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c1345a8878
qemu/hw/net/xen_nic.c
Ian Campbell c1345a8878 xen: Switch to libxengnttab interface for compat shims. 
In Xen 4.7 we are refactoring parts libxenctrl into a number of
separate libraries which will provide backward and forward API and ABI
compatiblity.

One such library will be libxengnttab which provides access to grant
tables.

In preparation for this switch the compatibility layer in xen_common.h
(which support building with older versions of Xen) to use what will
be the new library API. This means that the gnttab shim will disappear
for versions of Xen which include libxengnttab.

To simplify things for the <= 4.0.0 support we wrap the int fd in a
malloc(sizeof int) such that the handle is always a pointer. This
leads to less typedef headaches and the need for
XC_HANDLER_INITIAL_VALUE etc for these interfaces.

Note that this patch does not add any support for actually using
libxengnttab, it just adjusts the existing shims.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2016-01-26 17:19:28 +00:00

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/*
* 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 <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 = xengnttab_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);
}
xengnttab_unmap(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 = xengnttab_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);
xengnttab_unmap(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 = xengnttab_map_grant_ref(netdev->xendev.gnttabdev,
netdev->xendev.dom,
netdev->tx_ring_ref,
PROT_READ | PROT_WRITE);
if (!netdev->txs) {
return -1;
}
netdev->rxs = xengnttab_map_grant_ref(netdev->xendev.gnttabdev,
netdev->xendev.dom,
netdev->rx_ring_ref,
PROT_READ | PROT_WRITE);
if (!netdev->rxs) {
xengnttab_unmap(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) {
xengnttab_unmap(netdev->xendev.gnttabdev, netdev->txs, 1);
netdev->txs = NULL;
}
if (netdev->rxs) {
xengnttab_unmap(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,
};
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