[dpdk-dev] [PATCH v9 1/8] net/virtio: vring init for packed queues
Tiwei Bie
tiwei.bie at intel.com
Thu Oct 25 11:21:15 CEST 2018
On Wed, Oct 24, 2018 at 04:32:29PM +0200, Jens Freimann wrote:
> Add and initialize descriptor data structures.
>
> Signed-off-by: Jens Freimann <jfreimann at redhat.com>
> ---
> drivers/net/virtio/virtio_ethdev.c | 18 ++++----
> drivers/net/virtio/virtio_pci.h | 7 +++
> drivers/net/virtio/virtio_ring.h | 74 ++++++++++++++++++++++++++----
> drivers/net/virtio/virtqueue.h | 15 +++++-
> 4 files changed, 95 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index 730c41707..6130aef16 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -299,19 +299,21 @@ virtio_init_vring(struct virtqueue *vq)
>
> PMD_INIT_FUNC_TRACE();
>
> - /*
> - * Reinitialise since virtio port might have been stopped and restarted
> - */
Why above comments are removed?
> memset(ring_mem, 0, vq->vq_ring_size);
> - vring_init(vr, size, ring_mem, VIRTIO_PCI_VRING_ALIGN);
> + vring_init(vq->hw, vr, size, ring_mem, VIRTIO_PCI_VRING_ALIGN);
> +
> vq->vq_used_cons_idx = 0;
> vq->vq_desc_head_idx = 0;
> vq->vq_avail_idx = 0;
> vq->vq_desc_tail_idx = (uint16_t)(vq->vq_nentries - 1);
> vq->vq_free_cnt = vq->vq_nentries;
> memset(vq->vq_descx, 0, sizeof(struct vq_desc_extra) * vq->vq_nentries);
> -
> - vring_desc_init(vr->desc, size);
> + if (vtpci_packed_queue(vq->hw)) {
> + if (!vtpci_with_feature(vq->hw, VIRTIO_F_IN_ORDER))
> + vring_desc_init_packed(vq, size);
Don't we need to initialize descs in IN-ORDER case?
> + } else {
> + vring_desc_init_split(vr->desc, size);
> + }
>
> /*
> * Disable device(host) interrupting guest
> @@ -386,7 +388,7 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
> /*
> * Reserve a memzone for vring elements
> */
> - size = vring_size(vq_size, VIRTIO_PCI_VRING_ALIGN);
> + size = vring_size(hw, vq_size, VIRTIO_PCI_VRING_ALIGN);
> vq->vq_ring_size = RTE_ALIGN_CEIL(size, VIRTIO_PCI_VRING_ALIGN);
> PMD_INIT_LOG(DEBUG, "vring_size: %d, rounded_vring_size: %d",
> size, vq->vq_ring_size);
> @@ -489,7 +491,7 @@ virtio_init_queue(struct rte_eth_dev *dev, uint16_t vtpci_queue_idx)
> for (i = 0; i < vq_size; i++) {
> struct vring_desc *start_dp = txr[i].tx_indir;
>
> - vring_desc_init(start_dp, RTE_DIM(txr[i].tx_indir));
> + vring_desc_init_split(start_dp, RTE_DIM(txr[i].tx_indir));
>
> /* first indirect descriptor is always the tx header */
> start_dp->addr = txvq->virtio_net_hdr_mem
> diff --git a/drivers/net/virtio/virtio_pci.h b/drivers/net/virtio/virtio_pci.h
> index 58fdd3d45..c487d2be0 100644
> --- a/drivers/net/virtio/virtio_pci.h
> +++ b/drivers/net/virtio/virtio_pci.h
> @@ -113,6 +113,7 @@ struct virtnet_ctl;
>
> #define VIRTIO_F_VERSION_1 32
> #define VIRTIO_F_IOMMU_PLATFORM 33
> +#define VIRTIO_F_RING_PACKED 34
>
> /*
> * Some VirtIO feature bits (currently bits 28 through 31) are
> @@ -314,6 +315,12 @@ vtpci_with_feature(struct virtio_hw *hw, uint64_t bit)
> return (hw->guest_features & (1ULL << bit)) != 0;
> }
>
> +static inline int
> +vtpci_packed_queue(struct virtio_hw *hw)
> +{
> + return vtpci_with_feature(hw, VIRTIO_F_RING_PACKED);
> +}
> +
> /*
> * Function declaration from virtio_pci.c
> */
> diff --git a/drivers/net/virtio/virtio_ring.h b/drivers/net/virtio/virtio_ring.h
> index 9e3c2a015..e65da100b 100644
> --- a/drivers/net/virtio/virtio_ring.h
> +++ b/drivers/net/virtio/virtio_ring.h
> @@ -54,11 +54,38 @@ struct vring_used {
> struct vring_used_elem ring[0];
> };
>
> +/* For support of packed virtqueues in Virtio 1.1 the format of descriptors
> + * looks like this.
> + */
> +struct vring_desc_packed {
> + uint64_t addr;
> + uint32_t len;
> + uint16_t index;
s/index/id/
> + uint16_t flags;
> +} __attribute__ ((aligned(16)));
We don't need the "__attribute__ ((aligned(16)))" in descriptor
structure's definition.
> +
> +#define RING_EVENT_FLAGS_ENABLE 0x0
> +#define RING_EVENT_FLAGS_DISABLE 0x1
> +#define RING_EVENT_FLAGS_DESC 0x2
Please add an empty line here.
> +struct vring_packed_desc_event {
> + uint16_t desc_event_off_wrap;
> + uint16_t desc_event_flags;
> +};
> +
> struct vring {
> unsigned int num;
> - struct vring_desc *desc;
> - struct vring_avail *avail;
> - struct vring_used *used;
> + union {
> + struct vring_desc_packed *desc_packed;
> + struct vring_desc *desc;
> + };
> + union {
> + struct vring_avail *avail;
> + struct vring_packed_desc_event *driver_event;
> + };
> + union {
> + struct vring_used *used;
> + struct vring_packed_desc_event *device_event;
> + };
> };
>
We should define a new `vring` structure for packed ring.
Thanks
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