Re: [Qemu-devel] [BUG] [Seabios] PCI 64bit BARs on Win2008 - unable to start the device. (ACPI lacks the _DSM method)

[Alexey Korolev]

On 05/12/11 19:31, Michael S. Tsirkin wrote:
> On Mon, Dec 05, 2011 at 05:20:32PM +1300, Alexey Korolev wrote:
> > Hi Michael,
> >
> > Thank you for good advice, you are right.  When I added new range
> > above 4GB in _CRS the problem has gone.
> >    QWordMemory (ResourceProducer, PosDecode, MinFixed, MaxFixed,
> > NonCacheable, ReadWrite,
> >                     0x00000000,          // Address Space Granularity
> >                     0x100000000,        // Address Range Minimum
> >                     0x3FFFFFFFF,        // Address Range Maximum
> >                     0x00000000,          // Address Translation Offset
> >                     0x400000000,        // Address Length
> >                     ,, , AddressRangeMemory, TypeStatic)
> >
> > The only big problem with this range - as soon as I have more than
> > 3GB of RAM, windows will boot in BSOD. The problem relates to memory
> > range intersection.
> > Unfortunately it is not possible to predict how many GB of RAM the
> > virtual machine could have - so it's difficult to specify a
> > particular region.
> > Do you have any ideas what can be done to solve this problem?
> >
> > Regards,
> > Alexey
> Two possible ideas:
> 1. Pass the value in from qemu
Do you mean to create the 64bit region dynamically? I've tried to obtain 
RAM size somehow inside DSL code, but the ACPI spec doesn't tell how to 
do that.

> 2. Get a range toward the upper end of the memory, around 1<<40
Yes. This solution works great. And this is very simple as well. Just 
wondering if it will be good as a complete solution?