Re: [PATCH v2] KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock

[Sean Christopherson]

On Tue, 14 Jul 2026 15:32:13 +0200, Carlos López wrote:
> Fix an issue where userspace or the guest can program an Hyper-V
> synthetic timer to have a deadline in the past via integer overflow,
> preventing the CPU from making progress and triggering an RCU stall.
> 
> Hyper-V's SynIC exposes 4 per-vCPU synthetic timers to the
> guest, which are emulated by KVM. Each is programmed through the
> HV_X64_MSR_STIMERi_CONFIG and HV_X64_MSR_STIMERi_COUNT MSRs. Depending
> on CONFIG, COUNT represents either the absolute expiration time or the
> period of a periodic timer, both expressed in 100ns ticks. These timers
> may be set both by the guest (WRMSR) and the host (KVM_SET_MSRS).
> 
> [...]

Applied to kvm-x86 misc, thanks!

[1/1] KVM: x86: hyper-v: Clamp stimer deadline to avoid livelock
      https://github.com/kvm-x86/linux/commit/0ca49fbd2883

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