On Wed, 2025-03-26 at 19:36 +0000, Yosry Ahmed wrote:
> Currently, when a vCPU is migrated to a new physical CPU, the ASID
> generation is reset to trigger allocating a new ASID. In preparation for
> using a static ASID per VM, just flush the ASID in this case (falling
> back to flushing everything if FLUSBYASID is not available).
>
> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Signed-off-by: Yosry Ahmed <yosry.ahmed@xxxxxxxxx>
> ---
> arch/x86/kvm/svm/svm.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 5f71b125010d9..18bfc3d3f9ba1 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -3626,12 +3626,12 @@ static int pre_svm_run(struct kvm_vcpu *vcpu)
> struct vcpu_svm *svm = to_svm(vcpu);
>
> /*
> - * If the previous vmrun of the vmcb occurred on a different physical
> - * cpu, then mark the vmcb dirty and assign a new asid. Hardware's
> - * vmcb clean bits are per logical CPU, as are KVM's asid assignments.
> + * If the previous VMRUN of the VMCB occurred on a different physical
> + * CPU, then mark the VMCB dirty and flush the ASID. Hardware's
> + * VMCB clean bits are per logical CPU, as are KVM's ASID assignments.
> */
> if (unlikely(svm->current_vmcb->cpu != vcpu->cpu)) {
> - svm->current_vmcb->asid_generation = 0;
> + vmcb_set_flush_asid(svm->vmcb);
> vmcb_mark_all_dirty(svm->vmcb);
> svm->current_vmcb->cpu = vcpu->cpu;
> }
Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
Best regards,
Maxim Levitsky
