/* * xen paravirt network card backend * * (c) Gerd Hoffmann <kraxel@redhat.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; under version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, see <http://www.gnu.org/licenses/>. * * Contributions after 2012-01-13 are licensed under the terms of the * GNU GPL, version 2 or (at your option) any later version. */ #include <stdio.h> #include <stdlib.h> #include <stdarg.h> #include <string.h> #include <unistd.h> #include <signal.h> #include <inttypes.h> #include <fcntl.h> #include <errno.h> #include <sys/socket.h> #include <sys/ioctl.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/mman.h> #include <sys/wait.h> #include "hw.h" #include "net/net.h" #include "net/checksum.h" #include "net/util.h" #include "xen_backend.h" #include <xen/io/netif.h> /* ------------------------------------------------------------- */ struct XenNetDev { struct XenDevice xendev; /* must be first */ char *mac; int tx_work; int tx_ring_ref; int rx_ring_ref; struct netif_tx_sring *txs; struct netif_rx_sring *rxs; netif_tx_back_ring_t tx_ring; netif_rx_back_ring_t rx_ring; NICConf conf; NICState *nic; }; /* ------------------------------------------------------------- */ static void net_tx_response(struct XenNetDev *netdev, netif_tx_request_t *txp, int8_t st) { RING_IDX i = netdev->tx_ring.rsp_prod_pvt; netif_tx_response_t *resp; int notify; resp = RING_GET_RESPONSE(&netdev->tx_ring, i); resp->id = txp->id; resp->status = st; #if 0 if (txp->flags & NETTXF_extra_info) { RING_GET_RESPONSE(&netdev->tx_ring, ++i)->status = NETIF_RSP_NULL; } #endif netdev->tx_ring.rsp_prod_pvt = ++i; RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->tx_ring, notify); if (notify) { xen_be_send_notify(&netdev->xendev); } if (i == netdev->tx_ring.req_cons) { int more_to_do; RING_FINAL_CHECK_FOR_REQUESTS(&netdev->tx_ring, more_to_do); if (more_to_do) { netdev->tx_work++; } } } static void net_tx_error(struct XenNetDev *netdev, netif_tx_request_t *txp, RING_IDX end) { #if 0 /* * Hmm, why netback fails everything in the ring? * Should we do that even when not supporting SG and TSO? */ RING_IDX cons = netdev->tx_ring.req_cons; do { make_tx_response(netif, txp, NETIF_RSP_ERROR); if (cons >= end) { break; } txp = RING_GET_REQUEST(&netdev->tx_ring, cons++); } while (1); netdev->tx_ring.req_cons = cons; netif_schedule_work(netif); netif_put(netif); #else net_tx_response(netdev, txp, NETIF_RSP_ERROR); #endif } static void net_tx_packets(struct XenNetDev *netdev) { netif_tx_request_t txreq; RING_IDX rc, rp; void *page; void *tmpbuf = NULL; for (;;) { rc = netdev->tx_ring.req_cons; rp = netdev->tx_ring.sring->req_prod; xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ while ((rc != rp)) { if (RING_REQUEST_CONS_OVERFLOW(&netdev->tx_ring, rc)) { break; } memcpy(&txreq, RING_GET_REQUEST(&netdev->tx_ring, rc), sizeof(txreq)); netdev->tx_ring.req_cons = ++rc; #if 1 /* should not happen in theory, we don't announce the * * feature-{sg,gso,whatelse} flags in xenstore (yet?) */ if (txreq.flags & NETTXF_extra_info) { xen_be_printf(&netdev->xendev, 0, "FIXME: extra info flag\n"); net_tx_error(netdev, &txreq, rc); continue; } if (txreq.flags & NETTXF_more_data) { xen_be_printf(&netdev->xendev, 0, "FIXME: more data flag\n"); net_tx_error(netdev, &txreq, rc); continue; } #endif if (txreq.size < 14) { xen_be_printf(&netdev->xendev, 0, "bad packet size: %d\n", txreq.size); net_tx_error(netdev, &txreq, rc); continue; } if ((txreq.offset + txreq.size) > XC_PAGE_SIZE) { xen_be_printf(&netdev->xendev, 0, "error: page crossing\n"); net_tx_error(netdev, &txreq, rc); continue; } xen_be_printf(&netdev->xendev, 3, "tx packet ref %d, off %d, len %d, flags 0x%x%s%s%s%s\n", txreq.gref, txreq.offset, txreq.size, txreq.flags, (txreq.flags & NETTXF_csum_blank) ? " csum_blank" : "", (txreq.flags & NETTXF_data_validated) ? " data_validated" : "", (txreq.flags & NETTXF_more_data) ? " more_data" : "", (txreq.flags & NETTXF_extra_info) ? " extra_info" : ""); page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, netdev->xendev.dom, txreq.gref, PROT_READ); if (page == NULL) { xen_be_printf(&netdev->xendev, 0, "error: tx gref dereference failed (%d)\n", txreq.gref); net_tx_error(netdev, &txreq, rc); continue; } if (txreq.flags & NETTXF_csum_blank) { /* have read-only mapping -> can't fill checksum in-place */ if (!tmpbuf) { tmpbuf = g_malloc(XC_PAGE_SIZE); } memcpy(tmpbuf, page + txreq.offset, txreq.size); net_checksum_calculate(tmpbuf, txreq.size); qemu_send_packet(&netdev->nic->nc, tmpbuf, txreq.size); } else { qemu_send_packet(&netdev->nic->nc, page + txreq.offset, txreq.size); } xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); net_tx_response(netdev, &txreq, NETIF_RSP_OKAY); } if (!netdev->tx_work) { break; } netdev->tx_work = 0; } g_free(tmpbuf); } /* ------------------------------------------------------------- */ static void net_rx_response(struct XenNetDev *netdev, netif_rx_request_t *req, int8_t st, uint16_t offset, uint16_t size, uint16_t flags) { RING_IDX i = netdev->rx_ring.rsp_prod_pvt; netif_rx_response_t *resp; int notify; resp = RING_GET_RESPONSE(&netdev->rx_ring, i); resp->offset = offset; resp->flags = flags; resp->id = req->id; resp->status = (int16_t)size; if (st < 0) { resp->status = (int16_t)st; } xen_be_printf(&netdev->xendev, 3, "rx response: idx %d, status %d, flags 0x%x\n", i, resp->status, resp->flags); netdev->rx_ring.rsp_prod_pvt = ++i; RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(&netdev->rx_ring, notify); if (notify) { xen_be_send_notify(&netdev->xendev); } } #define NET_IP_ALIGN 2 static int net_rx_ok(NetClientState *nc) { struct XenNetDev *netdev = DO_UPCAST(NICState, nc, nc)->opaque; RING_IDX rc, rp; if (netdev->xendev.be_state != XenbusStateConnected) { return 0; } rc = netdev->rx_ring.req_cons; rp = netdev->rx_ring.sring->req_prod; xen_rmb(); if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { xen_be_printf(&netdev->xendev, 2, "%s: no rx buffers (%d/%d)\n", __FUNCTION__, rc, rp); return 0; } return 1; } static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size) { struct XenNetDev *netdev = DO_UPCAST(NICState, nc, nc)->opaque; netif_rx_request_t rxreq; RING_IDX rc, rp; void *page; if (netdev->xendev.be_state != XenbusStateConnected) { return -1; } rc = netdev->rx_ring.req_cons; rp = netdev->rx_ring.sring->req_prod; xen_rmb(); /* Ensure we see queued requests up to 'rp'. */ if (rc == rp || RING_REQUEST_CONS_OVERFLOW(&netdev->rx_ring, rc)) { xen_be_printf(&netdev->xendev, 2, "no buffer, drop packet\n"); return -1; } if (size > XC_PAGE_SIZE - NET_IP_ALIGN) { xen_be_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)", (unsigned long)size, XC_PAGE_SIZE - NET_IP_ALIGN); return -1; } memcpy(&rxreq, RING_GET_REQUEST(&netdev->rx_ring, rc), sizeof(rxreq)); netdev->rx_ring.req_cons = ++rc; page = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, netdev->xendev.dom, rxreq.gref, PROT_WRITE); if (page == NULL) { xen_be_printf(&netdev->xendev, 0, "error: rx gref dereference failed (%d)\n", rxreq.gref); net_rx_response(netdev, &rxreq, NETIF_RSP_ERROR, 0, 0, 0); return -1; } memcpy(page + NET_IP_ALIGN, buf, size); xc_gnttab_munmap(netdev->xendev.gnttabdev, page, 1); net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0); return size; } /* ------------------------------------------------------------- */ static NetClientInfo net_xen_info = { .type = NET_CLIENT_OPTIONS_KIND_NIC, .size = sizeof(NICState), .can_receive = net_rx_ok, .receive = net_rx_packet, }; static int net_init(struct XenDevice *xendev) { struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); /* read xenstore entries */ if (netdev->mac == NULL) { netdev->mac = xenstore_read_be_str(&netdev->xendev, "mac"); } /* do we have all we need? */ if (netdev->mac == NULL) { return -1; } if (net_parse_macaddr(netdev->conf.macaddr.a, netdev->mac) < 0) { return -1; } netdev->conf.peer = NULL; netdev->nic = qemu_new_nic(&net_xen_info, &netdev->conf, "xen", NULL, netdev); snprintf(netdev->nic->nc.info_str, sizeof(netdev->nic->nc.info_str), "nic: xenbus vif macaddr=%s", netdev->mac); /* fill info */ xenstore_write_be_int(&netdev->xendev, "feature-rx-copy", 1); xenstore_write_be_int(&netdev->xendev, "feature-rx-flip", 0); return 0; } static int net_connect(struct XenDevice *xendev) { struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); int rx_copy; if (xenstore_read_fe_int(&netdev->xendev, "tx-ring-ref", &netdev->tx_ring_ref) == -1) { return -1; } if (xenstore_read_fe_int(&netdev->xendev, "rx-ring-ref", &netdev->rx_ring_ref) == -1) { return 1; } if (xenstore_read_fe_int(&netdev->xendev, "event-channel", &netdev->xendev.remote_port) == -1) { return -1; } if (xenstore_read_fe_int(&netdev->xendev, "request-rx-copy", &rx_copy) == -1) { rx_copy = 0; } if (rx_copy == 0) { xen_be_printf(&netdev->xendev, 0, "frontend doesn't support rx-copy.\n"); return -1; } netdev->txs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, netdev->xendev.dom, netdev->tx_ring_ref, PROT_READ | PROT_WRITE); netdev->rxs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev, netdev->xendev.dom, netdev->rx_ring_ref, PROT_READ | PROT_WRITE); if (!netdev->txs || !netdev->rxs) { return -1; } BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XC_PAGE_SIZE); BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XC_PAGE_SIZE); xen_be_bind_evtchn(&netdev->xendev); xen_be_printf(&netdev->xendev, 1, "ok: tx-ring-ref %d, rx-ring-ref %d, " "remote port %d, local port %d\n", netdev->tx_ring_ref, netdev->rx_ring_ref, netdev->xendev.remote_port, netdev->xendev.local_port); net_tx_packets(netdev); return 0; } static void net_disconnect(struct XenDevice *xendev) { struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); xen_be_unbind_evtchn(&netdev->xendev); if (netdev->txs) { xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1); netdev->txs = NULL; } if (netdev->rxs) { xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->rxs, 1); netdev->rxs = NULL; } if (netdev->nic) { qemu_del_net_client(&netdev->nic->nc); netdev->nic = NULL; } } static void net_event(struct XenDevice *xendev) { struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); net_tx_packets(netdev); qemu_flush_queued_packets(&netdev->nic->nc); } static int net_free(struct XenDevice *xendev) { struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); g_free(netdev->mac); return 0; } /* ------------------------------------------------------------- */ struct XenDevOps xen_netdev_ops = { .size = sizeof(struct XenNetDev), .flags = DEVOPS_FLAG_NEED_GNTDEV, .init = net_init, .initialise = net_connect, .event = net_event, .disconnect = net_disconnect, .free = net_free, };