--- /dev/null
+/*
+ * 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/hw.h"
+#include "net/net.h"
+#include "net/checksum.h"
+#include "net/util.h"
+#include "hw/xen/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(qemu_get_queue(netdev->nic), tmpbuf,
+ txreq.size);
+ } else {
+ qemu_send_packet(qemu_get_queue(netdev->nic),
+ 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 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_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),
+ .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->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 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);
+ if (!netdev->txs) {
+ return -1;
+ }
+ netdev->rxs = xc_gnttab_map_grant_ref(netdev->xendev.gnttabdev,
+ netdev->xendev.dom,
+ netdev->rx_ring_ref,
+ PROT_READ | PROT_WRITE);
+ if (!netdev->rxs) {
+ xc_gnttab_munmap(netdev->xendev.gnttabdev, netdev->txs, 1);
+ 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_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;
+ }
+}
+
+static void net_event(struct XenDevice *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 XenDevice *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,
+};
Code Review / kvmfornfv.git / blobdiff