Commit 07c45a36 authored by Avi Kivity's avatar Avi Kivity

KVM: Allow kernel to select size of mmap() buffer

This allows us to store offsets in the kernel/user kvm_run area, and be
sure that userspace has them mapped.  As offsets can be outside the
kvm_run struct, userspace has no way of knowing how much to mmap.
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 1961d276
......@@ -2436,7 +2436,7 @@ static long kvm_dev_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int r = -EINVAL;
long r = -EINVAL;
switch (ioctl) {
case KVM_GET_API_VERSION:
......@@ -2478,6 +2478,12 @@ static long kvm_dev_ioctl(struct file *filp,
*/
r = 0;
break;
case KVM_GET_VCPU_MMAP_SIZE:
r = -EINVAL;
if (arg)
goto out;
r = PAGE_SIZE;
break;
default:
;
}
......
......@@ -253,6 +253,10 @@ struct kvm_signal_mask {
* return is 1 (yes) or 0 (no, sorry).
*/
#define KVM_CHECK_EXTENSION _IO(KVMIO, 0x03)
/*
* Get size for mmap(vcpu_fd)
*/
#define KVM_GET_VCPU_MMAP_SIZE _IO(KVMIO, 0x04) /* in bytes */
/*
* ioctls for VM fds
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment