From 578e4bf777aa141dc1b6f991282ba6c504aff427 Mon Sep 17 00:00:00 2001 From: "Justin T. Gibbs" Date: Wed, 21 Sep 2011 00:15:29 +0000 Subject: [PATCH] Update netfront so that it queries and honors published back-end features. sys/dev/xen/netfront/netfront.c: o Add xn_query_features() which reads the XenStore and records the TSO, LRO, and chained ring-request support of the backend. o Rename xn_configure_lro() to xn_configure_features() and use this routine to manage the setup of TSO, LRO, and checksum offload. o In create_netdev(), initialize if_capabilities and if_hwassist to the capabilities found on all backends. Delegate configuration of if_capenable and the TSO flag if if_hwassist to xn_configure_features(). Reported by: Hugo Silva (fix inspired by patch provided) Approved by: re MFC after: 1 week --- sys/dev/xen/netfront/netfront.c | 68 +++++++++++++++++++++++++-------- 1 file changed, 52 insertions(+), 16 deletions(-) diff --git a/sys/dev/xen/netfront/netfront.c b/sys/dev/xen/netfront/netfront.c index 1f426910ba39..8d6444a9f763 100644 --- a/sys/dev/xen/netfront/netfront.c +++ b/sys/dev/xen/netfront/netfront.c @@ -92,7 +92,8 @@ __FBSDID("$FreeBSD$"); #include "xenbus_if.h" -#define XN_CSUM_FEATURES (CSUM_TCP | CSUM_UDP | CSUM_TSO) +/* Features supported by all backends. TSO and LRO can be negotiated */ +#define XN_CSUM_FEATURES (CSUM_TCP | CSUM_UDP) #define NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE) #define NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE) @@ -159,7 +160,8 @@ static int xn_ioctl(struct ifnet *, u_long, caddr_t); static void xn_ifinit_locked(struct netfront_info *); static void xn_ifinit(void *); static void xn_stop(struct netfront_info *); -static int xn_configure_lro(struct netfront_info *np); +static void xn_query_features(struct netfront_info *np); +static int xn_configure_features(struct netfront_info *np); #ifdef notyet static void xn_watchdog(struct ifnet *); #endif @@ -262,6 +264,7 @@ struct netfront_info { u_int irq; u_int copying_receiver; u_int carrier; + u_int maxfrags; /* Receive-ring batched refills. */ #define RX_MIN_TARGET 32 @@ -1526,7 +1529,7 @@ xn_assemble_tx_request(struct netfront_info *sc, struct mbuf *m_head) * deal with nfrags > MAX_TX_REQ_FRAGS, which is a quirk of * the Linux network stack. */ - if (nfrags > MAX_TX_REQ_FRAGS) { + if (nfrags > sc->maxfrags) { m = m_defrag(m_head, M_DONTWAIT); if (!m) { /* @@ -1943,10 +1946,11 @@ network_connect(struct netfront_info *np) return (error); /* Step 1: Reinitialise variables. */ + xn_query_features(np); + xn_configure_features(np); netif_release_tx_bufs(np); /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */ - xn_configure_lro(np); for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) { struct mbuf *m; u_long pfn; @@ -2011,26 +2015,63 @@ show_device(struct netfront_info *sc) #endif } +static void +xn_query_features(struct netfront_info *np) +{ + int val; + + device_printf(np->xbdev, "backend features:"); + + if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev), + "feature-sg", NULL, "%d", &val) < 0) + val = 0; + + np->maxfrags = 1; + if (val) { + np->maxfrags = MAX_TX_REQ_FRAGS; + printf(" feature-sg"); + } + + if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev), + "feature-gso-tcpv4", NULL, "%d", &val) < 0) + val = 0; + + np->xn_ifp->if_capabilities &= ~(IFCAP_TSO4|IFCAP_LRO); + if (val) { + np->xn_ifp->if_capabilities |= IFCAP_TSO4|IFCAP_LRO; + printf(" feature-gso-tcp4"); + } + + printf("\n"); +} + static int -xn_configure_lro(struct netfront_info *np) +xn_configure_features(struct netfront_info *np) { int err; err = 0; #if __FreeBSD_version >= 700000 - if ((np->xn_ifp->if_capabilities & IFCAP_LRO) != 0) + if ((np->xn_ifp->if_capenable & IFCAP_LRO) != 0) tcp_lro_free(&np->xn_lro); - np->xn_ifp->if_capabilities &= ~IFCAP_LRO; - if (xn_enable_lro) { +#endif + np->xn_ifp->if_capenable = + np->xn_ifp->if_capabilities & ~(IFCAP_LRO|IFCAP_TSO4); + np->xn_ifp->if_hwassist &= ~CSUM_TSO; +#if __FreeBSD_version >= 700000 + if (xn_enable_lro && (np->xn_ifp->if_capabilities & IFCAP_LRO) != 0) { err = tcp_lro_init(&np->xn_lro); if (err) { device_printf(np->xbdev, "LRO initialization failed\n"); } else { np->xn_lro.ifp = np->xn_ifp; - np->xn_ifp->if_capabilities |= IFCAP_LRO; + np->xn_ifp->if_capenable |= IFCAP_LRO; } } - np->xn_ifp->if_capenable = np->xn_ifp->if_capabilities; + if ((np->xn_ifp->if_capabilities & IFCAP_TSO4) != 0) { + np->xn_ifp->if_capenable |= IFCAP_TSO4; + np->xn_ifp->if_hwassist |= CSUM_TSO; + } #endif return (err); } @@ -2059,7 +2100,7 @@ create_netdev(device_t dev) np->rx_target = RX_MIN_TARGET; np->rx_min_target = RX_MIN_TARGET; np->rx_max_target = RX_MAX_TARGET; - + /* Initialise {tx,rx}_skbs to be a free chain containing every entry. */ for (i = 0; i <= NET_TX_RING_SIZE; i++) { np->tx_mbufs[i] = (void *) ((u_long) i+1); @@ -2109,11 +2150,6 @@ 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; - xn_configure_lro(np); ether_ifattach(ifp, np->mac); callout_init(&np->xn_stat_ch, CALLOUT_MPSAFE);