Re: pv-ops domU not working with MSI interrupts on Nehalem

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

>  git clone  git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git
> 
> Initialized empty Git repository in
> /import/kaan/bedge/src/xen/kernel/pv-ops/xen/.git/
> remote: error: Could not read 59eab2f8f04147c5aadc99f2034ca7e5b81e890f
> remote: fatal: Failed to traverse parents of commit
> 979e121cb348add17ed8171bf447b27a3a9d1be3
> remote: aborting due to possible repository corruption on the remote side.
> fatal: early EOF
> fatal: index-pack failed

That should have worked, but it looks as my git repo is busted. Let me fix that
and once it done you should be able to do

cd xen
git checkout origin/pv/pcifront-2.6.32

> 
> >
> > It has the latest pcifront driver but without the PVonHVM enhancments
> > so we can try to eliminate the PvONHVM logic out of the picture.
> >
> >>
> >> >
> >> > > - the interrupt does happen. But the interrupt service routine of
> >> > > tachyon driver doesn't detect any interrupt status related to this
> >> > > interrupt, which inhibits the tachyon chip from coming on-line. And
> >> > > there are high count of tachyon interrupt in /proc/interrupts
> >> >
> >> > Is it checking the PCI_STATUS_INTERRUPT or the appropiate register
> >> > in the MMIO BAR?
> >> >
> >>
> >> The driver would check the appropriate register (tachyon registers) in
> >> the MMIO to determine the source of interrupts.
> >
> > OK, so that isn't it. Is there anything at these vectors:
> > 7c, 7d, 7e, and 7f? When you use xen debug-keys 'i' or 'q' it should give you
> > an inkling what device this is set for.
> 
> When I run a distro kernel in hvm mode, I get the expected irq mappings:
> 
> 'i' - Note 66 - 69
> (XEN)    IRQ:  66 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:3a
> type=PCI-MSI         status=00000010 in-flight=0
> domain-list=10:127(----),
> (XEN)    IRQ:  67 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:42
> type=PCI-MSI         status=00000010 in-flight=0
> domain-list=10:126(----),
> (XEN)    IRQ:  68 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:4a
> type=PCI-MSI         status=00000010 in-flight=0
> domain-list=10:125(----),
> (XEN)    IRQ:  69 affinity:ffffffff,ffffffff,ffffffff,ffffffff vec:52
> type=PCI-MSI         status=00000010 in-flight=0
> domain-list=10:124(----)
> 

What does cat /proc/interrupts (don't do the grep) for this HVM guest?
> 
> 'q'
> (XEN)     Interrupts { 32, 41-42, 47, 124-127 }