From 9fbad2ca36f099699ebdf91c523a9ddc34d6b1c4 Mon Sep 17 00:00:00 2001 From: Vincenzo Maffione Date: Wed, 24 Feb 2016 11:30:41 +0100 Subject: [PATCH] net: netmap: probe netmap interface for virtio-net header 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 Signed-off-by: Jason Wang --- net/netmap.c | 75 ++++++++++++++++++++++++++++++++-------------------- 1 file changed, 46 insertions(+), 29 deletions(-) diff --git a/net/netmap.c b/net/netmap.c index 971032120c..1b427287a7 100644 --- a/net/netmap.c +++ b/net/netmap.c @@ -323,30 +323,8 @@ static void netmap_cleanup(NetClientState *nc) } /* Offloading manipulation support callbacks. */ -static bool netmap_has_ufo(NetClientState *nc) +static int netmap_fd_set_vnet_hdr_len(NetmapState *s, int len) { - return true; -} - -static bool netmap_has_vnet_hdr(NetClientState *nc) -{ - return true; -} - -static bool netmap_has_vnet_hdr_len(NetClientState *nc, int len) -{ - return len == 0 || len == sizeof(struct virtio_net_hdr) || - len == sizeof(struct virtio_net_hdr_mrg_rxbuf); -} - -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 @@ -357,10 +335,50 @@ static void netmap_set_vnet_hdr_len(NetClientState *nc, int len) req.nr_version = NETMAP_API; req.nr_cmd = NETMAP_BDG_VNET_HDR; req.nr_arg1 = len; - err = ioctl(s->nmd->fd, NIOCREGIF, &req); + + return ioctl(s->nmd->fd, NIOCREGIF, &req); +} + +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_fd_set_vnet_hdr_len(s, len)) { + return false; + } + + /* Restore the previous length. */ + if (netmap_fd_set_vnet_hdr_len(s, prev_len)) { + error_report("Failed to restore vnet-hdr length %d on %s: %s", + prev_len, s->ifname, strerror(errno)); + abort(); + } + + return true; +} + +/* 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 netmap_has_vnet_hdr_len(nc, sizeof(struct virtio_net_hdr)); +} + +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; + + err = netmap_fd_set_vnet_hdr_len(s, len); if (err) { - error_report("Unable to execute NETMAP_BDG_VNET_HDR on %s: %s", - s->ifname, strerror(errno)); + error_report("Unable to set vnet-hdr length %d on %s: %s", + len, s->ifname, strerror(errno)); } else { /* Keep track of the current length. */ s->vnet_hdr_len = len; @@ -373,8 +391,7 @@ static void netmap_set_offload(NetClientState *nc, int csum, int tso4, int tso6, NetmapState *s = DO_UPCAST(NetmapState, nc, nc); /* Setting a virtio-net header length greater than zero automatically - * enables the offloadings. - */ + * enables the offloadings. */ if (!s->vnet_hdr_len) { netmap_set_vnet_hdr_len(nc, sizeof(struct virtio_net_hdr)); } @@ -388,7 +405,7 @@ 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, .has_vnet_hdr = netmap_has_vnet_hdr, .has_vnet_hdr_len = netmap_has_vnet_hdr_len, .using_vnet_hdr = netmap_using_vnet_hdr,