KVM: In-kernel string pio write support

Add string pio write support to support some version of Windows.

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index df9c05e9b34ea8c0a97d366de919636ba21e19ee..1be510b657fd4c50557d0b70fd97f1eb30972a63 100644 (file)
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1760,18 +1760,35 @@ static int complete_pio(struct kvm_vcpu *vcpu)
        return 0;
 }
 
-void kernel_pio(struct kvm_io_device *pio_dev, struct kvm_vcpu *vcpu)
+static void kernel_pio(struct kvm_io_device *pio_dev,
+                      struct kvm_vcpu *vcpu,
+                      void *pd)
 {
        /* TODO: String I/O for in kernel device */
 
        if (vcpu->pio.in)
                kvm_iodevice_read(pio_dev, vcpu->pio.port,
                                  vcpu->pio.size,
-                                 vcpu->pio_data);
+                                 pd);
        else
                kvm_iodevice_write(pio_dev, vcpu->pio.port,
                                   vcpu->pio.size,
-                                  vcpu->pio_data);
+                                  pd);
+}
+
+static void pio_string_write(struct kvm_io_device *pio_dev,
+                            struct kvm_vcpu *vcpu)
+{
+       struct kvm_pio_request *io = &vcpu->pio;
+       void *pd = vcpu->pio_data;
+       int i;
+
+       for (i = 0; i < io->cur_count; i++) {
+               kvm_iodevice_write(pio_dev, io->port,
+                                  io->size,
+                                  pd);
+               pd += io->size;
+       }
 }
 
 int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
@@ -1779,7 +1796,7 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
                  gva_t address, int rep, unsigned port)
 {
        unsigned now, in_page;
-       int i;
+       int i, ret = 0;
        int nr_pages = 1;
        struct page *page;
        struct kvm_io_device *pio_dev;
@@ -1806,15 +1823,12 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
                memcpy(vcpu->pio_data, &vcpu->regs[VCPU_REGS_RAX], 4);
                kvm_arch_ops->decache_regs(vcpu);
                if (pio_dev) {
-                       kernel_pio(pio_dev, vcpu);
+                       kernel_pio(pio_dev, vcpu, vcpu->pio_data);
                        complete_pio(vcpu);
                        return 1;
                }
                return 0;
        }
-       /* TODO: String I/O for in kernel device */
-       if (pio_dev)
-               printk(KERN_ERR "kvm_setup_pio: no string io support\n");
 
        if (!count) {
                kvm_arch_ops->skip_emulated_instruction(vcpu);
@@ -1862,9 +1876,21 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
                }
        }
 
-       if (!vcpu->pio.in)
-               return pio_copy_data(vcpu);
-       return 0;
+       if (!vcpu->pio.in) {
+               /* string PIO write */
+               ret = pio_copy_data(vcpu);
+               if (ret >= 0 && pio_dev) {
+                       pio_string_write(pio_dev, vcpu);
+                       complete_pio(vcpu);
+                       if (vcpu->pio.count == 0)
+                               ret = 1;
+               }
+       } else if (pio_dev)
+               printk(KERN_ERR "no string pio read support yet, "
+                      "port %x size %d count %ld\n",
+                       port, size, count);
+
+       return ret;
 }
 EXPORT_SYMBOL_GPL(kvm_setup_pio);