1 files changed, 21 insertions, 24 deletions

diff --git a/target/i386/machine.c b/target/i386/machine.c
index 704ba6d..b114609 100644
--- a/target/i386/machine.c
+++ b/target/i386/machine.c
@@ -7,6 +7,7 @@
 #include "hw/isa/isa.h"
 #include "migration/cpu.h"
 #include "hyperv.h"
+#include "kvm_i386.h"
 
 #include "sysemu/kvm.h"
 #include "sysemu/tcg.h"
@@ -232,10 +233,25 @@ static int cpu_pre_save(void *opaque)
     }
 
 #ifdef CONFIG_KVM
-    /* Verify we have nested virtualization state from kernel if required */
-    if (kvm_enabled() && cpu_has_vmx(env) && !env->nested_state) {
-        error_report("Guest enabled nested virtualization but kernel "
-                "does not support saving of nested state");
+    /*
+     * In case vCPU may have enabled VMX, we need to make sure kernel have
+     * required capabilities in order to perform migration correctly:
+     *
+     * 1) We must be able to extract vCPU nested-state from KVM.
+     *
+     * 2) In case vCPU is running in guest-mode and it has a pending exception,
+     * we must be able to determine if it's in a pending or injected state.
+     * Note that in case KVM don't have required capability to do so,
+     * a pending/injected exception will always appear as an
+     * injected exception.
+     */
+    if (kvm_enabled() && cpu_vmx_maybe_enabled(env) &&
+        (!env->nested_state ||
+         (!kvm_has_exception_payload() && (env->hflags & HF_GUEST_MASK) &&
+          env->exception_injected))) {
+        error_report("Guest maybe enabled nested virtualization but kernel "
+                "does not support required capabilities to save vCPU "
+                "nested state");
         return -EINVAL;
     }
 #endif
@@ -1019,31 +1035,13 @@ static const VMStateDescription vmstate_vmx_nested_state = {
     }
 };
 
-static bool svm_nested_state_needed(void *opaque)
-{
-    struct kvm_nested_state *nested_state = opaque;
-
-    return (nested_state->format == KVM_STATE_NESTED_FORMAT_SVM);
-}
-
-static const VMStateDescription vmstate_svm_nested_state = {
-    .name = "cpu/kvm_nested_state/svm",
-    .version_id = 1,
-    .minimum_version_id = 1,
-    .needed = svm_nested_state_needed,
-    .fields = (VMStateField[]) {
-        VMSTATE_END_OF_LIST()
-    }
-};
-
 static bool nested_state_needed(void *opaque)
 {
     X86CPU *cpu = opaque;
     CPUX86State *env = &cpu->env;
 
     return (env->nested_state &&
-            (vmx_nested_state_needed(env->nested_state) ||
-             svm_nested_state_needed(env->nested_state)));
+            vmx_nested_state_needed(env->nested_state));
 }
 
 static int nested_state_post_load(void *opaque, int version_id)
@@ -1105,7 +1103,6 @@ static const VMStateDescription vmstate_kvm_nested_state = {
     },
     .subsections = (const VMStateDescription*[]) {
         &vmstate_vmx_nested_state,
-        &vmstate_svm_nested_state,
         NULL
     }
 };