Date: Mon, 24 Aug 2009 08:58:02 +0200 From: martinko <gamato@users.sf.net> To: freebsd-emulation@freebsd.org Subject: Re: Automagic bridged networking with QEMU (tap) Message-ID: <h6tdlq$eqo$1@ger.gmane.org> In-Reply-To: <200908232215.n7NMFqkK007704@triton8.kn-bremen.de> References: <h6m7i2$pgt$1@ger.gmane.org> <200908232215.n7NMFqkK007704@triton8.kn-bremen.de>
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Juergen Lock wrote:
>
> I like the idea, but found it needs a patch to qemu or otherwise a
> KASSERT gets triggered in the tap driver (sys/net/if_tap.c:tap_destroy(),
> causing a `tapX flags is out of sync' panic if the driver is built with
> INVARIANTS) because the tap interface gets destroyed before its /dev/tap
> fd is closed:
>
> Index: qemu/net.c
> @@ -961,11 +961,12 @@
> {
> TAPState *s = vc->opaque;
>
> - if (s->down_script[0])
> - launch_script(s->down_script, s->down_script_arg, s->fd);
> -
> qemu_set_fd_handler(s->fd, NULL, NULL, NULL);
> close(s->fd);
> +
> + if (s->down_script[0])
> + launch_script(s->down_script, s->down_script_arg, -1);
> +
> qemu_free(s);
> }
>
> I guess the driver could handle this condition more gracefully, but
> until then... Oh and I also found the ifdown script doesn't get called
> in all cases, like when you quit qemu via the monitor.
>
> Btw, can someone test this on 6.3? I'm wondering if we could ship
> these ifup/down scripts in the qemu port(s) by default, maybe with an
> rcvar added to enable them or something like that. (and the other
> config instructions in the pkg-message file.) If you don't mind... :)
Hallo Juergen,
I certainly don't mind shipping those scripts of mine. Thank you for
the patch, I wasn't aware of any panics, though I was thinking along the
lines if it's ok to destroy a tap while Qemu apparently has got it open.
I don't use Qemu monitor but I quess quitting from there should behave
the same way and it's a Qemu bug if the scripts are not called, imho.
Regards and thank you for all the work on Qemu port.
Martin
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