On Thu, 13 Nov 2025 14:56:12 -0800, Sean Christopherson wrote:
> Hyper-V folks, y'all are getting Cc'd because of a change in
> include/hyperv/hvgdk.h to ensure HV_SVM_EXITCODE_ENL is an unsigned value.
> AFAICT, only KVM consumes that macro. That said, any insight you can provide
> on relevant Hyper-V behavior would be appreciated :-)
>
>
> Fix bugs in SVM that mostly impact nested SVM where KVM treats exit codes
> as 32-bit values instead of 64-bit values. I have no idea how KVM ended up
> with such an egregious flaw, as the blame trail goes all the way back to
> commit 6aa8b732ca01 ("[PATCH] kvm: userspace interface"). Maybe there was
> pre-production hardware or something?
>
> [...]
Applied 1 and 2 to kvm-x86 fixes. I'll send v2 for the rest soon-ish.
[1/9] KVM: nSVM: Clear exit_code_hi in VMCB when synthesizing nested VM-Exits
https://github.com/kvm-x86/linux/commit/da01f64e7470
[2/9] KVM: nSVM: Set exit_code_hi to -1 when synthesizing SVM_EXIT_ERR (failed
VMRUN)
https://github.com/kvm-x86/linux/commit/f402ecd7a8b6
--
https://github.com/kvm-x86/linux/tree/next
