From: Roy Vardi <r...@ezchip.com>
Add 'persistent' boolean flag to -net tap option.
When set to off - tap interface will be released on shutdown
When set to on\not specified - tap interface will remain
Running with -net tap,persistent=off will force the tap interface
down when qemu goes down, thus ensuring that there're no zombie tap
interfaces left
This is achieved using another ioctl
Note: This commit includes the above support only for linux systems
Signed-off-by: Roy Vardi <r...@ezchip.com>
---
net/tap-linux.c | 14 +++++++++++++-
net/tap.c | 10 ++++++----
net/tap_int.h | 2 +-
qapi-schema.json | 5 ++++-
qemu-options.hx | 3 ++-
5 files changed, 26 insertions(+), 8 deletions(-)
diff --git a/net/tap-linux.c b/net/tap-linux.c
index 812bf2d..2072166 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -29,6 +29,7 @@
#include <net/if.h>
#include <sys/ioctl.h>
+#include <linux/if_tun.h>
#include "sysemu/sysemu.h"
#include "qemu-common.h"
@@ -37,7 +38,7 @@
#define PATH_NET_TUN "/dev/net/tun"
int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
- int vnet_hdr_required, int mq_required)
+ int vnet_hdr_required, int mq_required, int persistent_required)
{
struct ifreq ifr;
int fd, ret;
@@ -109,6 +110,17 @@ int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
close(fd);
return -1;
}
+
+ if (!persistent_required) {
+ ret = ioctl(fd, TUNSETPERSIST, 0);
+ if (ret != 0) {
+ error_report("could not configure non-persistent %s (%s): %m",
+ PATH_NET_TUN, ifr.ifr_name);
+ close(fd);
+ return -1;
+ }
+ }
+
pstrcpy(ifname, ifname_size, ifr.ifr_name);
fcntl(fd, F_SETFL, O_NONBLOCK);
return fd;
diff --git a/net/tap.c b/net/tap.c
index bde6b58..43267bb 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -556,7 +556,8 @@ int net_init_bridge(const NetClientOptions *opts, const
char *name,
static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr,
const char *setup_script, char *ifname,
- size_t ifname_sz, int mq_required)
+ size_t ifname_sz, int mq_required,
+ int persistent_reuired)
{
int fd, vnet_hdr_required;
@@ -569,7 +570,7 @@ static int net_tap_init(const NetdevTapOptions *tap, int
*vnet_hdr,
}
TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required,
- mq_required));
+ mq_required, persistent_reuired));
if (fd < 0) {
return -1;
}
@@ -688,7 +689,7 @@ int net_init_tap(const NetClientOptions *opts, const char
*name,
NetClientState *peer)
{
const NetdevTapOptions *tap;
- int fd, vnet_hdr = 0, i = 0, queues;
+ int fd, vnet_hdr = 0, i = 0, queues, persistent;
/* for the no-fd, no-helper case */
const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */
const char *downscript = NULL;
@@ -699,6 +700,7 @@ int net_init_tap(const NetClientOptions *opts, const char
*name,
tap = opts->tap;
queues = tap->has_queues ? tap->queues : 1;
vhostfdname = tap->has_vhostfd ? tap->vhostfd : NULL;
+ persistent = tap->has_persistent ? tap->persistent : 1;
/* QEMU vlans does not support multiqueue tap, in this case peer is set.
* For -netdev, peer is always NULL. */
@@ -816,7 +818,7 @@ int net_init_tap(const NetClientOptions *opts, const char
*name,
for (i = 0; i < queues; i++) {
fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
- ifname, sizeof ifname, queues > 1);
+ ifname, sizeof ifname, queues > 1, persistent);
if (fd == -1) {
return -1;
}
diff --git a/net/tap_int.h b/net/tap_int.h
index 79afdf2..0eb2168 100644
--- a/net/tap_int.h
+++ b/net/tap_int.h
@@ -30,7 +30,7 @@
#include "qapi-types.h"
int tap_open(char *ifname, int ifname_size, int *vnet_hdr,
- int vnet_hdr_required, int mq_required);
+ int vnet_hdr_required, int mq_required, int persistent_required);
ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen);
diff --git a/qapi-schema.json b/qapi-schema.json
index 563b4ad..e4ea73f 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2007,6 +2007,8 @@
#
# @queues: #optional number of queues to be created for multiqueue capable tap
#
+# @persistent: #optional for opening tap in persistent mode
+#
# Since 1.2
##
{ 'type': 'NetdevTapOptions',
@@ -2023,7 +2025,8 @@
'*vhostfd': 'str',
'*vhostfds': 'str',
'*vhostforce': 'bool',
- '*queues': 'uint32'} }
+ '*queues': 'uint32',
+ '*persistent': 'bool'} }
##
# @NetdevSocketOptions
diff --git a/qemu-options.hx b/qemu-options.hx
index 10b9568..d26215a 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1417,7 +1417,7 @@ DEF("net", HAS_ARG, QEMU_OPTION_net,
"-net tap[,vlan=n][,name=str],ifname=name\n"
" connect the host TAP network interface to VLAN 'n'\n"
#else
- "-net
tap[,vlan=n][,name=str][,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off][,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n]\n"
+ "-net
tap[,vlan=n][,name=str][,fd=h][,fds=x:y:...:z][,ifname=name][,script=file][,downscript=dfile][,helper=helper][,sndbuf=nbytes][,vnet_hdr=on|off][,vhost=on|off][,vhostfd=h][,vhostfds=x:y:...:z][,vhostforce=on|off][,queues=n][persistent=on|off]\n"
" connect the host TAP network interface to VLAN 'n'\n"
" use network scripts 'file' (default="
DEFAULT_NETWORK_SCRIPT ")\n"
" to configure it and 'dfile' (default="
DEFAULT_NETWORK_DOWN_SCRIPT ")\n"
@@ -1437,6 +1437,7 @@ DEF("net", HAS_ARG, QEMU_OPTION_net,
" use 'vhostfd=h' to connect to an already opened vhost net
device\n"
" use 'vhostfds=x:y:...:z to connect to multiple already
opened vhost net devices\n"
" use 'queues=n' to specify the number of queues to be
created for multiqueue TAP\n"
+ " use persistent=off to release the TAP interface on
shutdown (default=on)\n"
"-net bridge[,vlan=n][,name=str][,br=bridge][,helper=helper]\n"
" connects a host TAP network interface to a host bridge
device 'br'\n"
" (default=" DEFAULT_BRIDGE_INTERFACE ") using the program
'helper'\n"
--
1.7.1
