Explicitly document why a vmcb must be marked dirty and assigned a new asid when it will be run on a different cpu. The "what" is relatively obvious, whereas the "why" requires reading the APM and/or KVM code.
Opportunistically remove a spurious period and several unnecessary newlines in the comment. No functional change intended. Signed-off-by: Sean Christopherson <[email protected]> --- arch/x86/kvm/svm/svm.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index f62c56adf7c9..afc275ba5d59 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -3336,11 +3336,10 @@ static void 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 we must mark the vmcb dirty. - * and assign a new asid. - */ - + * 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 (unlikely(svm->current_vmcb->cpu != vcpu->cpu)) { svm->current_vmcb->asid_generation = 0; vmcb_mark_all_dirty(svm->vmcb); -- 2.31.0.208.g409f899ff0-goog
