Commit 44f1b558 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

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: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20210406171811.4043363-5-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 554cf314

arch/x86/kvm/svm/svm.c

+4 −5
Original line number Diff line number Diff line
@@ -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);