Merge remote-tracking branch 'remotes/ehabkost/tags/x86-next-for-5.1-pull-request' into staging

x86 bug fix for -rc2

A fix from Vitaly Kuznetsov for a CPU reset bug
reported by Jan Kiszka.

# gpg: Signature made Thu 23 Jul 2020 20:10:40 BST
# gpg:                using RSA key 5A322FD5ABC4D3DBACCFD1AA2807936F984DC5A6
# gpg:                issuer "[email protected]"
# gpg: Good signature from "Eduardo Habkost <[email protected]>" [full]
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/x86-next-for-5.1-pull-request:
  KVM: fix CPU reset wrt HF2_GIF_MASK

Signed-off-by: Peter Maydell <[email protected]>

Author: pm215

target/i386/kvm.c

@@ -3877,7 +3877,9 @@ static int kvm_put_nested_state(X86CPU *cpu)
     } else {
         env->nested_state->flags &= ~KVM_STATE_NESTED_GUEST_MODE;
     }
-    if (env->hflags2 & HF2_GIF_MASK) {
+
+    /* Don't set KVM_STATE_NESTED_GIF_SET on VMX as it is illegal */
+    if (cpu_has_svm(env) && (env->hflags2 & HF2_GIF_MASK)) {
         env->nested_state->flags |= KVM_STATE_NESTED_GIF_SET;
     } else {
         env->nested_state->flags &= ~KVM_STATE_NESTED_GIF_SET;
@@ -3919,10 +3921,14 @@ static int kvm_get_nested_state(X86CPU *cpu)
     } else {
         env->hflags &= ~HF_GUEST_MASK;
     }
-    if (env->nested_state->flags & KVM_STATE_NESTED_GIF_SET) {
-        env->hflags2 |= HF2_GIF_MASK;
-    } else {
-        env->hflags2 &= ~HF2_GIF_MASK;
+
+    /* Keep HF2_GIF_MASK set on !SVM as x86_cpu_pending_interrupt() needs it */
+    if (cpu_has_svm(env)) {
+        if (env->nested_state->flags & KVM_STATE_NESTED_GIF_SET) {
+            env->hflags2 |= HF2_GIF_MASK;
+        } else {
+            env->hflags2 &= ~HF2_GIF_MASK;
+        }
     }
 
     return ret;