| /* | 
 |  *  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 "qemu/osdep.h" | 
 | #include <sys/socket.h> | 
 | #include <sys/ioctl.h> | 
 | #include <sys/wait.h> | 
 |  | 
 | #include "net/net.h" | 
 | #include "net/checksum.h" | 
 | #include "net/util.h" | 
 | #include "hw/xen/xen-legacy-backend.h" | 
 |  | 
 | #include "hw/xen/interface/io/netif.h" | 
 |  | 
 | /* ------------------------------------------------------------- */ | 
 |  | 
 | struct XenNetDev { | 
 |     struct XenLegacyDevice      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_pv_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_pv_printf(&netdev->xendev, 0, "FIXME: extra info flag\n"); | 
 |                 net_tx_error(netdev, &txreq, rc); | 
 |                 continue; | 
 |             } | 
 |             if (txreq.flags & NETTXF_more_data) { | 
 |                 xen_pv_printf(&netdev->xendev, 0, "FIXME: more data flag\n"); | 
 |                 net_tx_error(netdev, &txreq, rc); | 
 |                 continue; | 
 |             } | 
 | #endif | 
 |  | 
 |             if (txreq.size < 14) { | 
 |                 xen_pv_printf(&netdev->xendev, 0, "bad packet size: %d\n", | 
 |                               txreq.size); | 
 |                 net_tx_error(netdev, &txreq, rc); | 
 |                 continue; | 
 |             } | 
 |  | 
 |             if ((txreq.offset + txreq.size) > XEN_PAGE_SIZE) { | 
 |                 xen_pv_printf(&netdev->xendev, 0, "error: page crossing\n"); | 
 |                 net_tx_error(netdev, &txreq, rc); | 
 |                 continue; | 
 |             } | 
 |  | 
 |             xen_pv_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 = xen_be_map_grant_ref(&netdev->xendev, txreq.gref, | 
 |                                         PROT_READ); | 
 |             if (page == NULL) { | 
 |                 xen_pv_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(XEN_PAGE_SIZE); | 
 |                 } | 
 |                 memcpy(tmpbuf, page + txreq.offset, txreq.size); | 
 |                 net_checksum_calculate(tmpbuf, txreq.size, CSUM_ALL); | 
 |                 qemu_send_packet(qemu_get_queue(netdev->nic), tmpbuf, | 
 |                                  txreq.size); | 
 |             } else { | 
 |                 qemu_send_packet(qemu_get_queue(netdev->nic), | 
 |                                  page + txreq.offset, txreq.size); | 
 |             } | 
 |             xen_be_unmap_grant_ref(&netdev->xendev, page, txreq.gref); | 
 |             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_pv_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_pv_send_notify(&netdev->xendev); | 
 |     } | 
 | } | 
 |  | 
 | #define NET_IP_ALIGN 2 | 
 |  | 
 | static ssize_t net_rx_packet(NetClientState *nc, const uint8_t *buf, size_t size) | 
 | { | 
 |     struct XenNetDev *netdev = qemu_get_nic_opaque(nc); | 
 |     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)) { | 
 |         return 0; | 
 |     } | 
 |     if (size > XEN_PAGE_SIZE - NET_IP_ALIGN) { | 
 |         xen_pv_printf(&netdev->xendev, 0, "packet too big (%lu > %ld)", | 
 |                       (unsigned long)size, XEN_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 = xen_be_map_grant_ref(&netdev->xendev, rxreq.gref, PROT_WRITE); | 
 |     if (page == NULL) { | 
 |         xen_pv_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); | 
 |     xen_be_unmap_grant_ref(&netdev->xendev, page, rxreq.gref); | 
 |     net_rx_response(netdev, &rxreq, NETIF_RSP_OKAY, NET_IP_ALIGN, size, 0); | 
 |  | 
 |     return size; | 
 | } | 
 |  | 
 | /* ------------------------------------------------------------- */ | 
 |  | 
 | static NetClientInfo net_xen_info = { | 
 |     .type = NET_CLIENT_DRIVER_NIC, | 
 |     .size = sizeof(NICState), | 
 |     .receive = net_rx_packet, | 
 | }; | 
 |  | 
 | static int net_init(struct XenLegacyDevice *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->nic = qemu_new_nic(&net_xen_info, &netdev->conf, | 
 |                                "xen", NULL, netdev); | 
 |  | 
 |     qemu_set_info_str(qemu_get_queue(netdev->nic), | 
 |                       "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 XenLegacyDevice *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_pv_printf(&netdev->xendev, 0, | 
 |                       "frontend doesn't support rx-copy.\n"); | 
 |         return -1; | 
 |     } | 
 |  | 
 |     netdev->txs = xen_be_map_grant_ref(&netdev->xendev, | 
 |                                        netdev->tx_ring_ref, | 
 |                                        PROT_READ | PROT_WRITE); | 
 |     if (!netdev->txs) { | 
 |         return -1; | 
 |     } | 
 |     netdev->rxs = xen_be_map_grant_ref(&netdev->xendev, | 
 |                                        netdev->rx_ring_ref, | 
 |                                        PROT_READ | PROT_WRITE); | 
 |     if (!netdev->rxs) { | 
 |         xen_be_unmap_grant_ref(&netdev->xendev, netdev->txs, | 
 |                                netdev->tx_ring_ref); | 
 |         netdev->txs = NULL; | 
 |         return -1; | 
 |     } | 
 |     BACK_RING_INIT(&netdev->tx_ring, netdev->txs, XEN_PAGE_SIZE); | 
 |     BACK_RING_INIT(&netdev->rx_ring, netdev->rxs, XEN_PAGE_SIZE); | 
 |  | 
 |     xen_be_bind_evtchn(&netdev->xendev); | 
 |  | 
 |     xen_pv_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 XenLegacyDevice *xendev) | 
 | { | 
 |     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); | 
 |  | 
 |     xen_pv_unbind_evtchn(&netdev->xendev); | 
 |  | 
 |     if (netdev->txs) { | 
 |         xen_be_unmap_grant_ref(&netdev->xendev, netdev->txs, | 
 |                                netdev->tx_ring_ref); | 
 |         netdev->txs = NULL; | 
 |     } | 
 |     if (netdev->rxs) { | 
 |         xen_be_unmap_grant_ref(&netdev->xendev, netdev->rxs, | 
 |                                netdev->rx_ring_ref); | 
 |         netdev->rxs = NULL; | 
 |     } | 
 | } | 
 |  | 
 | static void net_event(struct XenLegacyDevice *xendev) | 
 | { | 
 |     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); | 
 |     net_tx_packets(netdev); | 
 |     qemu_flush_queued_packets(qemu_get_queue(netdev->nic)); | 
 | } | 
 |  | 
 | static int net_free(struct XenLegacyDevice *xendev) | 
 | { | 
 |     struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); | 
 |  | 
 |     if (netdev->nic) { | 
 |         qemu_del_nic(netdev->nic); | 
 |         netdev->nic = NULL; | 
 |     } | 
 |     g_free(netdev->mac); | 
 |     netdev->mac = NULL; | 
 |     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, | 
 | }; |