Re: [PATCH v7 0/7] Add support for FEAT_{LS64, LS64_V} and related tests

["Arnd Bergmann" <arnd@arndb.de>]

On Fri, Nov 7, 2025, at 08:21, Zhou Wang wrote:
> Armv8.7 introduces single-copy atomic 64-byte loads and stores
> instructions and its variants named under FEAT_{LS64, LS64_V}.
> Add support for Armv8.7 FEAT_{LS64, LS64_V}:
> - Add identifying and enabling in the cpufeature list
> - Expose the support of these features to userspace through HWCAP3 and cpuinfo
> - Add related hwcap test
> - Handle the trap of unsupported memory (normal/uncacheable) access in a VM
>
> A real scenario for this feature is that the userspace driver can make use of
> this to implement direct WQE (workqueue entry) - a mechanism to fill WQE
> directly into the hardware.
>
> Picked Marc's 2 patches form [1] for handling the LS64 trap in a VM on emulated
> MMIO and the introduce of KVM_EXIT_ARM_LDST64B.

This all looks good to me now, no further comments from my side,
and I hope we can get this into the next kernel.

Thanks a lot for taking care of this!

Acked-by: Arnd Bergmann <arnd@arndb.de>