KVM: Don't require explicit indication of completion of mmio or pio

It is illegal not to return from a pio or mmio request without completing
it, as mmio or pio is an atomic operation.  Therefore, we can simplify
the userspace interface by avoiding the completion indication.

Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 22 insertions, 22 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index f267dbb52845..c8b8cfa332bb 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1237,8 +1237,10 @@ int emulate_instruction(struct kvm_vcpu *vcpu,
 	kvm_arch_ops->decache_regs(vcpu);
 	kvm_arch_ops->set_rflags(vcpu, emulate_ctxt.eflags);
 
-	if (vcpu->mmio_is_write)
+	if (vcpu->mmio_is_write) {
+		vcpu->mmio_needed = 0;
 		return EMULATE_DO_MMIO;
+	}
 
 	return EMULATE_DONE;
 }
@@ -1692,8 +1694,6 @@ static int complete_pio(struct kvm_vcpu *vcpu)
 			vcpu->regs[VCPU_REGS_RSI] += delta;
 	}
 
-	vcpu->run->io_completed = 0;
-
 	kvm_arch_ops->decache_regs(vcpu);
 
 	io->count -= io->cur_count;
@@ -1800,25 +1800,25 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 	/* re-sync apic's tpr */
 	vcpu->cr8 = kvm_run->cr8;
 
-	if (kvm_run->io_completed) {
-		if (vcpu->pio.cur_count) {
-			r = complete_pio(vcpu);
-			if (r)
-				goto out;
-		} else if (!vcpu->mmio_is_write) {
-			memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
-			vcpu->mmio_read_completed = 1;
-			vcpu->mmio_needed = 0;
-			r = emulate_instruction(vcpu, kvm_run,
-					    vcpu->mmio_fault_cr2, 0);
-			if (r == EMULATE_DO_MMIO) {
-				/*
-				 * Read-modify-write.  Back to userspace.
-				 */
-				kvm_run->exit_reason = KVM_EXIT_MMIO;
-				r = 0;
-				goto out;
-			}
+	if (vcpu->pio.cur_count) {
+		r = complete_pio(vcpu);
+		if (r)
+			goto out;
+	}
+
+	if (vcpu->mmio_needed) {
+		memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
+		vcpu->mmio_read_completed = 1;
+		vcpu->mmio_needed = 0;
+		r = emulate_instruction(vcpu, kvm_run,
+					vcpu->mmio_fault_cr2, 0);
+		if (r == EMULATE_DO_MMIO) {
+			/*
+			 * Read-modify-write.  Back to userspace.
+			 */
+			kvm_run->exit_reason = KVM_EXIT_MMIO;
+			r = 0;
+			goto out;
 		}
 	}