[Qemu-devel] [PATCH v2 0/8] Improvements and clean-ups related to -net

[Qemu-devel] [PATCH v2 0/8] Improvements and clean-ups related to -net

[Thomas Huth]

"-net" is a legacy option that often causes confusion and
misconfigurations for the users, since most people are not aware
of the underlying "vlan" (i.e. hub) concept that is used for this
parameter. The prefered way of configuring your network stack is
to use "--netdev" instead, which gives you a clean 1:1 connection
between your emulated guest hardware and the host network backend.

However, there are two reasons why we could not completely deprecate
"-net" yet:

1) Convenience:
In some cases, it's more convenient to use "-net" instead of "--netdev",
e.g. if you just want to have a "tap" network connection, it's faster
to type "-net nic -net tap" instead of "--device e1000,netdev=n1
--netdev tap,id=n1".

2) On-board NICs:
Currently the "-net nic" parameter is the only way to configure on-board
NICs on certain (embedded) machines via the nd_table[] array.

So beside some generic clean-ups and removal of code that has been
marked as deprecated since QEMU 2.10 already, this patch series intro-
duces a new parameter "--nic" (in patch 7/8) which should be able to
replace "-net" in the long run completely: This new convenience parameter
can be used to configure the default/on-board guest HW together with a
host network backend in a very compact way. To configure a tap backend
for the default NIC, you just have to type "--nic tap" here for example.

The last patch finally makes "-net" less prominent in our qemu docs,
e.g. by replacing the examples that contain "-net" with "--netdev".

Note that "-net" itself is not marked as deprecated yet - I think we
should rather do that after one or two QEMU release with "--nic" so
that we have enough time to test / get used to the new parameter first.
Or we should likely even keep the "-net" around for a couple of years
since there are a lot of scripts and tools out there that still use
this legacy parameter...

v2:
- Renamed "-n" to "--nic" (suggested by Paolo)
- Improved the QAPI comment about the removal of 'dump (suggested by Eric)
- exit(0) instead of exit(1) after showing the "-netdev help" (Eric)
- Improved the documenation for hubport a little bit (suggested by Paolo)

Thomas Huth (8):
  net: Move error reporting from net_init_client/netdev to the calling
    site
  net: List available netdevs with "-netdev help"
  net: Only show vhost-user in the help text if CONFIG_POSIX is defined
  net: Make net_client_init() static
  net: Remove the deprecated way of dumping network packets
  net: Remove the deprecated 'host_net_add' and 'host_net_remove' HMP
    commands
  net: Add a new convenience option "--nic" to configure
    default/on-board NICs
  qemu-doc: Make "-net" less prominent

 hmp-commands.hx         |  30 ------
 hmp.h                   |   3 -
 include/net/net.h       |   4 +-
 include/sysemu/sysemu.h |   1 +
 monitor.c               |  61 ------------
 net/dump.c              | 102 +--------------------
 net/net.c               | 239 +++++++++++++++++++++++-------------------------
 qapi/net.json           |  29 ++----
 qemu-doc.texi           |  16 ----
 qemu-options.hx         | 224 ++++++++++++++++++++++++---------------------
 tests/test-hmp.c        |   2 -
 vl.c                    |  10 +-
 12 files changed, 256 insertions(+), 465 deletions(-)

-- 
1.8.3.1

[Qemu-devel] [PATCH v2 1/8] net: Move error reporting from net_init_client/netdev to the calling site

[Thomas Huth]

It looks strange that net_init_client() and net_init_netdev() both
take an "Error **errp" parameter, but then do the error reporting
with "error_report_err(local_err)" on their own. Let's move the
error reporting to the calling site instead to simplify this code
a little bit.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 include/net/net.h |  2 +-
 net/net.c         | 29 +++++------------------------
 vl.c              |  3 ++-
 3 files changed, 8 insertions(+), 26 deletions(-)

diff --git a/include/net/net.h b/include/net/net.h
index 3fc48e4..bdd4d9f 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -206,7 +206,7 @@ extern const char *legacy_bootp_filename;
 
 int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp);
 int net_client_parse(QemuOptsList *opts_list, const char *str);
-int net_init_clients(void);
+int net_init_clients(Error **errp);
 void net_check_clients(void);
 void net_cleanup(void);
 void hmp_host_net_add(Monitor *mon, const QDict *qdict);
diff --git a/net/net.c b/net/net.c
index 7d42925..e213a61 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1520,46 +1520,27 @@ void net_check_clients(void)
 
 static int net_init_client(void *dummy, QemuOpts *opts, Error **errp)
 {
-    Error *local_err = NULL;
-
-    net_client_init(opts, false, &local_err);
-    if (local_err) {
-        error_report_err(local_err);
-        return -1;
-    }
-
-    return 0;
+    return net_client_init(opts, false, errp);
 }
 
 static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
 {
-    Error *local_err = NULL;
-    int ret;
-
-    ret = net_client_init(opts, true, &local_err);
-    if (local_err) {
-        error_report_err(local_err);
-        return -1;
-    }
-
-    return ret;
+    return net_client_init(opts, true, errp);
 }
 
-int net_init_clients(void)
+int net_init_clients(Error **errp)
 {
-    QemuOptsList *net = qemu_find_opts("net");
-
     net_change_state_entry =
         qemu_add_vm_change_state_handler(net_vm_change_state_handler, NULL);
 
     QTAILQ_INIT(&net_clients);
 
     if (qemu_opts_foreach(qemu_find_opts("netdev"),
-                          net_init_netdev, NULL, NULL)) {
+                          net_init_netdev, NULL, errp)) {
         return -1;
     }
 
-    if (qemu_opts_foreach(net, net_init_client, NULL, NULL)) {
+    if (qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL, errp)) {
         return -1;
     }
 
diff --git a/vl.c b/vl.c
index 9e7235d..698b681 100644
--- a/vl.c
+++ b/vl.c
@@ -4476,7 +4476,8 @@ int main(int argc, char **argv, char **envp)
 
     colo_info_init();
 
-    if (net_init_clients() < 0) {
+    if (net_init_clients(&err) < 0) {
+        error_report_err(err);
         exit(1);
     }
 
-- 
1.8.3.1

[Qemu-devel] [PATCH v2 2/8] net: List available netdevs with "-netdev help"

[Thomas Huth]

Other options like "-chardev" or "-device" feature a nice help text
with the available devices when being called with "help" or "?".
Since it is quite useful, especially if you want to see which network
backends have been compiled into the QEMU binary, let's provide such
a help text for "-netdev", too.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 net/net.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/net/net.c b/net/net.c
index e213a61..cf07e15 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1086,6 +1086,38 @@ static int net_client_init1(const void *object, bool is_netdev, Error **errp)
     return 0;
 }
 
+static void show_netdevs(void)
+{
+    int idx;
+    const char *available_netdevs[] = {
+        "socket",
+        "hubport",
+        "tap",
+#ifdef CONFIG_SLIRP
+        "user",
+#endif
+#ifdef CONFIG_L2TPV3
+        "l2tpv3",
+#endif
+#ifdef CONFIG_VDE
+        "vde",
+#endif
+#ifdef CONFIG_NET_BRIDGE
+        "bridge",
+#endif
+#ifdef CONFIG_NETMAP
+        "netmap",
+#endif
+#ifdef CONFIG_POSIX
+        "vhost-user",
+#endif
+    };
+
+    printf("Available netdev backend types:\n");
+    for (idx = 0; idx < ARRAY_SIZE(available_netdevs); idx++) {
+        puts(available_netdevs[idx]);
+    }
+}
 
 int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
 {
@@ -1094,7 +1126,10 @@ int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
     int ret = -1;
     Visitor *v = opts_visitor_new(opts);
 
-    {
+    if (is_netdev && is_help_option(qemu_opt_get(opts, "type"))) {
+        show_netdevs();
+        exit(0);
+    } else {
         /* Parse convenience option format ip6-net=fec0::0[/64] */
         const char *ip6_net = qemu_opt_get(opts, "ipv6-net");
 
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v2 2/8] net: List available netdevs with "-netdev help"

[Eric Blake]

On 02/20/2018 11:40 AM, Thomas Huth wrote:
> Other options like "-chardev" or "-device" feature a nice help text
> with the available devices when being called with "help" or "?".
> Since it is quite useful, especially if you want to see which network
> backends have been compiled into the QEMU binary, let's provide such
> a help text for "-netdev", too.
> 
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---
>   net/net.c | 37 ++++++++++++++++++++++++++++++++++++-
>   1 file changed, 36 insertions(+), 1 deletion(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

[Qemu-devel] [PATCH v2 3/8] net: Only show vhost-user in the help text if CONFIG_POSIX is defined

[Thomas Huth]

According to net/Makefile.objs we only link in the vhost-user code
if CONFIG_POSIX has been set. So the help screen should also only
show this information if CONFIG_POSIX has been defined.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 qemu-options.hx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/qemu-options.hx b/qemu-options.hx
index 8ccd5dc..9ae49a0 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1998,8 +1998,10 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
     "                VALE port (created on the fly) called 'name' ('nmname' is name of the \n"
     "                netmap device, defaults to '/dev/netmap')\n"
 #endif
+#ifdef CONFIG_POSIX
     "-netdev vhost-user,id=str,chardev=dev[,vhostforce=on|off]\n"
     "                configure a vhost-user network, backed by a chardev 'dev'\n"
+#endif
     "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
     "                configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
 DEF("net", HAS_ARG, QEMU_OPTION_net,
-- 
1.8.3.1

[Qemu-devel] [PATCH v2 4/8] net: Make net_client_init() static

[Thomas Huth]

The function is only used within net.c, so there's no need that
this is a global function.

While we're at it, also remove the unused prototype compute_mcast_idx()
(the function has been removed in commit d9caeb09b107e91122d10ba4a08a).

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 include/net/net.h | 2 --
 net/net.c         | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/net/net.h b/include/net/net.h
index bdd4d9f..cd1708c 100644
--- a/include/net/net.h
+++ b/include/net/net.h
@@ -204,7 +204,6 @@ extern const char *host_net_devices[];
 extern const char *legacy_tftp_prefix;
 extern const char *legacy_bootp_filename;
 
-int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp);
 int net_client_parse(QemuOptsList *opts_list, const char *str);
 int net_init_clients(Error **errp);
 void net_check_clients(void);
@@ -228,7 +227,6 @@ void qdev_set_nic_properties(DeviceState *dev, NICInfo *nd);
 #define POLYNOMIAL_LE 0xedb88320
 uint32_t net_crc32(const uint8_t *p, int len);
 uint32_t net_crc32_le(const uint8_t *p, int len);
-unsigned compute_mcast_idx(const uint8_t *ep);
 
 #define vmstate_offset_macaddr(_state, _field)                       \
     vmstate_offset_array(_state, _field.a, uint8_t,                \
diff --git a/net/net.c b/net/net.c
index cf07e15..dd80f1b 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1119,7 +1119,7 @@ static void show_netdevs(void)
     }
 }
 
-int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
+static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
 {
     void *object = NULL;
     Error *err = NULL;
-- 
1.8.3.1

[Qemu-devel] [PATCH v2 5/8] net: Remove the deprecated way of dumping network packets

[Thomas Huth]

"-net dump" has been marked as deprecated since QEMU v2.10, since it
only works with the deprecated 'vlan' parameter (or hubs). Network
dumping should be done with "-object filter-dump" nowadays instead.
Since nobody complained so far about the deprecation message, let's
finally get rid of "-net dump" now.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 net/dump.c      | 102 ++------------------------------------------------------
 net/net.c       |   9 +----
 qapi/net.json   |  29 ++++------------
 qemu-doc.texi   |   6 ----
 qemu-options.hx |   8 -----
 5 files changed, 9 insertions(+), 145 deletions(-)

diff --git a/net/dump.c b/net/dump.c
index 15df9a4..f16c354 100644
--- a/net/dump.c
+++ b/net/dump.c
@@ -109,7 +109,7 @@ static int net_dump_state_init(DumpState *s, const char *filename,
 
     fd = open(filename, O_CREAT | O_TRUNC | O_WRONLY | O_BINARY, 0644);
     if (fd < 0) {
-        error_setg_errno(errp, errno, "-net dump: can't open %s", filename);
+        error_setg_errno(errp, errno, "net dump: can't open %s", filename);
         return -1;
     }
 
@@ -122,7 +122,7 @@ static int net_dump_state_init(DumpState *s, const char *filename,
     hdr.linktype = 1;
 
     if (write(fd, &hdr, sizeof(hdr)) < sizeof(hdr)) {
-        error_setg_errno(errp, errno, "-net dump write error");
+        error_setg_errno(errp, errno, "net dump write error");
         close(fd);
         return -1;
     }
@@ -136,104 +136,6 @@ static int net_dump_state_init(DumpState *s, const char *filename,
     return 0;
 }
 
-/* Dumping via VLAN netclient */
-
-struct DumpNetClient {
-    NetClientState nc;
-    DumpState ds;
-};
-typedef struct DumpNetClient DumpNetClient;
-
-static ssize_t dumpclient_receive(NetClientState *nc, const uint8_t *buf,
-                                  size_t size)
-{
-    DumpNetClient *dc = DO_UPCAST(DumpNetClient, nc, nc);
-    struct iovec iov = {
-        .iov_base = (void *)buf,
-        .iov_len = size
-    };
-
-    return dump_receive_iov(&dc->ds, &iov, 1);
-}
-
-static ssize_t dumpclient_receive_iov(NetClientState *nc,
-                                      const struct iovec *iov, int cnt)
-{
-    DumpNetClient *dc = DO_UPCAST(DumpNetClient, nc, nc);
-
-    return dump_receive_iov(&dc->ds, iov, cnt);
-}
-
-static void dumpclient_cleanup(NetClientState *nc)
-{
-    DumpNetClient *dc = DO_UPCAST(DumpNetClient, nc, nc);
-
-    dump_cleanup(&dc->ds);
-}
-
-static NetClientInfo net_dump_info = {
-    .type = NET_CLIENT_DRIVER_DUMP,
-    .size = sizeof(DumpNetClient),
-    .receive = dumpclient_receive,
-    .receive_iov = dumpclient_receive_iov,
-    .cleanup = dumpclient_cleanup,
-};
-
-int net_init_dump(const Netdev *netdev, const char *name,
-                  NetClientState *peer, Error **errp)
-{
-    int len, rc;
-    const char *file;
-    char def_file[128];
-    const NetdevDumpOptions *dump;
-    NetClientState *nc;
-    DumpNetClient *dnc;
-
-    assert(netdev->type == NET_CLIENT_DRIVER_DUMP);
-    dump = &netdev->u.dump;
-
-    assert(peer);
-
-    error_report("'-net dump' is deprecated. "
-                 "Please use '-object filter-dump' instead.");
-
-    if (dump->has_file) {
-        file = dump->file;
-    } else {
-        int id;
-        int ret;
-
-        ret = net_hub_id_for_client(peer, &id);
-        assert(ret == 0); /* peer must be on a hub */
-
-        snprintf(def_file, sizeof(def_file), "qemu-vlan%d.pcap", id);
-        file = def_file;
-    }
-
-    if (dump->has_len) {
-        if (dump->len > INT_MAX) {
-            error_setg(errp, "invalid length: %"PRIu64, dump->len);
-            return -1;
-        }
-        len = dump->len;
-    } else {
-        len = 65536;
-    }
-
-    nc = qemu_new_net_client(&net_dump_info, peer, "dump", name);
-    snprintf(nc->info_str, sizeof(nc->info_str),
-             "dump to %s (len=%d)", file, len);
-
-    dnc = DO_UPCAST(DumpNetClient, nc, nc);
-    rc = net_dump_state_init(&dnc->ds, file, len, errp);
-    if (rc) {
-        qemu_del_net_client(nc);
-    }
-    return rc;
-}
-
-/* Dumping via filter */
-
 #define TYPE_FILTER_DUMP "filter-dump"
 
 #define FILTER_DUMP(obj) \
diff --git a/net/net.c b/net/net.c
index dd80f1b..cbd553d 100644
--- a/net/net.c
+++ b/net/net.c
@@ -63,7 +63,6 @@ static QTAILQ_HEAD(, NetClientState) net_clients;
 const char *host_net_devices[] = {
     "tap",
     "socket",
-    "dump",
 #ifdef CONFIG_NET_BRIDGE
     "bridge",
 #endif
@@ -967,7 +966,6 @@ static int (* const net_client_init_fun[NET_CLIENT_DRIVER__MAX])(
 #ifdef CONFIG_NETMAP
         [NET_CLIENT_DRIVER_NETMAP]    = net_init_netmap,
 #endif
-        [NET_CLIENT_DRIVER_DUMP]      = net_init_dump,
 #ifdef CONFIG_NET_BRIDGE
         [NET_CLIENT_DRIVER_BRIDGE]    = net_init_bridge,
 #endif
@@ -993,8 +991,7 @@ static int net_client_init1(const void *object, bool is_netdev, Error **errp)
         netdev = object;
         name = netdev->id;
 
-        if (netdev->type == NET_CLIENT_DRIVER_DUMP ||
-            netdev->type == NET_CLIENT_DRIVER_NIC ||
+        if (netdev->type == NET_CLIENT_DRIVER_NIC ||
             !net_client_init_fun[netdev->type]) {
             error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "type",
                        "a netdev backend type");
@@ -1036,10 +1033,6 @@ static int net_client_init1(const void *object, bool is_netdev, Error **errp)
             legacy.type = NET_CLIENT_DRIVER_VDE;
             legacy.u.vde = opts->u.vde;
             break;
-        case NET_LEGACY_OPTIONS_TYPE_DUMP:
-            legacy.type = NET_CLIENT_DRIVER_DUMP;
-            legacy.u.dump = opts->u.dump;
-            break;
         case NET_LEGACY_OPTIONS_TYPE_BRIDGE:
             legacy.type = NET_CLIENT_DRIVER_BRIDGE;
             legacy.u.bridge = opts->u.bridge;
diff --git a/qapi/net.json b/qapi/net.json
index 1238ba5..09af929 100644
--- a/qapi/net.json
+++ b/qapi/net.json
@@ -39,8 +39,10 @@
 #
 # Add a network backend.
 #
-# @type: the type of network backend.  Current valid values are 'user', 'tap',
-#        'vde', 'socket', 'dump' and 'bridge'
+# @type: the type of network backend. Possible values in version
+#        2.11: 'user', 'tap', 'vde', 'socket', 'hubport', 'bridge',
+#              'dump', 'l2tpv3', 'netmap', 'vhost-user'
+#        2.12: 'dump' dropped
 #
 # @id: the name of the new network backend
 #
@@ -372,23 +374,6 @@
     '*mode':  'uint16' } }
 
 ##
-# @NetdevDumpOptions:
-#
-# Dump VLAN network traffic to a file.
-#
-# @len: per-packet size limit (64k default). Understands [TGMKkb]
-# suffixes.
-#
-# @file: dump file path (default is qemu-vlan0.pcap)
-#
-# Since: 1.2
-##
-{ 'struct': 'NetdevDumpOptions',
-  'data': {
-    '*len':  'size',
-    '*file': 'str' } }
-
-##
 # @NetdevBridgeOptions:
 #
 # Connect a host TAP network interface to a host bridge device.
@@ -468,7 +453,7 @@
 # Since: 2.7
 ##
 { 'enum': 'NetClientDriver',
-  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde', 'dump',
+  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
             'bridge', 'hubport', 'netmap', 'vhost-user' ] }
 
 ##
@@ -495,7 +480,6 @@
     'l2tpv3':   'NetdevL2TPv3Options',
     'socket':   'NetdevSocketOptions',
     'vde':      'NetdevVdeOptions',
-    'dump':     'NetdevDumpOptions',
     'bridge':   'NetdevBridgeOptions',
     'hubport':  'NetdevHubPortOptions',
     'netmap':   'NetdevNetmapOptions',
@@ -530,7 +514,7 @@
 ##
 { 'enum': 'NetLegacyOptionsType',
   'data': ['none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
-           'dump', 'bridge', 'netmap', 'vhost-user'] }
+           'bridge', 'netmap', 'vhost-user'] }
 
 ##
 # @NetLegacyOptions:
@@ -550,7 +534,6 @@
     'l2tpv3':   'NetdevL2TPv3Options',
     'socket':   'NetdevSocketOptions',
     'vde':      'NetdevVdeOptions',
-    'dump':     'NetdevDumpOptions',
     'bridge':   'NetdevBridgeOptions',
     'netmap':   'NetdevNetmapOptions',
     'vhost-user': 'NetdevVhostUserOptions' } }
diff --git a/qemu-doc.texi b/qemu-doc.texi
index 8e35569..97025c2 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -2707,12 +2707,6 @@ that can be specified with the ``-device'' parameter.
 The drive addr argument is replaced by the the addr argument
 that can be specified with the ``-device'' parameter.
 
-@subsection -net dump (since 2.10.0)
-
-The ``--net dump'' argument is now replaced with the
-``-object filter-dump'' argument which works in combination
-with the modern ``-netdev`` backends instead.
-
 @subsection -usbdevice (since 2.10.0)
 
 The ``-usbdevice DEV'' argument is now a synonym for setting
diff --git a/qemu-options.hx b/qemu-options.hx
index 9ae49a0..a9249b6 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2009,8 +2009,6 @@ DEF("net", HAS_ARG, QEMU_OPTION_net,
     "                configure or create an on-board (or machine default) NIC and\n"
     "                connect it either to VLAN 'n' or the netdev 'nd' (for pluggable\n"
     "                NICs please use '-device devtype,netdev=nd' instead)\n"
-    "-net dump[,vlan=n][,file=f][,len=n]\n"
-    "                dump traffic on vlan 'n' to file 'f' (max n bytes per packet)\n"
     "-net none       use it alone to have zero network devices. If no -net option\n"
     "                is provided, the default is '-net nic -net user'\n"
     "-net ["
@@ -2458,12 +2456,6 @@ qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,sha
      -device virtio-net-pci,netdev=net0
 @end example
 
-@item -net dump[,vlan=@var{n}][,file=@var{file}][,len=@var{len}]
-Dump network traffic on VLAN @var{n} to file @var{file} (@file{qemu-vlan0.pcap} by default).
-At most @var{len} bytes (64k by default) per packet are stored. The file format is
-libpcap, so it can be analyzed with tools such as tcpdump or Wireshark.
-Note: For devices created with '-netdev', use '-object filter-dump,...' instead.
-
 @item -net none
 Indicate that no network devices should be configured. It is used to
 override the default configuration (@option{-net nic -net user}) which
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v2 5/8] net: Remove the deprecated way of dumping network packets

[Eric Blake]

On 02/20/2018 11:40 AM, Thomas Huth wrote:
> "-net dump" has been marked as deprecated since QEMU v2.10, since it
> only works with the deprecated 'vlan' parameter (or hubs). Network
> dumping should be done with "-object filter-dump" nowadays instead.
> Since nobody complained so far about the deprecation message, let's
> finally get rid of "-net dump" now.
> 
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> Reviewed-by: Eric Blake <eblake@redhat.com>
> Signed-off-by: Thomas Huth <thuth@redhat.com>
> ---

> +++ b/qapi/net.json
> @@ -39,8 +39,10 @@
>   #
>   # Add a network backend.
>   #
> -# @type: the type of network backend.  Current valid values are 'user', 'tap',
> -#        'vde', 'socket', 'dump' and 'bridge'
> +# @type: the type of network backend. Possible values in version
> +#        2.11: 'user', 'tap', 'vde', 'socket', 'hubport', 'bridge',
> +#              'dump', 'l2tpv3', 'netmap', 'vhost-user'
> +#        2.12: 'dump' dropped
>   #

That's a bit fuzzy, especially since the command has been around since 
0.14.  It might be easier to word it as:

@type: the type of network backend. Possible values are listed in 
NetClientDriver.

Then defer the actual listing by version...

> @@ -468,7 +453,7 @@
>   # Since: 2.7
>   ##
>   { 'enum': 'NetClientDriver',
> -  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde', 'dump',
> +  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
>               'bridge', 'hubport', 'netmap', 'vhost-user' ] }

...to here (although this type only mentions 2.7 as its starting point). 
  (Hmm, I should see if it is worth reviving my attempted patches to 
properly QAPI-fy netdev_add into using a proper schema description - 
when I last proposed it, we ditched it at the last minute because of 
minor incompatibilities in parsing between a QAPI parse and the manual 
parse).

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] [PATCH v2 5/8] net: Remove the deprecated way of dumping network packets

[Thomas Huth]

On 20.02.2018 23:35, Eric Blake wrote:
> On 02/20/2018 11:40 AM, Thomas Huth wrote:
>> "-net dump" has been marked as deprecated since QEMU v2.10, since it
>> only works with the deprecated 'vlan' parameter (or hubs). Network
>> dumping should be done with "-object filter-dump" nowadays instead.
>> Since nobody complained so far about the deprecation message, let's
>> finally get rid of "-net dump" now.
>>
>> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>> Signed-off-by: Thomas Huth <thuth@redhat.com>
>> ---
> 
>> +++ b/qapi/net.json
>> @@ -39,8 +39,10 @@
>>   #
>>   # Add a network backend.
>>   #
>> -# @type: the type of network backend.  Current valid values are
>> 'user', 'tap',
>> -#        'vde', 'socket', 'dump' and 'bridge'
>> +# @type: the type of network backend. Possible values in version
>> +#        2.11: 'user', 'tap', 'vde', 'socket', 'hubport', 'bridge',
>> +#              'dump', 'l2tpv3', 'netmap', 'vhost-user'
>> +#        2.12: 'dump' dropped
>>   #
> 
> That's a bit fuzzy, especially since the command has been around since
> 0.14.  It might be easier to word it as:
> 
> @type: the type of network backend. Possible values are listed in
> NetClientDriver.

That's a really good idea to avoid that we have to maintain the list
multiple times...

> Then defer the actual listing by version...
> 
>> @@ -468,7 +453,7 @@
>>   # Since: 2.7
>>   ##
>>   { 'enum': 'NetClientDriver',
>> -  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
>> 'dump',
>> +  'data': [ 'none', 'nic', 'user', 'tap', 'l2tpv3', 'socket', 'vde',
>>               'bridge', 'hubport', 'netmap', 'vhost-user' ] }
> 
> ...to here
... but 'none' and 'nic' are not valid for netdev_add. Well, I guess I
can simply write something like "Possible values are listed in
NetClientDriver (excluding 'none' and 'nic')". I'll send a v3 with that.

 Thomas


PS: By the way, now that you've mentioned this, I think "dump" was also
not valid for netdev_add, so the comment was even wrong there.

[Qemu-devel] [PATCH v2 6/8] net: Remove the deprecated 'host_net_add' and 'host_net_remove' HMP commands

[Thomas Huth]

They are deprecated since QEMU v2.10, and so far nobody complained that
these commands are still necessary for any reason - and since you can use
'netdev_add' and 'netdev_remove' instead, there also should not be any
real reason. Since they are also standing in the way for the upcoming
'vlan' clean-up, it's now time to remove them.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 hmp-commands.hx  | 30 ------------------
 hmp.h            |  3 --
 monitor.c        | 61 ------------------------------------
 net/net.c        | 94 --------------------------------------------------------
 qemu-doc.texi    | 10 ------
 tests/test-hmp.c |  2 --
 6 files changed, 200 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index d26eb41..964eb51 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1291,36 +1291,6 @@ Inject PCIe AER error
 ETEXI
 
     {
-        .name       = "host_net_add",
-        .args_type  = "device:s,opts:s?",
-        .params     = "tap|user|socket|vde|netmap|bridge|vhost-user|dump [options]",
-        .help       = "add host VLAN client (deprecated, use netdev_add instead)",
-        .cmd        = hmp_host_net_add,
-        .command_completion = host_net_add_completion,
-    },
-
-STEXI
-@item host_net_add
-@findex host_net_add
-Add host VLAN client. Deprecated, please use @code{netdev_add} instead.
-ETEXI
-
-    {
-        .name       = "host_net_remove",
-        .args_type  = "vlan_id:i,device:s",
-        .params     = "vlan_id name",
-        .help       = "remove host VLAN client (deprecated, use netdev_del instead)",
-        .cmd        = hmp_host_net_remove,
-        .command_completion = host_net_remove_completion,
-    },
-
-STEXI
-@item host_net_remove
-@findex host_net_remove
-Remove host VLAN client. Deprecated, please use @code{netdev_del} instead.
-ETEXI
-
-    {
         .name       = "netdev_add",
         .args_type  = "netdev:O",
         .params     = "[user|tap|socket|vde|bridge|hubport|netmap|vhost-user],id=str[,prop=value][,...]",
diff --git a/hmp.h b/hmp.h
index 1143db4..b897338 100644
--- a/hmp.h
+++ b/hmp.h
@@ -132,9 +132,6 @@ void migrate_set_capability_completion(ReadLineState *rs, int nb_args,
                                        const char *str);
 void migrate_set_parameter_completion(ReadLineState *rs, int nb_args,
                                       const char *str);
-void host_net_add_completion(ReadLineState *rs, int nb_args, const char *str);
-void host_net_remove_completion(ReadLineState *rs, int nb_args,
-                                const char *str);
 void delvm_completion(ReadLineState *rs, int nb_args, const char *str);
 void loadvm_completion(ReadLineState *rs, int nb_args, const char *str);
 void hmp_rocker(Monitor *mon, const QDict *qdict);
diff --git a/monitor.c b/monitor.c
index 373bb8d..a4f1f28 100644
--- a/monitor.c
+++ b/monitor.c
@@ -3574,67 +3574,6 @@ void migrate_set_parameter_completion(ReadLineState *rs, int nb_args,
     }
 }
 
-void host_net_add_completion(ReadLineState *rs, int nb_args, const char *str)
-{
-    int i;
-    size_t len;
-    if (nb_args != 2) {
-        return;
-    }
-    len = strlen(str);
-    readline_set_completion_index(rs, len);
-    for (i = 0; host_net_devices[i]; i++) {
-        if (!strncmp(host_net_devices[i], str, len)) {
-            readline_add_completion(rs, host_net_devices[i]);
-        }
-    }
-}
-
-void host_net_remove_completion(ReadLineState *rs, int nb_args, const char *str)
-{
-    NetClientState *ncs[MAX_QUEUE_NUM];
-    int count, i, len;
-
-    len = strlen(str);
-    readline_set_completion_index(rs, len);
-    if (nb_args == 2) {
-        count = qemu_find_net_clients_except(NULL, ncs,
-                                             NET_CLIENT_DRIVER_NONE,
-                                             MAX_QUEUE_NUM);
-        for (i = 0; i < MIN(count, MAX_QUEUE_NUM); i++) {
-            int id;
-            char name[16];
-
-            if (net_hub_id_for_client(ncs[i], &id)) {
-                continue;
-            }
-            snprintf(name, sizeof(name), "%d", id);
-            if (!strncmp(str, name, len)) {
-                readline_add_completion(rs, name);
-            }
-        }
-        return;
-    } else if (nb_args == 3) {
-        count = qemu_find_net_clients_except(NULL, ncs,
-                                             NET_CLIENT_DRIVER_NIC,
-                                             MAX_QUEUE_NUM);
-        for (i = 0; i < MIN(count, MAX_QUEUE_NUM); i++) {
-            int id;
-            const char *name;
-
-            if (ncs[i]->info->type == NET_CLIENT_DRIVER_HUBPORT ||
-                net_hub_id_for_client(ncs[i], &id)) {
-                continue;
-            }
-            name = ncs[i]->name;
-            if (!strncmp(str, name, len)) {
-                readline_add_completion(rs, name);
-            }
-        }
-        return;
-    }
-}
-
 static void vm_completion(ReadLineState *rs, const char *str)
 {
     size_t len;
diff --git a/net/net.c b/net/net.c
index cbd553d..2d05808 100644
--- a/net/net.c
+++ b/net/net.c
@@ -60,25 +60,6 @@
 static VMChangeStateEntry *net_change_state_entry;
 static QTAILQ_HEAD(, NetClientState) net_clients;
 
-const char *host_net_devices[] = {
-    "tap",
-    "socket",
-#ifdef CONFIG_NET_BRIDGE
-    "bridge",
-#endif
-#ifdef CONFIG_NETMAP
-    "netmap",
-#endif
-#ifdef CONFIG_SLIRP
-    "user",
-#endif
-#ifdef CONFIG_VDE
-    "vde",
-#endif
-    "vhost-user",
-    NULL,
-};
-
 /***********************************************************/
 /* network device redirectors */
 
@@ -1174,81 +1155,6 @@ static int net_client_init(QemuOpts *opts, bool is_netdev, Error **errp)
     return ret;
 }
 
-
-static int net_host_check_device(const char *device)
-{
-    int i;
-    for (i = 0; host_net_devices[i]; i++) {
-        if (!strncmp(host_net_devices[i], device,
-                     strlen(host_net_devices[i]))) {
-            return 1;
-        }
-    }
-
-    return 0;
-}
-
-void hmp_host_net_add(Monitor *mon, const QDict *qdict)
-{
-    const char *device = qdict_get_str(qdict, "device");
-    const char *opts_str = qdict_get_try_str(qdict, "opts");
-    Error *local_err = NULL;
-    QemuOpts *opts;
-    static bool warned;
-
-    if (!warned && !qtest_enabled()) {
-        error_report("host_net_add is deprecated, use netdev_add instead");
-        warned = true;
-    }
-
-    if (!net_host_check_device(device)) {
-        monitor_printf(mon, "invalid host network device %s\n", device);
-        return;
-    }
-
-    opts = qemu_opts_parse_noisily(qemu_find_opts("net"),
-                                   opts_str ? opts_str : "", false);
-    if (!opts) {
-        return;
-    }
-
-    qemu_opt_set(opts, "type", device, &error_abort);
-
-    net_client_init(opts, false, &local_err);
-    if (local_err) {
-        error_report_err(local_err);
-        monitor_printf(mon, "adding host network device %s failed\n", device);
-    }
-}
-
-void hmp_host_net_remove(Monitor *mon, const QDict *qdict)
-{
-    NetClientState *nc;
-    int vlan_id = qdict_get_int(qdict, "vlan_id");
-    const char *device = qdict_get_str(qdict, "device");
-    static bool warned;
-
-    if (!warned && !qtest_enabled()) {
-        error_report("host_net_remove is deprecated, use netdev_del instead");
-        warned = true;
-    }
-
-    nc = net_hub_find_client_by_name(vlan_id, device);
-    if (!nc) {
-        error_report("Host network device '%s' on hub '%d' not found",
-                     device, vlan_id);
-        return;
-    }
-    if (nc->info->type == NET_CLIENT_DRIVER_NIC) {
-        error_report("invalid host network device '%s'", device);
-        return;
-    }
-
-    qemu_del_net_client(nc->peer);
-    qemu_del_net_client(nc);
-    qemu_opts_del(qemu_opts_find(qemu_find_opts("net"), device));
-}
-
 void netdev_add(QemuOpts *opts, Error **errp)
 {
     net_client_init(opts, true, errp);
diff --git a/qemu-doc.texi b/qemu-doc.texi
index 97025c2..36acfc9 100644
--- a/qemu-doc.texi
+++ b/qemu-doc.texi
@@ -2756,16 +2756,6 @@ by the ``convert -l snapshot_param'' argument instead.
 "autoload" parameter is now ignored. All bitmaps are automatically loaded
 from qcow2 images.
 
-@section System emulator human monitor commands
-
-@subsection host_net_add (since 2.10.0)
-
-The ``host_net_add'' command is replaced by the ``netdev_add'' command.
-
-@subsection host_net_remove (since 2.10.0)
-
-The ``host_net_remove'' command is replaced by the ``netdev_del'' command.
-
 @section System emulator devices
 
 @subsection ivshmem (since 2.6.0)
diff --git a/tests/test-hmp.c b/tests/test-hmp.c
index 5b7e447..5352c9c 100644
--- a/tests/test-hmp.c
+++ b/tests/test-hmp.c
@@ -37,10 +37,8 @@ static const char *hmp_cmds[] = {
     "dump-guest-memory /dev/null 0 4096",
     "dump-guest-memory /dev/null",
     "gdbserver",
-    "host_net_add user id=net0",
     "hostfwd_add tcp::43210-:43210",
     "hostfwd_remove tcp::43210-:43210",
-    "host_net_remove 0 net0",
     "i /w 0",
     "log all",
     "log none",
-- 
1.8.3.1

[Qemu-devel] [PATCH v2 7/8] net: Add a new convenience option "--nic" to configure default/on-board NICs

[Thomas Huth]

The legacy "-net" option can be quite confusing for the users since most
people do not expect to get a "vlan" hub between their emulated guest
hardware and the host backend. But so far, we are also not able to get
rid of "-net" completely, since it is the only way to configure on-board
NICs that can not be instantiated via "-device" yet. It's also a little
bit shorter to type "-net nic -net tap" instead of "-device xyz,netdev=n1
-netdev tap,id=n1".

So what we need is a new convenience option that is shorter to type than
the full -device + -netdev stuff, and which can be used to configure the
on-board NICs that can not be handled via -device yet. Thus this patch now
provides such a new option "--nic": It adds an entry in the nd_table to
configure a on-board / default NIC, creates a host backend and connects
the two directly, without a confusing "vlan" hub inbetween.

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 include/sysemu/sysemu.h |  1 +
 net/net.c               | 78 +++++++++++++++++++++++++++++++++++++++++++++++++
 qemu-options.hx         | 40 +++++++++++++++++++++----
 vl.c                    |  7 +++++
 4 files changed, 120 insertions(+), 6 deletions(-)

diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 77bb3da..66f0761 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -197,6 +197,7 @@ extern QemuOptsList bdrv_runtime_opts;
 extern QemuOptsList qemu_chardev_opts;
 extern QemuOptsList qemu_device_opts;
 extern QemuOptsList qemu_netdev_opts;
+extern QemuOptsList qemu_nic_opts;
 extern QemuOptsList qemu_net_opts;
 extern QemuOptsList qemu_global_opts;
 extern QemuOptsList qemu_mon_opts;
diff --git a/net/net.c b/net/net.c
index 2d05808..0bab269 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1462,6 +1462,67 @@ static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
     return net_client_init(opts, true, errp);
 }
 
+/* For the convenience "--nic" parameter */
+static int net_param_nic(void *dummy, QemuOpts *opts, Error **errp)
+{
+    char *mac, *nd_id;
+    int idx, ret;
+    NICInfo *ni;
+    const char *type;
+
+    type = qemu_opt_get(opts, "type");
+    if (type && g_str_equal(type, "none")) {
+        return 0;    /* Nothing to do, default_net is cleared in vl.c */
+    }
+
+    idx = nic_get_free_idx();
+    if (idx == -1 || nb_nics >= MAX_NICS) {
+        error_setg(errp, "no more on-board/default NIC slots available");
+        return -1;
+    }
+
+    if (!type) {
+        qemu_opt_set(opts, "type", "user", &error_abort);
+    }
+
+    ni = &nd_table[idx];
+    memset(ni, 0, sizeof(*ni));
+    ni->model = qemu_opt_get_del(opts, "model");
+
+    /* Create an ID if the user did not specify one */
+    nd_id = g_strdup(qemu_opts_id(opts));
+    if (!nd_id) {
+        nd_id = g_strdup_printf("__org.qemu.nic%i\n", idx);
+        qemu_opts_set_id(opts, nd_id);
+    }
+
+    /* Handle MAC address */
+    mac = qemu_opt_get_del(opts, "mac");
+    if (mac) {
+        ret = net_parse_macaddr(ni->macaddr.a, mac);
+        g_free(mac);
+        if (ret) {
+            error_setg(errp, "invalid syntax for ethernet address");
+            return -1;
+        }
+        if (is_multicast_ether_addr(ni->macaddr.a)) {
+            error_setg(errp, "NIC cannot have multicast MAC address");
+            return -1;
+        }
+    }
+    qemu_macaddr_default_if_unset(&ni->macaddr);
+
+    ret = net_client_init(opts, true, errp);
+    if (ret == 0) {
+        ni->netdev = qemu_find_netdev(nd_id);
+        ni->used = true;
+        nb_nics++;
+    }
+
+    g_free(nd_id);
+    return ret;
+}
+
 int net_init_clients(Error **errp)
 {
     net_change_state_entry =
@@ -1474,6 +1535,10 @@ int net_init_clients(Error **errp)
         return -1;
     }
 
+    if (qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL, errp)) {
+        return -1;
+    }
+
     if (qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL, errp)) {
         return -1;
     }
@@ -1549,6 +1614,19 @@ QemuOptsList qemu_netdev_opts = {
     },
 };
 
+QemuOptsList qemu_nic_opts = {
+    .name = "nic",
+    .implied_opt_name = "type",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_nic_opts.head),
+    .desc = {
+        /*
+         * no elements => accept any params
+         * validation will happen later
+         */
+        { /* end of list */ }
+    },
+};
+
 QemuOptsList qemu_net_opts = {
     .name = "net",
     .implied_opt_name = "type",
diff --git a/qemu-options.hx b/qemu-options.hx
index a9249b6..399905e 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2004,13 +2004,34 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
 #endif
     "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
     "                configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
+DEF("nic", HAS_ARG, QEMU_OPTION_nic,
+    "--nic [tap|bridge|"
+#ifdef CONFIG_SLIRP
+    "user|"
+#endif
+#ifdef __linux__
+    "l2tpv3|"
+#endif
+#ifdef CONFIG_VDE
+    "vde|"
+#endif
+#ifdef CONFIG_NETMAP
+    "netmap|"
+#endif
+#ifdef CONFIG_POSIX
+    "vhost-user|"
+#endif
+    "socket][,option][,...][mac=macaddr]\n"
+    "                initialize an on-board / default host NIC (using MAC address\n"
+    "                macaddr) and connect it to the given host network backend\n"
+    "--nic none      use it alone to have zero network devices (the default is to\n"
+    "                provided a 'user' network connection)\n",
+    QEMU_ARCH_ALL)
 DEF("net", HAS_ARG, QEMU_OPTION_net,
     "-net nic[,vlan=n][,netdev=nd][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
     "                configure or create an on-board (or machine default) NIC and\n"
     "                connect it either to VLAN 'n' or the netdev 'nd' (for pluggable\n"
     "                NICs please use '-device devtype,netdev=nd' instead)\n"
-    "-net none       use it alone to have zero network devices. If no -net option\n"
-    "                is provided, the default is '-net nic -net user'\n"
     "-net ["
 #ifdef CONFIG_SLIRP
     "user|"
@@ -2456,10 +2477,17 @@ qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,sha
      -device virtio-net-pci,netdev=net0
 @end example
 
-@item -net none
-Indicate that no network devices should be configured. It is used to
-override the default configuration (@option{-net nic -net user}) which
-is activated if no @option{-net} options are provided.
+@item --nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr]
+
+This option is a shortcut for setting both, the on-board (default) guest NIC
+hardware and the host network backend in one go. The host backend options are
+the same as with the corresponding @option{--netdev} option. The guest NIC
+hardware MAC address can be set with @option{mac=@var{macaddr}}.
+
+@item --nic none
+Indicate that no network devices should be configured. It is used to override
+the default configuration (default NIC with @option{--net user} backend) which
+is activated if no other networking options are provided.
 ETEXI
 
 STEXI
diff --git a/vl.c b/vl.c
index 698b681..59ffadb 100644
--- a/vl.c
+++ b/vl.c
@@ -3078,6 +3078,7 @@ int main(int argc, char **argv, char **envp)
     qemu_add_opts(&qemu_chardev_opts);
     qemu_add_opts(&qemu_device_opts);
     qemu_add_opts(&qemu_netdev_opts);
+    qemu_add_opts(&qemu_nic_opts);
     qemu_add_opts(&qemu_net_opts);
     qemu_add_opts(&qemu_rtc_opts);
     qemu_add_opts(&qemu_global_opts);
@@ -3298,6 +3299,12 @@ int main(int argc, char **argv, char **envp)
                     exit(1);
                 }
                 break;
+            case QEMU_OPTION_nic:
+                default_net = 0;
+                if (net_client_parse(qemu_find_opts("nic"), optarg) == -1) {
+                    exit(1);
+                }
+                break;
             case QEMU_OPTION_net:
                 default_net = 0;
                 if (net_client_parse(qemu_find_opts("net"), optarg) == -1) {
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v2 7/8] net: Add a new convenience option "--nic" to configure default/on-board NICs

[Paolo Bonzini]

On 20/02/2018 18:40, Thomas Huth wrote:
> The legacy "-net" option can be quite confusing for the users since most
> people do not expect to get a "vlan" hub between their emulated guest
> hardware and the host backend. But so far, we are also not able to get
> rid of "-net" completely, since it is the only way to configure on-board
> NICs that can not be instantiated via "-device" yet. It's also a little
> bit shorter to type "-net nic -net tap" instead of "-device xyz,netdev=n1
> -netdev tap,id=n1".
> 
> So what we need is a new convenience option that is shorter to type than
> the full -device + -netdev stuff, and which can be used to configure the
> on-board NICs that can not be handled via -device yet. Thus this patch now
> provides such a new option "--nic": It adds an entry in the nd_table to
> configure a on-board / default NIC, creates a host backend and connects
> the two directly, without a confusing "vlan" hub inbetween.
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Yay!

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

Paolo

> ---
>  include/sysemu/sysemu.h |  1 +
>  net/net.c               | 78 +++++++++++++++++++++++++++++++++++++++++++++++++
>  qemu-options.hx         | 40 +++++++++++++++++++++----
>  vl.c                    |  7 +++++
>  4 files changed, 120 insertions(+), 6 deletions(-)
> 
> diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
> index 77bb3da..66f0761 100644
> --- a/include/sysemu/sysemu.h
> +++ b/include/sysemu/sysemu.h
> @@ -197,6 +197,7 @@ extern QemuOptsList bdrv_runtime_opts;
>  extern QemuOptsList qemu_chardev_opts;
>  extern QemuOptsList qemu_device_opts;
>  extern QemuOptsList qemu_netdev_opts;
> +extern QemuOptsList qemu_nic_opts;
>  extern QemuOptsList qemu_net_opts;
>  extern QemuOptsList qemu_global_opts;
>  extern QemuOptsList qemu_mon_opts;
> diff --git a/net/net.c b/net/net.c
> index 2d05808..0bab269 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -1462,6 +1462,67 @@ static int net_init_netdev(void *dummy, QemuOpts *opts, Error **errp)
>      return net_client_init(opts, true, errp);
>  }
>  
> +/* For the convenience "--nic" parameter */
> +static int net_param_nic(void *dummy, QemuOpts *opts, Error **errp)
> +{
> +    char *mac, *nd_id;
> +    int idx, ret;
> +    NICInfo *ni;
> +    const char *type;
> +
> +    type = qemu_opt_get(opts, "type");
> +    if (type && g_str_equal(type, "none")) {
> +        return 0;    /* Nothing to do, default_net is cleared in vl.c */
> +    }
> +
> +    idx = nic_get_free_idx();
> +    if (idx == -1 || nb_nics >= MAX_NICS) {
> +        error_setg(errp, "no more on-board/default NIC slots available");
> +        return -1;
> +    }
> +
> +    if (!type) {
> +        qemu_opt_set(opts, "type", "user", &error_abort);
> +    }
> +
> +    ni = &nd_table[idx];
> +    memset(ni, 0, sizeof(*ni));
> +    ni->model = qemu_opt_get_del(opts, "model");
> +
> +    /* Create an ID if the user did not specify one */
> +    nd_id = g_strdup(qemu_opts_id(opts));
> +    if (!nd_id) {
> +        nd_id = g_strdup_printf("__org.qemu.nic%i\n", idx);
> +        qemu_opts_set_id(opts, nd_id);
> +    }
> +
> +    /* Handle MAC address */
> +    mac = qemu_opt_get_del(opts, "mac");
> +    if (mac) {
> +        ret = net_parse_macaddr(ni->macaddr.a, mac);
> +        g_free(mac);
> +        if (ret) {
> +            error_setg(errp, "invalid syntax for ethernet address");
> +            return -1;
> +        }
> +        if (is_multicast_ether_addr(ni->macaddr.a)) {
> +            error_setg(errp, "NIC cannot have multicast MAC address");
> +            return -1;
> +        }
> +    }
> +    qemu_macaddr_default_if_unset(&ni->macaddr);
> +
> +    ret = net_client_init(opts, true, errp);
> +    if (ret == 0) {
> +        ni->netdev = qemu_find_netdev(nd_id);
> +        ni->used = true;
> +        nb_nics++;
> +    }
> +
> +    g_free(nd_id);
> +    return ret;
> +}
> +
>  int net_init_clients(Error **errp)
>  {
>      net_change_state_entry =
> @@ -1474,6 +1535,10 @@ int net_init_clients(Error **errp)
>          return -1;
>      }
>  
> +    if (qemu_opts_foreach(qemu_find_opts("nic"), net_param_nic, NULL, errp)) {
> +        return -1;
> +    }
> +
>      if (qemu_opts_foreach(qemu_find_opts("net"), net_init_client, NULL, errp)) {
>          return -1;
>      }
> @@ -1549,6 +1614,19 @@ QemuOptsList qemu_netdev_opts = {
>      },
>  };
>  
> +QemuOptsList qemu_nic_opts = {
> +    .name = "nic",
> +    .implied_opt_name = "type",
> +    .head = QTAILQ_HEAD_INITIALIZER(qemu_nic_opts.head),
> +    .desc = {
> +        /*
> +         * no elements => accept any params
> +         * validation will happen later
> +         */
> +        { /* end of list */ }
> +    },
> +};
> +
>  QemuOptsList qemu_net_opts = {
>      .name = "net",
>      .implied_opt_name = "type",
> diff --git a/qemu-options.hx b/qemu-options.hx
> index a9249b6..399905e 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2004,13 +2004,34 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
>  #endif
>      "-netdev hubport,id=str,hubid=n[,netdev=nd]\n"
>      "                configure a hub port on QEMU VLAN 'n'\n", QEMU_ARCH_ALL)
> +DEF("nic", HAS_ARG, QEMU_OPTION_nic,
> +    "--nic [tap|bridge|"
> +#ifdef CONFIG_SLIRP
> +    "user|"
> +#endif
> +#ifdef __linux__
> +    "l2tpv3|"
> +#endif
> +#ifdef CONFIG_VDE
> +    "vde|"
> +#endif
> +#ifdef CONFIG_NETMAP
> +    "netmap|"
> +#endif
> +#ifdef CONFIG_POSIX
> +    "vhost-user|"
> +#endif
> +    "socket][,option][,...][mac=macaddr]\n"
> +    "                initialize an on-board / default host NIC (using MAC address\n"
> +    "                macaddr) and connect it to the given host network backend\n"
> +    "--nic none      use it alone to have zero network devices (the default is to\n"
> +    "                provided a 'user' network connection)\n",
> +    QEMU_ARCH_ALL)
>  DEF("net", HAS_ARG, QEMU_OPTION_net,
>      "-net nic[,vlan=n][,netdev=nd][,macaddr=mac][,model=type][,name=str][,addr=str][,vectors=v]\n"
>      "                configure or create an on-board (or machine default) NIC and\n"
>      "                connect it either to VLAN 'n' or the netdev 'nd' (for pluggable\n"
>      "                NICs please use '-device devtype,netdev=nd' instead)\n"
> -    "-net none       use it alone to have zero network devices. If no -net option\n"
> -    "                is provided, the default is '-net nic -net user'\n"
>      "-net ["
>  #ifdef CONFIG_SLIRP
>      "user|"
> @@ -2456,10 +2477,17 @@ qemu -m 512 -object memory-backend-file,id=mem,size=512M,mem-path=/hugetlbfs,sha
>       -device virtio-net-pci,netdev=net0
>  @end example
>  
> -@item -net none
> -Indicate that no network devices should be configured. It is used to
> -override the default configuration (@option{-net nic -net user}) which
> -is activated if no @option{-net} options are provided.
> +@item --nic [tap|bridge|user|l2tpv3|vde|netmap|vhost-user|socket][,...][,mac=macaddr]
> +
> +This option is a shortcut for setting both, the on-board (default) guest NIC
> +hardware and the host network backend in one go. The host backend options are
> +the same as with the corresponding @option{--netdev} option. The guest NIC
> +hardware MAC address can be set with @option{mac=@var{macaddr}}.
> +
> +@item --nic none
> +Indicate that no network devices should be configured. It is used to override
> +the default configuration (default NIC with @option{--net user} backend) which
> +is activated if no other networking options are provided.
>  ETEXI
>  
>  STEXI
> diff --git a/vl.c b/vl.c
> index 698b681..59ffadb 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3078,6 +3078,7 @@ int main(int argc, char **argv, char **envp)
>      qemu_add_opts(&qemu_chardev_opts);
>      qemu_add_opts(&qemu_device_opts);
>      qemu_add_opts(&qemu_netdev_opts);
> +    qemu_add_opts(&qemu_nic_opts);
>      qemu_add_opts(&qemu_net_opts);
>      qemu_add_opts(&qemu_rtc_opts);
>      qemu_add_opts(&qemu_global_opts);
> @@ -3298,6 +3299,12 @@ int main(int argc, char **argv, char **envp)
>                      exit(1);
>                  }
>                  break;
> +            case QEMU_OPTION_nic:
> +                default_net = 0;
> +                if (net_client_parse(qemu_find_opts("nic"), optarg) == -1) {
> +                    exit(1);
> +                }
> +                break;
>              case QEMU_OPTION_net:
>                  default_net = 0;
>                  if (net_client_parse(qemu_find_opts("net"), optarg) == -1) {
> 

[Qemu-devel] [PATCH v2 8/8] qemu-doc: Make "-net" less prominent

[Thomas Huth]

"-net" is clearly a legacy option. Yet we still use it in almost all
examples in the qemu documentation, and many other spots in the network
chapter. We should make it less prominent that users are not lured into
using it so often anymore. So instead of starting the network chapter with
"-net nic" and documenting "-net <backend>" below "-netdev <backend>"
everywhere, all the "-net" related documentation is now moved to the end
of the chapter. And the examples are changed to use the "--device" and
"--netdev" options instead of "-net nic -net <backend>".

Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 qemu-options.hx | 176 +++++++++++++++++++++++++++-----------------------------
 1 file changed, 86 insertions(+), 90 deletions(-)

diff --git a/qemu-options.hx b/qemu-options.hx
index 399905e..ff5da07 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -2048,41 +2048,18 @@ DEF("net", HAS_ARG, QEMU_OPTION_net,
     "                old way to initialize a host network interface\n"
     "                (use the -netdev option if possible instead)\n", QEMU_ARCH_ALL)
 STEXI
-@item -net nic[,vlan=@var{n}][,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
-@findex -net
-Configure or create an on-board (or machine default) Network Interface Card
-(NIC) and connect it either to VLAN @var{n} (@var{n} = 0 is the default), or
-to the netdev @var{nd}. The NIC is an e1000 by default on the PC
-target. Optionally, the MAC address can be changed to @var{mac}, the
-device address set to @var{addr} (PCI cards only),
-and a @var{name} can be assigned for use in monitor commands.
-Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
-that the card should have; this option currently only affects virtio cards; set
-@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
-NIC is created.  QEMU can emulate several different models of network card.
-Valid values for @var{type} are
-@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
-@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
-@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
-Not all devices are supported on all targets.  Use @code{-net nic,model=help}
-for a list of available devices for your target.
-
-@item -netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
-@findex -netdev
-@item -net user[,@var{option}][,@var{option}][,...]
-Use the user mode network stack which requires no administrator
+@item --netdev user,id=@var{id}[,@var{option}][,@var{option}][,...]
+@findex --netdev
+Configure user mode host network backend which requires no administrator
 privilege to run. Valid options are:
 
 @table @option
-@item vlan=@var{n}
-Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
-
 @item id=@var{id}
-@itemx name=@var{name}
 Assign symbolic name for use in monitor commands.
 
-@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
-be enabled.  If neither is specified both protocols are enabled.
+@item ipv4=on|off and ipv6=on|off
+Specify that either IPv4 or IPv6 must be enabled. If neither is specified
+both protocols are enabled.
 
 @item net=@var{addr}[/@var{mask}]
 Set IP network address the guest will see. Optionally specify the netmask,
@@ -2134,7 +2111,7 @@ can not be resolved.
 
 Example:
 @example
-qemu -net user,dnssearch=mgmt.example.org,dnssearch=example.org [...]
+qemu-system-i386 --device e1000,netdev=n1 --netdev user,id=n1,dnssearch=mgmt.example.org,dnssearch=example.org [...]
 @end example
 
 @item tftp=@var{dir}
@@ -2150,7 +2127,8 @@ a guest from a local directory.
 
 Example (using pxelinux):
 @example
-qemu-system-i386 -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
+qemu-system-i386 --hda linux.img --boot n --device e1000,netdev=n1 \
+    --netdev user,id=n1,tftp=/path/to/tftp/files,bootfile=/pxelinux.0
 @end example
 
 @item smb=@var{dir}[,smbserver=@var{addr}]
@@ -2185,7 +2163,7 @@ screen 0, use the following:
 
 @example
 # on the host
-qemu-system-i386 -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
+qemu-system-i386 --device virtio-net-pci,netdev=n1 --netdev user,id=n1,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
 # this host xterm should open in the guest X11 server
 xterm -display :1
 @end example
@@ -2195,7 +2173,7 @@ the guest, use the following:
 
 @example
 # on the host
-qemu-system-i386 -net user,hostfwd=tcp::5555-:23 [...]
+qemu-system-i386 --device e1000,netdev=n1 --netdev user,id=n1,hostfwd=tcp::5555-:23 [...]
 telnet localhost 5555
 @end example
 
@@ -2214,7 +2192,7 @@ lifetime, like in the following example:
 @example
 # open 10.10.1.1:4321 on bootup, connect 10.0.2.100:1234 to it whenever
 # the guest accesses it
-qemu -net user,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
+qemu-system-i386 --device e1000,netdev=n1 --netdev user,id=n1,guestfwd=tcp:10.0.2.100:1234-tcp:10.10.1.1:4321 [...]
 @end example
 
 Or you can execute a command on every TCP connection established by the guest,
@@ -2223,7 +2201,7 @@ so that QEMU behaves similar to an inetd process for that virtual server:
 @example
 # call "netcat 10.10.1.1 4321" on every TCP connection to 10.0.2.100:1234
 # and connect the TCP stream to its stdin/stdout
-qemu -net 'user,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
+qemu-system-i386 --device e1000,netdev=n1 --netdev 'user,id=n1,guestfwd=tcp:10.0.2.100:1234-cmd:netcat 10.10.1.1 4321'
 @end example
 
 @end table
@@ -2233,9 +2211,8 @@ processed and applied to -net user. Mixing them with the new configuration
 syntax gives undefined results. Their use for new applications is discouraged
 as they will be removed from future versions.
 
-@item -netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
-@itemx -net tap[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
-Connect the host TAP network interface @var{name} to VLAN @var{n}.
+@item --netdev tap,id=@var{id}[,fd=@var{h}][,ifname=@var{name}][,script=@var{file}][,downscript=@var{dfile}][,br=@var{bridge}][,helper=@var{helper}]
+Configure a host TAP network backend with ID @var{id}.
 
 Use the network script @var{file} to configure it and the network script
 @var{dfile} to deconfigure it. If @var{name} is not provided, the OS
@@ -2256,7 +2233,7 @@ Examples:
 
 @example
 #launch a QEMU instance with the default network script
-qemu-system-i386 linux.img -net nic -net tap
+qemu-system-i386 linux.img --netdev tap,id=n1 --device virtio-net-pci,netdev=n1
 @end example
 
 @example
@@ -2270,12 +2247,11 @@ qemu-system-i386 linux.img \
 @example
 #launch a QEMU instance with the default network helper to
 #connect a TAP device to bridge br0
-qemu-system-i386 linux.img \
-                 -net nic -net tap,"helper=/path/to/qemu-bridge-helper"
+qemu-system-i386 linux.img --device e1000,netdev=n1 \
+        --netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"
 @end example
 
-@item -netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
-@itemx -net bridge[,vlan=@var{n}][,name=@var{name}][,br=@var{bridge}][,helper=@var{helper}]
+@item --netdev bridge,id=@var{id}[,br=@var{bridge}][,helper=@var{helper}]
 Connect a host TAP network interface to a host bridge device.
 
 Use the network helper @var{helper} to configure the TAP interface and
@@ -2288,21 +2264,20 @@ Examples:
 @example
 #launch a QEMU instance with the default network helper to
 #connect a TAP device to bridge br0
-qemu-system-i386 linux.img -net bridge -net nic,model=virtio
+qemu-system-i386 linux.img --netdev bridge,id=n1 --device virtio-net,netdev=n1
 @end example
 
 @example
 #launch a QEMU instance with the default network helper to
 #connect a TAP device to bridge qemubr0
-qemu-system-i386 linux.img -net bridge,br=qemubr0 -net nic,model=virtio
+qemu-system-i386 linux.img --netdev bridge,br=qemubr0,id=n1 --device virtio-net,netdev=n1
 @end example
 
-@item -netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
-@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
+@item --netdev socket,id=@var{id}[,fd=@var{h}][,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}]
 
-Connect the VLAN @var{n} to a remote VLAN in another QEMU virtual
-machine using a TCP socket connection. If @option{listen} is
-specified, QEMU waits for incoming connections on @var{port}
+This host network backend can be used to connect the guest's network to
+another QEMU virtual machine using a TCP socket connection. If @option{listen}
+is specified, QEMU waits for incoming connections on @var{port}
 (@var{host} is optional). @option{connect} is used to connect to
 another QEMU instance using the @option{listen} option. @option{fd}=@var{h}
 specifies an already opened TCP socket.
@@ -2311,21 +2286,19 @@ Example:
 @example
 # launch a first QEMU instance
 qemu-system-i386 linux.img \
-                 -net nic,macaddr=52:54:00:12:34:56 \
-                 -net socket,listen=:1234
-# connect the VLAN 0 of this instance to the VLAN 0
-# of the first instance
+                 --device e1000,netdev=n1,mac=52:54:00:12:34:56 \
+                 --netdev socket,id=n1,listen=:1234
+# connect the network of this instance to the network of the first instance
 qemu-system-i386 linux.img \
-                 -net nic,macaddr=52:54:00:12:34:57 \
-                 -net socket,connect=127.0.0.1:1234
+                 --device e1000,netdev=n2,mac=52:54:00:12:34:57 \
+                 --netdev socket,id=n2,connect=127.0.0.1:1234
 @end example
 
-@item -netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
-@itemx -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
+@item --netdev socket,id=@var{id}[,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
 
-Create a VLAN @var{n} shared with another QEMU virtual
-machines using a UDP multicast socket, effectively making a bus for
-every QEMU with same multicast address @var{maddr} and @var{port}.
+Configure a socket host network backend to shared the guest's network traffic
+with another QEMU virtual machines using a UDP multicast socket, effectively
+making a bus for every QEMU with same multicast address @var{maddr} and @var{port}.
 NOTES:
 @enumerate
 @item
@@ -2342,25 +2315,24 @@ Example:
 @example
 # launch one QEMU instance
 qemu-system-i386 linux.img \
-                 -net nic,macaddr=52:54:00:12:34:56 \
-                 -net socket,mcast=230.0.0.1:1234
+                 --device e1000,netdev=n1,mac=52:54:00:12:34:56 \
+                 --netdev socket,id=n1,mcast=230.0.0.1:1234
 # launch another QEMU instance on same "bus"
 qemu-system-i386 linux.img \
-                 -net nic,macaddr=52:54:00:12:34:57 \
-                 -net socket,mcast=230.0.0.1:1234
+                 --device e1000,netdev=n2,mac=52:54:00:12:34:57 \
+                 --netdev socket,id=n2,mcast=230.0.0.1:1234
 # launch yet another QEMU instance on same "bus"
 qemu-system-i386 linux.img \
-                 -net nic,macaddr=52:54:00:12:34:58 \
-                 -net socket,mcast=230.0.0.1:1234
+                 --device e1000,netdev=n3,macaddr=52:54:00:12:34:58 \
+                 --netdev socket,id=n3,mcast=230.0.0.1:1234
 @end example
 
 Example (User Mode Linux compat.):
 @example
-# launch QEMU instance (note mcast address selected
-# is UML's default)
+# launch QEMU instance (note mcast address selected is UML's default)
 qemu-system-i386 linux.img \
-                 -net nic,macaddr=52:54:00:12:34:56 \
-                 -net socket,mcast=239.192.168.1:1102
+                 --device e1000,netdev=n1,mac=52:54:00:12:34:56 \
+                 --netdev socket,id=n1,mcast=239.192.168.1:1102
 # launch UML
 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
 @end example
@@ -2368,14 +2340,13 @@ qemu-system-i386 linux.img \
 Example (send packets from host's 1.2.3.4):
 @example
 qemu-system-i386 linux.img \
-                 -net nic,macaddr=52:54:00:12:34:56 \
-                 -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
+                 --device e1000,netdev=n1,mac=52:54:00:12:34:56 \
+                 --netdev socket,id=n1,mcast=239.192.168.1:1102,localaddr=1.2.3.4
 @end example
 
-@item -netdev l2tpv3,id=@var{id},src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
-@itemx -net l2tpv3[,vlan=@var{n}][,name=@var{name}],src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
-Connect VLAN @var{n} to L2TPv3 pseudowire. L2TPv3 (RFC3391) is a popular
-protocol to transport Ethernet (and other Layer 2) data frames between
+@item --netdev l2tpv3,id=@var{id},src=@var{srcaddr},dst=@var{dstaddr}[,srcport=@var{srcport}][,dstport=@var{dstport}],txsession=@var{txsession}[,rxsession=@var{rxsession}][,ipv6][,udp][,cookie64][,counter][,pincounter][,txcookie=@var{txcookie}][,rxcookie=@var{rxcookie}][,offset=@var{offset}]
+Configure a L2TPv3 pseudowire host network backend. L2TPv3 (RFC3391) is a
+popular protocol to transport Ethernet (and other Layer 2) data frames between
 two systems. It is present in routers, firewalls and the Linux kernel
 (from version 3.3 onwards).
 
@@ -2428,14 +2399,13 @@ brctl addif br-lan vmtunnel0
 # on 4.3.2.1
 # launch QEMU instance - if your network has reorder or is very lossy add ,pincounter
 
-qemu-system-i386 linux.img -net nic -net l2tpv3,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
-
+qemu-system-i386 linux.img --device e1000,netdev=n1 \
+    --netdev l2tpv3,id=n1,src=4.2.3.1,dst=1.2.3.4,udp,srcport=16384,dstport=16384,rxsession=0xffffffff,txsession=0xffffffff,counter
 
 @end example
 
-@item -netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
-@itemx -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
-Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
+@item --netdev vde,id=@var{id}[,sock=@var{socketpath}][,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
+Configure VDE backend to connect to PORT @var{n} of a vde switch running on host and
 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}
 and MODE @var{octalmode} to change default ownership and permissions for
 communication port. This option is only available if QEMU has been compiled
@@ -2446,20 +2416,21 @@ Example:
 # launch vde switch
 vde_switch -F -sock /tmp/myswitch
 # launch QEMU instance
-qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
+qemu-system-i386 linux.img --device e1000,netdev=n1 --netdev vde,id=n1,sock=/tmp/myswitch
 @end example
 
-@item -netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
+@item --netdev hubport,id=@var{id},hubid=@var{hubid}[,netdev=@var{nd}]
 
-Create a hub port on QEMU "vlan" @var{hubid}.
+Create a hub port on the emulated hub with ID @var{hubid}.
 
-The hubport netdev lets you connect a NIC to a QEMU "vlan" instead of a single
-netdev.  @code{-net} and @code{-device} with parameter @option{vlan} create the
-required hub automatically. Alternatively, you can also connect the hubport
-to another netdev with ID @var{nd} by using the @option{netdev=@var{nd}}
+The hubport netdev lets you connect a NIC to a QEMU emulated hub instead of a
+single netdev. @code{--net} and @code{--device} with the parameter @option{vlan}
+(deprecated), or @code{--nic hubport} can also be used to connect a
+network device or a NIC to a hub. Alternatively, you can also connect the
+hubport to another netdev with ID @var{nd} by using the @option{netdev=@var{nd}}
 option.
 
-@item -netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
+@item --netdev vhost-user,chardev=@var{id}[,vhostforce=on|off][,queues=n]
 
 Establish a vhost-user netdev, backed by a chardev @var{id}. The chardev should
 be a unix domain socket backed one. The vhost-user uses a specifically defined
@@ -2488,6 +2459,31 @@ hardware MAC address can be set with @option{mac=@var{macaddr}}.
 Indicate that no network devices should be configured. It is used to override
 the default configuration (default NIC with @option{--net user} backend) which
 is activated if no other networking options are provided.
+
+@item -net nic[,vlan=@var{n}][,netdev=@var{nd}][,macaddr=@var{mac}][,model=@var{type}] [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
+@findex -net
+Legacy option to configure or create an on-board (or machine default) Network
+Interface Card(NIC) and connect it either to the emulated hub port ("vlan")
+with number @var{n} (@var{n} = 0 is the default), or to the netdev @var{nd}.
+The NIC is an e1000 by default on the PC target. Optionally, the MAC address
+can be changed to @var{mac}, the device address set to @var{addr} (PCI cards
+only), and a @var{name} can be assigned for use in monitor commands.
+Optionally, for PCI cards, you can specify the number @var{v} of MSI-X vectors
+that the card should have; this option currently only affects virtio cards; set
+@var{v} = 0 to disable MSI-X. If no @option{-net} option is specified, a single
+NIC is created.  QEMU can emulate several different models of network card.
+Valid values for @var{type} are
+@code{virtio}, @code{i82551}, @code{i82557b}, @code{i82559er},
+@code{ne2k_pci}, @code{ne2k_isa}, @code{pcnet}, @code{rtl8139},
+@code{e1000}, @code{smc91c111}, @code{lance} and @code{mcf_fec}.
+Not all devices are supported on all targets.  Use @code{-net nic,model=help}
+for a list of available devices for your target.
+
+@item -net user|tap|bridge|socket|l2tpv3|vde[,...][,vlan=@var{n}][,name=@var{name}]
+Configure a host network backend (with the options corresponding to the same
+@option{--netdev} option) and connect it to the emulated hub ("vlan") with the
+number @var{n} (default is number 0). Use @var{name} to specify the name of the
+hub port.
 ETEXI
 
 STEXI
-- 
1.8.3.1

Re: [Qemu-devel] [PATCH v2 8/8] qemu-doc: Make "-net" less prominent

[Paolo Bonzini]

On 20/02/2018 18:40, Thomas Huth wrote:
> "-net" is clearly a legacy option. Yet we still use it in almost all
> examples in the qemu documentation, and many other spots in the network
> chapter. We should make it less prominent that users are not lured into
> using it so often anymore. So instead of starting the network chapter with
> "-net nic" and documenting "-net <backend>" below "-netdev <backend>"
> everywhere, all the "-net" related documentation is now moved to the end
> of the chapter. And the examples are changed to use the "--device" and
> "--netdev" options instead of "-net nic -net <backend>".

Do we want to change them to "-nic" instead?  The proof is in the
pudding, they say, :) and "-nic" is way easier to learn than "-device
-netdev".

And maybe we *should* go the extra mile and deprecate "-net" altogether.
 The only case where the newer syntax is a bit more uncomfortable is for
"-net nic -net nic -net tap|user", which however does work with "-nic
hubport -nic hubport -netdev tap|user,id=x -netdev hubport,netdev=x".

For now I suggest dropping this patch.

Paolo

Re: [Qemu-devel] [PATCH v2 8/8] qemu-doc: Make "-net" less prominent

[Thomas Huth]

On 20.02.2018 19:37, Paolo Bonzini wrote:
> On 20/02/2018 18:40, Thomas Huth wrote:
>> "-net" is clearly a legacy option. Yet we still use it in almost all
>> examples in the qemu documentation, and many other spots in the network
>> chapter. We should make it less prominent that users are not lured into
>> using it so often anymore. So instead of starting the network chapter with
>> "-net nic" and documenting "-net <backend>" below "-netdev <backend>"
>> everywhere, all the "-net" related documentation is now moved to the end
>> of the chapter. And the examples are changed to use the "--device" and
>> "--netdev" options instead of "-net nic -net <backend>".
> 
> Do we want to change them to "-nic" instead?  The proof is in the
> pudding, they say, :) and "-nic" is way easier to learn than "-device
> -netdev".

While -nic is easier to use than -netdev, I don't think that we should
put the focus in our main qemu-doc on -nic instead of -netdev. -nic is a
convenience option, while -netdev is the "architected" way to configure
network devices. We first should document how to do it "right", and
teach the user to proper distinguish between emulated guest hardware and
host network backend (with the old -net command, a lot of people seemed
to have mixed that up IIRC), and then finally explain -nic on top of it.

> And maybe we *should* go the extra mile and deprecate "-net" altogether.
>  The only case where the newer syntax is a bit more uncomfortable is for
> "-net nic -net nic -net tap|user", which however does work with "-nic
> hubport -nic hubport -netdev tap|user,id=x -netdev hubport,netdev=x".

I'd be glad to add such a deprecation patch to this series - I just
thought it might have been too early so far, but if you feel confident
that we can mark it as deprecated, I can spin a v3 with such a patch on
top...

 Thomas

Re: [Qemu-devel] [PATCH v2 8/8] qemu-doc: Make "-net" less prominent

[Paolo Bonzini]

On 21/02/2018 01:05, Thomas Huth wrote:
> On 20.02.2018 19:37, Paolo Bonzini wrote:
>> On 20/02/2018 18:40, Thomas Huth wrote:
>>> "-net" is clearly a legacy option. Yet we still use it in almost all
>>> examples in the qemu documentation, and many other spots in the network
>>> chapter. We should make it less prominent that users are not lured into
>>> using it so often anymore. So instead of starting the network chapter with
>>> "-net nic" and documenting "-net <backend>" below "-netdev <backend>"
>>> everywhere, all the "-net" related documentation is now moved to the end
>>> of the chapter. And the examples are changed to use the "--device" and
>>> "--netdev" options instead of "-net nic -net <backend>".
>>
>> Do we want to change them to "-nic" instead?  The proof is in the
>> pudding, they say, :) and "-nic" is way easier to learn than "-device
>> -netdev".
> 
> While -nic is easier to use than -netdev, I don't think that we should
> put the focus in our main qemu-doc on -nic instead of -netdev. -nic is a
> convenience option, while -netdev is the "architected" way to configure
> network devices. We first should document how to do it "right", and
> teach the user to proper distinguish between emulated guest hardware and
> host network backend (with the old -net command, a lot of people seemed
> to have mixed that up IIRC), and then finally explain -nic on top of it.

Heh, that's a philosophy question regarding the organization of the
whole manual.  Currently the "architected" way is pretty much confined
to docs/qdev-device-use.txt.  The manual is full of uses of -drive or
-hda, and I think it makes sense because honestly that's what users use.
 I should have explained this in the previous message, sorry.

>> And maybe we *should* go the extra mile and deprecate "-net" altogether.
>>  The only case where the newer syntax is a bit more uncomfortable is for
>> "-net nic -net nic -net tap|user", which however does work with "-nic
>> hubport -nic hubport -netdev tap|user,id=x -netdev hubport,netdev=x".
> 
> I'd be glad to add such a deprecation patch to this series - I just
> thought it might have been too early so far, but if you feel confident
> that we can mark it as deprecated, I can spin a v3 with such a patch on
> top...

I can't deny it's going to be a loooong deprecation.  But we have to
start somewhere, and -nic is a great start.

I think you should send v3 with the minimal changes required to accept
these patches, and then leave the rest to a separate submission, but of
course you don't have to do it that way.

Thanks,

Paolo