Re: [PATCH v7 0/2] KVM: VMX: Workaround VMX preemption timer erratum

From: Sean Christopherson

Date: Wed Aug 05 2026 - 13:02:53 EST


On Fri, 31 Jul 2026 10:19:24 -0700, Sean Christopherson wrote:
> Due to a widespread Intel erratum (e.g. EMR158), programming the VMX
> preemption timer with certain large values may cause the timer to expire
> earlier than expected. The recommended workaround is to cap the timer value
> to strictly less than 2^25 * CPUID.15H:EBX[31:0] / CPUID.15H:EAX[31:0].
>
> v7:
> - Ensure the timer doesn't exceed the architectural max. [Sashiko]
>
> [...]

Applied to kvm-x86 vmx, thanks!

[1/2] KVM: VMX: Bury all of the VMX preemption timer code under CONFIG_X86_64=y
https://github.com/kvm-x86/linux/commit/d0dea3ed847c
[2/2] KVM: VMX: Cap VMX preemption timer to work around Intel erratum
https://github.com/kvm-x86/linux/commit/0aaedada606a

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