target/arm: kvm: Inject events at the last stage of sync

KVM_SET_VCPU_EVENTS might actually lead to vcpu registers being modified.
As such this should be the last step of sync to avoid potential overwriting
of whatever changes KVM might have done.

Signed-off-by: Beata Michalska <beata.michalska@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Message-id: 20200312003401.29017-2-beata.michalska@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/target/arm/kvm64.c b/target/arm/kvm64.c
index 93ba1448da..be5b31c2b0 100644
--- a/target/arm/kvm64.c
+++ b/target/arm/kvm64.c
@@ -1094,17 +1094,22 @@ int kvm_arch_put_registers(CPUState *cs, int level)
         return ret;
     }
 
-    ret = kvm_put_vcpu_events(cpu);
-    if (ret) {
-        return ret;
-    }
-
     write_cpustate_to_list(cpu, true);
 
     if (!write_list_to_kvmstate(cpu, level)) {
         return -EINVAL;
     }
 
+   /*
+    * Setting VCPU events should be triggered after syncing the registers
+    * to avoid overwriting potential changes made by KVM upon calling
+    * KVM_SET_VCPU_EVENTS ioctl
+    */
+    ret = kvm_put_vcpu_events(cpu);
+    if (ret) {
+        return ret;
+    }
+
     kvm_arm_sync_mpstate_to_kvm(cpu);
 
     return ret;