KVM: x86 emulator: add new ->halt() callback

Instead of reaching into vcpu internals.
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/include/asm/kvm_emulate.h

@@ -186,6 +186,7 @@ struct x86_emulate_ops {
 	int (*set_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong value);
 	int (*set_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 data);
 	int (*get_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 *pdata);
+	void (*halt)(struct x86_emulate_ctxt *ctxt);
 	void (*get_fpu)(struct x86_emulate_ctxt *ctxt); /* disables preempt */
 	void (*put_fpu)(struct x86_emulate_ctxt *ctxt); /* reenables preempt */
 	int (*intercept)(struct x86_emulate_ctxt *ctxt,

arch/x86/kvm/emulate.c

@@ -3913,7 +3913,7 @@ x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
 		c->dst.type = OP_NONE;	/* Disable writeback. */
 		break;
 	case 0xf4:              /* hlt */
-		ctxt->vcpu->arch.halt_request = 1;
+		ctxt->ops->halt(ctxt);
 		break;
 	case 0xf5:	/* cmc */
 		/* complement carry flag from eflags reg */

arch/x86/kvm/x86.c

@@ -4351,6 +4351,11 @@ static int emulator_set_msr(struct x86_emulate_ctxt *ctxt,
 	return kvm_set_msr(emul_to_vcpu(ctxt), msr_index, data);
 }
 
+static void emulator_halt(struct x86_emulate_ctxt *ctxt)
+{
+	emul_to_vcpu(ctxt)->arch.halt_request = 1;
+}
+
 static void emulator_get_fpu(struct x86_emulate_ctxt *ctxt)
 {
 	preempt_disable();
@@ -4400,6 +4405,7 @@ static struct x86_emulate_ops emulate_ops = {
 	.set_dr              = emulator_set_dr,
 	.set_msr             = emulator_set_msr,
 	.get_msr             = emulator_get_msr,
+	.halt                = emulator_halt,
 	.get_fpu             = emulator_get_fpu,
 	.put_fpu             = emulator_put_fpu,
 	.intercept           = emulator_intercept,