net/virtio: support NAPI when using vhost_net backend
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Commit Message
In patch [1], NAPI has been supported in kernel tun driver to accelerate
packet processing received from vhost_net. This will greatly improve the
throughput of the tap device in the vhost_net backend.
[1]: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=fb3f903769e8
Signed-off-by: Harold Huang <baymaxhuang@gmail.com>
---
drivers/net/virtio/virtio_user/vhost_kernel.c | 9 +++++++--
drivers/net/virtio/virtio_user/vhost_kernel_tap.c | 4 ++--
drivers/net/virtio/virtio_user/vhost_kernel_tap.h | 3 ++-
3 files changed, 11 insertions(+), 5 deletions(-)
Comments
Hi Harold,
On 3/2/22 10:41, Harold Huang wrote:
> In patch [1], NAPI has been supported in kernel tun driver to accelerate
> packet processing received from vhost_net. This will greatly improve the
> throughput of the tap device in the vhost_net backend.
>
> [1]: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=fb3f903769e8
>
> Signed-off-by: Harold Huang <baymaxhuang@gmail.com>
> ---
> drivers/net/virtio/virtio_user/vhost_kernel.c | 9 +++++++--
> drivers/net/virtio/virtio_user/vhost_kernel_tap.c | 4 ++--
> drivers/net/virtio/virtio_user/vhost_kernel_tap.h | 3 ++-
> 3 files changed, 11 insertions(+), 5 deletions(-)
>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Thanks,
Maxime
On 3/2/22 10:41, Harold Huang wrote:
> In patch [1], NAPI has been supported in kernel tun driver to accelerate
> packet processing received from vhost_net. This will greatly improve the
> throughput of the tap device in the vhost_net backend.
>
> [1]: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=fb3f903769e8
>
> Signed-off-by: Harold Huang <baymaxhuang@gmail.com>
> ---
> drivers/net/virtio/virtio_user/vhost_kernel.c | 9 +++++++--
> drivers/net/virtio/virtio_user/vhost_kernel_tap.c | 4 ++--
> drivers/net/virtio/virtio_user/vhost_kernel_tap.h | 3 ++-
> 3 files changed, 11 insertions(+), 5 deletions(-)
>
Applied to dpdk-next-virtio/main.
Thanks,
Maxime
@@ -383,6 +383,7 @@ vhost_kernel_setup(struct virtio_user_dev *dev)
struct vhost_kernel_data *data;
unsigned int tap_features;
unsigned int tap_flags;
+ unsigned int r_flags;
const char *ifname;
uint32_t q, i;
int vhostfd;
@@ -394,6 +395,10 @@ vhost_kernel_setup(struct virtio_user_dev *dev)
PMD_INIT_LOG(ERR, "TAP does not support IFF_VNET_HDR");
return -1;
}
+ r_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
+
+ if (tap_features & IFF_NAPI)
+ r_flags |= IFF_NAPI;
data = malloc(sizeof(*data));
if (!data) {
@@ -429,7 +434,7 @@ vhost_kernel_setup(struct virtio_user_dev *dev)
}
ifname = dev->ifname != NULL ? dev->ifname : "tap%d";
- data->tapfds[0] = tap_open(ifname, (tap_features & IFF_MULTI_QUEUE) != 0);
+ data->tapfds[0] = tap_open(ifname, r_flags, (tap_features & IFF_MULTI_QUEUE) != 0);
if (data->tapfds[0] < 0)
goto err_tapfds;
if (dev->ifname == NULL && tap_get_name(data->tapfds[0], &dev->ifname) < 0) {
@@ -446,7 +451,7 @@ vhost_kernel_setup(struct virtio_user_dev *dev)
}
for (i = 1; i < dev->max_queue_pairs; i++) {
- data->tapfds[i] = tap_open(dev->ifname, true);
+ data->tapfds[i] = tap_open(dev->ifname, r_flags, true);
if (data->tapfds[i] < 0)
goto err_tapfds;
}
@@ -42,7 +42,7 @@ tap_support_features(unsigned int *tap_features)
}
int
-tap_open(const char *ifname, bool multi_queue)
+tap_open(const char *ifname, unsigned int r_flags, bool multi_queue)
{
struct ifreq ifr;
int tapfd;
@@ -61,7 +61,7 @@ tap_open(const char *ifname, bool multi_queue)
retry_mono_q:
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, ifname, IFNAMSIZ - 1);
- ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_VNET_HDR;
+ ifr.ifr_flags = r_flags;
if (multi_queue)
ifr.ifr_flags |= IFF_MULTI_QUEUE;
if (ioctl(tapfd, TUNSETIFF, (void *)&ifr) == -1) {
@@ -22,6 +22,7 @@
#define IFF_NO_PI 0x1000
#define IFF_VNET_HDR 0x4000
#define IFF_MULTI_QUEUE 0x0100
+#define IFF_NAPI 0x0010
/* Features for GSO (TUNSETOFFLOAD). */
#define TUN_F_CSUM 0x01 /* You can hand me unchecksummed packets. */
@@ -36,7 +37,7 @@
int vhost_kernel_tap_setup(int tapfd, int hdr_size, uint64_t features);
int tap_support_features(unsigned int *tap_features);
-int tap_open(const char *ifname, bool multi_queue);
+int tap_open(const char *ifname, unsigned int r_flags, bool multi_queue);
int tap_get_name(int tapfd, char **ifname);
int tap_get_flags(int tapfd, unsigned int *tap_flags);
int tap_set_mac(int tapfd, uint8_t *mac);