Re: [Qemu-devel] [SeaBIOS] [PATCH v5] fw/pci: Add support for mapping Intel IGD via QEMU

[Alex Williamson <alex.williamson@redhat.com>]

On Wed, 01 Jun 2016 11:26:54 +0200
Gerd Hoffmann <kraxel@redhat.com> wrote:

> On Di, 2016-05-17 at 14:44 -0600, Alex Williamson wrote:
> > QEMU provides two fw_cfg files to support IGD.  The first holds the
> > OpRegion data which holds the Video BIOS Table (VBT).  This needs to
> > be copied into reserved memory and the address stored in the ASL
> > Storage register of the device at 0xFC offset in PCI config space.
> > The OpRegion is generally 8KB.  This file is named "etc/igd-opregion".
> > 
> > The second file tells us the required size of the stolen memory space
> > for the device.  This space requires 1MB alignment and is generally
> > either 1MB to 8MB depending on hardware config, but may be hundreds of
> > MB for user specified stolen memory.  The base address of the reserved
> > memory allocated for this is written back to the Base Data of Stolen
> > Memory register (BDSM) at PCI config offset 0x5C on the device.  This
> > file is named "etc/igd-bdsm-size".
> > 
> > QEMU documents these fw_cfg entries in docs/igd-assign.txt.
> > 
> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> > ---
> > 
> > v6: fw_cfg BDSM entry now holds an 8-byte size integer as suggested
> >     by Gerd.  Also renamed to etc/igd-bdsm-size.  Filter based on bdf
> >     to only make use of this for the Intel VGA device at address
> >     00:02.0, not that QEMU should attach this to anything else.
> > 
> > As always, comments appreciated.  I expect this will be on hold
> > pending the QEMU support:
> > 
> > http://thread.gmane.org/gmane.comp.emulators.kvm.devel/152123  
> 
> qemu patches are merged meanwhile.
> 
> Patch applied to master and cherry-picked into 1.9-stable.

Thanks!