Re: [PATCH 0/2] KVM: selftests: Fix sync_regs race tests on AMD

From: Sean Christopherson
Date: Fri Aug 25 2023 - 15:03:05 EST


On Thu, 17 Aug 2023 16:34:28 -0700, Sean Christopherson wrote:
> The recently introduced sync_regs subtests to detect TOCTOU bugs hang on
> AMD because KVM synthesizes INIT on triple fault shutdown (because AMD says
> the VMCB is undefined after shutdown). Fix it by loading known good state
> if a shutdown occurs.
>
> Patch two explicitly injects #UD as the "good" vector so that the test
> doesn't rely on KVM inadvertantly setting the vector to #DE (old, buggy
> behavior).
>
> [...]

Applied to kvm-x86 selftests.

[1/2] KVM: selftests: Reload "good" vCPU state if vCPU hits shutdown
https://github.com/kvm-x86/linux/commit/5002b112a5ad
[2/2] KVM: selftests: Explicit set #UD when *potentially* injecting exception
https://github.com/kvm-x86/linux/commit/02dc2543e379

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