diff options
Diffstat (limited to 'hw/net/xen_nic.c')
| -rw-r--r-- | hw/net/xen_nic.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/hw/net/xen_nic.c b/hw/net/xen_nic.c new file mode 100644 index 000000000..5c815b4f0 --- /dev/null +++ b/hw/net/xen_nic.c @@ -0,0 +1,411 @@ +/* + * 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) > XC_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(XC_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); + 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 > XC_PAGE_SIZE - NET_IP_ALIGN) { + xen_pv_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 = 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); + 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); + + snprintf(qemu_get_queue(netdev->nic)->info_str, + sizeof(qemu_get_queue(netdev->nic)->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 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->txs = NULL; + 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_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->txs = NULL; + } + if (netdev->rxs) { + xen_be_unmap_grant_ref(&netdev->xendev, netdev->rxs); + 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, +}; |