Commit graph

55 commits

Author SHA1 Message Date
Jinrong Liang
019024e563 KVM: x86/ioapic: Remove unused "addr" and "length" of ioapic_read_indirect()
The "unsigned long addr" and "unsigned long length" parameter of
ioapic_read_indirect() is not used, so remove it.

No functional change intended.

Signed-off-by: Jinrong Liang <cloudliang@tencent.com>
Message-Id: <20220125095909.38122-14-cloudliang@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-10 13:47:13 -05:00
Marc Zyngier
46808a4cb8 KVM: Use 'unsigned long' as kvm_for_each_vcpu()'s index
Everywhere we use kvm_for_each_vpcu(), we use an int as the vcpu
index. Unfortunately, we're about to move rework the iterator,
which requires this to be upgrade to an unsigned long.

Let's bite the bullet and repaint all of it in one go.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Message-Id: <20211116160403.4074052-7-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:15 -05:00
Juergen Gross
a1c42ddedf kvm: rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDS
KVM_MAX_VCPU_ID is not specifying the highest allowed vcpu-id, but the
number of allowed vcpu-ids. This has already led to confusion, so
rename KVM_MAX_VCPU_ID to KVM_MAX_VCPU_IDS to make its semantics more
clear

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210913135745.13944-3-jgross@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30 04:27:05 -04:00
Juergen Gross
1e254d0d86 Revert "x86/kvm: fix vcpu-id indexed array sizes"
This reverts commit 76b4f357d0.

The commit has the wrong reasoning, as KVM_MAX_VCPU_ID is not defining the
maximum allowed vcpu-id as its name suggests, but the number of vcpu-ids.
So revert this patch again.

Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210913135745.13944-2-jgross@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-30 04:27:04 -04:00
Vitaly Kuznetsov
2f9b68f57c KVM: x86: Fix stack-out-of-bounds memory access from ioapic_write_indirect()
KASAN reports the following issue:

 BUG: KASAN: stack-out-of-bounds in kvm_make_vcpus_request_mask+0x174/0x440 [kvm]
 Read of size 8 at addr ffffc9001364f638 by task qemu-kvm/4798

 CPU: 0 PID: 4798 Comm: qemu-kvm Tainted: G               X --------- ---
 Hardware name: AMD Corporation DAYTONA_X/DAYTONA_X, BIOS RYM0081C 07/13/2020
 Call Trace:
  dump_stack+0xa5/0xe6
  print_address_description.constprop.0+0x18/0x130
  ? kvm_make_vcpus_request_mask+0x174/0x440 [kvm]
  __kasan_report.cold+0x7f/0x114
  ? kvm_make_vcpus_request_mask+0x174/0x440 [kvm]
  kasan_report+0x38/0x50
  kasan_check_range+0xf5/0x1d0
  kvm_make_vcpus_request_mask+0x174/0x440 [kvm]
  kvm_make_scan_ioapic_request_mask+0x84/0xc0 [kvm]
  ? kvm_arch_exit+0x110/0x110 [kvm]
  ? sched_clock+0x5/0x10
  ioapic_write_indirect+0x59f/0x9e0 [kvm]
  ? static_obj+0xc0/0xc0
  ? __lock_acquired+0x1d2/0x8c0
  ? kvm_ioapic_eoi_inject_work+0x120/0x120 [kvm]

The problem appears to be that 'vcpu_bitmap' is allocated as a single long
on stack and it should really be KVM_MAX_VCPUS long. We also seem to clear
the lower 16 bits of it with bitmap_zero() for no particular reason (my
guess would be that 'bitmap' and 'vcpu_bitmap' variables in
kvm_bitmap_or_dest_vcpus() caused the confusion: while the later is indeed
16-bit long, the later should accommodate all possible vCPUs).

Fixes: 7ee30bc132 ("KVM: x86: deliver KVM IOAPIC scan request to target vCPUs")
Fixes: 9a2ae9f6b6 ("KVM: x86: Zero the IOAPIC scan request dest vCPUs bitmap")
Reported-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210827092516.1027264-7-vkuznets@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-09-22 10:33:14 -04:00
Juergen Gross
76b4f357d0 x86/kvm: fix vcpu-id indexed array sizes
KVM_MAX_VCPU_ID is the maximum vcpu-id of a guest, and not the number
of vcpu-ids. Fix array indexed by vcpu-id to have KVM_MAX_VCPU_ID+1
elements.

Note that this is currently no real problem, as KVM_MAX_VCPU_ID is
an odd number, resulting in always enough padding being available at
the end of those arrays.

Nevertheless this should be fixed in order to avoid rare problems in
case someone is using an even number for KVM_MAX_VCPU_ID.

Signed-off-by: Juergen Gross <jgross@suse.com>
Message-Id: <20210701154105.23215-2-jgross@suse.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-07-27 16:58:59 -04:00
Vitaly Kuznetsov
77377064c3 KVM: ioapic: break infinite recursion on lazy EOI
During shutdown the IOAPIC trigger mode is reset to edge triggered
while the vfio-pci INTx is still registered with a resampler.
This allows us to get into an infinite loop:

ioapic_set_irq
  -> ioapic_lazy_update_eoi
  -> kvm_ioapic_update_eoi_one
  -> kvm_notify_acked_irq
  -> kvm_notify_acked_gsi
  -> (via irq_acked fn ptr) irqfd_resampler_ack
  -> kvm_set_irq
  -> (via set fn ptr) kvm_set_ioapic_irq
  -> kvm_ioapic_set_irq
  -> ioapic_set_irq

Commit 8be8f932e3 ("kvm: ioapic: Restrict lazy EOI update to
edge-triggered interrupts", 2020-05-04) acknowledges that this recursion
loop exists and tries to avoid it at the call to ioapic_lazy_update_eoi,
but at this point the scenario is already set, we have an edge interrupt
with resampler on the same gsi.

Fortunately, the only user of irq ack notifiers (in addition to resamplefd)
is i8254 timer interrupt reinjection.  These are edge-triggered, so in
principle they would need the call to kvm_ioapic_update_eoi_one from
ioapic_lazy_update_eoi, but they already disable AVIC(*), so they don't
need the lazy EOI behavior.  Therefore, remove the call to
kvm_ioapic_update_eoi_one from ioapic_lazy_update_eoi.

This fixes CVE-2020-27152.  Note that this issue cannot happen with
SR-IOV assigned devices because virtual functions do not have INTx,
only MSI.

Fixes: f458d039db ("kvm: ioapic: Lazy update IOAPIC EOI")
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-10-24 04:42:06 -04:00
Paolo Bonzini
8be8f932e3 kvm: ioapic: Restrict lazy EOI update to edge-triggered interrupts
Commit f458d039db ("kvm: ioapic: Lazy update IOAPIC EOI") introduces
the following infinite loop:

BUG: stack guard page was hit at 000000008f595917 \
(stack is 00000000bdefe5a4..00000000ae2b06f5)
kernel stack overflow (double-fault): 0000 [#1] SMP NOPTI
RIP: 0010:kvm_set_irq+0x51/0x160 [kvm]
Call Trace:
 irqfd_resampler_ack+0x32/0x90 [kvm]
 kvm_notify_acked_irq+0x62/0xd0 [kvm]
 kvm_ioapic_update_eoi_one.isra.0+0x30/0x120 [kvm]
 ioapic_set_irq+0x20e/0x240 [kvm]
 kvm_ioapic_set_irq+0x5c/0x80 [kvm]
 kvm_set_irq+0xbb/0x160 [kvm]
 ? kvm_hv_set_sint+0x20/0x20 [kvm]
 irqfd_resampler_ack+0x32/0x90 [kvm]
 kvm_notify_acked_irq+0x62/0xd0 [kvm]
 kvm_ioapic_update_eoi_one.isra.0+0x30/0x120 [kvm]
 ioapic_set_irq+0x20e/0x240 [kvm]
 kvm_ioapic_set_irq+0x5c/0x80 [kvm]
 kvm_set_irq+0xbb/0x160 [kvm]
 ? kvm_hv_set_sint+0x20/0x20 [kvm]
....

The re-entrancy happens because the irq state is the OR of
the interrupt state and the resamplefd state.  That is, we don't
want to show the state as 0 until we've had a chance to set the
resamplefd.  But if the interrupt has _not_ gone low then
ioapic_set_irq is invoked again, causing an infinite loop.

This can only happen for a level-triggered interrupt, otherwise
irqfd_inject would immediately set the KVM_USERSPACE_IRQ_SOURCE_ID high
and then low.  Fortunately, in the case of level-triggered interrupts the VMEXIT already happens because
TMR is set.  Thus, fix the bug by restricting the lazy invocation
of the ack notifier to edge-triggered interrupts, the only ones that
need it.

Tested-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reported-by: borisvk@bstnet.org
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://www.spinics.net/lists/kvm/msg213512.html
Fixes: f458d039db ("kvm: ioapic: Lazy update IOAPIC EOI")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=207489
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-05-04 12:29:05 -04:00
Nitesh Narayan Lal
0c22056f8c KVM: x86: Initializing all kvm_lapic_irq fields in ioapic_write_indirect
Previously all fields of structure kvm_lapic_irq were not initialized
before it was passed to kvm_bitmap_or_dest_vcpus(). Which will cause
an issue when any of those fields are used for processing a request.
For example not initializing the msi_redir_hint field before passing
to the kvm_bitmap_or_dest_vcpus(), may lead to a misbehavior of
kvm_apic_map_get_dest_lapic(). This will specifically happen when the
kvm_lowest_prio_delivery() returns TRUE due to a non-zero garbage
value of msi_redir_hint, which should not happen as the request belongs
to APIC fixed delivery mode and we do not want to deliver the
interrupt only to the lowest priority candidate.

This patch initializes all the fields of kvm_lapic_irq based on the
values of ioapic redirect_entry object before passing it on to
kvm_bitmap_or_dest_vcpus().

Fixes: 7ee30bc132 ("KVM: x86: deliver KVM IOAPIC scan request to target vCPUs")
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
[Set level to false since the value doesn't really matter. Suggested
 by Vitaly Kuznetsov. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-14 10:46:01 +01:00
Suravee Suthikulpanit
f458d039db kvm: ioapic: Lazy update IOAPIC EOI
In-kernel IOAPIC does not receive EOI with AMD SVM AVIC
since the processor accelerate write to APIC EOI register and
does not trap if the interrupt is edge-triggered.

Workaround this by lazy check for pending APIC EOI at the time when
setting new IOPIC irq, and update IOAPIC EOI if no pending APIC EOI.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-05 15:17:44 +01:00
Suravee Suthikulpanit
1ec2405c7c kvm: ioapic: Refactor kvm_ioapic_update_eoi()
Refactor code for handling IOAPIC EOI for subsequent patch.
There is no functional change.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-02-05 15:17:44 +01:00
Marios Pomonis
670564559c KVM: x86: Protect ioapic_write_indirect() from Spectre-v1/L1TF attacks
This fixes a Spectre-v1/L1TF vulnerability in ioapic_write_indirect().
This function contains index computations based on the
(attacker-controlled) IOREGSEL register.

This patch depends on patch
"KVM: x86: Protect ioapic_read_indirect() from Spectre-v1/L1TF attacks".

Fixes: 70f93dae32 ("KVM: Use temporary variable to shorten lines.")

Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27 19:59:38 +01:00
Marios Pomonis
8c86405f60 KVM: x86: Protect ioapic_read_indirect() from Spectre-v1/L1TF attacks
This fixes a Spectre-v1/L1TF vulnerability in ioapic_read_indirect().
This function contains index computations based on the
(attacker-controlled) IOREGSEL register.

Fixes: a2c118bfab ("KVM: Fix bounds checking in ioapic indirect register reads (CVE-2013-1798)")

Signed-off-by: Nick Finco <nifi@google.com>
Signed-off-by: Marios Pomonis <pomonis@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-27 19:59:37 +01:00
Miaohe Lin
00116795aa KVM: Fix some grammar mistakes
Fix some grammar mistakes in the comments.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-21 13:57:37 +01:00
Peter Xu
150a84fee8 KVM: X86: Convert the last users of "shorthand = 0" to use macros
Change the last users of "shorthand = 0" to use APIC_DEST_NOSHORT.

Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08 17:33:16 +01:00
Peter Xu
5c69d5c113 KVM: X86: Fix callers of kvm_apic_match_dest() to use correct macros
Callers of kvm_apic_match_dest() should always pass in APIC_DEST_*
macros for either dest_mode and short_hand parameters.  Fix up all the
callers of kvm_apic_match_dest() that are not following the rule.

Since at it, rename the parameter from short_hand to shorthand in
kvm_apic_match_dest(), as suggested by Vitaly.

Reported-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08 17:33:15 +01:00
Peter Xu
c96001c570 KVM: X86: Use APIC_DEST_* macros properly in kvm_lapic_irq.dest_mode
We were using either APIC_DEST_PHYSICAL|APIC_DEST_LOGICAL or 0|1 to
fill in kvm_lapic_irq.dest_mode.  It's fine only because in most cases
when we check against dest_mode it's against APIC_DEST_PHYSICAL (which
equals to 0).  However, that's not consistent.  We'll have problem
when we want to start checking against APIC_DEST_LOGICAL, which does
not equals to 1.

This patch firstly introduces kvm_lapic_irq_dest_mode() helper to take
any boolean of destination mode and return the APIC_DEST_* macro.
Then, it replaces the 0|1 settings of irq.dest_mode with the helper.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-08 17:33:14 +01:00
Nitesh Narayan Lal
9a2ae9f6b6 KVM: x86: Zero the IOAPIC scan request dest vCPUs bitmap
Not zeroing the bitmap used for identifying the destination vCPUs for an
IOAPIC scan request in fixed delivery mode could lead to waking up unwanted
vCPUs. This patch zeroes the vCPU bitmap before passing it to
kvm_bitmap_or_dest_vcpus(), which is responsible for setting the bitmap
with the bits corresponding to the destination vCPUs.

Fixes: 7ee30bc132c6("KVM: x86: deliver KVM IOAPIC scan request to target vCPUs")
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-20 14:23:24 +01:00
Nitesh Narayan Lal
7ee30bc132 KVM: x86: deliver KVM IOAPIC scan request to target vCPUs
In IOAPIC fixed delivery mode instead of flushing the scan
requests to all vCPUs, we should only send the requests to
vCPUs specified within the destination field.

This patch introduces kvm_get_dest_vcpus_mask() API which
retrieves an array of target vCPUs by using
kvm_apic_map_get_dest_lapic() and then based on the
vcpus_idx, it sets the bit in a bitmap. However, if the above
fails kvm_get_dest_vcpus_mask() finds the target vCPUs by
traversing all available vCPUs. Followed by setting the
bits in the bitmap.

If we had different vCPUs in the previous request for the
same redirection table entry then bits corresponding to
these vCPUs are also set. This to done to keep
ioapic_handled_vectors synchronized.

This bitmap is then eventually passed on to
kvm_make_vcpus_request_mask() to generate a masked request
only for the target vCPUs.

This would enable us to reduce the latency overhead on isolated
vCPUs caused by the IPI to process due to KVM_REQ_IOAPIC_SCAN.

Suggested-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-11-15 11:44:22 +01:00
Yi Wang
0d88800d54 kvm: x86: ioapic and apic debug macros cleanup
The ioapic_debug and apic_debug have been not used
for years, and kvm tracepoints are enough for debugging,
so remove them as Paolo suggested.

However, there may be something wrong when pv evi get/put
user, so it's better to retain some log there.

Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-07-15 20:39:01 +02:00
Ben Gardon
254272ce65 kvm: x86: Add memcg accounting to KVM allocations
There are many KVM kernel memory allocations which are tied to the life of
the VM process and should be charged to the VM process's cgroup. If the
allocations aren't tied to the process, the OOM killer will not know
that killing the process will free the associated kernel memory.
Add __GFP_ACCOUNT flags to many of the allocations which are not yet being
charged to the VM process's cgroup.

Tested:
	Ran all kvm-unit-tests on a 64 bit Haswell machine, the patch
	introduced no new failures.
	Ran a kernel memory accounting test which creates a VM to touch
	memory and then checks that the kernel memory allocated for the
	process is within certain bounds.
	With this patch we account for much more of the vmalloc and slab memory
	allocated for the VM.

There remain a few allocations which should be charged to the VM's
cgroup but are not. In x86, they include:
	vcpu->arch.pio_data
There allocations are unaccounted in this patch because they are mapped
to userspace, and accounting them to a cgroup causes problems. This
should be addressed in a future patch.

Signed-off-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-02-20 22:48:30 +01:00
Nikita Leshenko
b200dded0a KVM: x86: ioapic: Preserve read-only values in the redirection table
According to 82093AA (IOAPIC) manual, Remote IRR and Delivery Status are
read-only. QEMU implements the bits as RO in commit 479c2a1cb7fb
("ioapic: keep RO bits for IOAPIC entry").

Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-11-17 13:20:21 +01:00
Nikita Leshenko
a8bfec2930 KVM: x86: ioapic: Clear Remote IRR when entry is switched to edge-triggered
Some OSes (Linux, Xen) use this behavior to clear the Remote IRR bit for
IOAPICs without an EOI register. They simulate the EOI message manually
by changing the trigger mode to edge and then back to level, with the
entry being masked during this.

QEMU implements this feature in commit ed1263c363c9
("ioapic: clear remote irr bit for edge-triggered interrupts")

As a side effect, this commit removes an incorrect behavior where Remote
IRR was cleared when the redirection table entry was rewritten. This is not
consistent with the manual and also opens an opportunity for a strange
behavior when a redirection table entry is modified from an interrupt
handler that handles the same entry: The modification will clear the
Remote IRR bit even though the interrupt handler is still running.

Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-11-17 13:20:20 +01:00
Nikita Leshenko
7d2253684d KVM: x86: ioapic: Remove redundant check for Remote IRR in ioapic_set_irq
Remote IRR for level-triggered interrupts was previously checked in
ioapic_set_irq, but since we now have a check in ioapic_service we
can remove the redundant check from ioapic_set_irq.

This commit doesn't change semantics.

Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-11-17 13:20:19 +01:00
Nikita Leshenko
da3fe7bdfa KVM: x86: ioapic: Don't fire level irq when Remote IRR set
Avoid firing a level-triggered interrupt that has the Remote IRR bit set,
because that means that some CPU is already processing it. The Remote
IRR bit will be cleared after an EOI and the interrupt will refire
if the irq line is still asserted.

This behavior is aligned with QEMU's IOAPIC implementation that was
introduced by commit f99b86b94987
("x86: ioapic: ignore level irq during processing") in QEMU.

Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-11-17 13:20:18 +01:00
Nikita Leshenko
0fc5a36dd6 KVM: x86: ioapic: Fix level-triggered EOI and IOAPIC reconfigure race
KVM uses ioapic_handled_vectors to track vectors that need to notify the
IOAPIC on EOI. The problem is that IOAPIC can be reconfigured while an
interrupt with old configuration is pending or running and
ioapic_handled_vectors only remembers the newest configuration;
thus EOI from the old interrupt is not delievered to the IOAPIC.

A previous commit db2bdcbbbd
("KVM: x86: fix edge EOI and IOAPIC reconfig race")
addressed this issue by adding pending edge-triggered interrupts to
ioapic_handled_vectors, fixing this race for edge-triggered interrupts.
The commit explicitly ignored level-triggered interrupts,
but this race applies to them as well:

1) IOAPIC sends a level triggered interrupt vector to VCPU0
2) VCPU0's handler deasserts the irq line and reconfigures the IOAPIC
   to route the vector to VCPU1. The reconfiguration rewrites only the
   upper 32 bits of the IOREDTBLn register. (Causes KVM to update
   ioapic_handled_vectors for VCPU0 and it no longer includes the vector.)
3) VCPU0 sends EOI for the vector, but it's not delievered to the
   IOAPIC because the ioapic_handled_vectors doesn't include the vector.
4) New interrupts are not delievered to VCPU1 because remote_irr bit
   is set forever.

Therefore, the correct behavior is to add all pending and running
interrupts to ioapic_handled_vectors.

This commit introduces a slight performance hit similar to
commit db2bdcbbbd ("KVM: x86: fix edge EOI and IOAPIC reconfig race")
for the rare case that the vector is reused by a non-IOAPIC source on
VCPU0. We prefer to keep solution simple and not handle this case just
as the original commit does.

Fixes: db2bdcbbbd ("KVM: x86: fix edge EOI and IOAPIC reconfig race")

Signed-off-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-11-17 13:20:17 +01:00
David Hildenbrand
993225adf4 KVM: x86: rename kvm_vcpu_request_scan_ioapic()
Let's rename it into a proper arch specific callback.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:14 +02:00
David Hildenbrand
ca8ab3f895 KVM: x86: directly call kvm_make_scan_ioapic_request() in ioapic.c
We know there is an ioapic, so let's call it directly.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:14 +02:00
David Hildenbrand
d62f270b2d KVM: x86: remove all-vcpu request from kvm_ioapic_init()
kvm_ioapic_init() is guaranteed to be called without any created VCPUs,
so doing an all-vcpu request results in a NOP.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:14 +02:00
David Hildenbrand
49f520b99a KVM: x86: push usage of slots_lock down
Let's just move it to the place where it is actually needed.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:14 +02:00
David Hildenbrand
33392b4911 KVM: x86: convert kvm_(set|get)_ioapic() into void
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:14 +02:00
David Hildenbrand
4c0b06d886 KVM: x86: remove duplicate checks for ioapic
When handling KVM_GET_IRQCHIP, we already check irqchip_kernel(), which
implies a fully inititalized ioapic.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:14 +02:00
David Hildenbrand
0bceb15ad1 KVM: x86: use ioapic_in_kernel() to check for ioapic existence
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:13 +02:00
David Hildenbrand
0191e92d84 KVM: x86: get rid of ioapic_irqchip()
Let's just use kvm->arch.vioapic directly.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-04-12 20:17:13 +02:00
Peter Xu
950712eb8e KVM: x86: check existance before destroy
Mostly used for split irqchip mode. In that case, these two things are
not inited at all, so no need to release.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-03-23 19:02:03 +01:00
Radim Krčmář
81cdb259fb KVM: x86: fix out-of-bounds accesses of rtc_eoi map
KVM was using arrays of size KVM_MAX_VCPUS with vcpu_id, but ID can be
bigger that the maximal number of VCPUs, resulting in out-of-bounds
access.

Found by syzkaller:

  BUG: KASAN: slab-out-of-bounds in __apic_accept_irq+0xb33/0xb50 at addr [...]
  Write of size 1 by task a.out/27101
  CPU: 1 PID: 27101 Comm: a.out Not tainted 4.9.0-rc5+ #49
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
   [...]
  Call Trace:
   [...] __apic_accept_irq+0xb33/0xb50 arch/x86/kvm/lapic.c:905
   [...] kvm_apic_set_irq+0x10e/0x180 arch/x86/kvm/lapic.c:495
   [...] kvm_irq_delivery_to_apic+0x732/0xc10 arch/x86/kvm/irq_comm.c:86
   [...] ioapic_service+0x41d/0x760 arch/x86/kvm/ioapic.c:360
   [...] ioapic_set_irq+0x275/0x6c0 arch/x86/kvm/ioapic.c:222
   [...] kvm_ioapic_inject_all arch/x86/kvm/ioapic.c:235
   [...] kvm_set_ioapic+0x223/0x310 arch/x86/kvm/ioapic.c:670
   [...] kvm_vm_ioctl_set_irqchip arch/x86/kvm/x86.c:3668
   [...] kvm_arch_vm_ioctl+0x1a08/0x23c0 arch/x86/kvm/x86.c:3999
   [...] kvm_vm_ioctl+0x1fa/0x1a70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3099

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: stable@vger.kernel.org
Fixes: af1bae5497 ("KVM: x86: bump KVM_MAX_VCPU_ID to 1023")
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-11-24 18:37:19 +01:00
Jiri Slaby
8678654e3c kvm: x86: memset whole irq_eoi
gcc 7 warns:
arch/x86/kvm/ioapic.c: In function 'kvm_ioapic_reset':
arch/x86/kvm/ioapic.c:597:2: warning: 'memset' used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size]

And it is right. Memset whole array using sizeof operator.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: x86@kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
[Added x86 subject tag]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2016-10-20 14:54:11 +02:00
Paolo Bonzini
b0eaf4506f kvm: x86: correctly reset dest_map->vector when restoring LAPIC state
When userspace sends KVM_SET_LAPIC, KVM schedules a check between
the vCPU's IRR and ISR and the IOAPIC redirection table, in order
to re-establish the IOAPIC's dest_map (the list of CPUs servicing
the real-time clock interrupt with the corresponding vectors).

However, __rtc_irq_eoi_tracking_restore_one was forgetting to
set dest_map->vectors.  Because of this, the IOAPIC did not process
the real-time clock interrupt EOI, ioapic->rtc_status.pending_eoi
got stuck at a non-zero value, and further RTC interrupts were
reported to userspace as coalesced.

Fixes: 9e4aabe2bb
Fixes: 4d99ba898d
Cc: stable@vger.kernel.org
Cc: Joerg Roedel <jroedel@suse.de>
Cc: David Gilbert <dgilbert@redhat.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-09-15 18:00:32 +02:00
Suravee Suthikulpanit
dfb9595429 KVM: x86: Rename kvm_apic_get_reg to kvm_lapic_get_reg
Rename kvm_apic_get_reg to kvm_lapic_get_reg to be consistent with
the existing kvm_lapic_set_reg counterpart.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-05-18 18:04:25 +02:00
Joerg Roedel
4d99ba898d kvm: x86: Check dest_map->vector to match eoi signals for rtc
Using the vector stored at interrupt delivery makes the eoi
matching safe agains irq migration in the ioapic.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:18 +01:00
Joerg Roedel
9e4aabe2bb kvm: x86: Convert ioapic->rtc_status.dest_map to a struct
Currently this is a bitmap which tracks which CPUs we expect
an EOI from. Move this bitmap to a struct so that we can
track additional information there.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-03 14:36:17 +01:00
Andrey Smetanin
6308630bd3 kvm/x86: split ioapic-handled and EOI exit bitmaps
The function to determine if the vector is handled by ioapic used to
rely on the fact that only ioapic-handled vectors were set up to
cause vmexits when virtual apic was in use.

We're going to break this assumption when introducing Hyper-V
synthetic interrupts: they may need to cause vmexits too.

To achieve that, introduce a new bitmap dedicated specifically for
ioapic-handled vectors, and populate EOI exit bitmap from it for now.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-11-25 17:24:21 +01:00
Radim Krčmář
db2bdcbbbd KVM: x86: fix edge EOI and IOAPIC reconfig race
KVM uses eoi_exit_bitmap to track vectors that need an action on EOI.
The problem is that IOAPIC can be reconfigured while an interrupt with
old configuration is pending and eoi_exit_bitmap only remembers the
newest configuration;  thus EOI from the pending interrupt is not
recognized.

(Reconfiguration is not a problem for level interrupts, because IOAPIC
 sends interrupt with the new configuration.)

For an edge interrupt with ACK notifiers, like i8254 timer; things can
happen in this order
 1) IOAPIC inject a vector from i8254
 2) guest reconfigures that vector's VCPU and therefore eoi_exit_bitmap
    on original VCPU gets cleared
 3) guest's handler for the vector does EOI
 4) KVM's EOI handler doesn't pass that vector to IOAPIC because it is
    not in that VCPU's eoi_exit_bitmap
 5) i8254 stops working

A simple solution is to set the IOAPIC vector in eoi_exit_bitmap if the
vector is in PIR/IRR/ISR.

This creates an unwanted situation if the vector is reused by a
non-IOAPIC source, but I think it is so rare that we don't want to make
the solution more sophisticated.  The simple solution also doesn't work
if we are reconfiguring the vector.  (Shouldn't happen in the wild and
I'd rather fix users of ACK notifiers instead of working around that.)

The are no races because ioapic injection and reconfig are locked.

Fixes: b053b2aef2 ("KVM: x86: Add EOI exit bitmap inference")
[Before b053b2aef2, this bug happened only with APICv.]
Fixes: c7c9c56ca2 ("x86, apicv: add virtual interrupt delivery support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-14 16:41:08 +02:00
Paolo Bonzini
3bb345f387 KVM: x86: store IOAPIC-handled vectors in each VCPU
We can reuse the algorithm that computes the EOI exit bitmap to figure
out which vectors are handled by the IOAPIC.  The only difference
between the two is for edge-triggered interrupts other than IRQ8
that have no notifiers active; however, the IOAPIC does not have to
do anything special for these interrupts anyway.

This again limits the interactions between the IOAPIC and the LAPIC,
making it easier to move the former to userspace.

Inspired by a patch from Steve Rutherford.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:23 +02:00
Paolo Bonzini
bdaffe1d93 KVM: x86: set TMR when the interrupt is accepted
Do not compute TMR in advance.  Instead, set the TMR just before the interrupt
is accepted into the IRR.  This limits the coupling between IOAPIC and LAPIC.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:22 +02:00
Julia Lawall
d90e3a35e9 KVM: x86: drop unneeded null test
If the null test is needed, the call to cancel_delayed_work_sync would have
already crashed.  Normally, the destroy function should only be called
if the init function has succeeded, in which case ioapic is not null.

Problem found using Coccinelle.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-05-07 11:29:47 +02:00
James Sullivan
93bbf0b8bc kvm: x86: Extended struct kvm_lapic_irq with msi_redir_hint for MSI delivery
Extended struct kvm_lapic_irq with bool msi_redir_hint, which will
be used to determine if the delivery of the MSI should target only
the lowest priority CPU in the logical group specified for delivery.
(In physical dest mode, the RH bit is not relevant). Initialized the value
of msi_redir_hint to true when RH=1 in kvm_set_msi_irq(), and initialized
to false in all other cases.

Added value of msi_redir_hint to a debug message dump of an IRQ in
apic_send_ipi().

Signed-off-by: James Sullivan <sullivan.james.f@gmail.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-05-07 11:29:44 +02:00
Linus Torvalds
9003601310 The most interesting bit here is irqfd/ioeventfd support for ARM and ARM64.
ARM/ARM64: fixes for live migration, irqfd and ioeventfd support (enabling
 vhost, too), page aging
 
 s390: interrupt handling rework, allowing to inject all local interrupts
 via new ioctl and to get/set the full local irq state for migration
 and introspection.  New ioctls to access memory by virtual address,
 and to get/set the guest storage keys.  SIMD support.
 
 MIPS: FPU and MIPS SIMD Architecture (MSA) support.  Includes some patches
 from Ralf Baechle's MIPS tree.
 
 x86: bugfixes (notably for pvclock, the others are small) and cleanups.
 Another small latency improvement for the TSC deadline timer.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "First batch of KVM changes for 4.1

  The most interesting bit here is irqfd/ioeventfd support for ARM and
  ARM64.

  Summary:

  ARM/ARM64:
     fixes for live migration, irqfd and ioeventfd support (enabling
     vhost, too), page aging

  s390:
     interrupt handling rework, allowing to inject all local interrupts
     via new ioctl and to get/set the full local irq state for migration
     and introspection.  New ioctls to access memory by virtual address,
     and to get/set the guest storage keys.  SIMD support.

  MIPS:
     FPU and MIPS SIMD Architecture (MSA) support.  Includes some
     patches from Ralf Baechle's MIPS tree.

  x86:
     bugfixes (notably for pvclock, the others are small) and cleanups.
     Another small latency improvement for the TSC deadline timer"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (146 commits)
  KVM: use slowpath for cross page cached accesses
  kvm: mmu: lazy collapse small sptes into large sptes
  KVM: x86: Clear CR2 on VCPU reset
  KVM: x86: DR0-DR3 are not clear on reset
  KVM: x86: BSP in MSR_IA32_APICBASE is writable
  KVM: x86: simplify kvm_apic_map
  KVM: x86: avoid logical_map when it is invalid
  KVM: x86: fix mixed APIC mode broadcast
  KVM: x86: use MDA for interrupt matching
  kvm/ppc/mpic: drop unused IRQ_testbit
  KVM: nVMX: remove unnecessary double caching of MAXPHYADDR
  KVM: nVMX: checks for address bits beyond MAXPHYADDR on VM-entry
  KVM: x86: cache maxphyaddr CPUID leaf in struct kvm_vcpu
  KVM: vmx: pass error code with internal error #2
  x86: vdso: fix pvclock races with task migration
  KVM: remove kvm_read_hva and kvm_read_hva_atomic
  KVM: x86: optimize delivery of TSC deadline timer interrupt
  KVM: x86: extract blocking logic from __vcpu_run
  kvm: x86: fix x86 eflags fixed bit
  KVM: s390: migrate vcpu interrupt state
  ...
2015-04-13 09:47:01 -07:00
Paolo Bonzini
bf0fb67cf9 KVM/ARM changes for v4.1:
- fixes for live migration
 - irqfd support
 - kvm-io-bus & vgic rework to enable ioeventfd
 - page ageing for stage-2 translation
 - various cleanups
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Merge tag 'kvm-arm-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into 'kvm-next'

KVM/ARM changes for v4.1:

- fixes for live migration
- irqfd support
- kvm-io-bus & vgic rework to enable ioeventfd
- page ageing for stage-2 translation
- various cleanups
2015-04-07 18:09:20 +02:00
Nikolay Nikolaev
e32edf4fd0 KVM: Redesign kvm_io_bus_ API to pass VCPU structure to the callbacks.
This is needed in e.g. ARM vGIC emulation, where the MMIO handling
depends on the VCPU that does the access.

Signed-off-by: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26 21:43:11 +00:00