Re: Unexpected error in rme_configure_one() at ../target/arm/kvm-rme.c:159

[Itaru Kitayama <itaru.kitayama@linux.dev>]

Hi Jean,

> On May 31, 2024, at 19:21, Jean-Philippe Brucker <jean-philippe@linaro.org> wrote:
> 
> Hi Itaru,
> 
> On Fri, May 31, 2024 at 10:57:13AM +0100, Peter Maydell wrote:
>> On Fri, 31 May 2024 at 05:20, Itaru Kitayama <itaru.kitayama@linux.dev> wrote:
>>> 
>>> 
>>> 
>>>> On May 30, 2024, at 22:30, Philippe Mathieu-Daudé <philmd@linaro.org> wrote:
>>>> 
>>>> Cc'ing more developers
>>>> 
>>>> On 30/5/24 06:30, Itaru Kitayama wrote:
>>>>> Hi,
>>>>> When I see a Realm VM creation fails with:
>>>>> Unexpected error in rme_configure_one() at ../target/arm/kvm-rme.c:159:
>>>>> qemu-system-aarch64: RME: failed to configure SVE: Invalid argument
>>>>> test.sh: line 8:  2502 Aborted                 qemu-system-aarch64 -M 'virt,acpi=off,gic-version=3' -cpu host -enable-kvm -smp 2 -m 512M -overcommit 'mem-lock=on' -M 'confidential-guest-support=rme0' -object 'rme-guest,id=rme0,measurement-algo=sha512,num-pmu-counters=6,sve-vector-length=256' -kernel Image -initrd rootfs.cpio -append 'earycon console=ttyAMA0 rdinit=/sbin/init' -nographic -net none
>>>>> do I need to suspect first the VMM, QEMU, or the Image? The kernel is built with LLVM, does it matter?
>>>>> Thanks,
>>>>> Itaru.
>>>> 
>>> 
>>> I’m testing Jean’s repo at:
>>> 
>>> https://git.codelinaro.org/linaro/dcap/qemu/-/tree/cca/v2?ref_type=heads
> 
> Thanks again for testing, you can report issues by replying directly to
> my posting, so I can get to them quicker. If you want I can Cc you on the
> next one. The latest is:
> 
> [PATCH v2 00/22] arm: Run CCA VMs with KVM
> https://lore.kernel.org/qemu-devel/20240419155709.318866-2-jean-philippe@linaro.org/

Thanks! I wasn’t aware of it The good news is that after whole day of try and error attempts I was able to
bring up a Realm VM on FVP. Here’s my version of overlay yaml, cca-v2.yaml:

build:
  linux:
    repo:
      revision: cca-full/v2

#  kvmtool:
#    repo:
#      revision: cca/v2

  rmm:
    repo:
      revision: main



  tfa:
    repo:
      revision: master

  kvm-unit-tests:
    repo:
      revision: cca/v2

… and the QEMU options are below:

qemu-system-aarch64 -M 'virt,acpi=off,gic-version=3' \
-cpu host -enable-kvm -smp 2 -m 512M -overcommit 'mem-lock=on' \
-M 'confidential-guest-support=rme0' \
-object 'rme-guest,id=rme0,measurement-algo=sha512,num-pmu-counters=6,sve-vector-length=256' \
-kernel Image -initrd rootfs.cpio \
-append 'earycon console=ttyAMA0 rdinit=/sbin/init' -nographic -net none

Thanks,
Itaru.

> 
> That does sound like the KVM host doesn't support SVE, but the QEMU VMM
> version is also too old: in the latest series 'sve-vector-length' was
> removed and we use the existing -cpu parameters to configure SVE. Please
> make sure that the QEMU branch is cca/v2 to match the Linux KVM branch,
> because the older QEMU patches doesn't work with the newest KVM patches.
> You'll need to update the command-line as well, because paramaters have
> changed for cca/v2.
> 
> This may be the case of older build directories that aren't properly
> synchronized. They can be removed manually but the quicker way is usually
> to remove all source and build directories and start anew.
> 
> Thanks,
> Jean
> 
> 
>> 
>> OK, we should cc Jean-Philippe then.
>> 
>> I'm wondering if this is as simple as "RME via KVM doesn't support SVE yet",
>> perhaps.
>> 
>> thanks
>> -- PMM