Re: [PATCH, v2] physmem: avoid bounce buffer too small

[Heinrich Schuchardt <heinrich.schuchardt@canonical.com>]

On 29.02.24 13:34, Peter Maydell wrote:
> On Thu, 29 Feb 2024 at 11:17, Heinrich Schuchardt
> <heinrich.schuchardt@canonical.com> wrote:
>>> But yes, I'm not surprised that CXL runs into this. Heinrich,
>>> are you doing CXL testing, or is this some other workload?
>>
>> I am running the UEFI Self-Certification Tests (SCT) on EDK 2 using:
>>
>> qemu-system-riscv64 \
>>         -M virt,acpi=off -accel tcg -m 4096 \
>>         -serial mon:stdio \
>>         -device virtio-gpu-pci \
>>         -device qemu-xhci \
>>         -device usb-kbd \
>>         -drive
>> if=pflash,format=raw,unit=0,file=RISCV_VIRT_CODE.fd,readonly=on \
>>         -drive if=pflash,format=raw,unit=1,file=RISCV_VIRT_VARS.fd \
>>         -drive file=sct.img,format=raw,if=virtio \
>>         -device virtio-net-device,netdev=net0 \
>>         -netdev user,id=net0
>>
>> This does not invoke any CXL related stuff.
> 
> Hmm, that doesn't seem like it ought to be running into this.
> What underlying memory region is the guest trying to do
> the virtio queue access to?
> 
> -- PMM

The error occurs while the SCT is executing function 
BBTestReadBlocksConformanceAutoTest 
(https://github.com/tianocore/edk2-test/blob/cabb98d44be94e7547605435a0be7c4946d10f8b/uefi-sct/SctPkg/TestCase/UEFI/EFI/Protocol/BlockIo/BlackBoxTest/BlockIoBBTestConformance.c#L45)

This code is accessing the drive defined as
-drive file=sct.img,format=raw,if=virtio .

In the conformance test correct error handling for invalid parameters of 
the UEFI block IO protocol is tested. This includes calling the UEFI API to

* read with incorrectly aligned buffers
* read with invalid LBA parameter
* read with buffer size not being a multiple of the sector size

In all these cases the UEFI API implemented by EDK II is expected to 
return an error.

Best regards

Heinrich