Re: [libvirt] [PATCH 0/3] A couple of UML-related fixes
On Thu, Aug 12, 2010 at 11:08:16AM +0200, Soren Hansen wrote:
I've been trying to get UML working for the last couple of days.
As it stands,
at least bridged networking doesn't work for me. I've got a fix, but I'm
not
sure I'm doing it right.
I can get it to fail in three distinct ways:
* With the current code, it seems that the tap device disappears almost
immediately. This happens becuase the call to brAddTap includes an
(int *)tapfd argument, so the tap device isn't persistent. A few
lines after brAddTap, close(tapfd) is called and the tap device goes
missing.
Yep, this is a regression we introduced. It definitely needs to be
persistent.
* Passing a NULL tapfd argument to brAddTap and removing the call
to
close(tapfd) makes the tapfd persist, but when the uml domain
attempts to bring up the interface, it fails with EBUSY. This turns
out to be because brAddTap marks the tap device persistent, but
doesn't close the fd, so both libvirt and uml have the fd open and
that's doesn't work out well.
Ah, good point.
* Finally, I tried passing the tapfd result back up the call chain
so
that I have a list of them that I could tell virExecDaemonize to keep
open and then close them in libvirt after the fork. I think this is
when I got EPERM when trying to bring the interface up in UML domain,
but I'm not sure right now.
Daniel
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