4 files changed, 50 insertions, 3 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 901b8d917b55..59cbc5b1d905 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -274,6 +274,7 @@ struct kvm_vcpu {
         int mmio_size;
         unsigned char mmio_data[8];
         gpa_t mmio_phys_addr;
+        int pio_pending;
 
         struct {
                 int active;
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 42be8a8f299d..ff8bcfee76e5 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1504,6 +1504,44 @@ void save_msrs(struct vmx_msr_entry *e, int n)
 }
 EXPORT_SYMBOL_GPL(save_msrs);
 
+static void complete_pio(struct kvm_vcpu *vcpu)
+{
+        struct kvm_io *io = &vcpu->run->io;
+        long delta;
+
+        kvm_arch_ops->cache_regs(vcpu);
+
+        if (!io->string) {
+                if (io->direction == KVM_EXIT_IO_IN)
+                        memcpy(&vcpu->regs[VCPU_REGS_RAX], &io->value,
+                               io->size);
+        } else {
+                delta = 1;
+                if (io->rep) {
+                        delta *= io->count;
+                        /*
+                         * The size of the register should really depend on
+                         * current address size.
+                         */
+                        vcpu->regs[VCPU_REGS_RCX] -= delta;
+                }
+                if (io->string_down)
+                        delta = -delta;
+                delta *= io->size;
+                if (io->direction == KVM_EXIT_IO_IN)
+                        vcpu->regs[VCPU_REGS_RDI] += delta;
+                else
+                        vcpu->regs[VCPU_REGS_RSI] += delta;
+        }
+
+        vcpu->pio_pending = 0;
+        vcpu->run->io_completed = 0;
+
+        kvm_arch_ops->decache_regs(vcpu);
+
+        kvm_arch_ops->skip_emulated_instruction(vcpu);
+}
+
 static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
         int r;
@@ -1518,9 +1556,13 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                 kvm_run->emulated = 0;
         }
 
-        if (kvm_run->mmio_completed) {
-                memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
-                vcpu->mmio_read_completed = 1;
+        if (kvm_run->io_completed) {
+                if (vcpu->pio_pending)
+                        complete_pio(vcpu);
+                else {
+                        memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
+                        vcpu->mmio_read_completed = 1;
+                }
         }
 
         vcpu->mmio_needed = 0;
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 6787f11738cf..c35b8c83bf3f 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -1037,6 +1037,7 @@ static int io_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         kvm_run->io.size = ((io_info & SVM_IOIO_SIZE_MASK) >> SVM_IOIO_SIZE_SHIFT);
         kvm_run->io.string = (io_info & SVM_IOIO_STR_MASK) != 0;
         kvm_run->io.rep = (io_info & SVM_IOIO_REP_MASK) != 0;
+        kvm_run->io.count = 1;
 
         if (kvm_run->io.string) {
                 unsigned addr_mask;
@@ -1056,6 +1057,7 @@ static int io_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                 }
         } else
                 kvm_run->io.value = vcpu->svm->vmcb->save.rax;
+        vcpu->pio_pending = 1;
         return 0;
 }
 
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index a721b60f7385..4d5f40fcb651 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1459,12 +1459,14 @@ static int handle_io(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
                 = (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_DF) != 0;
         kvm_run->io.rep = (exit_qualification & 32) != 0;
         kvm_run->io.port = exit_qualification >> 16;
+        kvm_run->io.count = 1;
         if (kvm_run->io.string) {
                 if (!get_io_count(vcpu, &kvm_run->io.count))
                         return 1;
                 kvm_run->io.address = vmcs_readl(GUEST_LINEAR_ADDRESS);
         } else
                 kvm_run->io.value = vcpu->regs[VCPU_REGS_RAX]; /* rax */
+        vcpu->pio_pending = 1;
         return 0;
 }