diff options
Diffstat (limited to 'hw/xen_nic.c')
| -rw-r--r-- | hw/xen_nic.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/hw/xen_nic.c b/hw/xen_nic.c new file mode 100644 index 0000000..2364e82 --- /dev/null +++ b/hw/xen_nic.c @@ -0,0 +1,406 @@ +/* + * 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#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 <pthread.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 <linux/if.h> +#include <linux/if_tun.h> + +#include <xs.h> +#include <xenctrl.h> +#include <xen/io/xenbus.h> +#include <xen/io/netif.h> + +#include "hw.h" +#include "net.h" +#include "qemu-char.h" +#include "xen_backend.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; + VLANClientState *vs; +}; + +/* ------------------------------------------------------------- */ + +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 = malloc(PAGE_SIZE); + memcpy(tmpbuf, page + txreq.offset, txreq.size); + net_checksum_calculate(tmpbuf, txreq.size); + qemu_send_packet(netdev->vs, tmpbuf, txreq.size); + } else { + qemu_send_packet(netdev->vs, 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; + } + 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(void *opaque) +{ + struct XenNetDev *netdev = 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 void net_rx_packet(void *opaque, const uint8_t *buf, int size) +{ + struct XenNetDev *netdev = opaque; + netif_rx_request_t rxreq; + RING_IDX rc, rp; + void *page; + + if (netdev->xendev.be_state != XenbusStateConnected) + return; + + 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; + } + if (size > XC_PAGE_SIZE - NET_IP_ALIGN) { + xen_be_printf(&netdev->xendev, 0, "packet too big (%d > %ld)", + size, XC_PAGE_SIZE - NET_IP_ALIGN); + return; + } + + 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; + } + 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); +} + +/* ------------------------------------------------------------- */ + +static int net_init(struct XenDevice *xendev) +{ + struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); + VLANState *vlan; + + /* 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; + + vlan = qemu_find_vlan(netdev->xendev.dev); + netdev->vs = qemu_new_vlan_client(vlan, "xen", NULL, + net_rx_packet, net_rx_ok, NULL, + netdev); + snprintf(netdev->vs->info_str, sizeof(netdev->vs->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); + 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->vs) { + qemu_del_vlan_client(netdev->vs); + netdev->vs = NULL; + } +} + +static void net_event(struct XenDevice *xendev) +{ + struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); + net_tx_packets(netdev); +} + +static int net_free(struct XenDevice *xendev) +{ + struct XenNetDev *netdev = container_of(xendev, struct XenNetDev, xendev); + + qemu_free(netdev->mac); + return 0; +} + +/* ------------------------------------------------------------- */ + +struct XenDevOps xen_netdev_ops = { + .size = sizeof(struct XenNetDev), + .flags = DEVOPS_FLAG_NEED_GNTDEV, + .init = net_init, + .connect = net_connect, + .event = net_event, + .disconnect = net_disconnect, + .free = net_free, +}; |