linux-kernel - Re: [PATCH v6 0/4] KVM: x86: Fix hard lockup with periodic timer in guest

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Message-ID: <176350820887.2285264.85098693325976839.b4-ty@google.com>
Date: Tue, 18 Nov 2025 15:27:46 -0800
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	fuqiang wang <fuqiang.wng@...il.com>
Subject: Re: [PATCH v6 0/4] KVM: x86: Fix hard lockup with periodic timer in guest

On Thu, 13 Nov 2025 12:51:10 -0800, Sean Christopherson wrote:
> fuqiang's patch/series to fix a bug in KVM's local APIC timer emulation where
> it can trigger a hard lockup due to restarting an hrtimer with an expired
> deadline over and over (and over).
> 
> v6:
>  - Split the apic_timer_fn() change to a separate patch (mainly for a
>    bisection point).
>  - Handle (and WARN on) period=0 in apic_timer_fn().
>  - Add a patch to grab a pointer to the kvm_timer struct locally.
>  - Tag the fixes (and prep work) for stable@.
> 
> [...]

Applied to kvm-x86 misc, thanks!

[1/4] KVM: x86: WARN if hrtimer callback for periodic APIC timer fires with period=0
      https://github.com/kvm-x86/linux/commit/0ea9494be9c9
[2/4] KVM: x86: Explicitly set new periodic hrtimer expiration in apic_timer_fn()
      https://github.com/kvm-x86/linux/commit/9633f180ce99
[3/4] KVM: x86: Fix VM hard lockup after prolonged inactivity with periodic HV timer
      https://github.com/kvm-x86/linux/commit/18ab3fc8e880
[4/4] KVM: x86: Grab lapic_timer in a local variable to cleanup periodic code
      https://github.com/kvm-x86/linux/commit/a091fe60c2d3

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