2022-03-16 05:38:32

by Longpeng(Mike)

Subject: [PATCH v2 3/3] vdpa: support exposing the count of vqs to userspace

From: Longpeng <[email protected]>

- GET_VQS_COUNT: the count of virtqueues that exposed

Signed-off-by: Longpeng <[email protected]>
---
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 0c82eb5..69b3f05 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -370,6 +370,16 @@ 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)
{
@@ -510,6 +520,9 @@ 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 bc74e95..5d99e7c 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
--
1.8.3.1

2022-03-17 04:04:18

by Stefano Garzarella

Subject: Re: [PATCH v2 3/3] vdpa: support exposing the count of vqs to userspace

On Tue, Mar 15, 2022 at 11:25:53AM +0800, Longpeng(Mike) wrote:
>From: Longpeng <[email protected]>
>
>- GET_VQS_COUNT: the count of virtqueues that exposed
>
>Signed-off-by: Longpeng <[email protected]>
>---
> 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 0c82eb5..69b3f05 100644
>--- a/drivers/vhost/vdpa.c
>+++ b/drivers/vhost/vdpa.c
>@@ -370,6 +370,16 @@ 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)
> {
>@@ -510,6 +520,9 @@ 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 bc74e95..5d99e7c 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)

I'd prefer VHOST_VDPA_GET_NUM_QUEUES, since we use "num_queues" also in
the spec [1].

But I'm fine also with this:

Reviewed-by: Stefano Garzarella <[email protected]>

[1]
https://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.html#x1-1120003