Re: [RFC 0/9] WHPX support for Arm

[Pierrick Bouvier <pierrick.bouvier@linaro.org>]

On 8/1/25 11:52 AM, Mohamed Mediouni wrote:
> 
> 
>> On 1. Aug 2025, at 19:22, Pierrick Bouvier <pierrick.bouvier@linaro.org> wrote:
>>
>> On 8/1/25 5:43 AM, Mohamed Mediouni wrote:
>>>> On 1. Aug 2025, at 03:15, Pierrick Bouvier <pierrick.bouvier@linaro.org> wrote:
>>>>
>>>> Hi Mohamed,
>>>>
>>>> On 7/30/25 10:27 PM, Mohamed Mediouni wrote:
>>>>> This one took way longer for me to publish than I should have.
>>>>> There are a number of lingering bugs in this one including u-boot not working.
>>>>> Interrupt controller save/restore is entirely missing in this RFC, and some other state
>>>>> bits are likely still missing too.
>>>>> ITS not blocked by default yet, remember to use its=off when testing this series.
>>>>> You might also want the GICv3 + GICv2m support patch as part of the HVF vGIC patch series, which
>>>>> is not duplicated here.
>>>>> PS: on both this and HVF, interrupt controller initialisation needs to be done early so I ended
>>>>> up with hardcoded addresses. Wonder if the right way to go might be to defer virt and vCPU initialisation
>>>>> until late in the process post-gic_realize...
>>>>> Other than that, this boots both EDK2 and Linux in SMP, when using devicetree or ACPI.
>>>>
>>>> thanks for posting this, that's an exciting series!
>>>>
>>>> I applied it on top of your other series (20250728134114.77545-1-mohamed@unpredictable.fr) and solved the conflicts.
>>>> However, it would really help if you could push that exact branch somewhere, so people can easily pull it and try.
>>>> I'm fine if you want to duplicate gic patches in this series as well.
>>> Hello,
>>> My branches are at https://github.com/mediouni-m/qemu
>>>
>>
>> Thanks, it's worth adding it in cover letter for next versions.
>>
>>> whpx-v1 corresponding to this RFC, but latest rev of the whpx branch has some fixes
>>> Have some additional notes and binaries here too: https://github.com/mediouni-m/qemu/releases/tag/whpx-v1.1
>>> Thank you,
>>> -Mohamed
>>>> I tried to direct boot a kernel (6.15 defconfig) and ran into this error [1]:
>>>> $ ./build/qemu-system-aarch64.exe -M virt,its=off -cpu cortex-a76 -m 2G -nographic -accel whpx -kernel out/Image.gz out/host.ext4
>>> Syntax that I use is -M virt,accel=whpx,its=off -m 2048-cpu cortex-a72 -bios share/edk2-aarch64-code.fd.
>>> And on some kernel versions, you’ll also need irqchip.gicv3_nolpi=1.
>>>> Could you please share your exact command line?
>>>> Does it work with direct kernel boot also?
>>>>
>>>> Kind Regards,
>>>> Pierrick
>>>>
>>>> [1] Error when booting:
>>>> [    1.381525] Internal error: Oops: 0000000096000002 [#1]  SMP
>>>> [    1.458060] Modules linked in:
>>>> [    1.461172] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.15.0-00001-g7797e43a2520 #1 PREEMPT
>>>> [    1.470502] Hardware name: linux,dummy-virt (DT)
>>>> [    1.475102] pstate: 204000c5 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>> [    1.482023] pc : pci_generic_config_read+0x38/0xb8
>>>> [    1.486970] lr : pci_generic_config_read+0x24/0xb8
>>> I don’t think I saw this particular one before… which Windows version and hardware are you testing this on?
>>>
>>
>> I see the same error as before.
>>
>> I tried also binaries from https://github.com/mediouni-m/qemu/releases/tag/whpx-v1.1, when directly booting kernel, I still see the same pci issue with both binaries and my compiled whpx-v1.3.
>> When booting edk2 provided, I ran into this other error instead with both binaries [1].
>>
>> I'm running latest Windows 11 (stable channel, fully updated), on a microsoft volterra (devkit). It might be an issue specific to this platform.
>>
> I didn’t test anything on the stable branch for now but only on Canary so far.
> Just cursorily tested (EDK2 only) an X Elite device on prod (26100.4652) and this issue doesn’t appear.
> 
> I have 8cx Gen 3 and 8cx Gen 1 (SQ1) devices around, will test on those older SoCs later and see.
> 
> Random idea for testing: what if you put -M highmem=off, does that change anything?
>

Good guess, it solves the problem with edk2, and direct boots linux 
kernel successfully now.

> Thanks,
> -Mohamed
> 
>> In case you're interested, we can arrange an access to the machine, but I understand if it's not your priority now.
>>
>> [1]
>> Windows Hypervisor Platform accelerator is operational
>> UEFI firmware (version edk2-stable202408-prebuilt.qemu.org built at 16:28:50 on Sep 12 2024)
>> ArmTrngLib could not be correctly initialized.
>> Error: Image at 000BFDB6000 start failed: 00000001
>> Error: Image at 000BFD6D000 start failed: Not Found
>> MapGcdMmioSpace: failed to add GCD memory space for region [0x4010000000+0x10000000)
>> ASSERT_EFI_ERROR (Status = Unsupported)
>> ASSERT [PciHostBridgeDxe] /home/kraxel/projects/qemu/roms/edk2/OvmfPkg/Fdt/FdtPciHostBridgeLib/FdtPciHostBridgeLib.c(326): !(((INTN)(RETURN_STATUS)(Status)) < 0)
>>
>>> (Message was sent from the wrong email alias on mobile, resending)
>>> Thank you,
>>> -Mohamed
>>
>> Thanks,
>> Pierrick
>