> -----Original Message-----
> From: Liu, Yong <yong....@intel.com>
> Sent: Thursday, June 18, 2020 1:51 PM
> To: Fu, Patrick <patrick...@intel.com>
> Cc: Fu, Patrick <patrick...@intel.com>; Jiang, Cheng1
> <cheng1.ji...@intel.com>; Liang, Cunming <cunming.li...@intel.com>;
> dev@dpdk.org; maxime.coque...@redhat.com; Xia, Chenbo
> <chenbo....@intel.com>; Wang, Zhihong <zhihong.w...@intel.com>; Ye,
> Xiaolong <xiaolong...@intel.com>
> Subject: RE: [dpdk-dev] [PATCH v1 1/2] vhost: introduce async data path
> registration API
>
> Thanks, Patrick. So comments are inline.
>
> > -----Original Message-----
> > From: dev <dev-boun...@dpdk.org> On Behalf Of patrick...@intel.com
> > Sent: Thursday, June 11, 2020 6:02 PM
> > To: dev@dpdk.org; maxime.coque...@redhat.com; Xia, Chenbo
> > <chenbo....@intel.com>; Wang, Zhihong <zhihong.w...@intel.com>; Ye,
> > Xiaolong <xiaolong...@intel.com>
> > Cc: Fu, Patrick <patrick...@intel.com>; Jiang, Cheng1
> > <cheng1.ji...@intel.com>; Liang, Cunming <cunming.li...@intel.com>
> > Subject: [dpdk-dev] [PATCH v1 1/2] vhost: introduce async data path
> > registration API
> >
> > From: Patrick <patrick...@intel.com>
> >
> > This patch introduces registration/un-registration APIs for async data
> > path together with all required data structures and DMA callback
> > function proto-types.
> >
> > Signed-off-by: Patrick <patrick...@intel.com>
> > ---
> > lib/librte_vhost/Makefile | 3 +-
> > lib/librte_vhost/rte_vhost.h | 1 +
> > lib/librte_vhost/rte_vhost_async.h | 134
> > +++++++++++++++++++++++++++++++++++++
> > lib/librte_vhost/socket.c | 20 ++++++
> > lib/librte_vhost/vhost.c | 74 +++++++++++++++++++-
> > lib/librte_vhost/vhost.h | 30 ++++++++-
> > lib/librte_vhost/vhost_user.c | 28 ++++++--
> > 7 files changed, 283 insertions(+), 7 deletions(-) create mode
> > 100644 lib/librte_vhost/rte_vhost_async.h
> >
> > diff --git a/lib/librte_vhost/Makefile b/lib/librte_vhost/Makefile
> > index e592795..3aed094 100644
> > --- a/lib/librte_vhost/Makefile
> > +++ b/lib/librte_vhost/Makefile
> > @@ -41,7 +41,8 @@ SRCS-$(CONFIG_RTE_LIBRTE_VHOST) := fd_man.c
> iotlb.c
> > socket.c vhost.c \
> > vhost_user.c virtio_net.c vdpa.c
> >
> > # install includes
> > -SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_vhost.h
> rte_vdpa.h
> > +SYMLINK-$(CONFIG_RTE_LIBRTE_VHOST)-include += rte_vhost.h
> rte_vdpa.h
> > \
> > + rte_vhost_async.h
> >
> Hi Patrick,
> Please also update meson build for newly added file.
>
> Thanks,
> Marvin
>
> > # only compile vhost crypto when cryptodev is enabled ifeq
> > ($(CONFIG_RTE_LIBRTE_CRYPTODEV),y)
> > diff --git a/lib/librte_vhost/rte_vhost.h
> > b/lib/librte_vhost/rte_vhost.h index d43669f..cec4d07 100644
> > --- a/lib/librte_vhost/rte_vhost.h
> > +++ b/lib/librte_vhost/rte_vhost.h
> > @@ -35,6 +35,7 @@
> > #define RTE_VHOST_USER_EXTBUF_SUPPORT (1ULL << 5)
> > /* support only linear buffers (no chained mbufs) */
> > #define RTE_VHOST_USER_LINEARBUF_SUPPORT (1ULL << 6)
> > +#define RTE_VHOST_USER_ASYNC_COPY (1ULL << 7)
> >
> > /** Protocol features. */
> > #ifndef VHOST_USER_PROTOCOL_F_MQ
> > diff --git a/lib/librte_vhost/rte_vhost_async.h
> > b/lib/librte_vhost/rte_vhost_async.h
> > new file mode 100644
> > index 0000000..82f2ebe
> > --- /dev/null
> > +++ b/lib/librte_vhost/rte_vhost_async.h
> > @@ -0,0 +1,134 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright(c) 2018 Intel Corporation */
>
> s/2018/2020/
>
> > +
> > +#ifndef _RTE_VHOST_ASYNC_H_
> > +#define _RTE_VHOST_ASYNC_H_
> > +
> > +#include "rte_vhost.h"
> > +
> > +/**
> > + * iovec iterator
> > + */
> > +struct iov_it {
> > + /** offset to the first byte of interesting data */
> > + size_t offset;
> > + /** total bytes of data in this iterator */
> > + size_t count;
> > + /** pointer to the iovec array */
> > + struct iovec *iov;
> > + /** number of iovec in this iterator */
> > + unsigned long nr_segs;
> > +};
>
> Patrick,
> I think structure named as "it" is too generic for understanding, please use
> more meaningful name like "iov_iter".
>
> > +
> > +/**
> > + * dma transfer descriptor pair
> > + */
> > +struct dma_trans_desc {
> > + /** source memory iov_it */
> > + struct iov_it *src;
> > + /** destination memory iov_it */
> > + struct iov_it *dst;
> > +};
> > +
>
> This series patch named as sync copy, and dma is just one async copy
> method which underneath hardware supplied.
> IMHO, structure is better to named as "async_copy_desc" which matched the
> overall concept.
>
> > +/**
> > + * dma transfer status
> > + */
> > +struct dma_trans_status {
> > + /** An array of application specific data for source memory */
> > + uintptr_t *src_opaque_data;
> > + /** An array of application specific data for destination memory */
> > + uintptr_t *dst_opaque_data;
> > +};
> > +
> Same as pervious comment.
>
> > +/**
> > + * dma operation callbacks to be implemented by applications */
> > +struct rte_vhost_async_channel_ops {
> > + /**
> > + * instruct a DMA channel to perform copies for a batch of packets
> > + *
> > + * @param vid
> > + * id of vhost device to perform data copies
> > + * @param queue_id
> > + * queue id to perform data copies
> > + * @param descs
> > + * an array of DMA transfer memory descriptors
> > + * @param opaque_data
> > + * opaque data pair sending to DMA engine
> > + * @param count
> > + * number of elements in the "descs" array
> > + * @return
> > + * -1 on failure, number of descs processed on success
> > + */
> > + int (*transfer_data)(int vid, uint16_t queue_id,
> > + struct dma_trans_desc *descs,
> > + struct dma_trans_status *opaque_data,
> > + uint16_t count);
> > + /**
> > + * check copy-completed packets from a DMA channel
> > + * @param vid
> > + * id of vhost device to check copy completion
> > + * @param queue_id
> > + * queue id to check copyp completion
> > + * @param opaque_data
> > + * buffer to receive the opaque data pair from DMA engine
> > + * @param max_packets
> > + * max number of packets could be completed
> > + * @return
> > + * -1 on failure, number of iov segments completed on success
> > + */
> > + int (*check_completed_copies)(int vid, uint16_t queue_id,
> > + struct dma_trans_status *opaque_data,
> > + uint16_t max_packets);
> > +};
> > +
> > +/**
> > + * dma channel feature bit definition */ struct
> > +dma_channel_features {
> > + union {
> > + uint32_t intval;
> > + struct {
> > + uint32_t inorder:1;
> > + uint32_t resvd0115:15;
> > + uint32_t threshold:12;
> > + uint32_t resvd2831:4;
> > + };
> > + };
> > +};
> > +
>
> Naming feature bits as "intval" may cause confusion, why not just use its
> meaning like "engine_features"?
> I'm not sure whether format "resvd0115" match dpdk copy style. In my mind,
> dpdk will use resvd_0 and resvd_1 for two reserved elements.
>
For comments here above, I will take changes in v2 patch
> > + if (dev)
> > + dev->async_copy = 1;
> > + }
> > +
>
> IMHO, user can chose which queue utilize async copy as backend hardware
> resource is limited.
> So should async_copy enable flag be saved in virtqueue structure?
>
We have per queue flag to identify the enabling status of a specific queue.
"async_copy" flag is a dev level flag which identifies the async capability of
a vhost device.
This is necessary because we rely on this flag to do initialization work if the
vhost backend need to support async mode at any of its queues.
> > VHOST_LOG_CONFIG(INFO, "new device, handle is %d\n", vid);
> >
> > if (vsocket->notify_ops->new_connection) { @@ -891,6 +900,17 @@
> > struct vhost_user_reconnect_list {
> > goto out_mutex;
> > }
> >
> > + vsocket->async_copy = flags & RTE_VHOST_USER_ASYNC_COPY;
> > +
> > + if (vsocket->async_copy &&
> > + (flags & (RTE_VHOST_USER_IOMMU_SUPPORT |
> > + RTE_VHOST_USER_POSTCOPY_SUPPORT))) {
> > + VHOST_LOG_CONFIG(ERR, "error: enabling async copy and
> > IOMMU "
> > + "or post-copy feature simultaneously is not "
> > + "supported\n");
> > + goto out_mutex;
> > + }
> > +
> > /*
> > * Set the supported features correctly for the builtin vhost-user
> > * net driver.
> > diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c index
> > 0266318..e6b688a 100644
> > --- a/lib/librte_vhost/vhost.c
> > +++ b/lib/librte_vhost/vhost.c
> > @@ -332,8 +332,13 @@
> > {
> > if (vq_is_packed(dev))
> > rte_free(vq->shadow_used_packed);
> > - else
> > + else {
> > rte_free(vq->shadow_used_split);
> > + if (vq->async_pkts_pending)
> > + rte_free(vq->async_pkts_pending);
> > + if (vq->async_pending_info)
> > + rte_free(vq->async_pending_info);
> > + }
> > rte_free(vq->batch_copy_elems);
> > rte_mempool_free(vq->iotlb_pool);
> > rte_free(vq);
> > @@ -1527,3 +1532,70 @@ int rte_vhost_extern_callback_register(int vid,
> > if (vhost_data_log_level >= 0)
> > rte_log_set_level(vhost_data_log_level,
> > RTE_LOG_WARNING);
> > }
> > +
> > +int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
> > + uint32_t features,
> > + struct rte_vhost_async_channel_ops
> > *ops)
> > +{
> > + struct vhost_virtqueue *vq;
> > + struct virtio_net *dev = get_device(vid);
> > + struct dma_channel_features f;
> > +
> > + if (dev == NULL || ops == NULL)
> > + return -1;
> > +
> > + f.intval = features;
> > +
> > + vq = dev->virtqueue[queue_id];
> > +
> > + if (vq == NULL)
> > + return -1;
> > +
> > + /** packed queue is not supported */
> > + if (vq_is_packed(dev) || !f.inorder)
> > + return -1;
> > +
> Virtio already has in_order concept, these two names are so like and can be
> easily messed up. Please consider how to distinguish them.
>
What about "async_inorder"
> > + if (ops->check_completed_copies == NULL ||
> > + ops->transfer_data == NULL)
> > + return -1;
> > +
>
> Previous error is unlikely to be true, unlikely macro may be helpful for
> understanding.
>
Will update in v2 patch
> > + rte_spinlock_lock(&vq->access_lock);
> > +
> > + vq->async_ops.check_completed_copies = ops-
> > >check_completed_copies;
> > + vq->async_ops.transfer_data = ops->transfer_data;
> > +
> > + vq->async_inorder = f.inorder;
> > + vq->async_threshold = f.threshold;
> > +
> > + vq->async_registered = true;
> > +
> > + rte_spinlock_unlock(&vq->access_lock);
> > +
> > + return 0;
> > +}
> > +
> > +int rte_vhost_async_channel_unregister(int vid, uint16_t queue_id) {
> > + struct vhost_virtqueue *vq;
> > + struct virtio_net *dev = get_device(vid);
> > +
> > + if (dev == NULL)
> > + return -1;
> > +
> > + vq = dev->virtqueue[queue_id];
> > +
> > + if (vq == NULL)
> > + return -1;
> > +
> > + rte_spinlock_lock(&vq->access_lock);
> > +
> > + vq->async_ops.transfer_data = NULL;
> > + vq->async_ops.check_completed_copies = NULL;
> > +
> > + vq->async_registered = false;
> > +
> > + rte_spinlock_unlock(&vq->access_lock);
> > +
> > + return 0;
> > +}
> > +
> > diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> > df98d15..a7fbe23 100644
> > --- a/lib/librte_vhost/vhost.h
> > +++ b/lib/librte_vhost/vhost.h
> > @@ -23,6 +23,8 @@
> > #include "rte_vhost.h"
> > #include "rte_vdpa.h"
> >
> > +#include "rte_vhost_async.h"
> > +
> > /* Used to indicate that the device is running on a data core */
> > #define VIRTIO_DEV_RUNNING 1
> > /* Used to indicate that the device is ready to operate */ @@ -39,6
> > +41,11 @@
> >
> > #define VHOST_LOG_CACHE_NR 32
> >
> > +#define MAX_PKT_BURST 32
> > +
> > +#define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2) #define
> > +VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 2)
> > +
> > #define PACKED_DESC_ENQUEUE_USED_FLAG(w) \
> > ((w) ? (VRING_DESC_F_AVAIL | VRING_DESC_F_USED |
> > VRING_DESC_F_WRITE) : \
> > VRING_DESC_F_WRITE)
> > @@ -200,6 +207,25 @@ struct vhost_virtqueue {
> > TAILQ_HEAD(, vhost_iotlb_entry) iotlb_list;
> > int iotlb_cache_nr;
> > TAILQ_HEAD(, vhost_iotlb_entry) iotlb_pending_list;
> > +
> > + /* operation callbacks for async dma */
> > + struct rte_vhost_async_channel_ops async_ops;
> > +
> > + struct iov_it it_pool[VHOST_MAX_ASYNC_IT];
> > + struct iovec vec_pool[VHOST_MAX_ASYNC_VEC];
> > +
> > + /* async data transfer status */
> > + uintptr_t **async_pkts_pending;
> > + #define ASYNC_PENDING_INFO_N_MSK 0xFFFF
> > + #define ASYNC_PENDING_INFO_N_SFT 16
> > + uint64_t *async_pending_info;
> > + uint16_t async_pkts_idx;
> > + uint16_t async_pkts_inflight_n;
> > +
> > + /* vq async features */
> > + bool async_inorder;
> > + bool async_registered;
> > + uint16_t async_threshold;
> > } __rte_cache_aligned;
> >
> > /* Old kernels have no such macros defined */ @@ -353,6 +379,7 @@
> > struct virtio_net {
> > int16_t broadcast_rarp;
> > uint32_t nr_vring;
> > int dequeue_zero_copy;
> > + int async_copy;
> > int extbuf;
> > int linearbuf;
> > struct vhost_virtqueue *virtqueue[VHOST_MAX_QUEUE_PAIRS * 2];
> > @@ -702,7 +729,8 @@ uint64_t translate_log_addr(struct virtio_net
> > *dev, struct vhost_virtqueue *vq,
> > /* Don't kick guest if we don't reach index specified by guest. */
> > if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) {
> > uint16_t old = vq->signalled_used;
> > - uint16_t new = vq->last_used_idx;
> > + uint16_t new = vq->async_pkts_inflight_n ?
> > + vq->used->idx:vq->last_used_idx;
> > bool signalled_used_valid = vq->signalled_used_valid;
> >
> > vq->signalled_used = new;
> > diff --git a/lib/librte_vhost/vhost_user.c
> > b/lib/librte_vhost/vhost_user.c index 84bebad..d7600bf 100644
> > --- a/lib/librte_vhost/vhost_user.c
> > +++ b/lib/librte_vhost/vhost_user.c
> > @@ -464,12 +464,25 @@
> > } else {
> > if (vq->shadow_used_split)
> > rte_free(vq->shadow_used_split);
> > + if (vq->async_pkts_pending)
> > + rte_free(vq->async_pkts_pending);
> > + if (vq->async_pending_info)
> > + rte_free(vq->async_pending_info);
> > +
> > vq->shadow_used_split = rte_malloc(NULL,
> > vq->size * sizeof(struct vring_used_elem),
> > RTE_CACHE_LINE_SIZE);
> > - if (!vq->shadow_used_split) {
> > + vq->async_pkts_pending = rte_malloc(NULL,
> > + vq->size * sizeof(uintptr_t),
> > + RTE_CACHE_LINE_SIZE);
> > + vq->async_pending_info = rte_malloc(NULL,
> > + vq->size * sizeof(uint64_t),
> > + RTE_CACHE_LINE_SIZE);
> > + if (!vq->shadow_used_split ||
> > + !vq->async_pkts_pending ||
> > + !vq->async_pending_info) {
> > VHOST_LOG_CONFIG(ERR,
> > - "failed to allocate memory for
> > shadow used ring.\n");
> > + "failed to allocate memory for vq
> > internal data.\n");
>
> If async copy not enabled, there will be no need to allocate related
> structures.
>
Will update in v2 patch
Thanks,
Patrick
