Re: [PATCH] KVM: x86: Unify cross-vCPU IBPB

[Sean Christopherson]

On Thu, 20 Mar 2025 01:37:59 +0000, Yosry Ahmed wrote:
> Both SVM and VMX have similar implementation for executing an IBPB
> between running different vCPUs on the same CPU to create separate
> prediction domains for different vCPUs.
> 
> For VMX, when the currently loaded VMCS is changed in
> vmx_vcpu_load_vmcs(), an IBPB is executed if there is no 'buddy', which
> is the case on vCPU load. The intention is to execute an IBPB when
> switching vCPUs, but not when switching the VMCS within the same vCPU.
> Executing an IBPB on nested transitions within the same vCPU is handled
> separately and conditionally in nested_vmx_vmexit().
> 
> [...]

Applied to kvm-x86 misc, with the online=>possible change split out to its own
patch.  Thanks!

[1/2] KVM: SVM: Clear current_vmcb during vCPU free for all *possible* CPUs
      https://github.com/kvm-x86/linux/commit/1bee4838eb3a
[2/2] KVM: x86: Unify cross-vCPU IBPB
      https://github.com/kvm-x86/linux/commit/54a1a24fea19

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