@@ -6853,7 +6853,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
/*
* 1) We should set ->mode before checking ->requests. Please see
- * the comment in kvm_make_all_cpus_request.
+ * the comment in kvm_vcpu_exiting_guest_mode().
*
* 2) For APICv, we should set ->mode before checking PIR.ON. This
* pairs with the memory barrier implicit in pi_test_and_set_on
@@ -270,6 +270,12 @@ struct kvm_vcpu {
static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
{
+ /*
+ * The memory barrier ensures a previous write to vcpu->requests cannot
+ * be reordered with the read of vcpu->mode. It pairs with the general
+ * memory barrier following the write of vcpu->mode in VCPU RUN.
+ */
+ smp_mb__before_atomic();
return cmpxchg(&vcpu->mode, IN_GUEST_MODE, EXITING_GUEST_MODE);
}
@@ -183,9 +183,6 @@ bool kvm_make_all_cpus_request(struct kvm *kvm, unsigned int req)
kvm_make_request(req, vcpu);
cpu = vcpu->cpu;
- /* Set ->requests bit before we read ->mode. */
- smp_mb__after_atomic();
-
if (!(req & KVM_REQUEST_NO_WAKEUP))
kvm_vcpu_wake_up(vcpu);