[PATCH 5/5] KVM: Fix the usage of X86EMUL_* values in x86.c

[Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx>]

pio_copy_data() and load|save_guest_segment_descriptor()
return X86EMUL_* values. Mixing up these values with 0, 1, ...
may produce unpridictable bugs.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx>
---
 arch/x86/kvm/x86.c |   27 +++++++++++++++------------
 1 files changed, 15 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 78b8ddb..67f8231 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3454,7 +3454,6 @@ int complete_pio(struct kvm_vcpu *vcpu)
 {
 	struct kvm_pio_request *io = &vcpu->arch.pio;
 	long delta;
-	int r;
 	unsigned long val;
 
 	if (!io->string) {
@@ -3465,9 +3464,9 @@ int complete_pio(struct kvm_vcpu *vcpu)
 		}
 	} else {
 		if (io->in) {
-			r = pio_copy_data(vcpu);
-			if (r)
-				return r;
+			int ret = pio_copy_data(vcpu);
+			if (ret != X86EMUL_CONTINUE)
+				return 1;
 		}
 
 		delta = 1;
@@ -3567,7 +3566,6 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, int in,
 		  gva_t address, int rep, unsigned port)
 {
 	unsigned now, in_page;
-	int ret = 0;
 
 	vcpu->run->exit_reason = KVM_EXIT_IO;
 	vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
@@ -3613,20 +3611,22 @@ int kvm_emulate_pio_string(struct kvm_vcpu *vcpu, int in,
 
 	if (!vcpu->arch.pio.in) {
 		/* string PIO write */
-		ret = pio_copy_data(vcpu);
+		int ret = pio_copy_data(vcpu);
 		if (ret == X86EMUL_PROPAGATE_FAULT) {
 			kvm_inject_gp(vcpu, 0);
 			return 1;
 		}
-		if (ret == 0 && !pio_string_write(vcpu)) {
+		if (ret == X86EMUL_UNHANDLEABLE)
+			return 1;
+		if (ret == X86EMUL_CONTINUE && !pio_string_write(vcpu)) {
 			complete_pio(vcpu);
 			if (vcpu->arch.pio.count == 0)
-				ret = 1;
+				return 1;
 		}
 	}
 	/* no string PIO read support yet */
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(kvm_emulate_pio_string);
 
@@ -4743,7 +4743,8 @@ int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
 	if (is_vm86_segment(vcpu, seg) || !is_protmode(vcpu))
 		return kvm_load_realmode_segment(vcpu, selector, seg);
 
-	if (load_guest_segment_descriptor(vcpu, selector, &seg_desc))
+	if (load_guest_segment_descriptor(vcpu, selector, &seg_desc)
+		!= X86EMUL_CONTINUE)
 		return 1;
 	seg_desct_to_kvm_desct(&seg_desc, selector, &kvm_seg);
 
@@ -4971,10 +4972,12 @@ int kvm_task_switch(struct kvm_vcpu *vcpu, u16 tss_selector, int reason)
 	/* FIXME: Handle errors. Failure to read either TSS or their
 	 * descriptors should generate a pagefault.
 	 */
-	if (load_guest_segment_descriptor(vcpu, tss_selector, &nseg_desc))
+	if (load_guest_segment_descriptor(vcpu, tss_selector, &nseg_desc)
+		!= X86EMUL_CONTINUE)
 		goto out;
 
-	if (load_guest_segment_descriptor(vcpu, old_tss_sel, &cseg_desc))
+	if (load_guest_segment_descriptor(vcpu, old_tss_sel, &cseg_desc)
+		!= X86EMUL_CONTINUE)
 		goto out;
 
 	if (reason != TASK_SWITCH_IRET) {
-- 
1.6.3.3

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