On Tue, Feb 16, 2016 at 02:39:27PM -0700, 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 is a dummy file, it has no backing so we only > allocate the space without copying anything into it. This space > requires 1MB alignment and is generally either 1MB or 2MB, depending > on the hardware config. If the user has opted in QEMU to expose > additional stolen memory beyond the GTT (GGMS), the GMS may add an > additional 32MB to 512MB. 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". Thanks. I'd be interested in seeing how the discussion with Michael and Igor works out (wrt using a standardized interface for communicating addresses between qemu and firmware) before adopting this interface in SeaBIOS. -Kevin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
