[libvirt] [PATCHv2] qemu: add ability to set PCI device "rombar" on or off

Daniel Veillard veillard at redhat.com
Tue Sep 27 06:53:50 UTC 2011

On Fri, Sep 23, 2011 at 10:35:19AM -0600, Eric Blake wrote:
> On 09/22/2011 10:05 AM, Laine Stump wrote:
> >(This addresses Eric's comments in his review of V1. BTW, I'm a bit
> >surprised nobody has commented about the choice of name/placement of
> >the new attribute - speak now or forever hold your peace :-))
> I was okay with the xml naming - but I agree that if anyone else has
> a better suggestion, now is the time to speak up :)
> >
> >This patch was made in response to:
> >
> >   https://bugzilla.redhat.com/show_bug.cgi?id=738095
> >
> >In short, qemu's default for the rombar setting (which makes the
> >firmware ROM of a PCI device visible/not on the guest) was previously
> >0 (not visible), but they recently changed the default to 1
> >(visible). Unfortunately, there are some PCI devices that fail in the
> >guest when rombar is 1, so the setting must be exposed in libvirt to
> >prevent a regression in behavior (it will still require explicitly
> >setting<rom bar='off'/>  in the guest XML).
> >
> >rombar is forced on/off by adding:
> >
> >   <rom bar='on|off'/>
> >
> >inside a<hostdev>  element that defines a PCI device. It is currently
> >ignored for all other types of devices.

  Fine by me.
The doc section explain that behaviour is unclear if not set (i.e.
default to qemu's and that changed), so all fine IMHO


Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/

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