1 files changed, 168 insertions, 15 deletions

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index ba7f43a4459e..205998c141fb 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -346,6 +346,17 @@ static void kvm_free_physmem(struct kvm *kvm)
                 kvm_free_physmem_slot(&kvm->memslots[i], NULL);
 }
 
+static void free_pio_guest_pages(struct kvm_vcpu *vcpu)
+{
+        int i;
+
+        for (i = 0; i < 2; ++i)
+                if (vcpu->pio.guest_pages[i]) {
+                        __free_page(vcpu->pio.guest_pages[i]);
+                        vcpu->pio.guest_pages[i] = NULL;
+                }
+}
+
 static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
 {
         if (!vcpu->vmcs)
@@ -357,6 +368,9 @@ static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
         kvm_arch_ops->vcpu_free(vcpu);
         free_page((unsigned long)vcpu->run);
         vcpu->run = NULL;
+        free_page((unsigned long)vcpu->pio_data);
+        vcpu->pio_data = NULL;
+        free_pio_guest_pages(vcpu);
 }
 
 static void kvm_free_vcpus(struct kvm *kvm)
@@ -1550,44 +1564,168 @@ void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
 
-static void complete_pio(struct kvm_vcpu *vcpu)
+static int pio_copy_data(struct kvm_vcpu *vcpu)
 {
-        struct kvm_io *io = &vcpu->run->io;
+        void *p = vcpu->pio_data;
+        void *q;
+        unsigned bytes;
+        int nr_pages = vcpu->pio.guest_pages[1] ? 2 : 1;
+
+        kvm_arch_ops->vcpu_put(vcpu);
+        q = vmap(vcpu->pio.guest_pages, nr_pages, VM_READ|VM_WRITE,
+                 PAGE_KERNEL);
+        if (!q) {
+                kvm_arch_ops->vcpu_load(vcpu);
+                free_pio_guest_pages(vcpu);
+                return -ENOMEM;
+        }
+        q += vcpu->pio.guest_page_offset;
+        bytes = vcpu->pio.size * vcpu->pio.cur_count;
+        if (vcpu->pio.in)
+                memcpy(q, p, bytes);
+        else
+                memcpy(p, q, bytes);
+        q -= vcpu->pio.guest_page_offset;
+        vunmap(q);
+        kvm_arch_ops->vcpu_load(vcpu);
+        free_pio_guest_pages(vcpu);
+        return 0;
+}
+
+static int complete_pio(struct kvm_vcpu *vcpu)
+{
+        struct kvm_pio_request *io = &vcpu->pio;
         long delta;
+        int r;
 
         kvm_arch_ops->cache_regs(vcpu);
 
         if (!io->string) {
-                if (io->direction == KVM_EXIT_IO_IN)
-                        memcpy(&vcpu->regs[VCPU_REGS_RAX], &io->value,
+                if (io->in)
+                        memcpy(&vcpu->regs[VCPU_REGS_RAX], vcpu->pio_data,
                                io->size);
         } else {
+                if (io->in) {
+                        r = pio_copy_data(vcpu);
+                        if (r) {
+                                kvm_arch_ops->cache_regs(vcpu);
+                                return r;
+                        }
+                }
+
                 delta = 1;
                 if (io->rep) {
-                        delta *= io->count;
+                        delta *= io->cur_count;
                         /*
                          * The size of the register should really depend on
                          * current address size.
                          */
                         vcpu->regs[VCPU_REGS_RCX] -= delta;
                 }
-                if (io->string_down)
+                if (io->down)
                         delta = -delta;
                 delta *= io->size;
-                if (io->direction == KVM_EXIT_IO_IN)
+                if (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);
+        io->count -= io->cur_count;
+        io->cur_count = 0;
+
+        if (!io->count)
+                kvm_arch_ops->skip_emulated_instruction(vcpu);
+        return 0;
 }
 
+int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
+                  int size, unsigned long count, int string, int down,
+                  gva_t address, int rep, unsigned port)
+{
+        unsigned now, in_page;
+        int i;
+        int nr_pages = 1;
+        struct page *page;
+
+        vcpu->run->exit_reason = KVM_EXIT_IO;
+        vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
+        vcpu->run->io.size = size;
+        vcpu->run->io.data_offset = KVM_PIO_PAGE_OFFSET * PAGE_SIZE;
+        vcpu->run->io.count = count;
+        vcpu->run->io.port = port;
+        vcpu->pio.count = count;
+        vcpu->pio.cur_count = count;
+        vcpu->pio.size = size;
+        vcpu->pio.in = in;
+        vcpu->pio.string = string;
+        vcpu->pio.down = down;
+        vcpu->pio.guest_page_offset = offset_in_page(address);
+        vcpu->pio.rep = rep;
+
+        if (!string) {
+                kvm_arch_ops->cache_regs(vcpu);
+                memcpy(vcpu->pio_data, &vcpu->regs[VCPU_REGS_RAX], 4);
+                kvm_arch_ops->decache_regs(vcpu);
+                return 0;
+        }
+
+        if (!count) {
+                kvm_arch_ops->skip_emulated_instruction(vcpu);
+                return 1;
+        }
+
+        now = min(count, PAGE_SIZE / size);
+
+        if (!down)
+                in_page = PAGE_SIZE - offset_in_page(address);
+        else
+                in_page = offset_in_page(address) + size;
+        now = min(count, (unsigned long)in_page / size);
+        if (!now) {
+                /*
+                 * String I/O straddles page boundary.  Pin two guest pages
+                 * so that we satisfy atomicity constraints.  Do just one
+                 * transaction to avoid complexity.
+                 */
+                nr_pages = 2;
+                now = 1;
+        }
+        if (down) {
+                /*
+                 * String I/O in reverse.  Yuck.  Kill the guest, fix later.
+                 */
+                printk(KERN_ERR "kvm: guest string pio down\n");
+                inject_gp(vcpu);
+                return 1;
+        }
+        vcpu->run->io.count = now;
+        vcpu->pio.cur_count = now;
+
+        for (i = 0; i < nr_pages; ++i) {
+                spin_lock(&vcpu->kvm->lock);
+                page = gva_to_page(vcpu, address + i * PAGE_SIZE);
+                if (page)
+                        get_page(page);
+                vcpu->pio.guest_pages[i] = page;
+                spin_unlock(&vcpu->kvm->lock);
+                if (!page) {
+                        inject_gp(vcpu);
+                        free_pio_guest_pages(vcpu);
+                        return 1;
+                }
+        }
+
+        if (!vcpu->pio.in)
+                return pio_copy_data(vcpu);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(kvm_setup_pio);
+
 static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
         int r;
@@ -1602,9 +1740,11 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
         vcpu->cr8 = kvm_run->cr8;
 
         if (kvm_run->io_completed) {
-                if (vcpu->pio_pending)
-                        complete_pio(vcpu);
-                else {
+                if (vcpu->pio.cur_count) {
+                        r = complete_pio(vcpu);
+                        if (r)
+                                goto out;
+                } else {
                         memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
                         vcpu->mmio_read_completed = 1;
                 }
@@ -1620,6 +1760,7 @@ static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 
         r = kvm_arch_ops->run(vcpu, kvm_run);
 
+out:
         if (vcpu->sigset_active)
                 sigprocmask(SIG_SETMASK, &sigsaved, NULL);
 
@@ -1995,9 +2136,12 @@ static struct page *kvm_vcpu_nopage(struct vm_area_struct *vma,
 
         *type = VM_FAULT_MINOR;
         pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
-        if (pgoff != 0)
+        if (pgoff == 0)
+                page = virt_to_page(vcpu->run);
+        else if (pgoff == KVM_PIO_PAGE_OFFSET)
+                page = virt_to_page(vcpu->pio_data);
+        else
                 return NOPAGE_SIGBUS;
-        page = virt_to_page(vcpu->run);
         get_page(page);
         return page;
 }
@@ -2094,6 +2238,12 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
                 goto out_unlock;
         vcpu->run = page_address(page);
 
+        page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+        r = -ENOMEM;
+        if (!page)
+                goto out_free_run;
+        vcpu->pio_data = page_address(page);
+
         vcpu->host_fx_image = (char*)ALIGN((hva_t)vcpu->fx_buf,
                                            FX_IMAGE_ALIGN);
         vcpu->guest_fx_image = vcpu->host_fx_image + FX_IMAGE_SIZE;
@@ -2123,6 +2273,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
 
 out_free_vcpus:
         kvm_free_vcpu(vcpu);
+out_free_run:
+        free_page((unsigned long)vcpu->run);
+        vcpu->run = NULL;
 out_unlock:
         mutex_unlock(&vcpu->mutex);
 out:
@@ -2491,7 +2644,7 @@ static long kvm_dev_ioctl(struct file *filp,
                 r = -EINVAL;
                 if (arg)
                         goto out;
-                r = PAGE_SIZE;
+                r = 2 * PAGE_SIZE;
                 break;
         default:
                 ;