KVM: x86: move kvm_inject_gp up from kvm_set_dr to callers

Push the injection of #GP up to the callers, so that they can just use
kvm_complete_insn_gp. __kvm_set_dr is pretty much what the callers can use
together with kvm_complete_insn_gp, so rename it to kvm_set_dr and drop
the old kvm_set_dr wrapper.

This also allows nested VMX code, which really wanted to use __kvm_set_dr,
to use the right function.

While at it, remove the kvm_require_dr() check from the SVM interception.
The APM states:

  All normal exception checks take precedence over the SVM intercepts.

which includes the CR4.DE=1 #UD.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 5 insertions, 14 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dcb67429b75d..baa90ae76ba5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1143,7 +1143,7 @@ static u64 kvm_dr6_fixed(struct kvm_vcpu *vcpu)
 	return fixed;
 }
 
-static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
+int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
 {
 	size_t size = ARRAY_SIZE(vcpu->arch.db);
 
@@ -1156,13 +1156,13 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
 	case 4:
 	case 6:
 		if (!kvm_dr6_valid(val))
-			return -1; /* #GP */
+			return 1; /* #GP */
 		vcpu->arch.dr6 = (val & DR6_VOLATILE) | kvm_dr6_fixed(vcpu);
 		break;
 	case 5:
 	default: /* 7 */
 		if (!kvm_dr7_valid(val))
-			return -1; /* #GP */
+			return 1; /* #GP */
 		vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
 		kvm_update_dr7(vcpu);
 		break;
@@ -1170,15 +1170,6 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
 
 	return 0;
 }
-
-int kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
-{
-	if (__kvm_set_dr(vcpu, dr, val)) {
-		kvm_inject_gp(vcpu, 0);
-		return 1;
-	}
-	return 0;
-}
 EXPORT_SYMBOL_GPL(kvm_set_dr);
 
 void kvm_get_dr(struct kvm_vcpu *vcpu, int dr, unsigned long *val)
@@ -6619,7 +6610,7 @@ static int emulator_set_dr(struct x86_emulate_ctxt *ctxt, int dr,
 			   unsigned long value)
 {
 
-	return __kvm_set_dr(emul_to_vcpu(ctxt), dr, value);
+	return kvm_set_dr(emul_to_vcpu(ctxt), dr, value);
 }
 
 static u64 mk_cr_64(u64 curr_cr, u32 new_val)
@@ -8664,7 +8655,7 @@ static void enter_smm(struct kvm_vcpu *vcpu)
 	dt.address = dt.size = 0;
 	static_call(kvm_x86_set_idt)(vcpu, &dt);
 
-	__kvm_set_dr(vcpu, 7, DR7_FIXED_1);
+	kvm_set_dr(vcpu, 7, DR7_FIXED_1);
 
 	cs.selector = (vcpu->arch.smbase >> 4) & 0xffff;
 	cs.base = vcpu->arch.smbase;