[RFC 2/3] vdpa: support exposing the count of vqs to userspace

Longpeng(Mike)
2022-01-17T09:29:38Z

- GET_VQS_COUNT: the count of virtqueues that exposed

Signed-off-by: Longpeng <longpeng2@huawei.com>
---
drivers/vhost/vdpa.c | 13 +++++++++++++
include/uapi/linux/vhost.h | 3 +++
2 files changed, 16 insertions(+)

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 1eea14a4ea56..c1074278fc6b 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -369,6 +369,16 @@ static long vhost_vdpa_get_config_size(struct vhost_vdpa *v, u32 __user *argp)
return 0;
}

+static long vhost_vdpa_get_vqs_count(struct vhost_vdpa *v, u32 __user *argp)
+{
+ struct vdpa_device *vdpa = v->vdpa;
+
+ if (copy_to_user(argp, &vdpa->nvqs, sizeof(vdpa->nvqs)))
+ return -EFAULT;
+
+ return 0;
+}
+
static long vhost_vdpa_vring_ioctl(struct vhost_vdpa *v, unsigned int cmd,
void __user *argp)
{
@@ -509,6 +519,9 @@ static long vhost_vdpa_unlocked_ioctl(struct file *filep,
case VHOST_VDPA_GET_CONFIG_SIZE:
r = vhost_vdpa_get_config_size(v, argp);
break;
+ case VHOST_VDPA_GET_VQS_COUNT:
+ r = vhost_vdpa_get_vqs_count(v, argp);
+ break;
default:
r = vhost_dev_ioctl(&v->vdev, cmd, argp);
if (r == -ENOIOCTLCMD)
diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index bc74e95a273a..5d99e7c242a2 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h
@@ -154,4 +154,7 @@
/* Get the config size */
#define VHOST_VDPA_GET_CONFIG_SIZE _IOR(VHOST_VIRTIO, 0x79, __u32)

+/* Get the count of all virtqueues */
+#define VHOST_VDPA_GET_VQS_COUNT _IOR(VHOST_VIRTIO, 0x80, __u32)
+
#endif
--
2.23.0