diff options
| author | Avi Kivity <avi@qumranet.com> | 2007-03-07 13:05:38 +0200 |
|---|---|---|
| committer | Avi Kivity <avi@qumranet.com> | 2007-05-03 10:52:24 +0300 |
| commit | 07c45a366d89f8eaec5d9890e810171b408f9a52 (patch) | |
| tree | 2f54f8c4ba795a1432ee6ac2e8042a472b87550a | |
| parent | 1961d276c877b99f5f16aaf36377c75e0e191c3a (diff) | |
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: Avi Kivity <avi@qumranet.com>
| -rw-r--r-- | drivers/kvm/kvm_main.c | 8 | ||||
| -rw-r--r-- | include/linux/kvm.h | 4 |
2 files changed, 11 insertions, 1 deletions
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index df85f5f6548..cba0b87c34e 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -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: ; } diff --git a/include/linux/kvm.h b/include/linux/kvm.h index c0d10cd8088..dad90816cad 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -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 |