svn commit: r188754 - user/dfr/xenhvm/7/sys/dev/xen/netfront
Doug Rabson
dfr at FreeBSD.org
Wed Feb 18 10:27:49 PST 2009
Author: dfr
Date: Wed Feb 18 18:27:48 2009
New Revision: 188754
URL: http://svn.freebsd.org/changeset/base/188754
Log:
Eliminate the data copy on transmit and start getting ready to support TSO.
Modified:
user/dfr/xenhvm/7/sys/dev/xen/netfront/netfront.c
Modified: user/dfr/xenhvm/7/sys/dev/xen/netfront/netfront.c
==============================================================================
--- user/dfr/xenhvm/7/sys/dev/xen/netfront/netfront.c Wed Feb 18 18:25:16 2009 (r188753)
+++ user/dfr/xenhvm/7/sys/dev/xen/netfront/netfront.c Wed Feb 18 18:27:48 2009 (r188754)
@@ -95,6 +95,7 @@ static const int MODPARM_rx_copy = 1;
static const int MODPARM_rx_flip = 0;
#endif
+#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
#define RX_COPY_THRESHOLD 256
#define net_ratelimit() 0
@@ -339,28 +340,6 @@ xennet_get_rx_ref(struct netfront_info *
#define DPRINTK(fmt, args...)
#endif
-static __inline struct mbuf*
-makembuf (struct mbuf *buf)
-{
- struct mbuf *m = NULL;
-
- MGETHDR (m, M_DONTWAIT, MT_DATA);
-
- if (! m)
- return 0;
-
- M_MOVE_PKTHDR(m, buf);
-
- m_cljget(m, M_DONTWAIT, MJUMPAGESIZE);
- m->m_pkthdr.len = buf->m_pkthdr.len;
- m->m_len = buf->m_len;
- m_copydata(buf, 0, buf->m_pkthdr.len, mtod(m,caddr_t) );
-
- m->m_ext.ext_args = (caddr_t *)(uintptr_t)(vtophys(mtod(m,caddr_t)) >> PAGE_SHIFT);
-
- return m;
-}
-
/**
* Read the 'mac' node at the given device's node in the store, and parse that
* as colon-separated octets, placing result the given mac array. mac must be
@@ -500,7 +479,7 @@ talk_to_backend(device_t dev, struct net
message = "writing feature-sg";
goto abort_transaction;
}
-#ifdef HAVE_TSO
+#if __FreeBSD_version >= 700000
err = xenbus_printf(xbt, node, "feature-gso-tcpv4", "%d", 1);
if (err) {
message = "writing feature-gso-tcpv4";
@@ -1007,7 +986,12 @@ xn_txeof(struct netfront_info *np)
id = RING_GET_RESPONSE(&np->tx, i)->id;
m = np->xn_cdata.xn_tx_chain[id];
- ifp->if_opackets++;
+ /*
+ * Increment packet count if this is the last
+ * mbuf of the chain.
+ */
+ if (!m->m_next)
+ ifp->if_opackets++;
KASSERT(m != NULL, ("mbuf not found in xn_tx_chain"));
M_ASSERTVALID(m);
if (unlikely(gnttab_query_foreign_access(
@@ -1025,7 +1009,7 @@ xn_txeof(struct netfront_info *np)
np->xn_cdata.xn_tx_chain[id] = NULL;
add_id_to_freelist(np->xn_cdata.xn_tx_chain, id);
- m_freem(m);
+ m_free(m);
}
np->tx.rsp_cons = prod;
@@ -1320,13 +1304,14 @@ xn_start_locked(struct ifnet *ifp)
{
int otherend_id;
unsigned short id;
- struct mbuf *m_head, *new_m;
+ struct mbuf *m_head, *m;
struct netfront_info *sc;
netif_tx_request_t *tx;
+ netif_extra_info_t *extra;
RING_IDX i;
grant_ref_t ref;
u_long mfn, tx_bytes;
- int notify;
+ int notify, nfrags;
sc = ifp->if_softc;
otherend_id = xenbus_get_otherend_id(sc->xbdev);
@@ -1346,36 +1331,95 @@ xn_start_locked(struct ifnet *ifp)
break;
}
- id = get_id_from_freelist(sc->xn_cdata.xn_tx_chain);
+
+ /*
+ * Defragment the mbuf if necessary.
+ */
+ for (m = m_head, nfrags = 0; m; m = m->m_next)
+ nfrags++;
+ if (nfrags > MAX_SKB_FRAGS) {
+ m = m_defrag(m_head, M_DONTWAIT);
+ if (!m) {
+ m_freem(m_head);
+ break;
+ }
+ m_head = m;
+ }
/*
* Start packing the mbufs in this chain into
* the fragment pointers. Stop when we run out
* of fragments or hit the end of the mbuf chain.
*/
- new_m = makembuf(m_head);
- tx = RING_GET_REQUEST(&sc->tx, i);
- tx->id = id;
- ref = gnttab_claim_grant_reference(&sc->gref_tx_head);
- KASSERT((short)ref >= 0, ("Negative ref"));
- mfn = virt_to_mfn(mtod(new_m, vm_offset_t));
- gnttab_grant_foreign_access_ref(ref, otherend_id,
- mfn, GNTMAP_readonly);
- tx->gref = sc->grant_tx_ref[id] = ref;
- tx->size = new_m->m_pkthdr.len;
- if (new_m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
- tx->flags = NETTXF_csum_blank | NETTXF_data_validated;
- else
+ m = m_head;
+ extra = NULL;
+ for (m = m_head; m; m = m->m_next) {
+ tx = RING_GET_REQUEST(&sc->tx, i);
+ id = get_id_from_freelist(sc->xn_cdata.xn_tx_chain);
+ sc->xn_cdata.xn_tx_chain[id] = m;
+ tx->id = id;
+ ref = gnttab_claim_grant_reference(&sc->gref_tx_head);
+ KASSERT((short)ref >= 0, ("Negative ref"));
+ mfn = virt_to_mfn(mtod(m, vm_offset_t));
+ gnttab_grant_foreign_access_ref(ref, otherend_id,
+ mfn, GNTMAP_readonly);
+ tx->gref = sc->grant_tx_ref[id] = ref;
+ tx->offset = mtod(m, vm_offset_t) & (PAGE_SIZE - 1);
tx->flags = 0;
- new_m->m_next = NULL;
- new_m->m_nextpkt = NULL;
+ if (m == m_head) {
+ /*
+ * The first fragment has the entire packet
+ * size, subsequent fragments have just the
+ * fragment size. The backend works out the
+ * true size of the first fragment by
+ * subtracting the sizes of the other
+ * fragments.
+ */
+ tx->size = m->m_pkthdr.len;
- m_freem(m_head);
+ /*
+ * The first fragment contains the
+ * checksum flags and is optionally
+ * followed by extra data for TSO etc.
+ */
+ if (m->m_pkthdr.csum_flags
+ & CSUM_DELAY_DATA) {
+ tx->flags |= (NETTXF_csum_blank
+ | NETTXF_data_validated);
+ }
+#if __FreeBSD_version >= 700000
+ if (m->m_pkthdr.csum_flags & CSUM_TSO) {
+ struct netif_extra_info *gso =
+ (struct netif_extra_info *)
+ RING_GET_REQUEST(&sc->tx, ++i);
+
+ if (extra)
+ extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
+ else
+ tx->flags |= NETTXF_extra_info;
+
+ gso->u.gso.size = m->m_pkthdr.len;
+ gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4;
+ gso->u.gso.pad = 0;
+ gso->u.gso.features = 0;
+
+ gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
+ gso->flags = 0;
+ extra = gso;
+ }
+#endif
+ } else {
+ tx->size = m->m_len;
+ }
+ if (m->m_next) {
+ tx->flags |= NETTXF_more_data;
+ i++;
+ }
+ }
- sc->xn_cdata.xn_tx_chain[id] = new_m;
- BPF_MTAP(ifp, new_m);
+ BPF_MTAP(ifp, m_head);
- sc->stats.tx_bytes += new_m->m_pkthdr.len;
+ sc->stats.tx_bytes += m_head->m_pkthdr.len;
sc->stats.tx_packets++;
}
@@ -1518,11 +1562,14 @@ xn_ioctl(struct ifnet *ifp, u_long cmd,
case SIOCSIFCAP:
mask = ifr->ifr_reqcap ^ ifp->if_capenable;
if (mask & IFCAP_HWCSUM) {
- if (IFCAP_HWCSUM & ifp->if_capenable)
- ifp->if_capenable &= ~IFCAP_HWCSUM;
- else
- ifp->if_capenable |= IFCAP_HWCSUM;
+ ifp->if_capenable ^= IFCAP_HWCSUM;
}
+#if __FreeBSD_version >= 700000
+ if (mask & IFCAP_TSO4) {
+ ifp->if_capenable ^= IFCAP_TSO4;
+ /* XXX inform backend? */
+ }
+#endif
error = 0;
break;
case SIOCADDMULTI:
@@ -1733,6 +1780,9 @@ create_netdev(device_t dev)
ifp->if_hwassist = XN_CSUM_FEATURES;
ifp->if_capabilities = IFCAP_HWCSUM;
+#if __FreeBSD_version >= 700000
+ //ifp->if_capabilities |= IFCAP_TSO4;
+#endif
ifp->if_capenable = ifp->if_capabilities;
ether_ifattach(ifp, np->mac);
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