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* [Qemu-devel] [PATCH] net: Add persistent flag to -net tap option
@ 2014-12-15 12:05 Roy Vardi
  2014-12-19 13:13 ` Stefan Hajnoczi
  2014-12-19 15:29 ` Eric Blake
  0 siblings, 2 replies; 14+ messages in thread
From: Roy Vardi @ 2014-12-15 12:05 UTC (permalink / raw)
  To: qemu-devel; +Cc: aliguori, royv, armbru, lcapitulino, stefanha

From: Roy Vardi <royv@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 <royv@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

^ permalink raw reply related	[flat|nested] 14+ messages in thread
* [Qemu-devel] [PATCH] net: Add persistent flag to -net tap option
@ 2014-12-21  7:48 Roy Vardi
  2014-12-22  6:33 ` Jason Wang
  2015-01-22 15:25 ` Eric Blake
  0 siblings, 2 replies; 14+ messages in thread
From: Roy Vardi @ 2014-12-21  7:48 UTC (permalink / raw)
  To: qemu-devel; +Cc: aliguori, royv, armbru, lcapitulino, noamc, stefanha

From: Roy Vardi <royv@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 <royv@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..7a98390 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..055863a 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_required)
 {
     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_required));
     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..99e6482 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 (default: on) (Since: 2.3)
+#
 # 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..d8c033d 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

^ permalink raw reply related	[flat|nested] 14+ messages in thread
end of thread, other threads:[~2015-01-22 15:25 UTC | newest]

Thread overview: 14+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-12-15 12:05 [Qemu-devel] [PATCH] net: Add persistent flag to -net tap option Roy Vardi
2014-12-19 13:13 ` Stefan Hajnoczi
2014-12-19 13:18   ` Daniel P. Berrange
2014-12-21  7:17   ` Roy Vardi
2015-01-06 11:58     ` Stefan Hajnoczi
2014-12-19 15:29 ` Eric Blake
  -- strict thread matches above, loose matches on Subject: below --
2014-12-21  7:48 Roy Vardi
2014-12-22  6:33 ` Jason Wang
2014-12-23  8:44   ` Roy Vardi
     [not found]     ` <AM2PR02MB0532BC1703B005CE79A141FCAA570@AM2PR02MB0532.eurprd02.prod.outlook .com>
2014-12-23  9:13       ` Jason Wang
2014-12-29  7:38         ` Roy Vardi
2015-01-04  7:28           ` Jason Wang
2015-01-18  9:42             ` Roy Vardi
2015-01-22 15:25 ` Eric Blake

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