Hi Jiayu,
On 12/30/21 22:55, Jiayu Hu wrote:
Since dmadev is introduced in 21.11, to avoid the overhead of vhost DMA
abstraction layer and simplify application logics, this patch integrates
dmadev in asynchronous data path.
Signed-off-by: Jiayu Hu <jiayu...@intel.com>
Signed-off-by: Sunil Pai G <sunil.pa...@intel.com>
---
doc/guides/prog_guide/vhost_lib.rst | 70 ++++-----
examples/vhost/Makefile | 2 +-
examples/vhost/ioat.c | 218 --------------------------
examples/vhost/ioat.h | 63 --------
examples/vhost/main.c | 230 +++++++++++++++++++++++-----
examples/vhost/main.h | 11 ++
examples/vhost/meson.build | 6 +-
lib/vhost/meson.build | 3 +-
lib/vhost/rte_vhost_async.h | 121 +++++----------
lib/vhost/version.map | 3 +
lib/vhost/vhost.c | 130 +++++++++++-----
lib/vhost/vhost.h | 53 ++++++-
lib/vhost/virtio_net.c | 206 +++++++++++++++++++------
13 files changed, 587 insertions(+), 529 deletions(-)
delete mode 100644 examples/vhost/ioat.c
delete mode 100644 examples/vhost/ioat.h
diff --git a/doc/guides/prog_guide/vhost_lib.rst
b/doc/guides/prog_guide/vhost_lib.rst
index 76f5d303c9..bdce7cbf02 100644
--- a/doc/guides/prog_guide/vhost_lib.rst
+++ b/doc/guides/prog_guide/vhost_lib.rst
@@ -218,38 +218,12 @@ The following is an overview of some key Vhost API
functions:
Enable or disable zero copy feature of the vhost crypto backend.
-* ``rte_vhost_async_channel_register(vid, queue_id, config, ops)``
+* ``rte_vhost_async_channel_register(vid, queue_id)``
Register an async copy device channel for a vhost queue after vring
- is enabled. Following device ``config`` must be specified together
- with the registration:
+ is enabled.
- * ``features``
-
- This field is used to specify async copy device features.
-
- ``RTE_VHOST_ASYNC_INORDER`` represents the async copy device can
- guarantee the order of copy completion is the same as the order
- of copy submission.
-
- Currently, only ``RTE_VHOST_ASYNC_INORDER`` capable device is
- supported by vhost.
-
- Applications must provide following ``ops`` callbacks for vhost lib to
- work with the async copy devices:
-
- * ``transfer_data(vid, queue_id, descs, opaque_data, count)``
-
- vhost invokes this function to submit copy data to the async devices.
- For non-async_inorder capable devices, ``opaque_data`` could be used
- for identifying the completed packets.
-
- * ``check_completed_copies(vid, queue_id, opaque_data, max_packets)``
-
- vhost invokes this function to get the copy data completed by async
- devices.
-
-* ``rte_vhost_async_channel_register_thread_unsafe(vid, queue_id, config,
ops)``
+* ``rte_vhost_async_channel_register_thread_unsafe(vid, queue_id)``
Register an async copy device channel for a vhost queue without
performing any locking.
@@ -277,18 +251,13 @@ The following is an overview of some key Vhost API
functions:
This function is only safe to call in vhost callback functions
(i.e., struct rte_vhost_device_ops).
-* ``rte_vhost_submit_enqueue_burst(vid, queue_id, pkts, count, comp_pkts, comp_count)``
+* ``rte_vhost_submit_enqueue_burst(vid, queue_id, pkts, count, dma_id,
dma_vchan)``
Submit an enqueue request to transmit ``count`` packets from host to guest
- by async data path. Successfully enqueued packets can be transfer completed
- or being occupied by DMA engines; transfer completed packets are returned in
- ``comp_pkts``, but others are not guaranteed to finish, when this API
- call returns.
+ by async data path. Applications must not free the packets submitted for
+ enqueue until the packets are completed.
- Applications must not free the packets submitted for enqueue until the
- packets are completed.
-
-* ``rte_vhost_poll_enqueue_completed(vid, queue_id, pkts, count)``
+* ``rte_vhost_poll_enqueue_completed(vid, queue_id, pkts, count, dma_id,
dma_vchan)``
Poll enqueue completion status from async data path. Completed packets
are returned to applications through ``pkts``.
@@ -298,7 +267,7 @@ The following is an overview of some key Vhost API
functions:
This function returns the amount of in-flight packets for the vhost
queue using async acceleration.
-* ``rte_vhost_clear_queue_thread_unsafe(vid, queue_id, **pkts, count)``
+* ``rte_vhost_clear_queue_thread_unsafe(vid, queue_id, **pkts, count, dma_id,
dma_vchan)``
Clear inflight packets which are submitted to DMA engine in vhost async data
path. Completed packets are returned to applications through ``pkts``.
@@ -442,3 +411,26 @@ Finally, a set of device ops is defined for device
specific operations:
* ``get_notify_area``
Called to get the notify area info of the queue.
+
+Vhost asynchronous data path
+----------------------------
+
+Vhost asynchronous data path leverages DMA devices to offload memory
+copies from the CPU and it is implemented in an asynchronous way. It
+enables applcations, like OVS, to save CPU cycles and hide memory copy
s/applcations/applications/
+overhead, thus achieving higher throughput.
+
+Vhost doesn't manage DMA devices and applications, like OVS, need to
+manage and configure DMA devices. Applications need to tell vhost what
+DMA devices to use in every data path function call. This design enables
+the flexibility for applications to dynamically use DMA channels in
+different function modules, not limited in vhost.
+
+In addition, vhost supports M:N mapping between vrings and DMA virtual
+channels. Specifically, one vring can use multiple different DMA channels
+and one DMA channel can be shared by multiple vrings at the same time.
+The reason of enabling one vring to use multiple DMA channels is that
+it's possible that more than one dataplane threads enqueue packets to
+the same vring with their own DMA virtual channels. Besides, the number
+of DMA devices is limited. For the purpose of scaling, it's necessary to
+support sharing DMA channels among vrings.
diff --git a/examples/vhost/Makefile b/examples/vhost/Makefile
index 587ea2ab47..975a5dfe40 100644
--- a/examples/vhost/Makefile
+++ b/examples/vhost/Makefile
@@ -5,7 +5,7 @@
APP = vhost-switch
# all source are stored in SRCS-y
-SRCS-y := main.c virtio_net.c ioat.c
+SRCS-y := main.c virtio_net.c
PKGCONF ?= pkg-config
diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c
deleted file mode 100644
index 9aeeb12fd9..0000000000
--- a/examples/vhost/ioat.c
+++ /dev/null
@@ -1,218 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2010-2020 Intel Corporation
- */
-
-#include <sys/uio.h>
-#ifdef RTE_RAW_IOAT
-#include <rte_rawdev.h>
-#include <rte_ioat_rawdev.h>
-
-#include "ioat.h"
-#include "main.h"
-
-struct dma_for_vhost dma_bind[MAX_VHOST_DEVICE];
-
-struct packet_tracker {
- unsigned short size_track[MAX_ENQUEUED_SIZE];
- unsigned short next_read;
- unsigned short next_write;
- unsigned short last_remain;
- unsigned short ioat_space;
-};
-
-struct packet_tracker cb_tracker[MAX_VHOST_DEVICE];
-
-int
-open_ioat(const char *value)
-{
- struct dma_for_vhost *dma_info = dma_bind;
- char *input = strndup(value, strlen(value) + 1);
- char *addrs = input;
- char *ptrs[2];
- char *start, *end, *substr;
- int64_t vid, vring_id;
- struct rte_ioat_rawdev_config config;
- struct rte_rawdev_info info = { .dev_private = &config };
- char name[32];
- int dev_id;
- int ret = 0;
- uint16_t i = 0;
- char *dma_arg[MAX_VHOST_DEVICE];
- int args_nr;
-
- while (isblank(*addrs))
- addrs++;
- if (*addrs == '\0') {
- ret = -1;
- goto out;
- }
-
- /* process DMA devices within bracket. */
- addrs++;
- substr = strtok(addrs, ";]");
- if (!substr) {
- ret = -1;
- goto out;
- }
- args_nr = rte_strsplit(substr, strlen(substr),
- dma_arg, MAX_VHOST_DEVICE, ',');
- if (args_nr <= 0) {
- ret = -1;
- goto out;
- }
- while (i < args_nr) {
- char *arg_temp = dma_arg[i];
- uint8_t sub_nr;
- sub_nr = rte_strsplit(arg_temp, strlen(arg_temp), ptrs, 2, '@');
- if (sub_nr != 2) {
- ret = -1;
- goto out;
- }
-
- start = strstr(ptrs[0], "txd");
- if (start == NULL) {
- ret = -1;
- goto out;
- }
-
- start += 3;
- vid = strtol(start, &end, 0);
- if (end == start) {
- ret = -1;
- goto out;
- }
-
- vring_id = 0 + VIRTIO_RXQ;
- if (rte_pci_addr_parse(ptrs[1],
- &(dma_info + vid)->dmas[vring_id].addr) < 0) {
- ret = -1;
- goto out;
- }
-
- rte_pci_device_name(&(dma_info + vid)->dmas[vring_id].addr,
- name, sizeof(name));
- dev_id = rte_rawdev_get_dev_id(name);
- if (dev_id == (uint16_t)(-ENODEV) ||
- dev_id == (uint16_t)(-EINVAL)) {
- ret = -1;
- goto out;
- }
-
- if (rte_rawdev_info_get(dev_id, &info, sizeof(config)) < 0 ||
- strstr(info.driver_name, "ioat") == NULL) {
- ret = -1;
- goto out;
- }
-
- (dma_info + vid)->dmas[vring_id].dev_id = dev_id;
- (dma_info + vid)->dmas[vring_id].is_valid = true;
- config.ring_size = IOAT_RING_SIZE;
- config.hdls_disable = true;
- if (rte_rawdev_configure(dev_id, &info, sizeof(config)) < 0) {
- ret = -1;
- goto out;
- }
- rte_rawdev_start(dev_id);
- cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1;
- dma_info->nr++;
- i++;
- }
-out:
- free(input);
- return ret;
-}
-
-int32_t
-ioat_transfer_data_cb(int vid, uint16_t queue_id,
- struct rte_vhost_iov_iter *iov_iter,
- struct rte_vhost_async_status *opaque_data, uint16_t count)
-{
- uint32_t i_iter;
- uint16_t dev_id = dma_bind[vid].dmas[queue_id * 2 + VIRTIO_RXQ].dev_id;
- struct rte_vhost_iov_iter *iter = NULL;
- unsigned long i_seg;
- unsigned short mask = MAX_ENQUEUED_SIZE - 1;
- unsigned short write = cb_tracker[dev_id].next_write;
-
- if (!opaque_data) {
- for (i_iter = 0; i_iter < count; i_iter++) {
- iter = iov_iter + i_iter;
- i_seg = 0;
- if (cb_tracker[dev_id].ioat_space < iter->nr_segs)
- break;
- while (i_seg < iter->nr_segs) {
- rte_ioat_enqueue_copy(dev_id,
- (uintptr_t)(iter->iov[i_seg].src_addr),
- (uintptr_t)(iter->iov[i_seg].dst_addr),
- iter->iov[i_seg].len,
- 0,
- 0);
- i_seg++;
- }
- write &= mask;
- cb_tracker[dev_id].size_track[write] = iter->nr_segs;
- cb_tracker[dev_id].ioat_space -= iter->nr_segs;
- write++;
- }
- } else {
- /* Opaque data is not supported */
- return -1;
- }
- /* ring the doorbell */
- rte_ioat_perform_ops(dev_id);
- cb_tracker[dev_id].next_write = write;
- return i_iter;
-}
-
-int32_t
-ioat_check_completed_copies_cb(int vid, uint16_t queue_id,
- struct rte_vhost_async_status *opaque_data,
- uint16_t max_packets)
-{
- if (!opaque_data) {
- uintptr_t dump[255];
- int n_seg;
- unsigned short read, write;
- unsigned short nb_packet = 0;
- unsigned short mask = MAX_ENQUEUED_SIZE - 1;
- unsigned short i;
-
- uint16_t dev_id = dma_bind[vid].dmas[queue_id * 2
- + VIRTIO_RXQ].dev_id;
- n_seg = rte_ioat_completed_ops(dev_id, 255, NULL, NULL, dump,
dump);
- if (n_seg < 0) {
- RTE_LOG(ERR,
- VHOST_DATA,
- "fail to poll completed buf on IOAT device %u",
- dev_id);
- return 0;
- }
- if (n_seg == 0)
- return 0;
-
- cb_tracker[dev_id].ioat_space += n_seg;
- n_seg += cb_tracker[dev_id].last_remain;
-
- read = cb_tracker[dev_id].next_read;
- write = cb_tracker[dev_id].next_write;
- for (i = 0; i < max_packets; i++) {
- read &= mask;
- if (read == write)
- break;
- if (n_seg >= cb_tracker[dev_id].size_track[read]) {
- n_seg -= cb_tracker[dev_id].size_track[read];
- read++;
- nb_packet++;
- } else {
- break;
- }
- }
- cb_tracker[dev_id].next_read = read;
- cb_tracker[dev_id].last_remain = n_seg;
- return nb_packet;
- }
- /* Opaque data is not supported */
- return -1;
-}
-
-#endif /* RTE_RAW_IOAT */
diff --git a/examples/vhost/ioat.h b/examples/vhost/ioat.h
deleted file mode 100644
index d9bf717e8d..0000000000
--- a/examples/vhost/ioat.h
+++ /dev/null
@@ -1,63 +0,0 @@
-/* SPDX-License-Identifier: BSD-3-Clause
- * Copyright(c) 2010-2020 Intel Corporation
- */
-
-#ifndef _IOAT_H_
-#define _IOAT_H_
-
-#include <rte_vhost.h>
-#include <rte_pci.h>
-#include <rte_vhost_async.h>
-
-#define MAX_VHOST_DEVICE 1024
-#define IOAT_RING_SIZE 4096
-#define MAX_ENQUEUED_SIZE 4096
-
-struct dma_info {
- struct rte_pci_addr addr;
- uint16_t dev_id;
- bool is_valid;
-};
-
-struct dma_for_vhost {
- struct dma_info dmas[RTE_MAX_QUEUES_PER_PORT * 2];
- uint16_t nr;
-};
-
-#ifdef RTE_RAW_IOAT
-int open_ioat(const char *value);
-
-int32_t
-ioat_transfer_data_cb(int vid, uint16_t queue_id,
- struct rte_vhost_iov_iter *iov_iter,
- struct rte_vhost_async_status *opaque_data, uint16_t count);
-
-int32_t
-ioat_check_completed_copies_cb(int vid, uint16_t queue_id,
- struct rte_vhost_async_status *opaque_data,
- uint16_t max_packets);
-#else
-static int open_ioat(const char *value __rte_unused)
-{
- return -1;
-}
-
-static int32_t
-ioat_transfer_data_cb(int vid __rte_unused, uint16_t queue_id __rte_unused,
- struct rte_vhost_iov_iter *iov_iter __rte_unused,
- struct rte_vhost_async_status *opaque_data __rte_unused,
- uint16_t count __rte_unused)
-{
- return -1;
-}
-
-static int32_t
-ioat_check_completed_copies_cb(int vid __rte_unused,
- uint16_t queue_id __rte_unused,
- struct rte_vhost_async_status *opaque_data __rte_unused,
- uint16_t max_packets __rte_unused)
-{
- return -1;
-}
-#endif
-#endif /* _IOAT_H_ */
diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index 33d023aa39..44073499bc 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -24,8 +24,9 @@
#include <rte_ip.h>
#include <rte_tcp.h>
#include <rte_pause.h>
+#include <rte_dmadev.h>
+#include <rte_vhost_async.h>
-#include "ioat.h"
#include "main.h"
#ifndef MAX_QUEUES
@@ -56,6 +57,14 @@
#define RTE_TEST_TX_DESC_DEFAULT 512
#define INVALID_PORT_ID 0xFF
+#define INVALID_DMA_ID -1
+
+#define MAX_VHOST_DEVICE 1024
It is better to define RTE_VHOST_MAX_DEVICES in rte_vhost.h,
and use it here in in vhost library so that it will always be aligned
with the Vhost library.
+#define DMA_RING_SIZE 4096
As previous review, the DMA ring size should not be hard-coded.
Please use the DMA lib helpers to get the ring size also here.
Looking at the dmadev library, I would just use the max value provided
by the device. What would be the downside of doing so?
Looking at currently available DMA device drivers, this is their
max_desc value:
- CNXK: 15
- DPAA: 64
- HISI: 8192
- IDXD: 4192
- IOAT: 4192
- Skeleton: 8192
So harcoding to 4192 will prevent some to DMA devices to be used, and
will not make full benefit of their capabilities for others.
+struct dma_for_vhost dma_bind[MAX_VHOST_DEVICE];
+struct rte_vhost_async_dma_info dma_config[RTE_DMADEV_DEFAULT_MAX];
+static int dma_count;
/* mask of enabled ports */
static uint32_t enabled_port_mask = 0;
@@ -96,8 +105,6 @@ static int builtin_net_driver;
static int async_vhost_driver;
-static char *dma_type;
-
/* Specify timeout (in useconds) between retries on RX. */
static uint32_t burst_rx_delay_time = BURST_RX_WAIT_US;
/* Specify the number of retries on RX. */
@@ -196,13 +203,134 @@ struct vhost_bufftable *vhost_txbuff[RTE_MAX_LCORE *
MAX_VHOST_DEVICE];
#define MBUF_TABLE_DRAIN_TSC ((rte_get_tsc_hz() + US_PER_S - 1) \
/ US_PER_S * BURST_TX_DRAIN_US)
+static inline bool
+is_dma_configured(int16_t dev_id)
+{
+ int i;
+
+ for (i = 0; i < dma_count; i++) {
+ if (dma_config[i].dev_id == dev_id) {
+ return true;
+ }
+ }
No need for braces for both the loop and the if.
+ return false;
+}
+
static inline int
open_dma(const char *value)
{
- if (dma_type != NULL && strncmp(dma_type, "ioat", 4) == 0)
- return open_ioat(value);
+ struct dma_for_vhost *dma_info = dma_bind;
+ char *input = strndup(value, strlen(value) + 1);
+ char *addrs = input;
+ char *ptrs[2];
+ char *start, *end, *substr;
+ int64_t vid, vring_id;
+
+ struct rte_dma_info info;
+ struct rte_dma_conf dev_config = { .nb_vchans = 1 };
+ struct rte_dma_vchan_conf qconf = {
+ .direction = RTE_DMA_DIR_MEM_TO_MEM,
+ .nb_desc = DMA_RING_SIZE
+ };
+
+ int dev_id;
+ int ret = 0;
+ uint16_t i = 0;
+ char *dma_arg[MAX_VHOST_DEVICE];
+ int args_nr;
+
+ while (isblank(*addrs))
+ addrs++;
+ if (*addrs == '\0') {
+ ret = -1;
+ goto out;
+ }
+
+ /* process DMA devices within bracket. */
+ addrs++;
+ substr = strtok(addrs, ";]");
+ if (!substr) {
+ ret = -1;
+ goto out;
+ }
+
+ args_nr = rte_strsplit(substr, strlen(substr),
+ dma_arg, MAX_VHOST_DEVICE, ',');
+ if (args_nr <= 0) {
+ ret = -1;
+ goto out;
+ }
+
+ while (i < args_nr) {
+ char *arg_temp = dma_arg[i];
+ uint8_t sub_nr;
+
+ sub_nr = rte_strsplit(arg_temp, strlen(arg_temp), ptrs, 2, '@');
+ if (sub_nr != 2) {
+ ret = -1;
+ goto out;
+ }
+
+ start = strstr(ptrs[0], "txd");
+ if (start == NULL) {
+ ret = -1;
+ goto out;
+ }
+
+ start += 3;
+ vid = strtol(start, &end, 0);
+ if (end == start) {
+ ret = -1;
+ goto out;
+ }
+
+ vring_id = 0 + VIRTIO_RXQ;
+
+ dev_id = rte_dma_get_dev_id_by_name(ptrs[1]);
+ if (dev_id < 0) {
+ RTE_LOG(ERR, VHOST_CONFIG, "Fail to find DMA %s.\n",
ptrs[1]);
+ ret = -1;
+ goto out;
+ } else if (is_dma_configured(dev_id)) {
+ goto done;
+ }
+
+ if (rte_dma_configure(dev_id, &dev_config) != 0) {
+ RTE_LOG(ERR, VHOST_CONFIG, "Fail to configure DMA
%d.\n", dev_id);
+ ret = -1;
+ goto out;
+ }
+
+ if (rte_dma_vchan_setup(dev_id, 0, &qconf) != 0) {
+ RTE_LOG(ERR, VHOST_CONFIG, "Fail to set up DMA %d.\n",
dev_id);
+ ret = -1;
+ goto out;
+ }
- return -1;
+ rte_dma_info_get(dev_id, &info);
+ if (info.nb_vchans != 1) {
+ RTE_LOG(ERR, VHOST_CONFIG, "DMA %d has no queues.\n",
dev_id);
+ ret = -1;
+ goto out;
+ }
So, I would call rte_dma_info_get() before calling rte_dma_vchan_setup()
to get desc number value working with the DMA device.
+
+ if (rte_dma_start(dev_id) != 0) {
+ RTE_LOG(ERR, VHOST_CONFIG, "Fail to start DMA %u.\n",
dev_id);
+ ret = -1;
+ goto out;
+ }
+
+ dma_config[dma_count].dev_id = dev_id;
+ dma_config[dma_count].max_vchans = 1;
+ dma_config[dma_count++].max_desc = DMA_RING_SIZE;
+
+done:
+ (dma_info + vid)->dmas[vring_id].dev_id = dev_id;
+ i++;
+ }
+out:
+ free(input);
+ return ret;
}
/*
@@ -500,8 +628,6 @@ enum {
OPT_CLIENT_NUM,
#define OPT_BUILTIN_NET_DRIVER "builtin-net-driver"
OPT_BUILTIN_NET_DRIVER_NUM,
-#define OPT_DMA_TYPE "dma-type"
- OPT_DMA_TYPE_NUM,
#define OPT_DMAS "dmas"
OPT_DMAS_NUM,
};
@@ -539,8 +665,6 @@ us_vhost_parse_args(int argc, char **argv)
NULL, OPT_CLIENT_NUM},
{OPT_BUILTIN_NET_DRIVER, no_argument,
NULL, OPT_BUILTIN_NET_DRIVER_NUM},
- {OPT_DMA_TYPE, required_argument,
- NULL, OPT_DMA_TYPE_NUM},
{OPT_DMAS, required_argument,
NULL, OPT_DMAS_NUM},
{NULL, 0, 0, 0},
@@ -661,10 +785,6 @@ us_vhost_parse_args(int argc, char **argv)
}
break;
- case OPT_DMA_TYPE_NUM:
- dma_type = optarg;
- break;
-
case OPT_DMAS_NUM:
if (open_dma(optarg) == -1) {
RTE_LOG(INFO, VHOST_CONFIG,
@@ -841,9 +961,10 @@ complete_async_pkts(struct vhost_dev *vdev)
{
struct rte_mbuf *p_cpl[MAX_PKT_BURST];
uint16_t complete_count;
+ int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
- VIRTIO_RXQ, p_cpl, MAX_PKT_BURST);
+ VIRTIO_RXQ, p_cpl, MAX_PKT_BURST,
dma_id, 0);
if (complete_count) {
free_pkts(p_cpl, complete_count);
__atomic_sub_fetch(&vdev->pkts_inflight, complete_count,
__ATOMIC_SEQ_CST);
@@ -883,11 +1004,12 @@ drain_vhost(struct vhost_dev *vdev)
if (builtin_net_driver) {
ret = vs_enqueue_pkts(vdev, VIRTIO_RXQ, m, nr_xmit);
- } else if (async_vhost_driver) {
+ } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
uint16_t enqueue_fail = 0;
+ int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
complete_async_pkts(vdev);
- ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m,
nr_xmit);
+ ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m,
nr_xmit, dma_id, 0);
__atomic_add_fetch(&vdev->pkts_inflight, ret, __ATOMIC_SEQ_CST);
enqueue_fail = nr_xmit - ret;
@@ -905,7 +1027,7 @@ drain_vhost(struct vhost_dev *vdev)
__ATOMIC_SEQ_CST);
}
- if (!async_vhost_driver)
+ if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
free_pkts(m, nr_xmit);
}
@@ -1211,12 +1333,13 @@ drain_eth_rx(struct vhost_dev *vdev)
if (builtin_net_driver) {
enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
pkts, rx_count);
- } else if (async_vhost_driver) {
+ } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
uint16_t enqueue_fail = 0;
+ int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;
complete_async_pkts(vdev);
enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
- VIRTIO_RXQ, pkts, rx_count);
+ VIRTIO_RXQ, pkts, rx_count, dma_id, 0);
__atomic_add_fetch(&vdev->pkts_inflight, enqueue_count,
__ATOMIC_SEQ_CST);
enqueue_fail = rx_count - enqueue_count;
@@ -1235,7 +1358,7 @@ drain_eth_rx(struct vhost_dev *vdev)
__ATOMIC_SEQ_CST);
}
- if (!async_vhost_driver)
+ if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
free_pkts(pkts, rx_count);
}
@@ -1387,18 +1510,20 @@ destroy_device(int vid)
"(%d) device has been removed from data core\n",
vdev->vid);
- if (async_vhost_driver) {
+ if (dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled) {
uint16_t n_pkt = 0;
+ int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
struct rte_mbuf *m_cpl[vdev->pkts_inflight];
while (vdev->pkts_inflight) {
n_pkt = rte_vhost_clear_queue_thread_unsafe(vid,
VIRTIO_RXQ,
- m_cpl, vdev->pkts_inflight);
+ m_cpl, vdev->pkts_inflight,
dma_id, 0);
free_pkts(m_cpl, n_pkt);
__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt,
__ATOMIC_SEQ_CST);
}
rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
+ dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = false;
}
rte_free(vdev);
@@ -1468,20 +1593,14 @@ new_device(int vid)
"(%d) device has been added to data core %d\n",
vid, vdev->coreid);
- if (async_vhost_driver) {
- struct rte_vhost_async_config config = {0};
- struct rte_vhost_async_channel_ops channel_ops;
-
- if (dma_type != NULL && strncmp(dma_type, "ioat", 4) == 0) {
- channel_ops.transfer_data = ioat_transfer_data_cb;
- channel_ops.check_completed_copies =
- ioat_check_completed_copies_cb;
-
- config.features = RTE_VHOST_ASYNC_INORDER;
+ if (dma_bind[vid].dmas[VIRTIO_RXQ].dev_id != INVALID_DMA_ID) {
+ int ret;
- return rte_vhost_async_channel_register(vid, VIRTIO_RXQ,
- config, &channel_ops);
+ ret = rte_vhost_async_channel_register(vid, VIRTIO_RXQ);
+ if (ret == 0) {
+ dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = true;
}
+ return ret;
}
return 0;
@@ -1502,14 +1621,15 @@ vring_state_changed(int vid, uint16_t queue_id, int
enable)
if (queue_id != VIRTIO_RXQ)
return 0;
- if (async_vhost_driver) {
+ if (dma_bind[vid].dmas[queue_id].async_enabled) {
if (!enable) {
uint16_t n_pkt = 0;
+ int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
struct rte_mbuf *m_cpl[vdev->pkts_inflight];
while (vdev->pkts_inflight) {
n_pkt =
rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
- m_cpl,
vdev->pkts_inflight);
+ m_cpl,
vdev->pkts_inflight, dma_id, 0);
free_pkts(m_cpl, n_pkt);
__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt,
__ATOMIC_SEQ_CST);
}
@@ -1657,6 +1777,25 @@ create_mbuf_pool(uint16_t nr_port, uint32_t
nr_switch_core, uint32_t mbuf_size,
rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");
}
+static void
+init_dma(void)
+{
+ int i;
+
+ for (i = 0; i < MAX_VHOST_DEVICE; i++) {
+ int j;
+
+ for (j = 0; j < RTE_MAX_QUEUES_PER_PORT * 2; j++) {
+ dma_bind[i].dmas[j].dev_id = INVALID_DMA_ID;
+ dma_bind[i].dmas[j].async_enabled = false;
+ }
+ }
+
+ for (i = 0; i < RTE_DMADEV_DEFAULT_MAX; i++) {
+ dma_config[i].dev_id = INVALID_DMA_ID;
+ }
+}
+
/*
* Main function, does initialisation and calls the per-lcore functions.
*/
@@ -1679,6 +1818,9 @@ main(int argc, char *argv[])
argc -= ret;
argv += ret;
+ /* initialize dma structures */
+ init_dma();
+
/* parse app arguments */
ret = us_vhost_parse_args(argc, argv);
if (ret < 0)
@@ -1754,6 +1896,20 @@ main(int argc, char *argv[])
if (client_mode)
flags |= RTE_VHOST_USER_CLIENT;
+ if (async_vhost_driver) {
You should be able to get rid off async_vhost_driver and instead rely on
dma_count.
+ if (rte_vhost_async_dma_configure(dma_config, dma_count) < 0) {
+ RTE_LOG(ERR, VHOST_PORT, "Failed to configure DMA in
vhost.\n");
+ for (i = 0; i < dma_count; i++) {
+ if (dma_config[i].dev_id != INVALID_DMA_ID) {
+ rte_dma_stop(dma_config[i].dev_id);
+ dma_config[i].dev_id = INVALID_DMA_ID;
+ }
+ }
+ dma_count = 0;
+ async_vhost_driver = false;
Let's just exit the app if DMAs were provided in command line but cannot
be used.
+ }
+ }
+
/* Register vhost user driver to handle vhost messages. */
for (i = 0; i < nb_sockets; i++) {
char *file = socket_files + i * PATH_MAX;
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index e7b1ac60a6..b4a453e77e 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -8,6 +8,7 @@
#include <sys/queue.h>
#include <rte_ether.h>
+#include <rte_pci.h>
/* Macros for printing using RTE_LOG */
#define RTE_LOGTYPE_VHOST_CONFIG RTE_LOGTYPE_USER1
@@ -79,6 +80,16 @@ struct lcore_info {
struct vhost_dev_tailq_list vdev_list;
};
+struct dma_info {
+ struct rte_pci_addr addr;
+ int16_t dev_id;
+ bool async_enabled;
+};
+
+struct dma_for_vhost {
+ struct dma_info dmas[RTE_MAX_QUEUES_PER_PORT * 2];
+};
+
/* we implement non-extra virtio net features */
#define VIRTIO_NET_FEATURES 0
diff --git a/examples/vhost/meson.build b/examples/vhost/meson.build
index 3efd5e6540..87a637f83f 100644
--- a/examples/vhost/meson.build
+++ b/examples/vhost/meson.build
@@ -12,13 +12,9 @@ if not is_linux
endif
deps += 'vhost'
+deps += 'dmadev'
allow_experimental_apis = true
sources = files(
'main.c',
'virtio_net.c',
)
-
-if dpdk_conf.has('RTE_RAW_IOAT')
- deps += 'raw_ioat'
- sources += files('ioat.c')
-endif
diff --git a/lib/vhost/meson.build b/lib/vhost/meson.build
index cdb37a4814..8107329400 100644
--- a/lib/vhost/meson.build
+++ b/lib/vhost/meson.build
@@ -33,7 +33,8 @@ headers = files(
'rte_vhost_async.h',
'rte_vhost_crypto.h',
)
+
driver_sdk_headers = files(
'vdpa_driver.h',
)
-deps += ['ethdev', 'cryptodev', 'hash', 'pci']
+deps += ['ethdev', 'cryptodev', 'hash', 'pci', 'dmadev']
diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
index a87ea6ba37..23a7a2d8b3 100644
--- a/lib/vhost/rte_vhost_async.h
+++ b/lib/vhost/rte_vhost_async.h
@@ -27,70 +27,12 @@ struct rte_vhost_iov_iter {
};
/**
- * dma transfer status
+ * DMA device information
*/
-struct rte_vhost_async_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;
-};
-
-/**
- * dma operation callbacks to be implemented by applications
- */
-struct rte_vhost_async_channel_ops {
- /**
- * instruct async engines 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 iov_iter
- * an array of IOV iterators
- * @param opaque_data
- * opaque data pair sending to DMA engine
- * @param count
- * number of elements in the "descs" array
- * @return
- * number of IOV iterators processed, negative value means error
- */
- int32_t (*transfer_data)(int vid, uint16_t queue_id,
- struct rte_vhost_iov_iter *iov_iter,
- struct rte_vhost_async_status *opaque_data,
- uint16_t count);
- /**
- * check copy-completed packets from the async engine
- * @param vid
- * id of vhost device to check copy completion
- * @param queue_id
- * queue id to check copy 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
- * number of async descs completed, negative value means error
- */
- int32_t (*check_completed_copies)(int vid, uint16_t queue_id,
- struct rte_vhost_async_status *opaque_data,
- uint16_t max_packets);
-};
-
-/**
- * async channel features
- */
-enum {
- RTE_VHOST_ASYNC_INORDER = 1U << 0,
-};
-
-/**
- * async channel configuration
- */
-struct rte_vhost_async_config {
- uint32_t features;
- uint32_t rsvd[2];
+struct rte_vhost_async_dma_info {
+ int16_t dev_id; /* DMA device ID */
+ uint16_t max_vchans; /* max number of vchan */
+ uint16_t max_desc; /* max desc number of vchan */
};
/**
@@ -100,17 +42,11 @@ struct rte_vhost_async_config {
* vhost device id async channel to be attached to
* @param queue_id
* vhost queue id async channel to be attached to
- * @param config
- * Async channel configuration structure
- * @param ops
- * Async channel operation callbacks
* @return
* 0 on success, -1 on failures
*/
__rte_experimental
-int rte_vhost_async_channel_register(int vid, uint16_t queue_id,
- struct rte_vhost_async_config config,
- struct rte_vhost_async_channel_ops *ops);
+int rte_vhost_async_channel_register(int vid, uint16_t queue_id);
/**
* Unregister an async channel for a vhost queue
@@ -136,17 +72,11 @@ int rte_vhost_async_channel_unregister(int vid, uint16_t
queue_id);
* vhost device id async channel to be attached to
* @param queue_id
* vhost queue id async channel to be attached to
- * @param config
- * Async channel configuration
- * @param ops
- * Async channel operation callbacks
* @return
* 0 on success, -1 on failures
*/
__rte_experimental
-int rte_vhost_async_channel_register_thread_unsafe(int vid, uint16_t queue_id,
- struct rte_vhost_async_config config,
- struct rte_vhost_async_channel_ops *ops);
+int rte_vhost_async_channel_register_thread_unsafe(int vid, uint16_t queue_id);
/**
* Unregister an async channel for a vhost queue without performing any
@@ -179,12 +109,17 @@ int rte_vhost_async_channel_unregister_thread_unsafe(int
vid,
* array of packets to be enqueued
* @param count
* packets num to be enqueued
+ * @param dma_id
+ * the identifier of the DMA device
+ * @param vchan
+ * the identifier of virtual DMA channel
* @return
* num of packets enqueued
*/
__rte_experimental
uint16_t rte_vhost_submit_enqueue_burst(int vid, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count);
+ struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
+ uint16_t vchan);
Maybe using vchan_id would be clearer for the API user, same comment
below.
/**
* This function checks async completion status for a specific vhost
@@ -199,12 +134,17 @@ uint16_t rte_vhost_submit_enqueue_burst(int vid, uint16_t
queue_id,
* blank array to get return packet pointer
* @param count
* size of the packet array
+ * @param dma_id
+ * the identifier of the DMA device
+ * @param vchan
+ * the identifier of virtual DMA channel
* @return
* num of packets returned
*/
__rte_experimental
uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count);
+ struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
+ uint16_t vchan);
/**
* This function returns the amount of in-flight packets for the vhost
@@ -235,11 +175,32 @@ int rte_vhost_async_get_inflight(int vid, uint16_t
queue_id);
* Blank array to get return packet pointer
* @param count
* Size of the packet array
+ * @param dma_id
+ * the identifier of the DMA device
+ * @param vchan
+ * the identifier of virtual DMA channel
* @return
* Number of packets returned
*/
__rte_experimental
uint16_t rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count);
+ struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
+ uint16_t vchan);
+/**
+ * The DMA vChannels used in asynchronous data path must be configured
+ * first. So this function needs to be called before enabling DMA
+ * acceleration for vring. If this function fails, asynchronous data path
+ * cannot be enabled for any vring further.
+ *
+ * @param dmas
+ * DMA information
+ * @param count
+ * Element number of 'dmas'
+ * @return
+ * 0 on success, and -1 on failure
+ */
+__rte_experimental
+int rte_vhost_async_dma_configure(struct rte_vhost_async_dma_info *dmas,
+ uint16_t count);
#endif /* _RTE_VHOST_ASYNC_H_ */
diff --git a/lib/vhost/version.map b/lib/vhost/version.map
index a7ef7f1976..1202ba9c1a 100644
--- a/lib/vhost/version.map
+++ b/lib/vhost/version.map
@@ -84,6 +84,9 @@ EXPERIMENTAL {
# added in 21.11
rte_vhost_get_monitor_addr;
+
+ # added in 22.03
+ rte_vhost_async_dma_configure;
};
INTERNAL {
diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
index 13a9bb9dd1..32f37f4851 100644
--- a/lib/vhost/vhost.c
+++ b/lib/vhost/vhost.c
@@ -344,6 +344,7 @@ vhost_free_async_mem(struct vhost_virtqueue *vq)
return;
rte_free(vq->async->pkts_info);
+ rte_free(vq->async->pkts_cmpl_flag);
rte_free(vq->async->buffers_packed);
vq->async->buffers_packed = NULL;
@@ -1626,8 +1627,7 @@ rte_vhost_extern_callback_register(int vid,
}
static __rte_always_inline int
-async_channel_register(int vid, uint16_t queue_id,
- struct rte_vhost_async_channel_ops *ops)
+async_channel_register(int vid, uint16_t queue_id)
{
struct virtio_net *dev = get_device(vid);
struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
@@ -1656,6 +1656,14 @@ async_channel_register(int vid, uint16_t queue_id,
goto out_free_async;
}
+ async->pkts_cmpl_flag = rte_zmalloc_socket(NULL, vq->size * sizeof(bool),
+ RTE_CACHE_LINE_SIZE, node);
+ if (!async->pkts_cmpl_flag) {
+ VHOST_LOG_CONFIG(ERR, "failed to allocate async pkts_cmpl_flag (vid
%d, qid: %d)\n",
+ vid, queue_id);
+ goto out_free_async;
+ }
+
if (vq_is_packed(dev)) {
async->buffers_packed = rte_malloc_socket(NULL,
vq->size * sizeof(struct
vring_used_elem_packed),
@@ -1676,9 +1684,6 @@ async_channel_register(int vid, uint16_t queue_id,
}
}
- async->ops.check_completed_copies = ops->check_completed_copies;
- async->ops.transfer_data = ops->transfer_data;
-
vq->async = async;
return 0;
@@ -1691,15 +1696,13 @@ async_channel_register(int vid, uint16_t queue_id,
}
int
-rte_vhost_async_channel_register(int vid, uint16_t queue_id,
- struct rte_vhost_async_config config,
- struct rte_vhost_async_channel_ops *ops)
+rte_vhost_async_channel_register(int vid, uint16_t queue_id)
{
struct vhost_virtqueue *vq;
struct virtio_net *dev = get_device(vid);
int ret;
- if (dev == NULL || ops == NULL)
+ if (dev == NULL)
return -1;
if (queue_id >= VHOST_MAX_VRING)
@@ -1710,33 +1713,20 @@ rte_vhost_async_channel_register(int vid, uint16_t
queue_id,
if (unlikely(vq == NULL || !dev->async_copy))
return -1;
- if (unlikely(!(config.features & RTE_VHOST_ASYNC_INORDER))) {
- VHOST_LOG_CONFIG(ERR,
- "async copy is not supported on non-inorder mode "
- "(vid %d, qid: %d)\n", vid, queue_id);
- return -1;
- }
-
- if (unlikely(ops->check_completed_copies == NULL ||
- ops->transfer_data == NULL))
- return -1;
-
rte_spinlock_lock(&vq->access_lock);
- ret = async_channel_register(vid, queue_id, ops);
+ ret = async_channel_register(vid, queue_id);
rte_spinlock_unlock(&vq->access_lock);
return ret;
}
int
-rte_vhost_async_channel_register_thread_unsafe(int vid, uint16_t queue_id,
- struct rte_vhost_async_config config,
- struct rte_vhost_async_channel_ops *ops)
+rte_vhost_async_channel_register_thread_unsafe(int vid, uint16_t queue_id)
{
struct vhost_virtqueue *vq;
struct virtio_net *dev = get_device(vid);
- if (dev == NULL || ops == NULL)
+ if (dev == NULL)
return -1;
if (queue_id >= VHOST_MAX_VRING)
@@ -1747,18 +1737,7 @@ rte_vhost_async_channel_register_thread_unsafe(int vid,
uint16_t queue_id,
if (unlikely(vq == NULL || !dev->async_copy))
return -1;
- if (unlikely(!(config.features & RTE_VHOST_ASYNC_INORDER))) {
- VHOST_LOG_CONFIG(ERR,
- "async copy is not supported on non-inorder mode "
- "(vid %d, qid: %d)\n", vid, queue_id);
- return -1;
- }
-
- if (unlikely(ops->check_completed_copies == NULL ||
- ops->transfer_data == NULL))
- return -1;
-
- return async_channel_register(vid, queue_id, ops);
+ return async_channel_register(vid, queue_id);
}
int
@@ -1835,6 +1814,83 @@ rte_vhost_async_channel_unregister_thread_unsafe(int
vid, uint16_t queue_id)
return 0;
}
+static __rte_always_inline void
+vhost_free_async_dma_mem(void)
+{
+ uint16_t i;
+
+ for (i = 0; i < RTE_DMADEV_DEFAULT_MAX; i++) {
+ struct async_dma_info *dma = &dma_copy_track[i];
+ int16_t j;
+
+ if (dma->max_vchans == 0) {
+ continue;
+ }
+
+ for (j = 0; j < dma->max_vchans; j++) {
+ rte_free(dma->vchans[j].metadata);
+ }
+ rte_free(dma->vchans);
+ dma->vchans = NULL;
+ dma->max_vchans = 0;
+ }
+}
+
+int
+rte_vhost_async_dma_configure(struct rte_vhost_async_dma_info *dmas, uint16_t
count)
+{
+ uint16_t i;
+
+ if (!dmas) {
+ VHOST_LOG_CONFIG(ERR, "Invalid DMA configuration parameter.\n");
+ return -1;
+ }
+
+ for (i = 0; i < count; i++) {
+ struct async_dma_vchan_info *vchans;
+ int16_t dev_id;
+ uint16_t max_vchans;
+ uint16_t max_desc;
+ uint16_t j;
+
+ dev_id = dmas[i].dev_id;
+ max_vchans = dmas[i].max_vchans;
+ max_desc = dmas[i].max_desc;
+
+ if (!rte_is_power_of_2(max_desc)) {
+ max_desc = rte_align32pow2(max_desc);
+ }
That will be problematic with CNXK driver that reports 15 as max_desc.
+
+ vchans = rte_zmalloc(NULL, sizeof(struct async_dma_vchan_info)
* max_vchans,
+ RTE_CACHE_LINE_SIZE);
+ if (vchans == NULL) {
+ VHOST_LOG_CONFIG(ERR, "Failed to allocate vchans for
dma-%d."
+ " Cannot enable async data-path.\n",
dev_id);
+ vhost_free_async_dma_mem();
+ return -1;
+ }
+
+ for (j = 0; j < max_vchans; j++) {
+ vchans[j].metadata = rte_zmalloc(NULL, sizeof(bool *) *
max_desc,
+ RTE_CACHE_LINE_SIZE);
That's quite a huge allocation (4096 * 8B per channel).
+ if (!vchans[j].metadata) {
+ VHOST_LOG_CONFIG(ERR, "Failed to allocate metadata
for "
+ "dma-%d vchan-%u\n", dev_id, j);
+ vhost_free_async_dma_mem();
+ return -1;
+ }
+
+ vchans[j].ring_size = max_desc;
+ vchans[j].ring_mask = max_desc - 1;
+ }
+
+ dma_copy_track[dev_id].vchans = vchans;
+ dma_copy_track[dev_id].max_vchans = max_vchans;
+ }
+
+ return 0;
+}
+
int
rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
{
diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index 7085e0885c..d9bda34e11 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -19,6 +19,7 @@
#include <rte_ether.h>
#include <rte_rwlock.h>
#include <rte_malloc.h>
+#include <rte_dmadev.h>
#include "rte_vhost.h"
#include "rte_vdpa.h"
@@ -50,6 +51,7 @@
#define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST)
#define VHOST_MAX_ASYNC_VEC 2048
+#define VHOST_ASYNC_DMA_BATCHING_SIZE 32
#define PACKED_DESC_ENQUEUE_USED_FLAG(w) \
((w) ? (VRING_DESC_F_AVAIL | VRING_DESC_F_USED | VRING_DESC_F_WRITE) : \
@@ -119,6 +121,41 @@ struct vring_used_elem_packed {
uint32_t count;
};
+struct async_dma_vchan_info {
+ /* circular array to track copy metadata */
+ bool **metadata;
+
+ /* max elements in 'metadata' */
+ uint16_t ring_size;
+ /* ring index mask for 'metadata' */
+ uint16_t ring_mask;
Given cnxk, we cannot use a mask as the ring size may not be a pow2.
+
+ /* batching copies before a DMA doorbell */
+ uint16_t nr_batching;
+
+ /**
+ * DMA virtual channel lock. Although it is able to bind DMA
+ * virtual channels to data plane threads, vhost control plane
+ * thread could call data plane functions too, thus causing
+ * DMA device contention.
+ *
+ * For example, in VM exit case, vhost control plane thread needs
+ * to clear in-flight packets before disable vring, but there could
+ * be anotther data plane thread is enqueuing packets to the same
+ * vring with the same DMA virtual channel. But dmadev PMD functions
+ * are lock-free, so the control plane and data plane threads
+ * could operate the same DMA virtual channel at the same time.
+ */
+ rte_spinlock_t dma_lock;
+};
+
+struct async_dma_info {
+ uint16_t max_vchans;
+ struct async_dma_vchan_info *vchans;
+};
+
+extern struct async_dma_info dma_copy_track[RTE_DMADEV_DEFAULT_MAX];
+
/**
* inflight async packet information
*/
@@ -129,9 +166,6 @@ struct async_inflight_info {
};
struct vhost_async {
- /* operation callbacks for DMA */
- struct rte_vhost_async_channel_ops ops;
-
struct rte_vhost_iov_iter iov_iter[VHOST_MAX_ASYNC_IT];
struct rte_vhost_iovec iovec[VHOST_MAX_ASYNC_VEC];
uint16_t iter_idx;
@@ -139,6 +173,19 @@ struct vhost_async {
/* data transfer status */
struct async_inflight_info *pkts_info;
+ /**
+ * packet reorder array. "true" indicates that DMA
+ * device completes all copies for the packet.
+ *
+ * Note that this array could be written by multiple
+ * threads at the same time. For example, two threads
+ * enqueue packets to the same virtqueue with their
+ * own DMA devices. However, since offloading is
+ * per-packet basis, each packet flag will only be
+ * written by one thread. And single byte write is
+ * atomic, so no lock is needed.
+ */
The vq->access_lock is held by the threads (directly or indirectly)
anyway, right?
+ bool *pkts_cmpl_flag;
uint16_t pkts_idx;
uint16_t pkts_inflight_n;
union {
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index b3d954aab4..9f81fc9733 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -11,6 +11,7 @@
#include <rte_net.h>
#include <rte_ether.h>
#include <rte_ip.h>
+#include <rte_dmadev.h>
#include <rte_vhost.h>
#include <rte_tcp.h>
#include <rte_udp.h>
@@ -25,6 +26,9 @@
#define MAX_BATCH_LEN 256
+/* DMA device copy operation tracking array. */
+struct async_dma_info dma_copy_track[RTE_DMADEV_DEFAULT_MAX];
+
static __rte_always_inline bool
rxvq_is_mergeable(struct virtio_net *dev)
{
@@ -43,6 +47,108 @@ is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t
nr_vring)
return (is_tx ^ (idx & 1)) == 0 && idx < nr_vring;
}
+static __rte_always_inline uint16_t
+vhost_async_dma_transfer(struct vhost_virtqueue *vq, int16_t dma_id,
+ uint16_t vchan, uint16_t head_idx,
+ struct rte_vhost_iov_iter *pkts, uint16_t nr_pkts)
+{
+ struct async_dma_vchan_info *dma_info =
&dma_copy_track[dma_id].vchans[vchan];
+ uint16_t ring_mask = dma_info->ring_mask;
+ uint16_t pkt_idx;
+
+ rte_spinlock_lock(&dma_info->dma_lock);
+
+ for (pkt_idx = 0; pkt_idx < nr_pkts; pkt_idx++) {
+ struct rte_vhost_iovec *iov = pkts[pkt_idx].iov;
+ int copy_idx = 0;
+ uint16_t nr_segs = pkts[pkt_idx].nr_segs;
+ uint16_t i;
+
+ if (rte_dma_burst_capacity(dma_id, vchan) < nr_segs) {
+ goto out;
+ }
+
+ for (i = 0; i < nr_segs; i++) {
+ /**
+ * We have checked the available space before submit
copies to DMA
+ * vChannel, so we don't handle error here.
+ */
+ copy_idx = rte_dma_copy(dma_id, vchan,
(rte_iova_t)iov[i].src_addr,
+ (rte_iova_t)iov[i].dst_addr, iov[i].len,
+ RTE_DMA_OP_FLAG_LLC);
+
+ /**
+ * Only store packet completion flag address in the
last copy's
+ * slot, and other slots are set to NULL.
+ */
+ if (unlikely(i == (nr_segs - 1))) {
I don't think using unlikely() is appropriate here, as single-segment
packets are more the norm than the exception, isn't?
+ dma_info->metadata[copy_idx & ring_mask] =
dma_info->metadata[copy_idx % ring_size] instead.
+ &vq->async->pkts_cmpl_flag[head_idx %
vq->size];
+ }
+ }
+
+ dma_info->nr_batching += nr_segs;
+ if (unlikely(dma_info->nr_batching >=
VHOST_ASYNC_DMA_BATCHING_SIZE)) {
+ rte_dma_submit(dma_id, vchan);
+ dma_info->nr_batching = 0;
+ }
+
+ head_idx++;
+ }
+
+out:
+ if (dma_info->nr_batching > 0) {
+ rte_dma_submit(dma_id, vchan);
+ dma_info->nr_batching = 0;
+ }
+ rte_spinlock_unlock(&dma_info->dma_lock);
+
+ return pkt_idx;
+}
+
+static __rte_always_inline uint16_t
+vhost_async_dma_check_completed(int16_t dma_id, uint16_t vchan, uint16_t
max_pkts)
+{
+ struct async_dma_vchan_info *dma_info =
&dma_copy_track[dma_id].vchans[vchan];
+ uint16_t ring_mask = dma_info->ring_mask;
+ uint16_t last_idx = 0;
+ uint16_t nr_copies;
+ uint16_t copy_idx;
+ uint16_t i;
+
+ rte_spinlock_lock(&dma_info->dma_lock);
+
+ /**
+ * Since all memory is pinned and addresses should be valid,
+ * we don't check errors.
Please, check for errors to ease debugging, you can for now add a debug
print if error is set which would print rte_errno. And once we have my
Vhost statistics series in, I could add a counter for it.
The DMA device could be in a bad state for other reason than unpinned
memory or unvalid addresses.
+ */
+ nr_copies = rte_dma_completed(dma_id, vchan, max_pkts, &last_idx, NULL);
Are you sure max_pkts is valid here as a packet could contain several
segments?
+ if (nr_copies == 0) {
+ goto out;
+ }
+
+ copy_idx = last_idx - nr_copies + 1;
+ for (i = 0; i < nr_copies; i++) {
+ bool *flag;
+
+ flag = dma_info->metadata[copy_idx & ring_mask];
dma_info->metadata[copy_idx % ring_size]
+ if (flag) {
+ /**
+ * Mark the packet flag as received. The flag
+ * could belong to another virtqueue but write
+ * is atomic.
+ */
+ *flag = true;
+ dma_info->metadata[copy_idx & ring_mask] = NULL;
dma_info->metadata[copy_idx % ring_size]
+ }
+ copy_idx++;
+ }
+
+out:
+ rte_spinlock_unlock(&dma_info->dma_lock);
+ return nr_copies;
+}
+
static inline void
do_data_copy_enqueue(struct virtio_net *dev, struct vhost_virtqueue *vq)
{
@@ -1449,9 +1555,9 @@ store_dma_desc_info_packed(struct vring_used_elem_packed
*s_ring,
}
static __rte_noinline uint32_t
-virtio_dev_rx_async_submit_split(struct virtio_net *dev,
- struct vhost_virtqueue *vq, uint16_t queue_id,
- struct rte_mbuf **pkts, uint32_t count)
+virtio_dev_rx_async_submit_split(struct virtio_net *dev, struct
vhost_virtqueue *vq,
+ uint16_t queue_id, struct rte_mbuf **pkts, uint32_t count,
+ int16_t dma_id, uint16_t vchan)
{
struct buf_vector buf_vec[BUF_VECTOR_MAX];
uint32_t pkt_idx = 0;
@@ -1503,17 +1609,16 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev,
if (unlikely(pkt_idx == 0))
return 0;
- n_xfer = async->ops.transfer_data(dev->vid, queue_id, async->iov_iter, 0, pkt_idx);
- if (unlikely(n_xfer < 0)) {
- VHOST_LOG_DATA(ERR, "(%d) %s: failed to transfer data for queue id
%d.\n",
- dev->vid, __func__, queue_id);
- n_xfer = 0;
- }
+ n_xfer = vhost_async_dma_transfer(vq, dma_id, vchan, async->pkts_idx,
async->iov_iter,
+ pkt_idx);
pkt_err = pkt_idx - n_xfer;
if (unlikely(pkt_err)) {
uint16_t num_descs = 0;
+ VHOST_LOG_DATA(DEBUG, "(%d) %s: failed to transfer %u packets for queue %u.\n",
+ dev->vid, __func__, pkt_err, queue_id);
+
/* update number of completed packets */
pkt_idx = n_xfer;
@@ -1656,13 +1761,13 @@ dma_error_handler_packed(struct vhost_virtqueue *vq, uint16_t slot_idx,
}
static __rte_noinline uint32_t
-virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
- struct vhost_virtqueue *vq, uint16_t queue_id,
- struct rte_mbuf **pkts, uint32_t count)
+virtio_dev_rx_async_submit_packed(struct virtio_net *dev, struct
vhost_virtqueue *vq,
+ uint16_t queue_id, struct rte_mbuf **pkts, uint32_t count,
+ int16_t dma_id, uint16_t vchan)
{
uint32_t pkt_idx = 0;
uint32_t remained = count;
- int32_t n_xfer;
+ uint16_t n_xfer;
uint16_t num_buffers;
uint16_t num_descs;
@@ -1670,6 +1775,7 @@ virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
struct async_inflight_info *pkts_info = async->pkts_info;
uint32_t pkt_err = 0;
uint16_t slot_idx = 0;
+ uint16_t head_idx = async->pkts_idx % vq->size;
do {
rte_prefetch0(&vq->desc_packed[vq->last_avail_idx]);
@@ -1694,19 +1800,17 @@ virtio_dev_rx_async_submit_packed(struct virtio_net
*dev,
if (unlikely(pkt_idx == 0))
return 0;
- n_xfer = async->ops.transfer_data(dev->vid, queue_id, async->iov_iter, 0, pkt_idx);
- if (unlikely(n_xfer < 0)) {
- VHOST_LOG_DATA(ERR, "(%d) %s: failed to transfer data for queue id
%d.\n",
- dev->vid, __func__, queue_id);
- n_xfer = 0;
- }
-
- pkt_err = pkt_idx - n_xfer;
+ n_xfer = vhost_async_dma_transfer(vq, dma_id, vchan, head_idx,
+ async->iov_iter, pkt_idx);
async_iter_reset(async);
- if (unlikely(pkt_err))
+ pkt_err = pkt_idx - n_xfer;
+ if (unlikely(pkt_err)) {
+ VHOST_LOG_DATA(DEBUG, "(%d) %s: failed to transfer %u packets for
queue %u.\n",
+ dev->vid, __func__, pkt_err, queue_id);
dma_error_handler_packed(vq, slot_idx, pkt_err, &pkt_idx);
+ }
if (likely(vq->shadow_used_idx)) {
/* keep used descriptors. */
@@ -1826,28 +1930,37 @@ write_back_completed_descs_packed(struct
vhost_virtqueue *vq,
static __rte_always_inline uint16_t
vhost_poll_enqueue_completed(struct virtio_net *dev, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count)
+ struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
+ uint16_t vchan)
{
struct vhost_virtqueue *vq = dev->virtqueue[queue_id];
struct vhost_async *async = vq->async;
struct async_inflight_info *pkts_info = async->pkts_info;
- int32_t n_cpl;
+ uint16_t nr_cpl_pkts = 0;
uint16_t n_descs = 0, n_buffers = 0;
uint16_t start_idx, from, i;
- n_cpl = async->ops.check_completed_copies(dev->vid, queue_id, 0, count);
- if (unlikely(n_cpl < 0)) {
- VHOST_LOG_DATA(ERR, "(%d) %s: failed to check completed copies for
queue id %d.\n",
- dev->vid, __func__, queue_id);
- return 0;
- }
-
- if (n_cpl == 0)
- return 0;
+ /* Check completed copies for the given DMA vChannel */
+ vhost_async_dma_check_completed(dma_id, vchan, count);
start_idx = async_get_first_inflight_pkt_idx(vq);
- for (i = 0; i < n_cpl; i++) {
+ /**
+ * Calculate the number of copy completed packets.
+ * Note that there may be completed packets even if
+ * no copies are reported done by the given DMA vChannel,
+ * as DMA vChannels could be shared by other threads.
+ */
+ from = start_idx;
+ while (vq->async->pkts_cmpl_flag[from] && count--) {
+ vq->async->pkts_cmpl_flag[from] = false;
+ from++;
+ if (from >= vq->size)
+ from -= vq->size;
+ nr_cpl_pkts++;
+ }
+
+ for (i = 0; i < nr_cpl_pkts; i++) {
from = (start_idx + i) % vq->size;
/* Only used with packed ring */
n_buffers += pkts_info[from].nr_buffers;
@@ -1856,7 +1969,7 @@ vhost_poll_enqueue_completed(struct virtio_net *dev,
uint16_t queue_id,
pkts[i] = pkts_info[from].mbuf;
}
- async->pkts_inflight_n -= n_cpl;
+ async->pkts_inflight_n -= nr_cpl_pkts;
if (likely(vq->enabled && vq->access_ok)) {
if (vq_is_packed(dev)) {
@@ -1877,12 +1990,13 @@ vhost_poll_enqueue_completed(struct virtio_net *dev,
uint16_t queue_id,
}
}
- return n_cpl;
+ return nr_cpl_pkts;
}
uint16_t
rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count)
+ struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
+ uint16_t vchan)
{
struct virtio_net *dev = get_device(vid);
struct vhost_virtqueue *vq;
@@ -1908,7 +2022,7 @@ rte_vhost_poll_enqueue_completed(int vid, uint16_t
queue_id,
rte_spinlock_lock(&vq->access_lock);
- n_pkts_cpl = vhost_poll_enqueue_completed(dev, queue_id, pkts, count);
+ n_pkts_cpl = vhost_poll_enqueue_completed(dev, queue_id, pkts, count,
dma_id, vchan);
rte_spinlock_unlock(&vq->access_lock);
@@ -1917,7 +2031,8 @@ rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
uint16_t
rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count)
+ struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
+ uint16_t vchan)
{
struct virtio_net *dev = get_device(vid);
struct vhost_virtqueue *vq;
@@ -1941,14 +2056,14 @@ rte_vhost_clear_queue_thread_unsafe(int vid, uint16_t
queue_id,
return 0;
}
- n_pkts_cpl = vhost_poll_enqueue_completed(dev, queue_id, pkts, count);
+ n_pkts_cpl = vhost_poll_enqueue_completed(dev, queue_id, pkts, count,
dma_id, vchan);
return n_pkts_cpl;
}
static __rte_always_inline uint32_t
virtio_dev_rx_async_submit(struct virtio_net *dev, uint16_t queue_id,
- struct rte_mbuf **pkts, uint32_t count)
+ struct rte_mbuf **pkts, uint32_t count, int16_t dma_id, uint16_t vchan)
{
struct vhost_virtqueue *vq;
uint32_t nb_tx = 0;
@@ -1980,10 +2095,10 @@ virtio_dev_rx_async_submit(struct virtio_net *dev,
uint16_t queue_id,
if (vq_is_packed(dev))
nb_tx = virtio_dev_rx_async_submit_packed(dev, vq, queue_id,
- pkts, count);
+ pkts, count, dma_id, vchan);
else
nb_tx = virtio_dev_rx_async_submit_split(dev, vq, queue_id,
- pkts, count);
+ pkts, count, dma_id, vchan);
out:
if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM))
@@ -1997,7 +2112,8 @@ virtio_dev_rx_async_submit(struct virtio_net *dev,
uint16_t queue_id,
uint16_t
rte_vhost_submit_enqueue_burst(int vid, uint16_t queue_id,
- struct rte_mbuf **pkts, uint16_t count)
+ struct rte_mbuf **pkts, uint16_t count, int16_t dma_id,
+ uint16_t vchan)
{
struct virtio_net *dev = get_device(vid);
@@ -2011,7 +2127,7 @@ rte_vhost_submit_enqueue_burst(int vid, uint16_t queue_id,
return 0;
}
- return virtio_dev_rx_async_submit(dev, queue_id, pkts, count);
+ return virtio_dev_rx_async_submit(dev, queue_id, pkts, count, dma_id,
vchan);
}
static inline bool
