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;
                 }
         }