From: Sean Christopherson Date: Tue, 6 Apr 2021 17:18:11 +0000 (-0700) Subject: KVM: SVM: Enhance and clean up the vmcb tracking comment in pre_svm_run() X-Git-Tag: v5.13-rc1~76^2~87 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=44f1b5586df03b044704f3c57f529ea4120f406b;p=thirdparty%2Fkernel%2Flinux.git KVM: SVM: Enhance and clean up the vmcb tracking comment in pre_svm_run() 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 Message-Id: <20210406171811.4043363-5-seanjc@google.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 1207526cf8e78..5f1af41632510 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);