On Thu, Sep 26, 2019 at 04:35:18AM -0400, Michael S. Tsirkin wrote:

On Thu, Sep 26, 2019 at 12:54:27PM +0800, Tiwei Bie wrote:

[...]

quoted

diff --git a/include/uapi/linux/vhost.h b/include/uapi/linux/vhost.h
index 40d028eed645..5afbc2f08fa3 100644
--- a/include/uapi/linux/vhost.h
+++ b/include/uapi/linux/vhost.h

@@ -116,4 +116,12 @@
 #define VHOST_VSOCK_SET_GUEST_CID	_IOW(VHOST_VIRTIO, 0x60, __u64)
 #define VHOST_VSOCK_SET_RUNNING		_IOW(VHOST_VIRTIO, 0x61, int)
 
+/* VHOST_MDEV specific defines */
+
+#define VHOST_MDEV_SET_STATE	_IOW(VHOST_VIRTIO, 0x70, __u64)
+
+#define VHOST_MDEV_S_STOPPED	0
+#define VHOST_MDEV_S_RUNNING	1
+#define VHOST_MDEV_S_MAX	2
+
 #endif

So assuming we have an underlying device that behaves like virtio:

I think they are really good questions/suggestions. Thanks!

1. Should we use SET_STATUS maybe?

I like this idea. I will give it a try.

2. Do we want a reset ioctl?

I think it is helpful. If we use SET_STATUS, maybe we
can use it to support the reset.

3. Do we want ability to enable rings individually?

I will make it possible at least in the vhost layer.

4. Does device need to limit max ring size?
5. Does device need to limit max number of queues?

I think so. It's helpful to have ioctls to report the max
ring size and max number of queues.

Thanks!
Tiwei

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MST