d/numam-dpdk
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

net/virtio-user: enable multiqueue with kernel vhost

Browse Source 
With vhost kernel, to enable multiqueue, we need backend device
in kernel support multiqueue feature. Specifically, with tap
as the backend, as linux/Documentation/networking/tuntap.txt shows,
we check if tap supports IFF_MULTI_QUEUE feature.

And for vhost kernel, each queue pair has a vhost fd, and with a tap
fd binding this vhost fd. All tap fds are set with the same tap
interface name.

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
Acked-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
This commit is contained in:
Jianfeng Tan 2017-01-13 12:18:40 +00:00 committed by Yuanhan Liu
parent 5e97e42025
commit be7a4707f7
4 changed files with 67 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

68
drivers/net/virtio/virtio_user/vhost_kernel.c
View File

@ -187,6 +187,29 @@ prepare_vhost_memory_kernel(void)
(1ULL << VIRTIO_NET_F_HOST_TSO6) | \
(1ULL << VIRTIO_NET_F_CSUM))
static int
tap_supporte_mq(void)
{
int tapfd;
unsigned int tap_features;
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;
}
if (ioctl(tapfd, TUNGETFEATURES, &tap_features) == -1) {
PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
close(tapfd);
return -1;
}
close(tapfd);
return tap_features & IFF_MULTI_QUEUE;
}
static int
vhost_kernel_ioctl(struct virtio_user_dev *dev,
enum vhost_user_request req,
@ -196,6 +219,8 @@ vhost_kernel_ioctl(struct virtio_user_dev *dev,
unsigned int i;
uint64_t req_kernel;
struct vhost_memory_kernel *vm = NULL;
int vhostfd;
unsigned int queue_sel;
PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
@ -215,15 +240,37 @@ vhost_kernel_ioctl(struct virtio_user_dev *dev,
/* VHOST kernel does not know about below flags */
*(uint64_t *)arg &= ~VHOST_KERNEL_GUEST_OFFLOADS_MASK;
*(uint64_t *)arg &= ~VHOST_KERNEL_HOST_OFFLOADS_MASK;
*(uint64_t *)arg &= ~(1ULL << VIRTIO_NET_F_MQ);
}
for (i = 0; i < dev->max_queue_pairs; ++i) {
if (dev->vhostfds[i] < 0)
continue;
switch (req_kernel) {
case VHOST_SET_VRING_NUM:
case VHOST_SET_VRING_ADDR:
case VHOST_SET_VRING_BASE:
case VHOST_GET_VRING_BASE:
case VHOST_SET_VRING_KICK:
case VHOST_SET_VRING_CALL:
queue_sel = *(unsigned int *)arg;
vhostfd = dev->vhostfds[queue_sel / 2];
*(unsigned int *)arg = queue_sel % 2;
PMD_DRV_LOG(DEBUG, "vhostfd=%d, index=%u",
vhostfd, *(unsigned int *)arg);
break;
default:
vhostfd = -1;
}
if (vhostfd == -1) {
for (i = 0; i < dev->max_queue_pairs; ++i) {
if (dev->vhostfds[i] < 0)
continue;
ret = ioctl(dev->vhostfds[i], req_kernel, arg);
if (ret < 0)
break;
ret = ioctl(dev->vhostfds[i], req_kernel, arg);
if (ret < 0)
break;
}
} else {
ret = ioctl(vhostfd, req_kernel, arg);
}
if (!ret && req_kernel == VHOST_GET_FEATURES) {
@ -233,6 +280,12 @@ vhost_kernel_ioctl(struct virtio_user_dev *dev,
*/
*((uint64_t *)arg) |= VHOST_KERNEL_GUEST_OFFLOADS_MASK;
*((uint64_t *)arg) |= VHOST_KERNEL_HOST_OFFLOADS_MASK;
/* vhost_kernel will not declare this feature, but it does
* support multi-queue.
*/
if (tap_supporte_mq())
*(uint64_t *)arg |= (1ull << VIRTIO_NET_F_MQ);
}
if (vm)
@ -305,6 +358,7 @@ vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
int hdr_size;
int vhostfd;
int tapfd;
int req_mq = (dev->max_queue_pairs > 1);
vhostfd = dev->vhostfds[pair_idx];
@ -324,7 +378,7 @@ vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
else
hdr_size = sizeof(struct virtio_net_hdr);
tapfd = vhost_kernel_open_tap(&dev->ifname, hdr_size);
tapfd = vhost_kernel_open_tap(&dev->ifname, hdr_size, req_mq);
if (tapfd < 0) {
PMD_DRV_LOG(ERR, "fail to open tap for vhost kernel");
return -1;

5
drivers/net/virtio/virtio_user/vhost_kernel_tap.c
View File

@ -44,7 +44,7 @@
#include "../virtio_logs.h"
int
vhost_kernel_open_tap(char **p_ifname, int hdr_size)
vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq)
{
unsigned int tap_features;
int sndbuf = INT_MAX;
@ -91,6 +91,9 @@ vhost_kernel_open_tap(char **p_ifname, int hdr_size)
goto error;
}
if (req_mq)
ifr.ifr_flags |= IFF_MULTI_QUEUE;
if (*p_ifname)
strncpy(ifr.ifr_name, *p_ifname, IFNAMSIZ);
else

2
drivers/net/virtio/virtio_user/vhost_kernel_tap.h
View File

@ -64,4 +64,4 @@
/* Constants */
#define PATH_NET_TUN "/dev/net/tun"
int vhost_kernel_open_tap(char **p_ifname, int hdr_size);
int vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq);

1
drivers/net/virtio/virtio_user/virtio_user_dev.c
View File

@ -93,6 +93,7 @@ virtio_user_kick_queue(struct virtio_user_dev *dev, uint32_t queue_sel)
state.num = vring->num;
dev->ops->send_request(dev, VHOST_USER_SET_VRING_NUM, &state);
state.index = queue_sel;
state.num = 0; /* no reservation */
dev->ops->send_request(dev, VHOST_USER_SET_VRING_BASE, &state);