Re: [PATCH] KVM: x86: Ignore pending PV EOI if the vCPU has since disabled PV EOIs

[Sean Christopherson]

On Wed, 24 Jun 2026 15:05:16 -0700, Sean Christopherson wrote:
> Ignore KVM's internal "service pending PV EOI" request if the vCPU has
> disabled PV EOIs since the request was made.  Asserting that PV EOIs are
> enabled can fail if reading guest memory in pv_eoi_get_user() fails, i.e.
> if pv_eoi_test_and_clr_pending() bails early, *and* the vCPU also disables
> PV EOIs.
> 
>   kernel BUG at arch/x86/kvm/lapic.c:3338!
>   Oops: invalid opcode: 0000 [#1] SMP
>   CPU: 4 UID: 1000 PID: 890 Comm: pv_eoi_test Not tainted 7.0.0-d585aa5894d8-vm #337 PREEMPT
>   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
>   RIP: 0010:kvm_lapic_sync_from_vapic+0x12b/0x140 [kvm]
>   Call Trace:
>    <TASK>
>    kvm_arch_vcpu_ioctl_run+0x1075/0x1c30 [kvm]
>    kvm_vcpu_ioctl+0x2d5/0x980 [kvm]
>    __x64_sys_ioctl+0x8a/0xd0
>    do_syscall_64+0xb5/0xb40
>    entry_SYSCALL_64_after_hwframe+0x4b/0x53
>    </TASK>
>   Modules linked in: kvm_intel kvm irqbypass
>   ---[ end trace 0000000000000000 ]---
> 
> [...]

Applied to kvm-x86 fixes, thanks!

[1/1] KVM: x86: Ignore pending PV EOI if the vCPU has since disabled PV EOIs
      https://github.com/kvm-x86/linux/commit/9285e4070df2

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https://github.com/kvm-x86/linux/tree/next