On 5/29/19 5:12 PM, Laszlo Ersek wrote: > This reverts commit 60e95bf5094fbb9b728729ccfaf32184b3662317. > > 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 | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/OvmfPkg/PlatformPei/Platform.c b/OvmfPkg/PlatformPei/Platform.c > index 5e0a15484230..0876316eefbc 100644 > --- a/OvmfPkg/PlatformPei/Platform.c > +++ b/OvmfPkg/PlatformPei/Platform.c > @@ -190,10 +190,8 @@ MemMapInitialization ( > ASSERT (TopOfLowRam <= PciExBarBase); > ASSERT (PciExBarBase <= MAX_UINT32 - SIZE_256MB); > PciBase = (UINT32)(PciExBarBase + SIZE_256MB); > - PciSize = 0xFC000000 - PciBase; > } else { > PciBase = (TopOfLowRam < BASE_2GB) ? BASE_2GB : TopOfLowRam; > - PciSize = 0xFC000000 - PciBase; > } > > // > @@ -209,6 +207,7 @@ MemMapInitialization ( > // 0xFED20000 gap 896 KB > // 0xFEE00000 LAPIC 1 MB > // > + PciSize = 0xFC000000 - PciBase; > AddIoMemoryBaseSizeHob (PciBase, PciSize); > PcdStatus = PcdSet64S (PcdPciMmio32Base, PciBase); > ASSERT_RETURN_ERROR (PcdStatus); > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#41637): https://edk2.groups.io/g/devel/message/41637 Mute This Topic: https://groups.io/mt/31834717/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-