Re: [Qemu-devel] [PATCH v9 2/7] virtio-pmem: Add virtio pmem driver

Pankaj Gupta
2019-05-17T05:36:05Z

Hi Jakub,

>
> On 5/14/19 7:54 AM, Pankaj Gupta wrote:
> > + if (!list_empty(&vpmem->req_list)) {
> > + req_buf = list_first_entry(&vpmem->req_list,
> > + struct virtio_pmem_request, list);
> > + req_buf->wq_buf_avail = true;
> > + wake_up(&req_buf->wq_buf);
> > + list_del(&req_buf->list);
> Yes, this change is the right one, thank you!

Thank you for the confirmation.

>
> > + /*
> > + * If virtqueue_add_sgs returns -ENOSPC then req_vq virtual
> > + * queue does not have free descriptor. We add the request
> > + * to req_list and wait for host_ack to wake us up when free
> > + * slots are available.
> > + */
> > + while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req,
> > + GFP_ATOMIC)) == -ENOSPC) {
> > +
> > + dev_err(&vdev->dev, "failed to send command to virtio pmem" \
> > + "device, no free slots in the virtqueue\n");
> > + req->wq_buf_avail = false;
> > + list_add_tail(&req->list, &vpmem->req_list);
> > + spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
> > +
> > + /* A host response results in "host_ack" getting called */
> > + wait_event(req->wq_buf, req->wq_buf_avail);
> > + spin_lock_irqsave(&vpmem->pmem_lock, flags);
> > + }
> > + err1 = virtqueue_kick(vpmem->req_vq);
> > + spin_unlock_irqrestore(&vpmem->pmem_lock, flags);
> > +
> > + /*
> > + * virtqueue_add_sgs failed with error different than -ENOSPC, we can't
> > + * do anything about that.
> > + */
> > + if (err || !err1) {
> > + dev_info(&vdev->dev, "failed to send command to virtio pmem device\n");
> > + err = -EIO;
> > + } else {
> > + /* A host repsonse results in "host_ack" getting called */
> > + wait_event(req->host_acked, req->done);
> > + err = req->ret;
> > +I confirm that the failures I was facing with the `-ENOSPC` error path are
> > not present in v9.

Can I take it your reviewed/acked-by? or tested-by tag? for the virtio patch :)

Thank you,
Pankaj

>
> Best,
> Jakub Staron
>
>