3 files changed, 28 insertions, 0 deletions

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index 81f1b974c06a..228f9cf5a5b5 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2957,6 +2957,15 @@ HVC instruction based PSCI call from the vcpu. The 'type' field describes
 the system-level event type. The 'flags' field describes architecture
 specific flags for the system-level event.
 
+Valid values for 'type' are:
+  KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the
+   VM. Userspace is not obliged to honour this, and if it does honour
+   this does not need to destroy the VM synchronously (ie it may call
+   KVM_RUN again before shutdown finally occurs).
+  KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM.
+   As with SHUTDOWN, userspace can choose to ignore the request, or
+   to schedule the reset to occur in the future and may call KVM_RUN again.
+
                 /* Fix the size of the union. */
                 char padding[256];
         };
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 09cf37737ee2..58cb3248d277 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -15,6 +15,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/preempt.h>
 #include <linux/kvm_host.h>
 #include <linux/wait.h>
 
@@ -166,6 +167,23 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
 
 static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
 {
+        int i;
+        struct kvm_vcpu *tmp;
+
+        /*
+         * The KVM ABI specifies that a system event exit may call KVM_RUN
+         * again and may perform shutdown/reboot at a later time that when the
+         * actual request is made.  Since we are implementing PSCI and a
+         * caller of PSCI reboot and shutdown expects that the system shuts
+         * down or reboots immediately, let's make sure that VCPUs are not run
+         * after this call is handled and before the VCPUs have been
+         * re-initialized.
+         */
+        kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
+                tmp->arch.pause = true;
+                kvm_vcpu_kick(tmp);
+        }
+
         memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
         vcpu->run->system_event.type = type;
         vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 65c615294589..0b7dfdb931df 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -198,6 +198,7 @@ struct kvm_vcpu *kvm_arm_get_running_vcpu(void);
 struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void);
 
 u64 kvm_call_hyp(void *hypfn, ...);
+void force_vm_exit(const cpumask_t *mask);
 
 int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
                 int exception_index);