On 02/05/2016 06:30 PM, Vincenzo Maffione wrote:
> Previous implementation of has_ufo, has_vnet_hdr, has_vnet_hdr_len, etc.
> did not really probe for virtio-net header support for the netmap
> interface attached to the backend. These callbacks were correct for
> VALE ports, but incorrect for hardware NICs, pipes, monitors, etc.
>
> This patch fixes the implementation to work properly with all kinds
> of netmap ports.
>
> Signed-off-by: Vincenzo Maffione <v.maffi...@gmail.com>
> ---
> net/netmap.c | 70
> ++++++++++++++++++++++++++++++++++++++----------------------
> 1 file changed, 44 insertions(+), 26 deletions(-)
>
> diff --git a/net/netmap.c b/net/netmap.c
> index 9710321..f2dcaeb 100644
> --- a/net/netmap.c
> +++ b/net/netmap.c
> @@ -323,20 +323,55 @@ static void netmap_cleanup(NetClientState *nc)
> }
>
> /* Offloading manipulation support callbacks. */
> -static bool netmap_has_ufo(NetClientState *nc)
> +static int netmap_do_set_vnet_hdr_len(NetmapState *s, int len, bool
> err_report)
Passing something like err_report usually means it was the
responsibility of caller to report. So let's remove the err_report and
let caller to decide based on the return value.
> {
> - return true;
> + struct nmreq req;
> + int err;
> +
> + /* Issue a NETMAP_BDG_VNET_HDR command to change the virtio-net header
> + * length for the netmap adapter associated to 's->ifname'.
> + */
> + memset(&req, 0, sizeof(req));
> + pstrcpy(req.nr_name, sizeof(req.nr_name), s->ifname);
> + req.nr_version = NETMAP_API;
> + req.nr_cmd = NETMAP_BDG_VNET_HDR;
> + req.nr_arg1 = len;
> + err = ioctl(s->nmd->fd, NIOCREGIF, &req);
> + if (err) {
> + if (err_report) {
> + error_report("Unable to execute NETMAP_BDG_VNET_HDR on %s: %s",
> + s->ifname, strerror(errno));
> + }
> + return -1;
> + }
> +
> + /* Keep track of the current length. */
> + s->vnet_hdr_len = len;
> +
> + return 0;
> }
>
> -static bool netmap_has_vnet_hdr(NetClientState *nc)
> +static bool netmap_has_vnet_hdr_len(NetClientState *nc, int len)
> {
> + NetmapState *s = DO_UPCAST(NetmapState, nc, nc);
> + int prev_len = s->vnet_hdr_len;
> +
> + /* Check that we can set the new length. */
> + if (netmap_do_set_vnet_hdr_len(s, len, false)) {
> + return false;
> + }
> +
> + /* Restore the previous length. */
> + netmap_do_set_vnet_hdr_len(s, prev_len, true);
> +
> return true;
> }
>
> -static bool netmap_has_vnet_hdr_len(NetClientState *nc, int len)
> +/* A netmap interface that supports virtio-net headers always
> + * supports UFO, so we use this callback also for the has_ufo hook. */
> +static bool netmap_has_vnet_hdr(NetClientState *nc)
> {
> - return len == 0 || len == sizeof(struct virtio_net_hdr) ||
> - len == sizeof(struct virtio_net_hdr_mrg_rxbuf);
> + return netmap_has_vnet_hdr_len(nc, sizeof(struct virtio_net_hdr));
> }
>
> static void netmap_using_vnet_hdr(NetClientState *nc, bool enable)
> @@ -346,25 +381,8 @@ static void netmap_using_vnet_hdr(NetClientState *nc,
> bool enable)
> static void netmap_set_vnet_hdr_len(NetClientState *nc, int len)
> {
> NetmapState *s = DO_UPCAST(NetmapState, nc, nc);
> - int err;
> - struct nmreq req;
>
> - /* Issue a NETMAP_BDG_VNET_HDR command to change the virtio-net header
> - * length for the netmap adapter associated to 's->ifname'.
> - */
> - memset(&req, 0, sizeof(req));
> - pstrcpy(req.nr_name, sizeof(req.nr_name), s->ifname);
> - req.nr_version = NETMAP_API;
> - req.nr_cmd = NETMAP_BDG_VNET_HDR;
> - req.nr_arg1 = len;
> - err = ioctl(s->nmd->fd, NIOCREGIF, &req);
> - if (err) {
> - error_report("Unable to execute NETMAP_BDG_VNET_HDR on %s: %s",
> - s->ifname, strerror(errno));
> - } else {
> - /* Keep track of the current length. */
> - s->vnet_hdr_len = len;
> - }
> + netmap_do_set_vnet_hdr_len(s, len, true);
> }
>
> static void netmap_set_offload(NetClientState *nc, int csum, int tso4, int
> tso6,
> @@ -376,7 +394,7 @@ static void netmap_set_offload(NetClientState *nc, int
> csum, int tso4, int tso6,
> * enables the offloadings.
> */
> if (!s->vnet_hdr_len) {
> - netmap_set_vnet_hdr_len(nc, sizeof(struct virtio_net_hdr));
> + netmap_do_set_vnet_hdr_len(s, sizeof(struct virtio_net_hdr), true);
> }
> }
>
> @@ -388,7 +406,7 @@ static NetClientInfo net_netmap_info = {
> .receive_iov = netmap_receive_iov,
> .poll = netmap_poll,
> .cleanup = netmap_cleanup,
> - .has_ufo = netmap_has_ufo,
> + .has_ufo = netmap_has_vnet_hdr,
This look suspicious, I'm not sure this is correct for netmap. May need
a comment to explain. Usually vnet hdr does not imply ufo.
> .has_vnet_hdr = netmap_has_vnet_hdr,
> .has_vnet_hdr_len = netmap_has_vnet_hdr_len,
> .using_vnet_hdr = netmap_using_vnet_hdr,
