Re: [Qemu-devel] [PATCH V13 3/4] pc: add a Virtual Machine Generation ID device

[Michael S. Tsirkin]

On Mon, Mar 02, 2015 at 06:05:43PM +0100, Igor Mammedov wrote:
> On Sun, 1 Mar 2015 16:09:33 +0100
> "Michael S. Tsirkin" <address@hidden> wrote:
> 
> > On Wed, Feb 25, 2015 at 05:08:52PM +0000, Igor Mammedov wrote:
> > > Based on Microsoft's sepecifications (paper can be dowloaded from
> > > http://go.microsoft.com/fwlink/?LinkId=260709), add a device
> > > description to the SSDT ACPI table and its implementation.
> > > 
> > > The GUID is set using "vmgenid.uuid" property.
> > > 
> > > Example of using vmgenid device:
> > >  -device vmgenid,id=FOO,uuid="324e6eaf-d1d1-4bf6-bf41-b9bb6c91fb87"
> > 
> > If you do this, doesn't windows then prompt for a driver?
> it doesn't since PCI_CLASS_MEMORY_RAM is displayed as driver less 
> "PCI standard RAM Controller" binding in device manager.
> 
> There was an issue with
>  virtio balloon device + pseries firmware + kernel bug
>  http://lists.gnu.org/archive/html/qemu-devel/2012-03/msg04704.html
> but it shouldn't be an issue for x86 targets with which device is
> supposed to be used.
> CCing David and Laszlo in case UEFI might do some crazy stuff like
> pseries firmware.

I have to say, if it's not RAM, using PCI_CLASS_MEMORY_RAM seems
wrong. Can't we tag it in ACPI in some way?

I guess I can somewhat buy 0580 "other memory controller".

I think we also want some space for future expansion
in this device.
How about we reserve first 4K, and set bit 0 to mean
"has uuid"?

-- 
MST