Re: [edk2-devel] [PATCH 1/1] OvmfPkg/PlatformInitLib: pass through reservations from qemu

["Lendacky, Thomas" <thomas.lendacky@amd.com>]

On 1/17/23 10:49, Ard Biesheuvel wrote:
> On Mon, 16 Jan 2023 at 21:10, Tom Lendacky <thomas.lendacky@amd.com> wrote:
>>
>> On 1/16/23 11:09, Ard Biesheuvel wrote:
>>> On Thu, 12 Jan 2023 at 18:09, Tom Lendacky <thomas.lendacky@amd.com> wrote:
>>>>
>>>> On 12/6/22 23:32, Gerd Hoffmann via groups.io wrote:
>>>>> qemu uses the etc/e820 fw_cfg file not only for memory, but
>>>>> also for reservations.  Handle reservations by adding resource
>>>>> descriptor hobs for them.
>>>>>
>>>>> A typical qemu configuration has a small reservation between
>>>>> lapic and flash:
>>>>>
>>>>>      # sudo cat /proc/iomem
>>>>>      [ ... ]
>>>>>      fee00000-fee00fff : Local APIC
>>>>>      feffc000-feffffff : Reserved          <= HERE
>>>>>      ffc00000-ffffffff : Reserved
>>>>>      [ ... ]
>>>>>
>>>>> Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
>>>>
>>>> On newer versions of Qemu, this patch causes a boot failure on my
>>>> AMD system with the following output:
>>>>
>>>> ...
>>>> PciHostBridgeUtilityInitRootBridge: populated root bus 0, with room for 255 subordinate bus(es)
>>>> RootBridge: PciRoot(0x0)
>>>>      Support/Attr: 70069 / 70069
>>>>        DmaAbove4G: No
>>>> NoExtConfSpace: No
>>>>         AllocAttr: 3 (CombineMemPMem Mem64Decode)
>>>>               Bus: 0 - FF Translation=0
>>>>                Io: 6000 - FFFF Translation=0
>>>>               Mem: C0000000 - FBFFFFFF Translation=0
>>>>        MemAbove4G: E000000000 - FFFFFFFFFF Translation=0
>>>>              PMem: FFFFFFFFFFFFFFFF - 0 Translation=0
>>>>       PMemAbove4G: FFFFFFFFFFFFFFFF - 0 Translation=0
>>>> PciHostBridgeDxe: IntersectMemoryDescriptor: desc [FD00000000, 10000000000) type 1 cap 8000000000026000 conflicts with aperture [E000000000, 10000000000) cap 1
>>>>
>>>> ASSERT_EFI_ERROR (Status = Invalid Parameter)
>>>> ASSERT [PciHostBridgeDxe] /root/kernels/ovmf-build-X64/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciHostBridge.c(550): !(((INTN)(RETURN_STATUS)(Status)) < 0)
>>>>
>>>> Doing some bisecting, before Qemu patch
>>>>
>>>>       8504f129450b ("i386/pc: relocate 4g start to 1T where applicable")
>>>>
>>>> this issue wasn't observed. And before this OVMF patch, the newer version
>>>> of Qemu doesn't have an issue.
>>>>
>>>> Also, if I add host-phys-bits=true to the Qemu -cpu parameter, then
>>>> the issue isn't observed regardless of Qemu/OVMF level.
>>>>
>>>> I'm hoping someone has an understanding of what is going on and what
>>>> can be done to fix it.
>>>>
>>>
>>> Could someone look into this please? Gerd?
>>
>> Looks like Gerd is already on it.
>>
>> See https://bugzilla.tianocore.org/show_bug.cgi?id=4251
>>
> 
> Right, I didn't realize these things were related.
> 
> In any case, those patches have been merged now - care to check
> whether the issue has been resolved? Thanks.

Yes, the issue is now resolved.

Thanks,
Tom