KVM: x86: Make kvm_queued_exception a properly named, visible struct

Move the definition of "struct kvm_queued_exception" out of kvm_vcpu_arch
in anticipation of adding a second instance in kvm_vcpu_arch to handle
exceptions that occur when vectoring an injected exception and are
morphed to VM-Exit instead of leading to #DF.

Opportunistically take advantage of the churn to rename "nr" to "vector".

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Link: https://lore.kernel.org/r/20220830231614.3580124-15-seanjc@google.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 38 insertions, 42 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4cb177b616c5..b156dde99504 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -561,16 +561,13 @@ static int exception_type(int vector)
 	return EXCPT_FAULT;
 }
 
-void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu)
+void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu,
+				   struct kvm_queued_exception *ex)
 {
-	unsigned nr = vcpu->arch.exception.nr;
-	bool has_payload = vcpu->arch.exception.has_payload;
-	unsigned long payload = vcpu->arch.exception.payload;
-
-	if (!has_payload)
+	if (!ex->has_payload)
 		return;
 
-	switch (nr) {
+	switch (ex->vector) {
 	case DB_VECTOR:
 		/*
 		 * "Certain debug exceptions may clear bit 0-3.  The
@@ -595,8 +592,8 @@ void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu)
 		 * So they need to be flipped for DR6.
 		 */
 		vcpu->arch.dr6 |= DR6_ACTIVE_LOW;
-		vcpu->arch.dr6 |= payload;
-		vcpu->arch.dr6 ^= payload & DR6_ACTIVE_LOW;
+		vcpu->arch.dr6 |= ex->payload;
+		vcpu->arch.dr6 ^= ex->payload & DR6_ACTIVE_LOW;
 
 		/*
 		 * The #DB payload is defined as compatible with the 'pending
@@ -607,12 +604,12 @@ void kvm_deliver_exception_payload(struct kvm_vcpu *vcpu)
 		vcpu->arch.dr6 &= ~BIT(12);
 		break;
 	case PF_VECTOR:
-		vcpu->arch.cr2 = payload;
+		vcpu->arch.cr2 = ex->payload;
 		break;
 	}
 
-	vcpu->arch.exception.has_payload = false;
-	vcpu->arch.exception.payload = 0;
+	ex->has_payload = false;
+	ex->payload = 0;
 }
 EXPORT_SYMBOL_GPL(kvm_deliver_exception_payload);
 
@@ -651,17 +648,18 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
 			vcpu->arch.exception.injected = false;
 		}
 		vcpu->arch.exception.has_error_code = has_error;
-		vcpu->arch.exception.nr = nr;
+		vcpu->arch.exception.vector = nr;
 		vcpu->arch.exception.error_code = error_code;
 		vcpu->arch.exception.has_payload = has_payload;
 		vcpu->arch.exception.payload = payload;
 		if (!is_guest_mode(vcpu))
-			kvm_deliver_exception_payload(vcpu);
+			kvm_deliver_exception_payload(vcpu,
+						      &vcpu->arch.exception);
 		return;
 	}
 
 	/* to check exception */
-	prev_nr = vcpu->arch.exception.nr;
+	prev_nr = vcpu->arch.exception.vector;
 	if (prev_nr == DF_VECTOR) {
 		/* triple fault -> shutdown */
 		kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
@@ -679,7 +677,7 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
 		vcpu->arch.exception.pending = true;
 		vcpu->arch.exception.injected = false;
 		vcpu->arch.exception.has_error_code = true;
-		vcpu->arch.exception.nr = DF_VECTOR;
+		vcpu->arch.exception.vector = DF_VECTOR;
 		vcpu->arch.exception.error_code = 0;
 		vcpu->arch.exception.has_payload = false;
 		vcpu->arch.exception.payload = 0;
@@ -5015,25 +5013,24 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
 static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
 					       struct kvm_vcpu_events *events)
 {
+	struct kvm_queued_exception *ex = &vcpu->arch.exception;
+
 	process_nmi(vcpu);
 
 	if (kvm_check_request(KVM_REQ_SMI, vcpu))
 		process_smi(vcpu);
 
 	/*
-	 * In guest mode, payload delivery should be deferred,
-	 * so that the L1 hypervisor can intercept #PF before
-	 * CR2 is modified (or intercept #DB before DR6 is
-	 * modified under nVMX). Unless the per-VM capability,
-	 * KVM_CAP_EXCEPTION_PAYLOAD, is set, we may not defer the delivery of
-	 * an exception payload and handle after a KVM_GET_VCPU_EVENTS. Since we
-	 * opportunistically defer the exception payload, deliver it if the
-	 * capability hasn't been requested before processing a
-	 * KVM_GET_VCPU_EVENTS.
+	 * In guest mode, payload delivery should be deferred if the exception
+	 * will be intercepted by L1, e.g. KVM should not modifying CR2 if L1
+	 * intercepts #PF, ditto for DR6 and #DBs.  If the per-VM capability,
+	 * KVM_CAP_EXCEPTION_PAYLOAD, is not set, userspace may or may not
+	 * propagate the payload and so it cannot be safely deferred.  Deliver
+	 * the payload if the capability hasn't been requested.
 	 */
 	if (!vcpu->kvm->arch.exception_payload_enabled &&
-	    vcpu->arch.exception.pending && vcpu->arch.exception.has_payload)
-		kvm_deliver_exception_payload(vcpu);
+	    ex->pending && ex->has_payload)
+		kvm_deliver_exception_payload(vcpu, ex);
 
 	/*
 	 * The API doesn't provide the instruction length for software
@@ -5041,26 +5038,25 @@ static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
 	 * isn't advanced, we should expect to encounter the exception
 	 * again.
 	 */
-	if (kvm_exception_is_soft(vcpu->arch.exception.nr)) {
+	if (kvm_exception_is_soft(ex->vector)) {
 		events->exception.injected = 0;
 		events->exception.pending = 0;
 	} else {
-		events->exception.injected = vcpu->arch.exception.injected;
-		events->exception.pending = vcpu->arch.exception.pending;
+		events->exception.injected = ex->injected;
+		events->exception.pending = ex->pending;
 		/*
 		 * For ABI compatibility, deliberately conflate
 		 * pending and injected exceptions when
 		 * KVM_CAP_EXCEPTION_PAYLOAD isn't enabled.
 		 */
 		if (!vcpu->kvm->arch.exception_payload_enabled)
-			events->exception.injected |=
-				vcpu->arch.exception.pending;
+			events->exception.injected |= ex->pending;
 	}
-	events->exception.nr = vcpu->arch.exception.nr;
-	events->exception.has_error_code = vcpu->arch.exception.has_error_code;
-	events->exception.error_code = vcpu->arch.exception.error_code;
-	events->exception_has_payload = vcpu->arch.exception.has_payload;
-	events->exception_payload = vcpu->arch.exception.payload;
+	events->exception.nr = ex->vector;
+	events->exception.has_error_code = ex->has_error_code;
+	events->exception.error_code = ex->error_code;
+	events->exception_has_payload = ex->has_payload;
+	events->exception_payload = ex->payload;
 
 	events->interrupt.injected =
 		vcpu->arch.interrupt.injected && !vcpu->arch.interrupt.soft;
@@ -5132,7 +5128,7 @@ static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
 	process_nmi(vcpu);
 	vcpu->arch.exception.injected = events->exception.injected;
 	vcpu->arch.exception.pending = events->exception.pending;
-	vcpu->arch.exception.nr = events->exception.nr;
+	vcpu->arch.exception.vector = events->exception.nr;
 	vcpu->arch.exception.has_error_code = events->exception.has_error_code;
 	vcpu->arch.exception.error_code = events->exception.error_code;
 	vcpu->arch.exception.has_payload = events->exception_has_payload;
@@ -9718,7 +9714,7 @@ int kvm_check_nested_events(struct kvm_vcpu *vcpu)
 
 static void kvm_inject_exception(struct kvm_vcpu *vcpu)
 {
-	trace_kvm_inj_exception(vcpu->arch.exception.nr,
+	trace_kvm_inj_exception(vcpu->arch.exception.vector,
 				vcpu->arch.exception.has_error_code,
 				vcpu->arch.exception.error_code,
 				vcpu->arch.exception.injected);
@@ -9790,12 +9786,12 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit)
 		 * describe the behavior of General Detect #DBs, which are
 		 * fault-like.  They do _not_ set RF, a la code breakpoints.
 		 */
-		if (exception_type(vcpu->arch.exception.nr) == EXCPT_FAULT)
+		if (exception_type(vcpu->arch.exception.vector) == EXCPT_FAULT)
 			__kvm_set_rflags(vcpu, kvm_get_rflags(vcpu) |
 					     X86_EFLAGS_RF);
 
-		if (vcpu->arch.exception.nr == DB_VECTOR) {
-			kvm_deliver_exception_payload(vcpu);
+		if (vcpu->arch.exception.vector == DB_VECTOR) {
+			kvm_deliver_exception_payload(vcpu, &vcpu->arch.exception);
 			if (vcpu->arch.dr7 & DR7_GD) {
 				vcpu->arch.dr7 &= ~DR7_GD;
 				kvm_update_dr7(vcpu);