user_pages()

 - Thomas Gleixner has contributed some maintenance and optimization
   work for the vmalloc code

 - Baolin Wang has provided some compaction cleanups,

 - SeongJae Park continues maintenance work on the DAMON code

 - Huang Ying has done some maintenance on the swap code's usage of
   device refcounting

 - Christoph Hellwig has some cleanups for the filemap/directio code

 - Ryan Roberts provides two patch series which yield some
   rationalization of the kernel's access to pte entries - use the
   provided APIs rather than open-coding accesses

 - Lorenzo Stoakes has some fixes to the interaction between pagecache
   and directio access to file mappings

 - John Hubbard has a series of fixes to the MM selftesting code

 - ZhangPeng continues the folio conversion campaign

 - Hugh Dickins has been working on the pagetable handling code, mainly
   with a view to reducing the load on the mmap_lock

 - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment
   from 128 to 8

 - Domenico Cerasuolo has improved the zswap reclaim mechanism by
   reorganizing the LRU management

 - Matthew Wilcox provides some fixups to make gfs2 work better with the
   buffer_head code

 - Vishal Moola also has done some folio conversion work

 - Matthew Wilcox has removed the remnants of the pagevec code - their
   functionality is migrated over to struct folio_batch

* tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits)
  mm/hugetlb: remove hugetlb_set_page_subpool()
  mm: nommu: correct the range of mmap_sem_read_lock in task_mem()
  hugetlb: revert use of page_cache_next_miss()
  Revert "page cache: fix page_cache_next/prev_miss off by one"
  mm/vmscan: fix root proactive reclaim unthrottling unbalanced node
  mm: memcg: rename and document global_reclaim()
  mm: kill [add|del]_page_to_lru_list()
  mm: compaction: convert to use a folio in isolate_migratepages_block()
  mm: zswap: fix double invalidate with exclusive loads
  mm: remove unnecessary pagevec includes
  mm: remove references to pagevec
  mm: rename invalidate_mapping_pagevec to mapping_try_invalidate
  mm: remove struct pagevec
  net: convert sunrpc from pagevec to folio_batch
  i915: convert i915_gpu_error to use a folio_batch
  pagevec: rename fbatch_count()
  mm: remove check_move_unevictable_pages()
  drm: convert drm_gem_put_pages() to use a folio_batch
  i915: convert shmem_sg_free_table() to use a folio_batch
  scatterlist: add sg_set_folio()
  ...
2023-06-28 10:28:11 -07:00
Linus Torvalds 72dc6db7e3 workqueue: Ordered workqueue creation cleanups
For historical reasons, unbound workqueues with max concurrency limit of 1
 are considered ordered, even though the concurrency limit hasn't been
 system-wide for a long time. This creates ambiguity around whether ordered
 execution is actually required for correctness, which was actually confusing
 for e.g. btrfs (btrfs updates are being routed through the btrfs tree).
 
 There aren't that many users in the tree which use the combination and there
 are pending improvements to unbound workqueue affinity handling which will
 make inadvertent use of ordered workqueue a bigger loss. This pull request
 clarifies the situation for most of them by updating the ones which require
 ordered execution to use alloc_ordered_workqueue().
 
 There are some conversions being routed through subsystem-specific trees and
 likely a few stragglers. Once they're all converted, workqueue can trigger a
 warning on unbound + @max_active==1 usages and eventually drop the implicit
 ordered behavior.
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Merge tag 'wq-for-6.5-cleanup-ordered' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull ordered workqueue creation updates from Tejun Heo:
 "For historical reasons, unbound workqueues with max concurrency limit
  of 1 are considered ordered, even though the concurrency limit hasn't
  been system-wide for a long time.

  This creates ambiguity around whether ordered execution is actually
  required for correctness, which was actually confusing for e.g. btrfs
  (btrfs updates are being routed through the btrfs tree).

  There aren't that many users in the tree which use the combination and
  there are pending improvements to unbound workqueue affinity handling
  which will make inadvertent use of ordered workqueue a bigger loss.

  This clarifies the situation for most of them by updating the ones
  which require ordered execution to use alloc_ordered_workqueue().

  There are some conversions being routed through subsystem-specific
  trees and likely a few stragglers. Once they're all converted,
  workqueue can trigger a warning on unbound + @max_active==1 usages and
  eventually drop the implicit ordered behavior"

* tag 'wq-for-6.5-cleanup-ordered' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  rxrpc: Use alloc_ordered_workqueue() to create ordered workqueues
  net: qrtr: Use alloc_ordered_workqueue() to create ordered workqueues
  net: wwan: t7xx: Use alloc_ordered_workqueue() to create ordered workqueues
  dm integrity: Use alloc_ordered_workqueue() to create ordered workqueues
  media: amphion: Use alloc_ordered_workqueue() to create ordered workqueues
  scsi: NCR5380: Use default @max_active for hostdata->work_q
  media: coda: Use alloc_ordered_workqueue() to create ordered workqueues
  crypto: octeontx2: Use alloc_ordered_workqueue() to create ordered workqueues
  wifi: ath10/11/12k: Use alloc_ordered_workqueue() to create ordered workqueues
  wifi: mwifiex: Use default @max_active for workqueues
  wifi: iwlwifi: Use default @max_active for trans_pcie->rba.alloc_wq
  xen/pvcalls: Use alloc_ordered_workqueue() to create ordered workqueues
  virt: acrn: Use alloc_ordered_workqueue() to create ordered workqueues
  net: octeontx2: Use alloc_ordered_workqueue() to create ordered workqueues
  net: thunderx: Use alloc_ordered_workqueue() to create ordered workqueues
  greybus: Use alloc_ordered_workqueue() to create ordered workqueues
  powerpc, workqueue: Use alloc_ordered_workqueue() to create ordered workqueues
2023-06-27 16:46:06 -07:00
Ryan Roberts c33c794828 mm: ptep_get() conversion
Convert all instances of direct pte_t* dereferencing to instead use
ptep_get() helper.  This means that by default, the accesses change from a
C dereference to a READ_ONCE().  This is technically the correct thing to
do since where pgtables are modified by HW (for access/dirty) they are
volatile and therefore we should always ensure READ_ONCE() semantics.

But more importantly, by always using the helper, it can be overridden by
the architecture to fully encapsulate the contents of the pte.  Arch code
is deliberately not converted, as the arch code knows best.  It is
intended that arch code (arm64) will override the default with its own
implementation that can (e.g.) hide certain bits from the core code, or
determine young/dirty status by mixing in state from another source.

Conversion was done using Coccinelle:

----

// $ make coccicheck \
//          COCCI=ptepget.cocci \
//          SPFLAGS="--include-headers" \
//          MODE=patch

virtual patch

@ depends on patch @
pte_t *v;
@@

- *v
+ ptep_get(v)

----

Then reviewed and hand-edited to avoid multiple unnecessary calls to
ptep_get(), instead opting to store the result of a single call in a
variable, where it is correct to do so.  This aims to negate any cost of
READ_ONCE() and will benefit arch-overrides that may be more complex.

Included is a fix for an issue in an earlier version of this patch that
was pointed out by kernel test robot.  The issue arose because config
MMU=n elides definition of the ptep helper functions, including
ptep_get().  HUGETLB_PAGE=n configs still define a simple
huge_ptep_clear_flush() for linking purposes, which dereferences the ptep.
So when both configs are disabled, this caused a build error because
ptep_get() is not defined.  Fix by continuing to do a direct dereference
when MMU=n.  This is safe because for this config the arch code cannot be
trying to virtualize the ptes because none of the ptep helpers are
defined.

Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-19 16:19:25 -07:00
Linus Torvalds 4e893b5aa4 xen: branch for v6.4-rc4
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Merge tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - a double free fix in the Xen pvcalls backend driver

 - a fix for a regression causing the MSI related sysfs entries to not
   being created in Xen PV guests

 - a fix in the Xen blkfront driver for handling insane input data
   better

* tag 'for-linus-6.4-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  x86/pci/xen: populate MSI sysfs entries
  xen/pvcalls-back: fix double frees with pvcalls_new_active_socket()
  xen/blkfront: Only check REQ_FUA for writes
2023-05-27 09:42:56 -07:00
Dan Carpenter 8fafac202d xen/pvcalls-back: fix double frees with pvcalls_new_active_socket()
In the pvcalls_new_active_socket() function, most error paths call
pvcalls_back_release_active(fedata->dev, fedata, map) which calls
sock_release() on "sock".  The bug is that the caller also frees sock.

Fix this by making every error path in pvcalls_new_active_socket()
release the sock, and don't free it in the caller.

Fixes: 5db4d286a8 ("xen/pvcalls: implement connect command")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/e5f98dc2-0305-491f-a860-71bbd1398a2f@kili.mountain
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-05-24 17:25:43 +02:00
Tejun Heo 715557b02c xen/pvcalls: Use alloc_ordered_workqueue() to create ordered workqueues
BACKGROUND
==========

When multiple work items are queued to a workqueue, their execution order
doesn't match the queueing order. They may get executed in any order and
simultaneously. When fully serialized execution - one by one in the queueing
order - is needed, an ordered workqueue should be used which can be created
with alloc_ordered_workqueue().

However, alloc_ordered_workqueue() was a later addition. Before it, an
ordered workqueue could be obtained by creating an UNBOUND workqueue with
@max_active==1. This originally was an implementation side-effect which was
broken by 4c16bd327c ("workqueue: restore WQ_UNBOUND/max_active==1 to be
ordered"). Because there were users that depended on the ordered execution,
5c0338c687 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered")
made workqueue allocation path to implicitly promote UNBOUND workqueues w/
@max_active==1 to ordered workqueues.

While this has worked okay, overloading the UNBOUND allocation interface
this way creates other issues. It's difficult to tell whether a given
workqueue actually needs to be ordered and users that legitimately want a
min concurrency level wq unexpectedly gets an ordered one instead. With
planned UNBOUND workqueue updates to improve execution locality and more
prevalence of chiplet designs which can benefit from such improvements, this
isn't a state we wanna be in forever.

This patch series audits all callsites that create an UNBOUND workqueue w/
@max_active==1 and converts them to alloc_ordered_workqueue() as necessary.

WHAT TO LOOK FOR
================

The conversions are from

  alloc_workqueue(WQ_UNBOUND | flags, 1, args..)

to 

  alloc_ordered_workqueue(flags, args...)

which don't cause any functional changes. If you know that fully ordered
execution is not ncessary, please let me know. I'll drop the conversion and
instead add a comment noting the fact to reduce confusion while conversion
is in progress.

If you aren't fully sure, it's completely fine to let the conversion
through. The behavior will stay exactly the same and we can always
reconsider later.

As there are follow-up workqueue core changes, I'd really appreciate if the
patch can be routed through the workqueue tree w/ your acks. Thanks.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: xen-devel@lists.xenproject.org
2023-05-08 15:33:12 -10:00
Linus Torvalds 35fab9271b xen: branch for v6.4-rc1
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Merge tag 'for-linus-6.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen updates from Juergen Gross:

 - some cleanups in the Xen blkback driver

 - fix potential sleeps under lock in various Xen drivers

* tag 'for-linus-6.4-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/blkback: move blkif_get_x86_*_req() into blkback.c
  xen/blkback: simplify free_persistent_gnts() interface
  xen/blkback: remove stale prototype
  xen/blkback: fix white space code style issues
  xen/pvcalls: don't call bind_evtchn_to_irqhandler() under lock
  xen/scsiback: don't call scsiback_free_translation_entry() under lock
  xen/pciback: don't call pcistub_device_put() under lock
2023-04-27 17:27:06 -07:00
Linus Torvalds 888d3c9f7f sysctl-6.4-rc1
This pull request goes with only a few sysctl moves from the
 kernel/sysctl.c file, the rest of the work has been put towards
 deprecating two API calls which incur recursion and prevent us
 from simplifying the registration process / saving memory per
 move. Most of the changes have been soaking on linux-next since
 v6.3-rc3.
 
 I've slowed down the kernel/sysctl.c moves due to Matthew Wilcox's
 feedback that we should see if we could *save* memory with these
 moves instead of incurring more memory. We currently incur more
 memory since when we move a syctl from kernel/sysclt.c out to its
 own file we end up having to add a new empty sysctl used to register
 it. To achieve saving memory we want to allow syctls to be passed
 without requiring the end element being empty, and just have our
 registration process rely on ARRAY_SIZE(). Without this, supporting
 both styles of sysctls would make the sysctl registration pretty
 brittle, hard to read and maintain as can be seen from Meng Tang's
 efforts to do just this [0]. Fortunately, in order to use ARRAY_SIZE()
 for all sysctl registrations also implies doing the work to deprecate
 two API calls which use recursion in order to support sysctl
 declarations with subdirectories.
 
 And so during this development cycle quite a bit of effort went into
 this deprecation effort. I've annotated the following two APIs are
 deprecated and in few kernel releases we should be good to remove them:
 
   * register_sysctl_table()
   * register_sysctl_paths()
 
 During this merge window we should be able to deprecate and unexport
 register_sysctl_paths(), we can probably do that towards the end
 of this merge window.
 
 Deprecating register_sysctl_table() will take a bit more time but
 this pull request goes with a few example of how to do this.
 
 As it turns out each of the conversions to move away from either of
 these two API calls *also* saves memory. And so long term, all these
 changes *will* prove to have saved a bit of memory on boot.
 
 The way I see it then is if remove a user of one deprecated call, it
 gives us enough savings to move one kernel/sysctl.c out from the
 generic arrays as we end up with about the same amount of bytes.
 
 Since deprecating register_sysctl_table() and register_sysctl_paths()
 does not require maintainer coordination except the final unexport
 you'll see quite a bit of these changes from other pull requests, I've
 just kept the stragglers after rc3.
 
 Most of these changes have been soaking on linux-next since around rc3.
 
 [0] https://lkml.kernel.org/r/ZAD+cpbrqlc5vmry@bombadil.infradead.org
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Merge tag 'sysctl-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux

Pull sysctl updates from Luis Chamberlain:
 "This only does a few sysctl moves from the kernel/sysctl.c file, the
  rest of the work has been put towards deprecating two API calls which
  incur recursion and prevent us from simplifying the registration
  process / saving memory per move. Most of the changes have been
  soaking on linux-next since v6.3-rc3.

  I've slowed down the kernel/sysctl.c moves due to Matthew Wilcox's
  feedback that we should see if we could *save* memory with these moves
  instead of incurring more memory. We currently incur more memory since
  when we move a syctl from kernel/sysclt.c out to its own file we end
  up having to add a new empty sysctl used to register it. To achieve
  saving memory we want to allow syctls to be passed without requiring
  the end element being empty, and just have our registration process
  rely on ARRAY_SIZE(). Without this, supporting both styles of sysctls
  would make the sysctl registration pretty brittle, hard to read and
  maintain as can be seen from Meng Tang's efforts to do just this [0].
  Fortunately, in order to use ARRAY_SIZE() for all sysctl registrations
  also implies doing the work to deprecate two API calls which use
  recursion in order to support sysctl declarations with subdirectories.

  And so during this development cycle quite a bit of effort went into
  this deprecation effort. I've annotated the following two APIs are
  deprecated and in few kernel releases we should be good to remove
  them:

   - register_sysctl_table()
   - register_sysctl_paths()

  During this merge window we should be able to deprecate and unexport
  register_sysctl_paths(), we can probably do that towards the end of
  this merge window.

  Deprecating register_sysctl_table() will take a bit more time but this
  pull request goes with a few example of how to do this.

  As it turns out each of the conversions to move away from either of
  these two API calls *also* saves memory. And so long term, all these
  changes *will* prove to have saved a bit of memory on boot.

  The way I see it then is if remove a user of one deprecated call, it
  gives us enough savings to move one kernel/sysctl.c out from the
  generic arrays as we end up with about the same amount of bytes.

  Since deprecating register_sysctl_table() and register_sysctl_paths()
  does not require maintainer coordination except the final unexport
  you'll see quite a bit of these changes from other pull requests, I've
  just kept the stragglers after rc3"

Link: https://lkml.kernel.org/r/ZAD+cpbrqlc5vmry@bombadil.infradead.org [0]

* tag 'sysctl-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (29 commits)
  fs: fix sysctls.c built
  mm: compaction: remove incorrect #ifdef checks
  mm: compaction: move compaction sysctl to its own file
  mm: memory-failure: Move memory failure sysctls to its own file
  arm: simplify two-level sysctl registration for ctl_isa_vars
  ia64: simplify one-level sysctl registration for kdump_ctl_table
  utsname: simplify one-level sysctl registration for uts_kern_table
  ntfs: simplfy one-level sysctl registration for ntfs_sysctls
  coda: simplify one-level sysctl registration for coda_table
  fs/cachefiles: simplify one-level sysctl registration for cachefiles_sysctls
  xfs: simplify two-level sysctl registration for xfs_table
  nfs: simplify two-level sysctl registration for nfs_cb_sysctls
  nfs: simplify two-level sysctl registration for nfs4_cb_sysctls
  lockd: simplify two-level sysctl registration for nlm_sysctls
  proc_sysctl: enhance documentation
  xen: simplify sysctl registration for balloon
  md: simplify sysctl registration
  hv: simplify sysctl registration
  scsi: simplify sysctl registration with register_sysctl()
  csky: simplify alignment sysctl registration
  ...
2023-04-27 16:52:33 -07:00
Linus Torvalds b68ee1c613 SCSI misc on 20230426
Updates to the usual drivers (megaraid_sas, scsi_debug, lpfc, target,
 mpi3mr, hisi_sas, arcmsr).  The major core change is the
 constification of the host templates (which touches everything) along
 with other minor fixups and clean ups.
 
 Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "Updates to the usual drivers (megaraid_sas, scsi_debug, lpfc, target,
  mpi3mr, hisi_sas, arcmsr).

  The major core change is the constification of the host templates
  (which touches everything) along with other minor fixups and clean
  ups"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (207 commits)
  scsi: ufs: mcq: Use pointer arithmetic in ufshcd_send_command()
  scsi: ufs: mcq: Annotate ufshcd_inc_sq_tail() appropriately
  scsi: cxlflash: s/semahpore/semaphore/
  scsi: lpfc: Silence an incorrect device output
  scsi: mpi3mr: Use IRQ save variants of spinlock to protect chain frame allocation
  scsi: scsi_debug: Fix missing error code in scsi_debug_init()
  scsi: hisi_sas: Work around build failure in suspend function
  scsi: lpfc: Fix ioremap issues in lpfc_sli4_pci_mem_setup()
  scsi: mpt3sas: Fix an issue when driver is being removed
  scsi: mpt3sas: Remove HBA BIOS version in the kernel log
  scsi: target: core: Fix invalid memory access
  scsi: scsi_debug: Drop sdebug_queue
  scsi: scsi_debug: Only allow sdebug_max_queue be modified when no shosts
  scsi: scsi_debug: Use scsi_host_busy() in delay_store() and ndelay_store()
  scsi: scsi_debug: Use blk_mq_tagset_busy_iter() in stop_all_queued()
  scsi: scsi_debug: Use blk_mq_tagset_busy_iter() in sdebug_blk_mq_poll()
  scsi: scsi_debug: Dynamically allocate sdebug_queued_cmd
  scsi: scsi_debug: Use scsi_block_requests() to block queues
  scsi: scsi_debug: Protect block_unblock_all_queues() with mutex
  scsi: scsi_debug: Change shost list lock to a mutex
  ...
2023-04-26 15:39:25 -07:00
Juergen Gross c66bb48edd xen/pvcalls: don't call bind_evtchn_to_irqhandler() under lock
bind_evtchn_to_irqhandler() shouldn't be called under spinlock, as it
can sleep.

This requires to move the calls of create_active() out of the locked
regions. This is no problem, as the worst which could happen would be
a spurious call of the interrupt handler, causing a spurious wake_up().

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/lkml/Y+JUIl64UDmdkboh@kadam/
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20230403092711.15285-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-04-24 07:27:10 +02:00
Juergen Gross b2c042cc80 xen/scsiback: don't call scsiback_free_translation_entry() under lock
scsiback_free_translation_entry() shouldn't be called under spinlock,
as it can sleep.

This requires to split removing a translation entry from the v2p list
from actually calling kref_put() for the entry.

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/lkml/Y+JUIl64UDmdkboh@kadam/
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/20230328084602.20729-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-04-24 07:27:10 +02:00
Juergen Gross fae65ef3a1 xen/pciback: don't call pcistub_device_put() under lock
pcistub_device_put() shouldn't be called under spinlock, as it can
sleep.

For this reason pcistub_device_get_pci_dev() needs to be modified:
instead of always calling pcistub_device_get() just do the call of
pcistub_device_get() only if it is really needed. This removes the
need to call pcistub_device_put().

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/lkml/Y+JUIl64UDmdkboh@kadam/
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Link: https://lore.kernel.org/r/20230328084549.20695-1-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-04-24 07:27:10 +02:00
Luis Chamberlain 9f17a75b2d xen: simplify sysctl registration for balloon
register_sysctl_table() is a deprecated compatibility wrapper.
register_sysctl_init() can do the directory creation for you so just
use that.

Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
2023-04-13 11:49:20 -07:00
Roger Pau Monne 073828e954 ACPI: processor: Fix evaluating _PDC method when running as Xen dom0
In ACPI systems, the OS can direct power management, as opposed to the
firmware.  This OS-directed Power Management is called OSPM.  Part of
telling the firmware that the OS going to direct power management is
making ACPI "_PDC" (Processor Driver Capabilities) calls.  These _PDC
methods must be evaluated for every processor object.  If these _PDC
calls are not completed for every processor it can lead to
inconsistency and later failures in things like the CPU frequency
driver.

In a Xen system, the dom0 kernel is responsible for system-wide power
management.  The dom0 kernel is in charge of OSPM.  However, the
number of CPUs available to dom0 can be different than the number of
CPUs physically present on the system.

This leads to a problem: the dom0 kernel needs to evaluate _PDC for
all the processors, but it can't always see them.

In dom0 kernels, ignore the existing ACPI method for determining if a
processor is physically present because it might not be accurate.
Instead, ask the hypervisor for this information.

Fix this by introducing a custom function to use when running as Xen
dom0 in order to check whether a processor object matches a CPU that's
online.  Such checking is done using the existing information fetched
by the Xen pCPU subsystem, extending it to also store the ACPI ID.

This ensures that _PDC method gets evaluated for all physically online
CPUs, regardless of the number of CPUs made available to dom0.

Fixes: 5d554a7bb0 ("ACPI: processor: add internal processor_physically_present()")
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-03-22 19:36:31 +01:00
Linus Torvalds 0eb392ec09 xen: branch for v6.3-rc3
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Merge tag 'for-linus-6.3-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull xen fixes from Juergen Gross:

 - cleanup for xen time handling

 - enable the VGA console in a Xen PVH dom0

 - cleanup in the xenfs driver

* tag 'for-linus-6.3-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: remove unnecessary (void*) conversions
  x86/PVH: obtain VGA console info in Dom0
  x86/xen/time: cleanup xen_tsc_safe_clocksource
  xen: update arch/x86/include/asm/xen/cpuid.h
2023-03-17 10:45:49 -07:00
Dmitry Bogdanov 355c3d6135 scsi: xen-scsiback: Remove default fabric ops callouts
Remove callouts that are identical to the default implementations in TCM
Core.

Acked-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com>
Link: https://lore.kernel.org/r/20230313181110.20566-10-d.bogdanov@yadro.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2023-03-16 23:36:36 -04:00
Yu Zhe 7ad2c39860 xen: remove unnecessary (void*) conversions
Pointer variables of void * type do not require type cast.

Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20230316083954.4223-1-yuzhe@nfschina.com
Signed-off-by: Juergen Gross <jgross@suse.com>
2023-03-16 12:04:00 +01:00
Linus Torvalds a93e884edf Driver core changes for 6.3-rc1
Here is the large set of driver core changes for 6.3-rc1.
 
 There's a lot of changes this development cycle, most of the work falls
 into two different categories:
   - fw_devlink fixes and updates.  This has gone through numerous review
     cycles and lots of review and testing by lots of different devices.
     Hopefully all should be good now, and Saravana will be keeping a
     watch for any potential regression on odd embedded systems.
   - driver core changes to work to make struct bus_type able to be moved
     into read-only memory (i.e. const)  The recent work with Rust has
     pointed out a number of areas in the driver core where we are
     passing around and working with structures that really do not have
     to be dynamic at all, and they should be able to be read-only making
     things safer overall.  This is the contuation of that work (started
     last release with kobject changes) in moving struct bus_type to be
     constant.  We didn't quite make it for this release, but the
     remaining patches will be finished up for the release after this
     one, but the groundwork has been laid for this effort.
 
 Other than that we have in here:
   - debugfs memory leak fixes in some subsystems
   - error path cleanups and fixes for some never-able-to-be-hit
     codepaths.
   - cacheinfo rework and fixes
   - Other tiny fixes, full details are in the shortlog
 
 All of these have been in linux-next for a while with no reported
 problems.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.3-rc1.

  There's a lot of changes this development cycle, most of the work
  falls into two different categories:

   - fw_devlink fixes and updates. This has gone through numerous review
     cycles and lots of review and testing by lots of different devices.
     Hopefully all should be good now, and Saravana will be keeping a
     watch for any potential regression on odd embedded systems.

   - driver core changes to work to make struct bus_type able to be
     moved into read-only memory (i.e. const) The recent work with Rust
     has pointed out a number of areas in the driver core where we are
     passing around and working with structures that really do not have
     to be dynamic at all, and they should be able to be read-only
     making things safer overall. This is the contuation of that work
     (started last release with kobject changes) in moving struct
     bus_type to be constant. We didn't quite make it for this release,
     but the remaining patches will be finished up for the release after
     this one, but the groundwork has been laid for this effort.

  Other than that we have in here:

   - debugfs memory leak fixes in some subsystems

   - error path cleanups and fixes for some never-able-to-be-hit
     codepaths.

   - cacheinfo rework and fixes

   - Other tiny fixes, full details are in the shortlog

  All of these have been in linux-next for a while with no reported
  problems"

[ Geert Uytterhoeven points out that that last sentence isn't true, and
  that there's a pending report that has a fix that is queued up - Linus ]

* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
  debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
  OPP: fix error checking in opp_migrate_dentry()
  debugfs: update comment of debugfs_rename()
  i3c: fix device.h kernel-doc warnings
  dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
  driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
  Revert "driver core: add error handling for devtmpfs_create_node()"
  Revert "devtmpfs: add debug info to handle()"
  Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
  driver core: cpu: don't hand-override the uevent bus_type callback.
  devtmpfs: remove return value of devtmpfs_delete_node()
  devtmpfs: add debug info to handle()
  driver core: add error handling for devtmpfs_create_node()
  driver core: bus: update my copyright notice
  driver core: bus: add bus_get_dev_root() function
  driver core: bus: constify bus_unregister()
  driver core: bus: constify some internal functions
  driver core: bus: constify bus_get_kset()
  driver core: bus: constify bus_register/unregister_notifier()
  driver core: remove private pointer from struct bus_type
  ...
2023-02-24 12:58:55 -08:00