KVM: Limit vcpu mmap size to one page on non-x86

The second page is only needed on archs that support pio.

Noted by Carsten Otte.

Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 121e65cccc58132f5aac387058305d4b599ce124..7972e3aa2caedd85f47ed7a8aef7e9ff1b455918 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1061,7 +1061,10 @@ static long kvm_dev_ioctl(struct file *filp,
                r = -EINVAL;
                if (arg)
                        goto out;
-               r = 2 * PAGE_SIZE;
+               r = PAGE_SIZE;     /* struct kvm_run */
+#ifdef CONFIG_X86
+               r += PAGE_SIZE;    /* pio data page */
+#endif
                break;
        default:
                return kvm_arch_dev_ioctl(filp, ioctl, arg);