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 <seanjc@xxxxxxxxxx>
---
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
