Enable UFO on virtio-net and tap devices

Enable UFO on the host tap device if supported and allow setting UFO
on virtio-net in the guest.

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 32 insertions, 4 deletions

diff --git a/net.c b/net.c
index b061491..feb3022 100644
--- a/net.c
+++ b/net.c
@@ -1295,6 +1295,10 @@ void do_info_usernet(Monitor *mon)
 #endif /* CONFIG_SLIRP */
 
 #if defined(_WIN32)
+int tap_has_ufo(VLANClientState *vc)
+{
+    return 0;
+}
 int tap_has_vnet_hdr(VLANClientState *vc)
 {
     return 0;
@@ -1302,7 +1306,8 @@ int tap_has_vnet_hdr(VLANClientState *vc)
 void tap_using_vnet_hdr(VLANClientState *vc, int using_vnet_hdr)
 {
 }
-void tap_set_offload(VLANClientState *vc, int csum, int tso4, int tso6, int ecn)
+void tap_set_offload(VLANClientState *vc, int csum, int tso4,
+                     int tso6, int ecn, int ufo)
 {
 }
 #else /* !defined(_WIN32) */
@@ -1322,6 +1327,7 @@ typedef struct TAPState {
     unsigned int write_poll : 1;
     unsigned int has_vnet_hdr : 1;
     unsigned int using_vnet_hdr : 1;
+    unsigned int has_ufo: 1;
 } TAPState;
 
 static int launch_script(const char *setup_script, const char *ifname, int fd);
@@ -1509,6 +1515,15 @@ static int tap_set_sndbuf(TAPState *s, QemuOpts *opts)
     return 0;
 }
 
+int tap_has_ufo(VLANClientState *vc)
+{
+    TAPState *s = vc->opaque;
+
+    assert(vc->type == NET_CLIENT_TYPE_TAP);
+
+    return s->has_ufo;
+}
+
 int tap_has_vnet_hdr(VLANClientState *vc)
 {
     TAPState *s = vc->opaque;
@@ -1542,7 +1557,8 @@ static int tap_probe_vnet_hdr(int fd)
     return ifr.ifr_flags & IFF_VNET_HDR;
 }
 
-void tap_set_offload(VLANClientState *vc, int csum, int tso4, int tso6, int ecn)
+void tap_set_offload(VLANClientState *vc, int csum, int tso4,
+                     int tso6, int ecn, int ufo)
 {
     TAPState *s = vc->opaque;
     unsigned int offload = 0;
@@ -1555,11 +1571,16 @@ void tap_set_offload(VLANClientState *vc, int csum, int tso4, int tso6, int ecn)
             offload |= TUN_F_TSO6;
         if ((tso4 || tso6) && ecn)
             offload |= TUN_F_TSO_ECN;
+        if (ufo)
+            offload |= TUN_F_UFO;
     }
 
     if (ioctl(s->fd, TUNSETOFFLOAD, offload) != 0) {
-        fprintf(stderr, "TUNSETOFFLOAD ioctl() failed: %s\n",
-                strerror(errno));
+        offload &= ~TUN_F_UFO;
+        if (ioctl(s->fd, TUNSETOFFLOAD, offload) != 0) {
+            fprintf(stderr, "TUNSETOFFLOAD ioctl() failed: %s\n",
+                    strerror(errno));
+        }
     }
 }
 
@@ -1587,6 +1608,7 @@ static TAPState *net_tap_fd_init(VLANState *vlan,
                                  int vnet_hdr)
 {
     TAPState *s;
+    unsigned int offload;
 
     s = qemu_mallocz(sizeof(TAPState));
     s->fd = fd;
@@ -1596,6 +1618,12 @@ static TAPState *net_tap_fd_init(VLANState *vlan,
                                  vlan, NULL, model, name, NULL,
                                  tap_receive, tap_receive_raw,
                                  tap_receive_iov, tap_cleanup, s);
+    s->has_ufo = 0;
+    /* Check if tap supports UFO */
+    offload = TUN_F_CSUM | TUN_F_UFO;
+    if (ioctl(s->fd, TUNSETOFFLOAD, offload) == 0)
+       s->has_ufo = 1;
+    tap_set_offload(s->vc, 0, 0, 0, 0, 0);
     tap_read_poll(s, 1);
     return s;
 }