Re: [PATCH v2 1/4] gdb/aarch64: record/replay support for LRCPC3

[Thiago Jung Bauermann <thiago.bauermann@linaro.org>]

Ezra Sitorus <ezra.sitorus@arm.com> writes:

> On Fri, May 15, 2026 at 12:50:30AM -0300, Thiago Jung Bauermann wrote:
>
>> By the way, is there something specific I need to do to get an FVP
>> supporting LRCPC3? I set up FVP with:
>> 
>> $ shrinkwrap build --overlay=arch/v9.6.yaml ns-edk2.yaml
>> 
> You need to enable the feature in an overlay file. So I have something like this:
>
> run:
>   rtvars:
>     ROOTFS:
>       value: /path/to/rootfs
>     CMDLINE:
>       value: loglevel=3 ip=dhcp kpti=off root=/dev/vda2 console=ttyAMA0
>     KERNEL:
>       value: path/to/Image
>   params:
>     -C bp.hostbridge.userNetworking: 1
>     -C bp.hostbridge.userNetPorts: 8022=22,8123=8123
>     -C bp.smsc_91c111.enabled: 1
>     -C bp.virtio_net.enabled: 0
>     -C cluster0.NUM_CORES: 1
>     -C cluster0.has_lrcpc3: 1
>     -C cluster0.has_rprfm: 1
>     -C pctl.CPU-affinities: 0.0.0.0
>
> which enables LRCPC3, RPRFM and some networking. Then I run like so:
> $ shrinkwrap run ns-edk2.yaml --overlay file.yaml.

Thanks! That worked but I had to make some adjustments:

1. Remove the pctl.CPU-affinities parameter. It was causing FVP to get
   really slow after the edk2 UEFI firmware loads.
2. Add the same cluster0 settings to cluster1, otherwise lrcpc3 and
   rprfm didn't actually get enabled. I think the CPU-affinities
   parameter was meant to disable cluster1, but for some reason it
   didn't work here.

> Also, you can do:
> $ shrinkwrap build --overlay=arch/v8.9.yaml ns-edk2.yaml 
>
> which should enable fewer features so it'll run slightly quicker.

Thanks, that's useful. Slightly quicker already helps.

> On another note, it seems like patch 2 and 3 are OK? Can these be pushed while
> I resend this one and wait for Guinevere for patch 4? 

Yes for patch 3, but regarding patches 1, 2 and 4 I'd like to see if
she's happy with how you addressed her suggestions.

-- 
Thiago