| Message ID | 1303477168-4663-1-git-send-email-pclouds@gmail.com |
|---|---|
| State | New |
| Headers | show |
2011/4/22 Nguyễn Thái Ngọc Duy <pclouds@gmail.com>: > Also mention the default value 4096. > > Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> > --- > free new buffers in net_socket_cleanup() > > net.c | 4 ++++ > net/socket.c | 52 ++++++++++++++++++++++++++++++++++++---------------- > qemu-options.hx | 11 ++++++----- > 3 files changed, 46 insertions(+), 21 deletions(-) Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
On Fri, Apr 22, 2011 at 07:59:28PM +0700, Nguyễn Thái Ngọc Duy wrote: > Also mention the default value 4096. > > Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> IS the option really necessary? Why not just allocate 128K or so and be done with it? That should be big enough even with GSO etc. > --- > free new buffers in net_socket_cleanup() > > net.c | 4 ++++ > net/socket.c | 52 ++++++++++++++++++++++++++++++++++++---------------- > qemu-options.hx | 11 ++++++----- > 3 files changed, 46 insertions(+), 21 deletions(-) > > diff --git a/net.c b/net.c > index 8d6a555..6746bc7 100644 > --- a/net.c > +++ b/net.c > @@ -1001,6 +1001,10 @@ static const struct { > .name = "localaddr", > .type = QEMU_OPT_STRING, > .help = "source address for multicast packets", > + }, { > + .name = "mtu", > + .type = QEMU_OPT_NUMBER, > + .help = "MTU size", > }, > { /* end of list */ } > }, > diff --git a/net/socket.c b/net/socket.c > index 7337f4f..e932064 100644 > --- a/net/socket.c > +++ b/net/socket.c > @@ -38,7 +38,8 @@ typedef struct NetSocketState { > int state; /* 0 = getting length, 1 = getting data */ > unsigned int index; > unsigned int packet_len; > - uint8_t buf[4096]; > + unsigned int mtu; > + uint8_t *buf, *buf1; > struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */ > } NetSocketState; > > @@ -47,6 +48,7 @@ typedef struct NetSocketListenState { > char *model; > char *name; > int fd; > + unsigned int mtu; > } NetSocketListenState; > > /* XXX: we consider we can send the whole packet without blocking */ > @@ -73,10 +75,10 @@ static void net_socket_send(void *opaque) > NetSocketState *s = opaque; > int size, err; > unsigned l; > - uint8_t buf1[4096]; > + uint8_t *buf1 = s->buf1; > const uint8_t *buf; > > - size = recv(s->fd, (void *)buf1, sizeof(buf1), 0); > + size = recv(s->fd, (void *)buf1, s->mtu, 0); > if (size < 0) { > err = socket_error(); > if (err != EWOULDBLOCK) > @@ -111,7 +113,7 @@ static void net_socket_send(void *opaque) > l = s->packet_len - s->index; > if (l > size) > l = size; > - if (s->index + l <= sizeof(s->buf)) { > + if (s->index + l <= s->mtu) { > memcpy(s->buf + s->index, buf, l); > } else { > fprintf(stderr, "serious error: oversized packet received," > @@ -138,7 +140,7 @@ static void net_socket_send_dgram(void *opaque) > NetSocketState *s = opaque; > int size; > > - size = recv(s->fd, (void *)s->buf, sizeof(s->buf), 0); > + size = recv(s->fd, (void *)s->buf, s->mtu, 0); > if (size < 0) > return; > if (size == 0) { > @@ -228,6 +230,8 @@ static void net_socket_cleanup(VLANClientState *nc) > NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc); > qemu_set_fd_handler(s->fd, NULL, NULL, NULL); > close(s->fd); > + qemu_free(s->buf); > + qemu_free(s->buf1); > } > > static NetClientInfo net_dgram_socket_info = { > @@ -238,6 +242,7 @@ static NetClientInfo net_dgram_socket_info = { > }; > > static NetSocketState *net_socket_fd_init_dgram(VLANState *vlan, > + unsigned int mtu, > const char *model, > const char *name, > int fd, int is_connected) > @@ -288,6 +293,10 @@ static NetSocketState *net_socket_fd_init_dgram(VLANState *vlan, > > s = DO_UPCAST(NetSocketState, nc, nc); > > + s->mtu = mtu; > + s->buf = qemu_malloc(s->mtu); > + s->buf1 = qemu_malloc(s->mtu); > + > s->fd = fd; > > qemu_set_fd_handler(s->fd, net_socket_send_dgram, NULL, s); > @@ -312,6 +321,7 @@ static NetClientInfo net_socket_info = { > }; > > static NetSocketState *net_socket_fd_init_stream(VLANState *vlan, > + unsigned int mtu, > const char *model, > const char *name, > int fd, int is_connected) > @@ -325,6 +335,10 @@ static NetSocketState *net_socket_fd_init_stream(VLANState *vlan, > > s = DO_UPCAST(NetSocketState, nc, nc); > > + s->mtu = mtu; > + s->buf = qemu_malloc(s->mtu); > + s->buf1 = qemu_malloc(s->mtu); > + > s->fd = fd; > > if (is_connected) { > @@ -335,7 +349,7 @@ static NetSocketState *net_socket_fd_init_stream(VLANState *vlan, > return s; > } > > -static NetSocketState *net_socket_fd_init(VLANState *vlan, > +static NetSocketState *net_socket_fd_init(VLANState *vlan, unsigned int mtu, > const char *model, const char *name, > int fd, int is_connected) > { > @@ -348,13 +362,13 @@ static NetSocketState *net_socket_fd_init(VLANState *vlan, > } > switch(so_type) { > case SOCK_DGRAM: > - return net_socket_fd_init_dgram(vlan, model, name, fd, is_connected); > + return net_socket_fd_init_dgram(vlan, mtu, model, name, fd, is_connected); > case SOCK_STREAM: > - return net_socket_fd_init_stream(vlan, model, name, fd, is_connected); > + return net_socket_fd_init_stream(vlan, mtu, model, name, fd, is_connected); > default: > /* who knows ... this could be a eg. a pty, do warn and continue as stream */ > fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd); > - return net_socket_fd_init_stream(vlan, model, name, fd, is_connected); > + return net_socket_fd_init_stream(vlan, mtu, model, name, fd, is_connected); > } > return NULL; > } > @@ -376,7 +390,7 @@ static void net_socket_accept(void *opaque) > break; > } > } > - s1 = net_socket_fd_init(s->vlan, s->model, s->name, fd, 1); > + s1 = net_socket_fd_init(s->vlan, s->mtu, s->model, s->name, fd, 1); > if (!s1) { > closesocket(fd); > } else { > @@ -387,6 +401,7 @@ static void net_socket_accept(void *opaque) > } > > static int net_socket_listen_init(VLANState *vlan, > + unsigned int mtu, > const char *model, > const char *name, > const char *host_str) > @@ -425,11 +440,13 @@ static int net_socket_listen_init(VLANState *vlan, > s->model = qemu_strdup(model); > s->name = name ? qemu_strdup(name) : NULL; > s->fd = fd; > + s->mtu = mtu; > qemu_set_fd_handler(fd, net_socket_accept, NULL, s); > return 0; > } > > static int net_socket_connect_init(VLANState *vlan, > + unsigned int mtu, > const char *model, > const char *name, > const char *host_str) > @@ -470,7 +487,7 @@ static int net_socket_connect_init(VLANState *vlan, > break; > } > } > - s = net_socket_fd_init(vlan, model, name, fd, connected); > + s = net_socket_fd_init(vlan, mtu, model, name, fd, connected); > if (!s) > return -1; > snprintf(s->nc.info_str, sizeof(s->nc.info_str), > @@ -480,6 +497,7 @@ static int net_socket_connect_init(VLANState *vlan, > } > > static int net_socket_mcast_init(VLANState *vlan, > + unsigned int mtu, > const char *model, > const char *name, > const char *host_str, > @@ -505,7 +523,7 @@ static int net_socket_mcast_init(VLANState *vlan, > if (fd < 0) > return -1; > > - s = net_socket_fd_init(vlan, model, name, fd, 0); > + s = net_socket_fd_init(vlan, mtu, model, name, fd, 0); > if (!s) > return -1; > > @@ -523,6 +541,8 @@ int net_init_socket(QemuOpts *opts, > const char *name, > VLANState *vlan) > { > + unsigned int mtu = qemu_opt_get_number(opts, "mtu", 4096); > + > if (qemu_opt_get(opts, "fd")) { > int fd; > > @@ -539,7 +559,7 @@ int net_init_socket(QemuOpts *opts, > return -1; > } > > - if (!net_socket_fd_init(vlan, "socket", name, fd, 1)) { > + if (!net_socket_fd_init(vlan, mtu, "socket", name, fd, 1)) { > close(fd); > return -1; > } > @@ -556,7 +576,7 @@ int net_init_socket(QemuOpts *opts, > > listen = qemu_opt_get(opts, "listen"); > > - if (net_socket_listen_init(vlan, "socket", name, listen) == -1) { > + if (net_socket_listen_init(vlan, mtu, "socket", name, listen) == -1) { > return -1; > } > } else if (qemu_opt_get(opts, "connect")) { > @@ -572,7 +592,7 @@ int net_init_socket(QemuOpts *opts, > > connect = qemu_opt_get(opts, "connect"); > > - if (net_socket_connect_init(vlan, "socket", name, connect) == -1) { > + if (net_socket_connect_init(vlan, mtu, "socket", name, connect) == -1) { > return -1; > } > } else if (qemu_opt_get(opts, "mcast")) { > @@ -588,7 +608,7 @@ int net_init_socket(QemuOpts *opts, > mcast = qemu_opt_get(opts, "mcast"); > localaddr = qemu_opt_get(opts, "localaddr"); > > - if (net_socket_mcast_init(vlan, "socket", name, mcast, localaddr) == -1) { > + if (net_socket_mcast_init(vlan, mtu, "socket", name, mcast, localaddr) == -1) { > return -1; > } > } else { > diff --git a/qemu-options.hx b/qemu-options.hx > index 66fffe3..4d5af96 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -1095,9 +1095,9 @@ DEF("net", HAS_ARG, QEMU_OPTION_net, > " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" > " use 'vhostfd=h' to connect to an already opened vhost net device\n" > #endif > - "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n" > + "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port][,mtu=mtu]\n" > " connect the vlan 'n' to another VLAN using a socket connection\n" > - "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" > + "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]][,mtu=mtu]\n" > " connect the vlan 'n' to multicast maddr and port\n" > " use 'localaddr=addr' to specify the host address to send packets from\n" > #ifdef CONFIG_VDE > @@ -1273,14 +1273,14 @@ qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ > -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 > @end example > > -@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] > +@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}][,mtu=@var{mtu}] > > 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} > (@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. > +specifies an already opened TCP socket. MTU is 4096 by default. > > Example: > @example > @@ -1293,11 +1293,12 @@ qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \ > -net socket,connect=127.0.0.1:1234 > @end example > > -@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] > +@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]][,mtu=@var{mtu}] > > 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}. > +MTU is 4096 by default. > NOTES: > @enumerate > @item > -- > 1.7.4.74.g639db >
2011/5/16 Michael S. Tsirkin <mst@redhat.com>: > On Fri, Apr 22, 2011 at 07:59:28PM +0700, Nguyễn Thái Ngọc Duy wrote: >> Also mention the default value 4096. >> >> Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> > > IS the option really necessary? Why not just allocate 128K or so and be > done with it? That should be big enough even with GSO etc. If it's big enough for practically everything, then yes, that way would be simpler.
diff --git a/net.c b/net.c index 8d6a555..6746bc7 100644 --- a/net.c +++ b/net.c @@ -1001,6 +1001,10 @@ static const struct { .name = "localaddr", .type = QEMU_OPT_STRING, .help = "source address for multicast packets", + }, { + .name = "mtu", + .type = QEMU_OPT_NUMBER, + .help = "MTU size", }, { /* end of list */ } }, diff --git a/net/socket.c b/net/socket.c index 7337f4f..e932064 100644 --- a/net/socket.c +++ b/net/socket.c @@ -38,7 +38,8 @@ typedef struct NetSocketState { int state; /* 0 = getting length, 1 = getting data */ unsigned int index; unsigned int packet_len; - uint8_t buf[4096]; + unsigned int mtu; + uint8_t *buf, *buf1; struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */ } NetSocketState; @@ -47,6 +48,7 @@ typedef struct NetSocketListenState { char *model; char *name; int fd; + unsigned int mtu; } NetSocketListenState; /* XXX: we consider we can send the whole packet without blocking */ @@ -73,10 +75,10 @@ static void net_socket_send(void *opaque) NetSocketState *s = opaque; int size, err; unsigned l; - uint8_t buf1[4096]; + uint8_t *buf1 = s->buf1; const uint8_t *buf; - size = recv(s->fd, (void *)buf1, sizeof(buf1), 0); + size = recv(s->fd, (void *)buf1, s->mtu, 0); if (size < 0) { err = socket_error(); if (err != EWOULDBLOCK) @@ -111,7 +113,7 @@ static void net_socket_send(void *opaque) l = s->packet_len - s->index; if (l > size) l = size; - if (s->index + l <= sizeof(s->buf)) { + if (s->index + l <= s->mtu) { memcpy(s->buf + s->index, buf, l); } else { fprintf(stderr, "serious error: oversized packet received," @@ -138,7 +140,7 @@ static void net_socket_send_dgram(void *opaque) NetSocketState *s = opaque; int size; - size = recv(s->fd, (void *)s->buf, sizeof(s->buf), 0); + size = recv(s->fd, (void *)s->buf, s->mtu, 0); if (size < 0) return; if (size == 0) { @@ -228,6 +230,8 @@ static void net_socket_cleanup(VLANClientState *nc) NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc); qemu_set_fd_handler(s->fd, NULL, NULL, NULL); close(s->fd); + qemu_free(s->buf); + qemu_free(s->buf1); } static NetClientInfo net_dgram_socket_info = { @@ -238,6 +242,7 @@ static NetClientInfo net_dgram_socket_info = { }; static NetSocketState *net_socket_fd_init_dgram(VLANState *vlan, + unsigned int mtu, const char *model, const char *name, int fd, int is_connected) @@ -288,6 +293,10 @@ static NetSocketState *net_socket_fd_init_dgram(VLANState *vlan, s = DO_UPCAST(NetSocketState, nc, nc); + s->mtu = mtu; + s->buf = qemu_malloc(s->mtu); + s->buf1 = qemu_malloc(s->mtu); + s->fd = fd; qemu_set_fd_handler(s->fd, net_socket_send_dgram, NULL, s); @@ -312,6 +321,7 @@ static NetClientInfo net_socket_info = { }; static NetSocketState *net_socket_fd_init_stream(VLANState *vlan, + unsigned int mtu, const char *model, const char *name, int fd, int is_connected) @@ -325,6 +335,10 @@ static NetSocketState *net_socket_fd_init_stream(VLANState *vlan, s = DO_UPCAST(NetSocketState, nc, nc); + s->mtu = mtu; + s->buf = qemu_malloc(s->mtu); + s->buf1 = qemu_malloc(s->mtu); + s->fd = fd; if (is_connected) { @@ -335,7 +349,7 @@ static NetSocketState *net_socket_fd_init_stream(VLANState *vlan, return s; } -static NetSocketState *net_socket_fd_init(VLANState *vlan, +static NetSocketState *net_socket_fd_init(VLANState *vlan, unsigned int mtu, const char *model, const char *name, int fd, int is_connected) { @@ -348,13 +362,13 @@ static NetSocketState *net_socket_fd_init(VLANState *vlan, } switch(so_type) { case SOCK_DGRAM: - return net_socket_fd_init_dgram(vlan, model, name, fd, is_connected); + return net_socket_fd_init_dgram(vlan, mtu, model, name, fd, is_connected); case SOCK_STREAM: - return net_socket_fd_init_stream(vlan, model, name, fd, is_connected); + return net_socket_fd_init_stream(vlan, mtu, model, name, fd, is_connected); default: /* who knows ... this could be a eg. a pty, do warn and continue as stream */ fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd); - return net_socket_fd_init_stream(vlan, model, name, fd, is_connected); + return net_socket_fd_init_stream(vlan, mtu, model, name, fd, is_connected); } return NULL; } @@ -376,7 +390,7 @@ static void net_socket_accept(void *opaque) break; } } - s1 = net_socket_fd_init(s->vlan, s->model, s->name, fd, 1); + s1 = net_socket_fd_init(s->vlan, s->mtu, s->model, s->name, fd, 1); if (!s1) { closesocket(fd); } else { @@ -387,6 +401,7 @@ static void net_socket_accept(void *opaque) } static int net_socket_listen_init(VLANState *vlan, + unsigned int mtu, const char *model, const char *name, const char *host_str) @@ -425,11 +440,13 @@ static int net_socket_listen_init(VLANState *vlan, s->model = qemu_strdup(model); s->name = name ? qemu_strdup(name) : NULL; s->fd = fd; + s->mtu = mtu; qemu_set_fd_handler(fd, net_socket_accept, NULL, s); return 0; } static int net_socket_connect_init(VLANState *vlan, + unsigned int mtu, const char *model, const char *name, const char *host_str) @@ -470,7 +487,7 @@ static int net_socket_connect_init(VLANState *vlan, break; } } - s = net_socket_fd_init(vlan, model, name, fd, connected); + s = net_socket_fd_init(vlan, mtu, model, name, fd, connected); if (!s) return -1; snprintf(s->nc.info_str, sizeof(s->nc.info_str), @@ -480,6 +497,7 @@ static int net_socket_connect_init(VLANState *vlan, } static int net_socket_mcast_init(VLANState *vlan, + unsigned int mtu, const char *model, const char *name, const char *host_str, @@ -505,7 +523,7 @@ static int net_socket_mcast_init(VLANState *vlan, if (fd < 0) return -1; - s = net_socket_fd_init(vlan, model, name, fd, 0); + s = net_socket_fd_init(vlan, mtu, model, name, fd, 0); if (!s) return -1; @@ -523,6 +541,8 @@ int net_init_socket(QemuOpts *opts, const char *name, VLANState *vlan) { + unsigned int mtu = qemu_opt_get_number(opts, "mtu", 4096); + if (qemu_opt_get(opts, "fd")) { int fd; @@ -539,7 +559,7 @@ int net_init_socket(QemuOpts *opts, return -1; } - if (!net_socket_fd_init(vlan, "socket", name, fd, 1)) { + if (!net_socket_fd_init(vlan, mtu, "socket", name, fd, 1)) { close(fd); return -1; } @@ -556,7 +576,7 @@ int net_init_socket(QemuOpts *opts, listen = qemu_opt_get(opts, "listen"); - if (net_socket_listen_init(vlan, "socket", name, listen) == -1) { + if (net_socket_listen_init(vlan, mtu, "socket", name, listen) == -1) { return -1; } } else if (qemu_opt_get(opts, "connect")) { @@ -572,7 +592,7 @@ int net_init_socket(QemuOpts *opts, connect = qemu_opt_get(opts, "connect"); - if (net_socket_connect_init(vlan, "socket", name, connect) == -1) { + if (net_socket_connect_init(vlan, mtu, "socket", name, connect) == -1) { return -1; } } else if (qemu_opt_get(opts, "mcast")) { @@ -588,7 +608,7 @@ int net_init_socket(QemuOpts *opts, mcast = qemu_opt_get(opts, "mcast"); localaddr = qemu_opt_get(opts, "localaddr"); - if (net_socket_mcast_init(vlan, "socket", name, mcast, localaddr) == -1) { + if (net_socket_mcast_init(vlan, mtu, "socket", name, mcast, localaddr) == -1) { return -1; } } else { diff --git a/qemu-options.hx b/qemu-options.hx index 66fffe3..4d5af96 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -1095,9 +1095,9 @@ DEF("net", HAS_ARG, QEMU_OPTION_net, " use vhostforce=on to force vhost on for non-MSIX virtio guests\n" " use 'vhostfd=h' to connect to an already opened vhost net device\n" #endif - "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n" + "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port][,mtu=mtu]\n" " connect the vlan 'n' to another VLAN using a socket connection\n" - "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n" + "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]][,mtu=mtu]\n" " connect the vlan 'n' to multicast maddr and port\n" " use 'localaddr=addr' to specify the host address to send packets from\n" #ifdef CONFIG_VDE @@ -1273,14 +1273,14 @@ qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \ -net nic,vlan=1 -net tap,vlan=1,ifname=tap1 @end example -@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}] +@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,listen=[@var{host}]:@var{port}][,connect=@var{host}:@var{port}][,mtu=@var{mtu}] 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} (@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. +specifies an already opened TCP socket. MTU is 4096 by default. Example: @example @@ -1293,11 +1293,12 @@ qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \ -net socket,connect=127.0.0.1:1234 @end example -@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]] +@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]][,mtu=@var{mtu}] 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}. +MTU is 4096 by default. NOTES: @enumerate @item
Also mention the default value 4096. Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> --- free new buffers in net_socket_cleanup() net.c | 4 ++++ net/socket.c | 52 ++++++++++++++++++++++++++++++++++++---------------- qemu-options.hx | 11 ++++++----- 3 files changed, 46 insertions(+), 21 deletions(-)