qemu-e2k/net/tap-bsd.c
Jason Wang 264986e2c8 tap: multiqueue support
Recently, linux support multiqueue tap which could let userspace call TUNSETIFF
for a signle device many times to create multiple file descriptors as
independent queues. User could also enable/disabe a specific queue through
TUNSETQUEUE.

The patch adds the generic infrastructure to create multiqueue taps. To achieve
this a new parameter "queues" were introduced to specify how many queues were
expected to be created for tap by qemu itself. Alternatively, management could
also pass multiple pre-created tap file descriptors separated with ':' through a
new parameter fds like -netdev tap,id=hn0,fds="X:Y:..:Z". Multiple vhost file
descriptors could also be passed in this way.

Each TAPState were still associated to a tap fd, which mean multiple TAPStates
were created when user needs multiqueue taps. Since each TAPState contains one
NetClientState, with the multiqueue nic support, an N peers of NetClientState
were built up.

A new parameter, mq_required were introduce in tap_open() to create multiqueue
tap fds.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2013-02-01 11:03:02 -06:00

164 lines
4.0 KiB
C

/*
* QEMU System Emulator
*
* Copyright (c) 2003-2008 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "tap_int.h"
#include "qemu-common.h"
#include "sysemu/sysemu.h"
#include "qemu/error-report.h"
#ifdef __NetBSD__
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_tap.h>
#endif
int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
int vnet_hdr_required, int mq_required)
{
int fd;
#ifdef TAPGIFNAME
struct ifreq ifr;
#else
char *dev;
struct stat s;
#endif
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
/* if no ifname is given, always start the search from tap0/tun0. */
int i;
char dname[100];
for (i = 0; i < 10; i++) {
if (*ifname) {
snprintf(dname, sizeof dname, "/dev/%s", ifname);
} else {
#if defined(__OpenBSD__)
snprintf(dname, sizeof dname, "/dev/tun%d", i);
#else
snprintf(dname, sizeof dname, "/dev/tap%d", i);
#endif
}
TFR(fd = open(dname, O_RDWR));
if (fd >= 0) {
break;
}
else if (errno == ENXIO || errno == ENOENT) {
break;
}
if (*ifname) {
break;
}
}
if (fd < 0) {
error_report("warning: could not open %s (%s): no virtual network emulation",
dname, strerror(errno));
return -1;
}
#else
TFR(fd = open("/dev/tap", O_RDWR));
if (fd < 0) {
fprintf(stderr,
"warning: could not open /dev/tap: no virtual network emulation: %s\n",
strerror(errno));
return -1;
}
#endif
#ifdef TAPGIFNAME
if (ioctl(fd, TAPGIFNAME, (void *)&ifr) < 0) {
fprintf(stderr, "warning: could not get tap name: %s\n",
strerror(errno));
return -1;
}
pstrcpy(ifname, ifname_size, ifr.ifr_name);
#else
if (fstat(fd, &s) < 0) {
fprintf(stderr,
"warning: could not stat /dev/tap: no virtual network emulation: %s\n",
strerror(errno));
return -1;
}
dev = devname(s.st_rdev, S_IFCHR);
pstrcpy(ifname, ifname_size, dev);
#endif
if (*vnet_hdr) {
/* BSD doesn't have IFF_VNET_HDR */
*vnet_hdr = 0;
if (vnet_hdr_required && !*vnet_hdr) {
error_report("vnet_hdr=1 requested, but no kernel "
"support for IFF_VNET_HDR available");
close(fd);
return -1;
}
}
fcntl(fd, F_SETFL, O_NONBLOCK);
return fd;
}
int tap_set_sndbuf(int fd, const NetdevTapOptions *tap)
{
return 0;
}
int tap_probe_vnet_hdr(int fd)
{
return 0;
}
int tap_probe_has_ufo(int fd)
{
return 0;
}
int tap_probe_vnet_hdr_len(int fd, int len)
{
return 0;
}
void tap_fd_set_vnet_hdr_len(int fd, int len)
{
}
void tap_fd_set_offload(int fd, int csum, int tso4,
int tso6, int ecn, int ufo)
{
}
int tap_fd_enable(int fd)
{
return -1;
}
int tap_fd_disable(int fd)
{
return -1;
}
int tap_fd_get_ifname(int fd, char *ifname)
{
return -1;
}