Re: [Qemu-devel] [PULL v4 00/18] pci,misc enhancements

[Michael S. Tsirkin]

On Wed, Jul 10, 2013 at 04:34:30PM +0100, Stefano Stabellini wrote:
> On Wed, 10 Jul 2013, Michael S. Tsirkin wrote:
> > On Wed, Jul 10, 2013 at 03:30:01PM +0100, Stefano Stabellini wrote:
> > > On Wed, 10 Jul 2013, Michael S. Tsirkin wrote:
> > > > On Wed, Jul 10, 2013 at 03:11:27PM +0100, Stefano Stabellini wrote:
> > > > > On Sun, 7 Jul 2013, Michael S. Tsirkin wrote:
> > > > > > From: Michael S. Tsirkin <address@hidden>
> > > > > > 
> > > > > > Changes from v3:
> > > > > >     - fix up xen build
> > > > > > 
> > > > > > Changes from v2:
> > > > > >     - rebased to origin/master
> > > > > >     - fixed up botched posting
> > > > > > 
> > > > > > The following changes since commit 
> > > > > > ab8bf29078e0ab8347e2ff8b4e5542f7a0c751cf:
> > > > > > 
> > > > > >   Merge remote-tracking branch 'qemu-kvm/uq/master' into staging 
> > > > > > (2013-07-03 08:37:00 -0500)
> > > > > > 
> > > > > > are available in the git repository at:
> > > > > > 
> > > > > > 
> > > > > >   git://git.kernel.org/pub/scm/virt/kvm/mst/qemu.git 
> > > > > > tags/for_anthony
> > > > > > 
> > > > > > for you to fetch changes up to 
> > > > > > 7588e2b0559ae72d3c2952c7807fc05c03099970:
> > > > > > 
> > > > > >   pci: Fold host_buses list into PCIHostState functionality 
> > > > > > (2013-07-07 23:10:57 +0300)
> > > > > 
> > > > > This patch series breaks Xen support in QEMU.
> > > > > Unfortunately QEMU exits at boot time with no output, I'll try to get
> > > > > back to you with more info.
> > > > 
> > > > This is the main change for Xen:
> > > > 
> > > > -    bus = pci_find_root_bus(0);
> > > > +    bus = pci_find_primary_bus();
> > > > 
> > > > Could you please try 1ef7a2a2afedbba47e06af5081a8b4bf6dc1cf71
> > > > that made this change, and 1ef7a2a2afedbba47e06af5081a8b4bf6dc1cf71~1 
> > > > before it?
> > > > 
> > > 
> > > git bisect tells me that the problem is caused by:
> > > 
> > > commit f8c457b88d72a48989f190bc3d7b79f4f3b7d11c
> > > Author: Michael S. Tsirkin <address@hidden>
> > > Date:   Mon May 13 20:00:23 2013 +0300
> > > 
> > >     pc: pass PCI hole ranges to Guests
> > >         
> > 
> > 
> > Does this help?
> > 
> > 
> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> > index 9f9207d..c7fc475 100644
> > --- a/hw/i386/pc.c
> > +++ b/hw/i386/pc.c
> > @@ -999,7 +999,7 @@ typedef struct PcRomPciInfo {
> >  static void pc_fw_cfg_guest_info(PcGuestInfo *guest_info)
> >  {
> >      PcRomPciInfo *info;
> > -    if (!guest_info->has_pci_info) {
> > +    if (!guest_info->has_pci_info || !guest_info->fw_cfg) {
> >          return;
> >      }
> >  
> 
> Yes, it does.
> Can we introduce a couple of macros to test for fw_cfg availability?
> Maybe they would help avoiding these issues in the future.

Needs some thought, but let's fix this quickly so master isn't broken for
people.