1 files changed, 46 insertions, 4 deletions

diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index c1ac106ace8c..52bd5f079df1 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -34,6 +34,9 @@ MODULE_LICENSE("GPL");
 static DEFINE_PER_CPU(struct vmcs *, vmxarea);
 static DEFINE_PER_CPU(struct vmcs *, current_vmcs);
 
+static struct page *vmx_io_bitmap_a;
+static struct page *vmx_io_bitmap_b;
+
 #ifdef CONFIG_X86_64
 #define HOST_IS_64 1
 #else
@@ -1129,8 +1132,8 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
         vmcs_write32(GUEST_PENDING_DBG_EXCEPTIONS, 0);
 
         /* I/O */
-        vmcs_write64(IO_BITMAP_A, 0);
-        vmcs_write64(IO_BITMAP_B, 0);
+        vmcs_write64(IO_BITMAP_A, page_to_phys(vmx_io_bitmap_a));
+        vmcs_write64(IO_BITMAP_B, page_to_phys(vmx_io_bitmap_b));
 
         guest_write_tsc(0);
 
@@ -1150,7 +1153,7 @@ static int vmx_vcpu_setup(struct kvm_vcpu *vcpu)
                                CPU_BASED_HLT_EXITING         /* 20.6.2 */
                                | CPU_BASED_CR8_LOAD_EXITING    /* 20.6.2 */
                                | CPU_BASED_CR8_STORE_EXITING   /* 20.6.2 */
-                               | CPU_BASED_UNCOND_IO_EXITING   /* 20.6.2 */
+                               | CPU_BASED_ACTIVATE_IO_BITMAP  /* 20.6.2 */
                                | CPU_BASED_MOV_DR_EXITING
                                | CPU_BASED_USE_TSC_OFFSETING   /* 21.3 */
                         );
@@ -2188,11 +2191,50 @@ static struct kvm_arch_ops vmx_arch_ops = {
 
 static int __init vmx_init(void)
 {
-        return kvm_init_arch(&vmx_arch_ops, THIS_MODULE);
+        void *iova;
+        int r;
+
+        vmx_io_bitmap_a = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+        if (!vmx_io_bitmap_a)
+                return -ENOMEM;
+
+        vmx_io_bitmap_b = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
+        if (!vmx_io_bitmap_b) {
+                r = -ENOMEM;
+                goto out;
+        }
+
+        /*
+         * Allow direct access to the PC debug port (it is often used for I/O
+         * delays, but the vmexits simply slow things down).
+         */
+        iova = kmap(vmx_io_bitmap_a);
+        memset(iova, 0xff, PAGE_SIZE);
+        clear_bit(0x80, iova);
+        kunmap(iova);
+
+        iova = kmap(vmx_io_bitmap_b);
+        memset(iova, 0xff, PAGE_SIZE);
+        kunmap(iova);
+
+        r = kvm_init_arch(&vmx_arch_ops, THIS_MODULE);
+        if (r)
+                goto out1;
+
+        return 0;
+
+out1:
+        __free_page(vmx_io_bitmap_b);
+out:
+        __free_page(vmx_io_bitmap_a);
+        return r;
 }
 
 static void __exit vmx_exit(void)
 {
+        __free_page(vmx_io_bitmap_b);
+        __free_page(vmx_io_bitmap_a);
+
         kvm_exit_arch();
 }