| Message ID | 1600712588-9514-3-git-send-email-michael.christie@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | vhost scsi: fixes and cleanups | expand |
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 <michael.christie@oracle.com> > --- > 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,
On 2020-09-21 11:23, Mike Christie wrote: > +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; > +} Has it been considered changing the body of this function into "return vq->avail && vq->desc && vq->used && vhost_vq_access_ok(vq)"? I'm concerned otherwise one or another build bot will suggest to make that change. Thanks, Bart.
> On Sep 21, 2020, at 9:45 PM, Bart Van Assche <bvanassche@acm.org> wrote: > > On 2020-09-21 11:23, Mike Christie wrote: >> +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; >> +} > > Has it been considered changing the body of this function into > "return vq->avail && vq->desc && vq->used && vhost_vq_access_ok(vq)"? I'm If we do not go the VHOST_SET_VRING_ENABLE route, then I'll do what you suggest. > concerned otherwise one or another build bot will suggest to make that > change.
On 9/21/20 9:02 PM, Jason Wang wrote: > > 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 <michael.christie@oracle.com> >> --- >> 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. It looks like I can make that work. Some questions: 1. Do you mean a generic VHOST_SET_VRING_ENABLE or a SCSI specific one VHOST_SCSI_SET_VRING_ENABLE? 2. I can see the VHOST_VDPA_SET_VRING_ENABLE kernel code and the vhost_set_vring_enable qemu code, so I have an idea of how it should work for vhost scsi. However, I'm not sure the requirements for a generic VHOST_SET_VRING_ENABLE if that is what you meant. I could not find it in the spec either. Could you send me a pointer to the section? For example, for vhost-net we seem to enable a device in the VHOST_NET_SET_BACKEND ioctl, so I'm not sure what behavior should be or needs to be implemented for net and vsock.
On 2020/9/24 上午3:12, Mike Christie wrote: > On 9/21/20 9:02 PM, Jason Wang wrote: >> 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 <michael.christie@oracle.com> >>> --- >>> 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. > It looks like I can make that work. Some questions: > > 1. Do you mean a generic VHOST_SET_VRING_ENABLE or a SCSI specific one VHOST_SCSI_SET_VRING_ENABLE? It would be better if we can make it generic. > > 2. I can see the VHOST_VDPA_SET_VRING_ENABLE kernel code and the vhost_set_vring_enable qemu code, so I have an idea of how it should work for vhost scsi. However, I'm not sure the requirements for a generic VHOST_SET_VRING_ENABLE if that is what you meant. I could not find it in the spec either. Could you send me a pointer to the section? In the spec, for PCI, it's the queue_enable for modern device. > > For example, for vhost-net we seem to enable a device in the VHOST_NET_SET_BACKEND ioctl, so I'm not sure what behavior should be or needs to be implemented for net and vsock. Yes, but VHOST_NET_SET_BACKEND is for the whole device not a specific virtqueue. Thanks >
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); + 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,
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 <michael.christie@oracle.com> --- drivers/vhost/vhost.c | 9 +++++++++ drivers/vhost/vhost.h | 1 + 2 files changed, 10 insertions(+)