On Fri, Feb 22, 2013 at 10:54:47AM +0100, Markus Armbruster wrote:
> Stefan Hajnoczi <stefa...@redhat.com> writes:
>
> > On Thu, Feb 21, 2013 at 03:17:51PM +0100, Markus Armbruster wrote:
> >> Stefan Hajnoczi <stefa...@redhat.com> writes:
> >>
> >> > Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
> >> > ---
> >> > qemu-options.hx | 11 ++++++++++-
> >> > 1 file changed, 10 insertions(+), 1 deletion(-)
> >> >
> >> > diff --git a/qemu-options.hx b/qemu-options.hx
> >> > index 4bc9c85..cd18ad1 100644
> >> > --- a/qemu-options.hx
> >> > +++ b/qemu-options.hx
> >> > @@ -1404,7 +1404,8 @@ DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
> >> > #ifdef CONFIG_VDE
> >> > "vde|"
> >> > #endif
> >> > - "socket],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
> >> > + "socket|"
> >> > + "hubport],id=str[,option][,option][,...]\n", QEMU_ARCH_ALL)
> >> > STEXI
> >> > @item -net nic[,vlan=@var{n}][,macaddr=@var{mac}][,model=@var{type}]
> >> > [,name=@var{name}][,addr=@var{addr}][,vectors=@var{v}]
> >> > @findex -net
> >> > @@ -1726,6 +1727,14 @@ vde_switch -F -sock /tmp/myswitch
> >> > qemu-system-i386 linux.img -net nic -net vde,sock=/tmp/myswitch
> >> > @end example
> >> >
> >> > +@item -netdev hubport,id=@var{id},hubid=@var{hubid}
> >> > +
> >> > +Create a hub port on QEMU "vlan" @var{hubid}. This syntax is an
> >> > alternative to
> >> > +the @code{-net @option{vlan}} argument and can be used to connect a NIC
> >> > +specified with @code{-device ...,netdev=@var{id}} to a QEMU "vlan".
> >>
> >> A simpler way to use a "vlan" with -device is "-device e1000,vlan=0".
> >> How is that related to hubport?
> >
> > That is yet another shortcut syntax. It does the same thing as -netdev
> > hubport,id=tmphubport0,hubid=0 -device e1000,netdev=tmphubport0.
>
> Perhaps documentation should point to the shorthand syntax. Let me try:
>
> Create a hub port on QEMU "vlan" @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.
Your version is easier to read. Works fine by me.
> >> > +
> >> > +Note that only NICs can be connected to a hubport, other -netdevs
> >> > cannot.
> >> > +
> >>
> >> Well, netdevs can't be connected to a netdev in general, and hubport is
> >> one. You can connect up to one device model to a netdev. I figure you
> >> can additionally connect any number of old-style -net thingies to it,
> >> whether they are NICs or not. Correct?
> >
> > net.c doesn't stop NetClients from connecting to each other. It's just
> > our -netdev option parsing code which doesn't allow -netdevs to connect
> > with each other.
> >
> > -net instances can only connect to hub ports.
>
> I find the note confusing. "Only NICs" suggests only NICs can connect,
> which isn't true; one NIC and any number of "vlan" clients (defined with
> -net) can connect. The fact that the code would happily connect
> arbitrary netdevs is of no interest to the user. Drop the note?
I was trying to express that -netdev hubport -netdev slirp cannot be
used together, only -netdev hubport -device virtio-net-pci. In other
words, -netdev hubport only works with -device <NIC>.
Let's drop the note.
I'll send a v3.
Stefan
