[dpdk-dev] [PATCH 2/3] net/virtio_user: add vhost kernel support
Jianfeng Tan
jianfeng.tan at intel.com
Fri Dec 2 15:31:14 CET 2016
This patch add support vhost kernel support under vhost abstraction
layer.
Three main hook functions are added:
- vhost_kernel_setup() to open char device, each vq pair (Rx and Tx)
would need open it once;
- vhost_kernel_ioctl() to communicate control messages with vhost
kernel module;
- vhost_kernel_enable_queue_pair() to open tap device and set it
as the backend of corresonding vhost fd (that is to say, vq pair).
Signed-off-by: Jianfeng Tan <jianfeng.tan at intel.com>
---
drivers/net/virtio/Makefile | 1 +
drivers/net/virtio/virtio_user/vhost.c | 21 +-
drivers/net/virtio/virtio_user/vhost.h | 5 +
drivers/net/virtio/virtio_user/vhost_kernel.c | 413 ++++++++++++++++++++++++++
4 files changed, 439 insertions(+), 1 deletion(-)
create mode 100644 drivers/net/virtio/virtio_user/vhost_kernel.c
diff --git a/drivers/net/virtio/Makefile b/drivers/net/virtio/Makefile
index 17f7129..f671f1f 100644
--- a/drivers/net/virtio/Makefile
+++ b/drivers/net/virtio/Makefile
@@ -61,6 +61,7 @@ endif
ifeq ($(CONFIG_RTE_VIRTIO_USER),y)
SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost.c
SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost_user.c
+SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/vhost_kernel.c
SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user/virtio_user_dev.c
SRCS-$(CONFIG_RTE_LIBRTE_VIRTIO_PMD) += virtio_user_ethdev.c
endif
diff --git a/drivers/net/virtio/virtio_user/vhost.c b/drivers/net/virtio/virtio_user/vhost.c
index 09e2e92..5384992 100644
--- a/drivers/net/virtio/virtio_user/vhost.c
+++ b/drivers/net/virtio/virtio_user/vhost.c
@@ -56,7 +56,7 @@ vhost_internal_valid_vid(int vid)
static int
vhost_internal_alloc(void)
{
- int i;
+ int i, q;
for (i = 0; i < VHOST_MAX_DEVICES; ++i)
if (internals[i].ops == NULL)
@@ -69,16 +69,32 @@ vhost_internal_alloc(void)
internals[i].vhostfd = -1;
+ for (q = 0; q < VHOST_KERNEL_MAX_QUEUES; ++q) {
+ internals[i].vhostfds[q] = -1;
+ internals[i].tapfds[q] = -1;
+ }
+
return 0;
}
static void
vhost_internal_free(int id)
{
+ int q;
+
internals[id].ops = NULL;
if (internals[id].vhostfd >= 0)
close(internals[id].vhostfd);
+
+ for (q = 0; q < VHOST_KERNEL_MAX_QUEUES; ++q) {
+ if (internals[id].vhostfds[q] >= 0)
+ close(internals[id].vhostfds[q]);
+ if (internals[id].tapfds[q] >= 0)
+ close(internals[id].tapfds[q]);
+ }
+ if (internals[id].ifname)
+ free(internals[id].ifname);
}
@@ -107,6 +123,9 @@ vhost_setup(const char *path)
if (is_vhost_user_by_type(path)) {
ret = vhost_ops_user.setup(&internals[vid], path);
internals[vid].ops = &vhost_ops_user;
+ } else {
+ ret = vhost_ops_kernel.setup(&internals[vid], path);
+ internals[vid].ops = &vhost_ops_kernel;
}
if (ret < 0)
diff --git a/drivers/net/virtio/virtio_user/vhost.h b/drivers/net/virtio/virtio_user/vhost.h
index b476ecc..b6fd092 100644
--- a/drivers/net/virtio/virtio_user/vhost.h
+++ b/drivers/net/virtio/virtio_user/vhost.h
@@ -114,6 +114,10 @@ struct vhost_internal {
int vhostfd;
/* for vhost-kernel */
+ char *ifname;
+#define VHOST_KERNEL_MAX_QUEUES 8
+ int vhostfds[VHOST_KERNEL_MAX_QUEUES];
+ int tapfds[VHOST_KERNEL_MAX_QUEUES];
};
typedef int (*vhost_setup_t)(struct vhost_internal *internal,
@@ -132,6 +136,7 @@ struct vhost_ops {
};
struct vhost_ops vhost_ops_user;
+struct vhost_ops vhost_ops_kernel;
int vhost_setup(const char *path);
int vhost_call(int vid, enum vhost_user_request req, void *arg);
diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c b/drivers/net/virtio/virtio_user/vhost_kernel.c
new file mode 100644
index 0000000..9a9e8bd
--- /dev/null
+++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
@@ -0,0 +1,413 @@
+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2010-2016 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <net/if.h>
+#include <string.h>
+#include <errno.h>
+
+#include <rte_memory.h>
+#include <rte_eal_memconfig.h>
+
+#include "vhost.h"
+
+struct vhost_memory_kernel {
+ uint32_t nregions;
+ uint32_t padding;
+ struct vhost_memory_region regions[0];
+};
+
+/* vhost kernel ioctls */
+#define VHOST_VIRTIO 0xAF
+#define VHOST_GET_FEATURES _IOR(VHOST_VIRTIO, 0x00, __u64)
+#define VHOST_SET_FEATURES _IOW(VHOST_VIRTIO, 0x00, __u64)
+#define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
+#define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
+#define VHOST_SET_MEM_TABLE _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory_kernel)
+#define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
+#define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
+#define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
+#define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
+#define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
+#define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
+#define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
+#define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
+#define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
+#define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
+
+/* TUN ioctls */
+#define TUNSETIFF _IOW('T', 202, int)
+#define TUNGETFEATURES _IOR('T', 207, unsigned int)
+#define TUNSETOFFLOAD _IOW('T', 208, unsigned int)
+#define TUNGETIFF _IOR('T', 210, unsigned int)
+#define TUNSETSNDBUF _IOW('T', 212, int)
+#define TUNGETVNETHDRSZ _IOR('T', 215, int)
+#define TUNSETVNETHDRSZ _IOW('T', 216, int)
+#define TUNSETQUEUE _IOW('T', 217, int)
+#define TUNSETVNETLE _IOW('T', 220, int)
+#define TUNSETVNETBE _IOW('T', 222, int)
+
+/* TUNSETIFF ifr flags */
+#define IFF_TAP 0x0002
+#define IFF_NO_PI 0x1000
+#define IFF_ONE_QUEUE 0x2000
+#define IFF_VNET_HDR 0x4000
+#define IFF_MULTI_QUEUE 0x0100
+#define IFF_ATTACH_QUEUE 0x0200
+#define IFF_DETACH_QUEUE 0x0400
+
+/* Features for GSO (TUNSETOFFLOAD). */
+#define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */
+#define TUN_F_TSO4 0x02 /* I can handle TSO for IPv4 packets */
+#define TUN_F_TSO6 0x04 /* I can handle TSO for IPv6 packets */
+#define TUN_F_TSO_ECN 0x08 /* I can handle TSO with ECN bits. */
+#define TUN_F_UFO 0x10 /* I can handle UFO packets */
+
+/* Constants */
+#define TUN_DEF_SNDBUF (1ull << 20)
+#define PATH_NET_TUN "/dev/net/tun"
+#define VHOST_KERNEL_MAX_REGIONS 64
+
+static uint64_t vhost_req_user_to_kernel[] = {
+ [VHOST_USER_SET_OWNER] = VHOST_SET_OWNER,
+ [VHOST_USER_RESET_OWNER] = VHOST_RESET_OWNER,
+ [VHOST_USER_SET_FEATURES] = VHOST_SET_FEATURES,
+ [VHOST_USER_GET_FEATURES] = VHOST_GET_FEATURES,
+ [VHOST_USER_SET_VRING_CALL] = VHOST_SET_VRING_CALL,
+ [VHOST_USER_SET_VRING_NUM] = VHOST_SET_VRING_NUM,
+ [VHOST_USER_SET_VRING_BASE] = VHOST_SET_VRING_BASE,
+ [VHOST_USER_GET_VRING_BASE] = VHOST_GET_VRING_BASE,
+ [VHOST_USER_SET_VRING_ADDR] = VHOST_SET_VRING_ADDR,
+ [VHOST_USER_SET_VRING_KICK] = VHOST_SET_VRING_KICK,
+ [VHOST_USER_SET_MEM_TABLE] = VHOST_SET_MEM_TABLE,
+};
+
+/* By default, vhost kernel module allows 64 regions, but DPDK allows
+ * 256 segments. As a relief, below function merges those virtually
+ * adjacent memsegs into one region.
+ */
+static struct vhost_memory_kernel *
+prepare_vhost_memory_kernel(void)
+{
+ uint32_t i, j, k = 0;
+ struct rte_memseg *seg;
+ struct vhost_memory_region *mr;
+ struct vhost_memory_kernel *vm;
+
+ vm = malloc(sizeof(struct vhost_memory_kernel) +
+ VHOST_KERNEL_MAX_REGIONS *
+ sizeof(struct vhost_memory_region));
+
+ for (i = 0; i < RTE_MAX_MEMSEG; ++i) {
+ seg = &rte_eal_get_configuration()->mem_config->memseg[i];
+ if (!seg->addr)
+ break;
+
+ int new_region = 1;
+
+ for (j = 0; j < k; ++j) {
+ mr = &vm->regions[j];
+
+ if (mr->userspace_addr + mr->memory_size ==
+ (uint64_t)seg->addr) {
+ mr->memory_size += seg->len;
+ new_region = 0;
+ break;
+ }
+
+ if ((uint64_t)seg->addr + seg->len ==
+ mr->userspace_addr) {
+ mr->guest_phys_addr = (uint64_t)seg->addr;
+ mr->userspace_addr = (uint64_t)seg->addr;
+ mr->memory_size += seg->len;
+ new_region = 0;
+ break;
+ }
+ }
+
+ if (new_region == 0)
+ continue;
+
+ mr = &vm->regions[k++];
+ mr->guest_phys_addr = (uint64_t)seg->addr; /* use vaddr here! */
+ mr->userspace_addr = (uint64_t)seg->addr;
+ mr->memory_size = seg->len;
+ mr->mmap_offset = 0;
+
+ if (k >= VHOST_KERNEL_MAX_REGIONS) {
+ free(vm);
+ return NULL;
+ }
+ }
+
+ vm->nregions = k;
+ vm->padding = 0;
+ return vm;
+}
+
+static const uint64_t guest_offloads_mask =
+ (1ULL << VIRTIO_NET_F_GUEST_CSUM) |
+ (1ULL << VIRTIO_NET_F_GUEST_TSO4) |
+ (1ULL << VIRTIO_NET_F_GUEST_TSO6) |
+ (1ULL << VIRTIO_NET_F_GUEST_ECN) |
+ (1ULL << VIRTIO_NET_F_GUEST_UFO);
+
+static int
+vhost_kernel_ioctl(struct vhost_internal *internal,
+ enum vhost_user_request req,
+ void *arg)
+{
+ int i, ret = -1;
+ uint64_t req_kernel;
+ struct vhost_memory_kernel *vm = NULL;
+
+ req_kernel = vhost_req_user_to_kernel[req];
+
+ if (req_kernel == VHOST_SET_MEM_TABLE) {
+ vm = prepare_vhost_memory_kernel();
+ if (!vm)
+ return -1;
+ arg = (void *)vm;
+ }
+
+ /* Does not work when VIRTIO_F_IOMMU_PLATFORM now, why? */
+ if (req_kernel == VHOST_SET_FEATURES)
+ *(uint64_t *)arg &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
+
+ for (i = 0; i < VHOST_KERNEL_MAX_QUEUES; ++i) {
+ if (internal->vhostfds[i] < 0)
+ continue;
+
+ ret = ioctl(internal->vhostfds[i], req_kernel, arg);
+ if (ret < 0)
+ break;
+ }
+
+ if (!ret && req_kernel == VHOST_SET_FEATURES)
+ internal->features = *((uint64_t *)arg);
+
+ /* with tap as the backend, all these features are supported but not
+ * claimed by vhost-net, so we add them back when reporting to upper
+ * layer
+ */
+ if (!ret && req_kernel == VHOST_GET_FEATURES)
+ *((uint64_t *)arg) |= guest_offloads_mask;
+
+ if (vm)
+ free(vm);
+
+ return ret;
+}
+
+/**
+ * Set up environment to talk with a vhost kernel backend.
+ * @param path
+ * - The path to vhost net (kernel) character file.
+ *
+ * @return
+ * - (-1) if fail to set up;
+ * - (>=0) if successful.
+ */
+static int
+vhost_kernel_setup(struct vhost_internal *internal, const char *path)
+{
+ int vhostfd;
+ uint32_t q;
+ uint32_t queue_pairs = 1;
+
+ for (q = 0; q < queue_pairs; ++q) {
+ vhostfd = open(path, O_RDWR);
+ if (vhostfd < 0) {
+ PMD_DRV_LOG(ERR, "fail to open %s, %s",
+ path, strerror(errno));
+ return -1;
+ }
+
+ internal->vhostfds[q] = vhostfd;
+ }
+
+ return 0;
+}
+
+static int
+_vhost_kernel_enable_queue_pair(int vhostfd, int tapfd)
+{
+ struct vhost_vring_file f;
+
+ f.fd = tapfd;
+ f.index = 0;
+ if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
+ PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
+ strerror(errno));
+ return -1;
+ }
+
+ f.index = 1;
+ if (ioctl(vhostfd, VHOST_NET_SET_BACKEND, &f) < 0) {
+ PMD_DRV_LOG(ERR, "VHOST_NET_SET_BACKEND fails, %s",
+ strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+static int
+vhost_kernel_enable_queue_pair(struct vhost_internal *internal,
+ uint16_t pair_idx,
+ int enable)
+{
+ unsigned int offload =
+ TUN_F_CSUM |
+ TUN_F_TSO4 |
+ TUN_F_TSO6 |
+ TUN_F_TSO_ECN |
+ TUN_F_UFO;
+ unsigned int features;
+ int sndbuf = TUN_DEF_SNDBUF;
+ struct ifreq ifr;
+ int hdr_size;
+ int vhostfd;
+ int tapfd;
+ int req_mq;
+
+
+ vhostfd = internal->vhostfds[pair_idx];
+
+ if (!enable) {
+ if (internal->tapfds[pair_idx]) {
+ close(internal->tapfds[pair_idx]);
+ internal->tapfds[pair_idx] = -1;
+ }
+ return _vhost_kernel_enable_queue_pair(vhostfd, -1);
+ }
+
+ if ((internal->features & (1ULL << VIRTIO_NET_F_MRG_RXBUF)) ||
+ (internal->features & (1ULL << VIRTIO_F_VERSION_1)))
+ hdr_size = sizeof(struct virtio_net_hdr_mrg_rxbuf);
+ else
+ hdr_size = sizeof(struct virtio_net_hdr);
+
+ req_mq = !!(internal->features & (1ULL << VIRTIO_NET_F_MQ));
+
+ /* TODO:
+ * 1. get/set offload capability, tap_probe_has_ufo, tap_fd_set_offload
+ * 2. verify we can get/set vnet_hdr_len, tap_probe_vnet_hdr_len
+ * 3. get number of memory regions from vhost module parameter
+ * max_mem_regions, supported in newer version linux kernel
+ */
+ tapfd = open(PATH_NET_TUN, O_RDWR);
+ if (tapfd < 0) {
+ PMD_DRV_LOG(ERR, "fail to open %s: %s",
+ PATH_NET_TUN, strerror(errno));
+ return -1;
+ }
+
+ /* Construct ifr */
+ memset(&ifr, 0, sizeof(ifr));
+ ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+
+ if (ioctl(tapfd, TUNGETFEATURES, &features) == -1) {
+ PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
+ goto error;
+ }
+ if (features & IFF_ONE_QUEUE)
+ ifr.ifr_flags |= IFF_ONE_QUEUE;
+
+ /* Let tap instead of vhost-net handle vnet header, as the latter does
+ * not support offloading. And in this case, we should not set feature
+ * bit VHOST_NET_F_VIRTIO_NET_HDR.
+ */
+ if (features & IFF_VNET_HDR) {
+ ifr.ifr_flags |= IFF_VNET_HDR;
+ } else {
+ PMD_DRV_LOG(ERR, "TAP does not support IFF_VNET_HDR");
+ goto error;
+ }
+
+ if (req_mq) {
+ if (features & IFF_MULTI_QUEUE)
+ ifr.ifr_flags |= IFF_MULTI_QUEUE;
+ else {
+ PMD_DRV_LOG(ERR, "multiqueue not supported by kernel");
+ goto error;
+ }
+ }
+
+ if (internal->ifname)
+ strncpy(ifr.ifr_name, internal->ifname, IFNAMSIZ);
+ else
+ strncpy(ifr.ifr_name, "tap%d", IFNAMSIZ);
+ if (ioctl(tapfd, TUNSETIFF, (void *)&ifr) == -1) {
+ PMD_DRV_LOG(ERR, "TUNSETIFF failed: %s", strerror(errno));
+ goto error;
+ }
+
+ fcntl(tapfd, F_SETFL, O_NONBLOCK);
+
+ if (ioctl(tapfd, TUNSETVNETHDRSZ, &hdr_size) < 0) {
+ PMD_DRV_LOG(ERR, "TUNSETVNETHDRSZ failed: %s", strerror(errno));
+ goto error;
+ }
+
+ if (ioctl(tapfd, TUNSETSNDBUF, &sndbuf) < 0) {
+ PMD_DRV_LOG(ERR, "TUNSETSNDBUF failed: %s", strerror(errno));
+ goto error;
+ }
+
+ if (_vhost_kernel_enable_queue_pair(vhostfd, tapfd) < 0)
+ goto error;
+
+ /* Only try best to set offload */
+ if (ioctl(tapfd, TUNSETOFFLOAD, offload) != 0)
+ PMD_DRV_LOG(ERR, "TUNSETOFFLOAD ioctl() failed: %s",
+ strerror(errno));
+
+ internal->tapfds[pair_idx] = tapfd;
+ if (!internal->ifname)
+ internal->ifname = strdup(ifr.ifr_name);
+
+ return 0;
+error:
+ return -1;
+}
+
+struct vhost_ops vhost_ops_kernel = {
+ .setup = vhost_kernel_setup,
+ .control = vhost_kernel_ioctl,
+ .enable_qp = vhost_kernel_enable_queue_pair
+};
--
2.7.4
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