# Re: \[PATCH 07/17\] vhost scsi: support delayed IO vq creation

- From: Jason Wang \<hidden\>
- Date: 2020-10-26 03:52:01 
- List: virtualization
- Page: https://ratatoskr.run/virtualization/2020/10/6741071
- Thread: https://ratatoskr.run/linux-scsi/2020/10/6741004/t.md

```text

On 2020/10/22 上午8:34, Mike Christie wrote:
> Each vhost-scsi device will need a evt and ctl queue, but the number
> of IO queues depends on whatever the user has configured in userspace.
> This patch has vhost-scsi create the evt, ctl and one IO vq at device
> open time. We then create the other IO vqs when userspace starts to
> set them up. We still waste some mem on the vq and scsi vq structs,
> but we don't waste mem on iovec related arrays and for later patches
> we know which queues are used by the dev->nvqs value.
>
> Signed-off-by: Mike Christie <michael.christie@oracle.com>
> ---
>   drivers/vhost/scsi.c | 19 +++++++++++++++----
>   1 file changed, 15 insertions(+), 4 deletions(-)


Not familiar with SCSI. But I wonder if it could behave like vhost-net.

E.g userspace should known the number of virtqueues so it can just open and close multiple vhost-scsi file descriptors.

Thanks

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```