KVM: x86: add kvm_fast_pio() to consolidate fast PIO code

Add kvm_fast_pio() to consolidate duplicate code in VMX and SVM.
Unexport kvm_fast_pio_in() and kvm_fast_pio_out().
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -1210,8 +1210,7 @@ int kvm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr);
 
 struct x86_emulate_ctxt;
 
-int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port);
-int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port);
+int kvm_fast_pio(struct kvm_vcpu *vcpu, int size, unsigned short port, int in);
 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu);
 int kvm_emulate_halt(struct kvm_vcpu *vcpu);
 int kvm_vcpu_halt(struct kvm_vcpu *vcpu);

arch/x86/kvm/svm.c

@@ -2640,7 +2640,7 @@ static int io_interception(struct vcpu_svm *svm)
 {
 	struct kvm_vcpu *vcpu = &svm->vcpu;
 	u32 io_info = svm->vmcb->control.exit_info_1; /* address size bug? */
-	int size, in, string, ret;
+	int size, in, string;
 	unsigned port;
 
 	++svm->vcpu.stat.io_exits;
@@ -2652,16 +2652,8 @@ static int io_interception(struct vcpu_svm *svm)
 	port = io_info >> 16;
 	size = (io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT;
 	svm->next_rip = svm->vmcb->control.exit_info_2;
-	ret = kvm_skip_emulated_instruction(&svm->vcpu);
 
-	/*
-	 * TODO: we might be squashing a KVM_GUESTDBG_SINGLESTEP-triggered
-	 * KVM_EXIT_DEBUG here.
-	 */
-	if (in)
-		return kvm_fast_pio_in(vcpu, size, port) && ret;
-	else
-		return kvm_fast_pio_out(vcpu, size, port) && ret;
+	return kvm_fast_pio(&svm->vcpu, size, port, in);
 }
 
 static int nmi_interception(struct vcpu_svm *svm)

arch/x86/kvm/vmx.c

@@ -6265,7 +6265,7 @@ static int handle_triple_fault(struct kvm_vcpu *vcpu)
 static int handle_io(struct kvm_vcpu *vcpu)
 {
 	unsigned long exit_qualification;
-	int size, in, string, ret;
+	int size, in, string;
 	unsigned port;
 
 	exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
@@ -6280,16 +6280,7 @@ static int handle_io(struct kvm_vcpu *vcpu)
 	size = (exit_qualification & 7) + 1;
 	in = (exit_qualification & 8) != 0;
 
-	ret = kvm_skip_emulated_instruction(vcpu);
-
-	/*
-	 * TODO: we might be squashing a KVM_GUESTDBG_SINGLESTEP-triggered
-	 * KVM_EXIT_DEBUG here.
-	 */
-	if (in)
-		return kvm_fast_pio_in(vcpu, size, port) && ret;
-	else
-		return kvm_fast_pio_out(vcpu, size, port) && ret;
+	return kvm_fast_pio(vcpu, size, port, in);
 }
 
 static void

arch/x86/kvm/x86.c

@@ -6061,7 +6061,8 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
 }
 EXPORT_SYMBOL_GPL(x86_emulate_instruction);
 
-int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port)
+static int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size,
+			    unsigned short port)
 {
 	unsigned long val = kvm_register_read(vcpu, VCPU_REGS_RAX);
 	int ret = emulator_pio_out_emulated(&vcpu->arch.emulate_ctxt,
@@ -6070,7 +6071,6 @@ int kvm_fast_pio_out(struct kvm_vcpu *vcpu, int size, unsigned short port)
 	vcpu->arch.pio.count = 0;
 	return ret;
 }
-EXPORT_SYMBOL_GPL(kvm_fast_pio_out);
 
 static int complete_fast_pio_in(struct kvm_vcpu *vcpu)
 {
@@ -6094,7 +6094,8 @@ static int complete_fast_pio_in(struct kvm_vcpu *vcpu)
 	return 1;
 }
 
-int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port)
+static int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size,
+			   unsigned short port)
 {
 	unsigned long val;
 	int ret;
@@ -6113,7 +6114,21 @@ int kvm_fast_pio_in(struct kvm_vcpu *vcpu, int size, unsigned short port)
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(kvm_fast_pio_in);
+
+int kvm_fast_pio(struct kvm_vcpu *vcpu, int size, unsigned short port, int in)
+{
+	int ret = kvm_skip_emulated_instruction(vcpu);
+
+	/*
+	 * TODO: we might be squashing a KVM_GUESTDBG_SINGLESTEP-triggered
+	 * KVM_EXIT_DEBUG here.
+	 */
+	if (in)
+		return kvm_fast_pio_in(vcpu, size, port) && ret;
+	else
+		return kvm_fast_pio_out(vcpu, size, port) && ret;
+}
+EXPORT_SYMBOL_GPL(kvm_fast_pio);
 
 static int kvmclock_cpu_down_prep(unsigned int cpu)
 {