Patch for MS Hyper V (virtualization)

[John Baldwin]

On Tuesday 07 April 2009 9:14:26 pm Sergey Babkin wrote:
> John Baldwin wrote:
> > 
> > On Monday 06 April 2009 11:12:33 pm Sergey Babkin wrote:
> 
> > > Anyway, as far as I can tell, it's only the base register of
> > > the simulated DEC21140 device that has this issue, so it's
> > > quite possible that the bug is in that device's simulator.
> > >
> > > I've attached a modified patch that checks conservatively for this
> > > precise situation, so it should not break compatibility with
> > > anything else. I've tested it on Hyper-V.
> > 
> > Can you test unmodified FreeBSD 8 on Hyper-V?  It has an extra fix 
relative to
> > 7 to disable decoding via the PCI command register while sizing BARs that 
may
> > address this.
> 
> 8.0 (February snapshot) seems to have the same issue.

Ok.

> I've also saved the log of writes that 7.1 does for this device:
> 
> reg 10 val ec01
> reg 14 val febff000
> reg 18 val 0
> reg 1c val 0
> reg 20 val 0
> reg 24 val 0
> reg 30 val febe0000
> reg 4 val 117
> reg 3c val b
> reg 3d val 1
> reg 3e val 14
> reg 3f val 28
> reg c val 8
> reg d val 40
> reg 9 val 0
> reg 8 val 20
> reg 10 val ec00
> reg 14 val febff000
> reg 4 val 117
> reg 4 val 117
> 
> I don't see any ffffffff values.

Your printf() probably isn't in the right place.  pci_add_map() uses 
PCIB_READ_CONFIG() directly and doesn't use pci_read_config(), so if your 
printf is in pci_read_config_method() in pci.c it won't see them.  Try 
hooking the cfg operations in sys/amd64/pci/pci_cfgreg.c instead.

-- 
John Baldwin