On Tue, 30 Dec 2025 13:13:39 -0800, Sean Christopherson wrote:
> Fix (mostly benign) bugs in SVM where KVM treats exit codes as 32-bit values
> instead of 64-bit values.
>
> The most dangerous aspect of the mess is that simply fixing KVM would likely
> break KVM-on-KVM setups if only L1 is patched. To try and avoid such
> breakage while also fixing KVM, I opted to have KVM retain its checks on
> only bits 31:0 if KVM is running as a VM (as detected by
> X86_FEATURE_HYPERVISOR).
>
> [...]
Applied to kvm-x86 svm, thanks!
[1/8] KVM: SVM: Add a helper to detect VMRUN failures
https://github.com/kvm-x86/linux/commit/217463aa329e
[2/8] KVM: SVM: Open code handling of unexpected exits in
svm_invoke_exit_handler()
https://github.com/kvm-x86/linux/commit/2450c9774510
[3/8] KVM: SVM: Check for an unexpected VM-Exit after RETPOLINE "fast" handling
https://github.com/kvm-x86/linux/commit/194c17bf5eba
[4/8] KVM: SVM: Filter out 64-bit exit codes when invoking exit handlers on
bare metal
https://github.com/kvm-x86/linux/commit/405fce694bd1
[5/8] KVM: SVM: Treat exit_code as an unsigned 64-bit value through all of KVM
https://github.com/kvm-x86/linux/commit/d7507a94a072
[6/8] KVM: SVM: Limit incorrect check on SVM_EXIT_ERR to running as a VM
https://github.com/kvm-x86/linux/commit/a08ca6691fd3
[7/8] KVM: SVM: Harden exit_code against being used in Spectre-like attacks
https://github.com/kvm-x86/linux/commit/1e3dddafecee
[8/8] KVM: SVM: Assert that Hyper-V's HV_SVM_EXITCODE_ENL == SVM_EXIT_SW
https://github.com/kvm-x86/linux/commit/d6c20d19f7d3
--
https://github.com/kvm-x86/linux/tree/next
