Hi Gavin,
> -----Original Message-----
> From: Gavin Hu [mailto:gavin...@arm.com]
> Sent: Wednesday, December 18, 2019 5:52 PM
> To: Jiang, Cheng1 <cheng1.ji...@intel.com>; maxime.coque...@redhat.com;
> Bie, Tiwei <tiwei....@intel.com>; Wang, Zhihong
> <zhihong.w...@intel.com>; Liu, Yong <yong....@intel.com>
> Cc: dev@dpdk.org; nd <n...@arm.com>
> Subject: RE: [dpdk-dev] [PATCH v2] net/virtio: packed ring notification data
> feature support
>
> Hi Jiang,
>
> > -----Original Message-----
> > From: dev <dev-boun...@dpdk.org> On Behalf Of Cheng Jiang
> > Sent: Wednesday, December 18, 2019 4:17 PM
> > To: maxime.coque...@redhat.com; tiwei....@intel.com;
> > zhihong.w...@intel.com; yong....@intel.com
> > Cc: dev@dpdk.org; Cheng Jiang <cheng1.ji...@intel.com>
> > Subject: [dpdk-dev] [PATCH v2] net/virtio: packed ring notification
> > data feature support
> >
> > This patch supports the feature that the driver passes extra data
> > (besides identifying the virtqueue) in its device notifications.
> Can the commit log be more specific about the extra data? Something like
> "expand the notification to include the avail index and avail wrap counter, if
> any"?
It makes more sense. I will add more specific commit log in the next version.
Thank you.
> >
> > Signed-off-by: Cheng Jiang <cheng1.ji...@intel.com>
> > ---
> >
> > v2:
> > * Removed rte_unused attribute in *hw.
> > * Added some comments on notify_data.
> >
> > drivers/net/virtio/virtio_ethdev.h | 3 ++-
> > drivers/net/virtio/virtio_pci.c | 27 +++++++++++++++++++++++++--
> > drivers/net/virtio/virtio_pci.h | 6 ++++++
> > 3 files changed, 33 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/virtio/virtio_ethdev.h
> > b/drivers/net/virtio/virtio_ethdev.h
> > index a10111758..cd8947656 100644
> > --- a/drivers/net/virtio/virtio_ethdev.h
> > +++ b/drivers/net/virtio/virtio_ethdev.h
> > @@ -36,7 +36,8 @@
> > 1ULL << VIRTIO_F_IN_ORDER | \
> > 1ULL << VIRTIO_F_RING_PACKED | \
> > 1ULL << VIRTIO_F_IOMMU_PLATFORM | \
> > - 1ULL << VIRTIO_F_ORDER_PLATFORM)
> > + 1ULL << VIRTIO_F_ORDER_PLATFORM | \
> > + 1ULL << VIRTIO_F_NOTIFICATION_DATA)
> >
> > #define VIRTIO_PMD_SUPPORTED_GUEST_FEATURES \
> > (VIRTIO_PMD_DEFAULT_GUEST_FEATURES | \
> > diff --git a/drivers/net/virtio/virtio_pci.c
> > b/drivers/net/virtio/virtio_pci.c index 4468e89cb..8b4e001a1 100644
> > --- a/drivers/net/virtio/virtio_pci.c
> > +++ b/drivers/net/virtio/virtio_pci.c
> > @@ -416,9 +416,32 @@ modern_del_queue(struct virtio_hw *hw, struct
> > virtqueue *vq) }
> >
> > static void
> > -modern_notify_queue(struct virtio_hw *hw __rte_unused, struct
> > virtqueue
> > *vq)
> > +modern_notify_queue(struct virtio_hw *hw, struct virtqueue *vq)
> > {
> > - rte_write16(vq->vq_queue_index, vq->notify_addr);
> > + uint32_t notify_data;
> > +
> > + if (!vtpci_with_feature(hw, VIRTIO_F_NOTIFICATION_DATA)) {
> > + rte_write16(vq->vq_queue_index, vq->notify_addr);
> > + return;
> > + }
> > +
> > + if (vtpci_with_feature(hw, VIRTIO_F_RING_PACKED)) {
> > + /*
> > + * Bit[0:15]: vq queue index
> > + * Bit[16:30]: avail index
> > + * Bit[31]: avail wrap counter
> > + */
> > + notify_data = ((((uint32_t)vq-
> > >vq_packed.used_wrap_counter << 15) |
> Why not do ' used_wrap_counter << 31' to be more straightforward and
> matches the above comment?
Sure, you're right. I'll modify the patch in the next version.
Thanks again.
Cheng
> > + vq->vq_avail_idx) << 16) | vq-
> > >vq_queue_index;
>
> > + } else {
> > + /*
> > + * Bit[0:15]: vq queue index
> > + * Bit[16:31]: avail index
> > + */
> > + notify_data = ((uint32_t)vq->vq_avail_idx << 16) |
> > + vq->vq_queue_index;
> > + }
> > + rte_write32(notify_data, vq->notify_addr);
> > }
> >
> > const struct virtio_pci_ops modern_ops = { diff --git
> > a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
> > index a38cb45ad..7433d2f08 100644
> > --- a/drivers/net/virtio/virtio_pci.h
> > +++ b/drivers/net/virtio/virtio_pci.h
> > @@ -135,6 +135,12 @@ struct virtnet_ctl;
> > */
> > #define VIRTIO_F_ORDER_PLATFORM 36
> >
> > +/*
> > + * This feature indicates that the driver passes extra data (besides
> > + * identifying the virtqueue) in its device notifications.
> > + */
> > +#define VIRTIO_F_NOTIFICATION_DATA 38
> > +
> > /* The Guest publishes the used index for which it expects an interrupt
> > * at the end of the avail ring. Host should ignore the avail->flags
> > field. */
> > /* The Host publishes the avail index for which it expects a kick
> > --
> > 2.17.1
