On 5/29/19 5:12 PM, Laszlo Ersek wrote: > This reverts commit 9a2e8d7c65ef7f39c6754d27e52954b616bc6628. > > The original fix for <https://bugzilla.tianocore.org/show_bug.cgi?id=1814> > triggered a bug / incorrect assumption in QEMU. > > QEMU assumes that the PCIEXBAR is below the 32-bit PCI window, not above > it. When the firmware doesn't satisfy this assumption, QEMU generates an > \_SB.PCI0._CRS object in the ACPI DSDT that does not reflect the > firmware's 32-bit MMIO BAR assignments. This causes OSes to re-assign > 32-bit MMIO BARs. > > Working around the problem in the firmware looks less problematic than > fixing QEMU. Revert the original changes first, before implementing an > alternative fix. > > Cc: Ard Biesheuvel <ard.biesheu...@linaro.org> > Cc: Gerd Hoffmann <kra...@redhat.com> > Cc: Jordan Justen <jordan.l.jus...@intel.com> > Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1859 > Signed-off-by: Laszlo Ersek <ler...@redhat.com>
Reviewed-by: Philippe Mathieu-Daude <phi...@redhat.com> > --- > OvmfPkg/PlatformPei/Platform.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/OvmfPkg/PlatformPei/Platform.c b/OvmfPkg/PlatformPei/Platform.c > index 9c013613a1a0..5e0a15484230 100644 > --- a/OvmfPkg/PlatformPei/Platform.c > +++ b/OvmfPkg/PlatformPei/Platform.c > @@ -181,7 +181,6 @@ MemMapInitialization ( > > TopOfLowRam = GetSystemMemorySizeBelow4gb (); > PciExBarBase = 0; > - PciBase = (TopOfLowRam < BASE_2GB) ? BASE_2GB : TopOfLowRam; > if (mHostBridgeDevId == INTEL_Q35_MCH_DEVICE_ID) { > // > // The MMCONFIG area is expected to fall between the top of low RAM and > @@ -193,6 +192,7 @@ MemMapInitialization ( > PciBase = (UINT32)(PciExBarBase + SIZE_256MB); > PciSize = 0xFC000000 - PciBase; > } else { > + PciBase = (TopOfLowRam < BASE_2GB) ? BASE_2GB : TopOfLowRam; > PciSize = 0xFC000000 - PciBase; > } > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#41636): https://edk2.groups.io/g/devel/message/41636 Mute This Topic: https://groups.io/mt/31834715/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-