WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] Re: Comments on Xen bug 1732

On Thu, 2011-03-17 at 07:48 +0000, Jan Beulich wrote:
> >>> On 16.03.11 at 14:50, Gianni Tedesco <gianni.tedesco@xxxxxxxxxx> wrote:
> > On Wed, 2011-03-16 at 08:22 +0000, Jan Beulich wrote:
> >> >>> On 15.03.11 at 19:30, Gianni Tedesco <gianni.tedesco@xxxxxxxxxx> wrote:
> >> > Furthermore this used to work on xen 3.4 but fails on 4.1 so it seems to
> >> > be a regression. One other notable change is the assignments of the
> >> > MSI-X vectors that I see when hitting the Q debug key:
> >> > 
> >> > On 3.4:
> >> > (XEN) 04:10.0 - dom 1   - MSIs < 66 74 82 >
> >> > 
> >> > On 4.1:
> >> > (XEN) 04:10.1 - dom 0   - MSIs < 117 118 119 >
> >> 
> >> dom 1 on 3.4 vs dom 0 on 4.1? And different functions? Doesn't
> >> look like a 1:1 comparison to me.
> > 
> > Yeah they are different machines with the same SR-IOV NIC (similar
> > enough hardware wise). But the point is the different assigned domains,
> > bear in mind that in both cases the function in question is assigned to
> > a guest at the time the debug key was pressed.
> 
> And even iommu=verbose doesn't produce anything more
> informative? Something must be going wrong during the
> assignment...

Just a bunch of stuff like this:
(XEN) [VT-D]iommu.c:1363: d0:PCIe: map bdf = c:10.1
(XEN) PCI add Virtual Function 0c:10.1

> Are the kernels in host and guest exactly the same in both the
> 3.4 and the 4.1 cases? Using pciback or pci-stub?

Well I am currently working on getting a repro on two identical boxes
differing only by hypervisor versions, will let you know.

> >> > Any ideas?
> >> 
> >> Not really. Despite me not thinking that the change in question
> >> (that introduced the WARN_ON()s) has any functionality impact
> >> (it's really only about trying to write protect certain MMIO
> >> ranges, with the WARN_ON()s reporting that this didn't work as
> >> expected) - did you try reverting it (and its follow-up fixes)?
> > 
> > No change.
> 
> With that, the regression then clearly must be elsewhere, and
> I'm afraid we're having to hope that Intel folks will take a look.

*nods*

Gianni


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>