[PATCH V4 10/10] target/arm/kvm: Write CPU state back to KVM on reset

[Salil Mehta]

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

When a KVM vCPU is reset following a PSCI CPU_ON call, its power state
is not synchronized with KVM at the moment. Because the vCPU is not
marked dirty, we miss the call to kvm_arch_put_registers() that writes
to KVM's MP_STATE. Force mp_state synchronization.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Gavin Shan <gshan@redhat.com>
---
 target/arm/kvm.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/target/arm/kvm.c b/target/arm/kvm.c
index b66b936a95..8cb70b9e7c 100644
--- a/target/arm/kvm.c
+++ b/target/arm/kvm.c
@@ -642,11 +642,12 @@ void kvm_arm_cpu_post_load(ARMCPU *cpu)
 void kvm_arm_reset_vcpu(ARMCPU *cpu)
 {
     int ret;
+    CPUState *cs = CPU(cpu);
 
     /* Re-init VCPU so that all registers are set to
      * their respective reset values.
      */
-    ret = kvm_arm_vcpu_init(CPU(cpu));
+    ret = kvm_arm_vcpu_init(cs);
     if (ret < 0) {
         fprintf(stderr, "kvm_arm_vcpu_init failed: %s\n", strerror(-ret));
         abort();
@@ -663,6 +664,11 @@ void kvm_arm_reset_vcpu(ARMCPU *cpu)
      * for the same reason we do so in kvm_arch_get_registers().
      */
     write_list_to_cpustate(cpu);
+    /*
+     * Ensure we call kvm_arch_put_registers(). The vCPU isn't marked dirty if
+     * it was parked in KVM and is now booting from a PSCI CPU_ON call.
+     */
+    cs->vcpu_dirty = true;
 }
 
 /*
-- 
2.34.1