On Thu, Aug 09, 2018 at 01:34:55PM -0500, Allain Legacy wrote:
> From: eric zhang <eric.zh...@windriver.com>
>
> This patch checks negotiated features to see if necessary to offload
> before set the tap device offload capabilities. It also checks if kernel
> support the TUNSETOFFLOAD operation.
>
> Signed-off-by: eric zhang <eric.zh...@windriver.com>
> Signed-off-by: Allain Legacy <allain.leg...@windriver.com>
> ---
> drivers/net/virtio/virtio_user/vhost_kernel.c | 2 +-
> drivers/net/virtio/virtio_user/vhost_kernel_tap.c | 56
> +++++++++++++++++------
> drivers/net/virtio/virtio_user/vhost_kernel_tap.h | 2 +-
> 3 files changed, 44 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c
> b/drivers/net/virtio/virtio_user/vhost_kernel.c
> index b2444096c..66f2eaca9 100644
> --- a/drivers/net/virtio/virtio_user/vhost_kernel.c
> +++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
> @@ -339,7 +339,7 @@ vhost_kernel_enable_queue_pair(struct virtio_user_dev
> *dev,
> hdr_size = sizeof(struct virtio_net_hdr);
>
> tapfd = vhost_kernel_open_tap(&dev->ifname, hdr_size, req_mq,
> - (char *)dev->mac_addr);
> + (char *)dev->mac_addr, dev->features);
> if (tapfd < 0) {
> PMD_DRV_LOG(ERR, "fail to open tap for vhost kernel");
> return -1;
> diff --git a/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
> b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
> index 9ea7ade74..eda9fb78c 100644
> --- a/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
> +++ b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
> @@ -16,21 +16,54 @@
>
> #include "vhost_kernel_tap.h"
> #include "../virtio_logs.h"
> +#include "../virtio_pci.h"
> +
> +static int
> +vhost_kernel_tap_set_offload(int fd, uint64_t feature)
> +{
> + unsigned int offload = 0;
> +
> + if (feature & (1ULL << VIRTIO_NET_F_GUEST_CSUM))
> + offload |= TUN_F_CSUM;
> + if (feature & (1ULL << VIRTIO_NET_F_GUEST_TSO4))
> + offload |= TUN_F_TSO4;
> + if (feature & (1ULL << VIRTIO_NET_F_GUEST_TSO6))
> + offload |= TUN_F_TSO6;
> + if (feature & ((1ULL << VIRTIO_NET_F_GUEST_TSO4) |
> + (1ULL << VIRTIO_NET_F_GUEST_TSO6)) &&
> + (feature & (1ULL << VIRTIO_NET_F_GUEST_ECN)))
> + offload |= TUN_F_TSO_ECN;
> + if (feature & (1ULL << VIRTIO_NET_F_GUEST_UFO))
> + offload |= TUN_F_UFO;
> +
> + if (offload != 0) {
> + /* Check if our kernel supports TUNSETOFFLOAD */
> + if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) {
> + PMD_DRV_LOG(ERR, "Kernel does't support
> TUNSETOFFLOAD\n");
> + return -ENOTSUP;
> + }
> +
> + if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
> + offload &= ~TUN_F_UFO;
> + if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
> + PMD_DRV_LOG(ERR, "TUNSETOFFLOAD ioctl() failed:
> %s\n",
> + strerror(errno));
> + return -1;
> + }
> + }
I'm not quite sure whether it's a good idea to
return failure when failed to set offloads to
tap. And QEMU also doesn't do this:
https://github.com/qemu/qemu/blob/6ad90805383e/net/tap-linux.c#L261
We should also check whether offloads available
when handling VHOST_GET_FEATURES.
Thanks
> + }
> +
> + return 0;
> +}
>
> int
> vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq,
> - const char *mac)
> + const char *mac, uint64_t features)
> {
> unsigned int tap_features;
> int sndbuf = INT_MAX;
> struct ifreq ifr;
> int tapfd;
> - unsigned int offload =
> - TUN_F_CSUM |
> - TUN_F_TSO4 |
> - TUN_F_TSO6 |
> - TUN_F_TSO_ECN |
> - TUN_F_UFO;
>
> /* TODO:
> * 1. verify we can get/set vnet_hdr_len, tap_probe_vnet_hdr_len
> @@ -90,13 +123,8 @@ vhost_kernel_open_tap(char **p_ifname, int hdr_size, int
> req_mq,
> goto error;
> }
>
> - /* TODO: before set the offload capabilities, we'd better (1) check
> - * negotiated features to see if necessary to offload; (2) query tap
> - * to see if it supports the offload capabilities.
> - */
> - if (ioctl(tapfd, TUNSETOFFLOAD, offload) != 0)
> - PMD_DRV_LOG(ERR, "TUNSETOFFLOAD ioctl() failed: %s",
> - strerror(errno));
> + if (vhost_kernel_tap_set_offload(tapfd, features) != 0)
> + goto error;
>
> memset(&ifr, 0, sizeof(ifr));
> ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
> diff --git a/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
> b/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
> index 01a026f50..e0e95b4f5 100644
> --- a/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
> +++ b/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
> @@ -36,4 +36,4 @@
> #define PATH_NET_TUN "/dev/net/tun"
>
> int vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq,
> - const char *mac);
> + const char *mac, uint64_t features);
> --
> 2.12.1
>
