Re: [PATCH 0/5] KVM: SVM: Fix and clean up OSVW handling

[Sean Christopherson]

On Thu, 13 Nov 2025 15:14:15 -0800, Sean Christopherson wrote:
> Fix a long-standing bug where KVM could clobber its OS-visible workarounds
> handling (not that anyone would notice), and then clean up the code to make
> it easier understand and maintain (I didn't even know what "osvw" stood for
> until I ran into this code when trying to moving actual SVM pieces of
> svm_enable_virtualization_cpu() out of KVM (for TDX purposes)).
> 
> Tested by running in a VM and generating unique per-vCPU MSR values in the
> host (see below), and verifying KVM ended up with the right values.
> 
> [...]

Applied to kvm-x86 svm, thanks!

[1/5] KVM: SVM: Serialize updates to global OS-Visible Workarounds variables
      https://github.com/kvm-x86/linux/commit/f35043d0f973
[2/5] KVM: SVM: Skip OSVW MSR reads if KVM is treating all errata as present
      https://github.com/kvm-x86/linux/commit/089af84641b5
[3/5] KVM: SVM: Extract OS-visible workarounds setup to helper function
      https://github.com/kvm-x86/linux/commit/c65106af8393
[4/5] KVM: SVM: Skip OSVW variable updates if current CPU's errata are a subset
      https://github.com/kvm-x86/linux/commit/3b7a320e491c
[5/5] KVM: SVM: Skip OSVW MSR reads if current CPU doesn't support the feature
      https://github.com/kvm-x86/linux/commit/a56444d5e738

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