From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Date: Tue, 22 Sep 2020 02:02:15 +0000 Subject: Re: [PATCH 2/8] vhost: add helper to check if a vq has been setup Message-Id: List-Id: References: <1600712588-9514-1-git-send-email-michael.christie@oracle.com> <1600712588-9514-3-git-send-email-michael.christie@oracle.com> In-Reply-To: <1600712588-9514-3-git-send-email-michael.christie@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit To: Mike Christie , martin.petersen@oracle.com, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, mst@redhat.com, pbonzini@redhat.com, stefanha@redhat.com, virtualization@lists.linux-foundation.org On 2020/9/22 上午2:23, Mike Christie wrote: > This adds a helper check if a vq has been setup. The next patches > will use this when we move the vhost scsi cmd preallocation from per > session to per vq. In the per vq case, we only want to allocate cmds > for vqs that have actually been setup and not for all the possible > vqs. > > Signed-off-by: Mike Christie > --- > drivers/vhost/vhost.c | 9 +++++++++ > drivers/vhost/vhost.h | 1 + > 2 files changed, 10 insertions(+) > > diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c > index b45519c..5dd9eb1 100644 > --- a/drivers/vhost/vhost.c > +++ b/drivers/vhost/vhost.c > @@ -305,6 +305,15 @@ static void vhost_vring_call_reset(struct vhost_vring_call *call_ctx) > spin_lock_init(&call_ctx->ctx_lock); > } > > +bool vhost_vq_is_setup(struct vhost_virtqueue *vq) > +{ > + if (vq->avail && vq->desc && vq->used && vhost_vq_access_ok(vq)) > + return true; > + else > + return false; > +} > +EXPORT_SYMBOL_GPL(vhost_vq_is_setup); This is probably ok but I wonder maybe we should have something like what vDPA did (VHOST_SET_VRING_ENABLE) to match virtio 1.0 device definition. Thanks > + > static void vhost_vq_reset(struct vhost_dev *dev, > struct vhost_virtqueue *vq) > { > diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h > index 9032d3c..3d30b3d 100644 > --- a/drivers/vhost/vhost.h > +++ b/drivers/vhost/vhost.h > @@ -190,6 +190,7 @@ int vhost_get_vq_desc(struct vhost_virtqueue *, > struct vhost_log *log, unsigned int *log_num); > void vhost_discard_vq_desc(struct vhost_virtqueue *, int n); > > +bool vhost_vq_is_setup(struct vhost_virtqueue *vq); > int vhost_vq_init_access(struct vhost_virtqueue *); > int vhost_add_used(struct vhost_virtqueue *, unsigned int head, int len); > int vhost_add_used_n(struct vhost_virtqueue *, struct vring_used_elem *heads,