KVM: arm/arm64: use vcpu requests for power_off

System shutdown is currently using request-less VCPU kicks. This
leaves open a tiny race window, as it doesn't ensure the state
change to power_off is seen by a VCPU just about to enter guest
mode. VCPU requests, OTOH, are guaranteed to be seen (see "Ensuring
Requests Are Seen" of Documentation/virtual/kvm/vcpu-requests.rst)
This patch applies the EXIT request used by pause to power_off,
fixing the race.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
This commit is contained in:
Andrew Jones 2017-06-04 14:43:56 +02:00 committed by Christoffer Dall
parent 0592c00562
commit cc9b43f99d

View File

@ -179,10 +179,9 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
* after this call is handled and before the VCPUs have been * after this call is handled and before the VCPUs have been
* re-initialized. * re-initialized.
*/ */
kvm_for_each_vcpu(i, tmp, vcpu->kvm) { kvm_for_each_vcpu(i, tmp, vcpu->kvm)
tmp->arch.power_off = true; tmp->arch.power_off = true;
kvm_vcpu_kick(tmp); kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_VCPU_EXIT);
}
memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
vcpu->run->system_event.type = type; vcpu->run->system_event.type = type;