[PATCH v6 0/7] Add support for FEAT_{LS64, LS64_V} and related tests

[Zhou Wang]

On 2025/10/25 0:22, Arnd Bergmann wrote:
> On Fri, Oct 24, 2025, at 11:08, 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.
>>
>> As Yicong has left HiSilicon, I will help to continue to upstream this patchset.
>>
>> [1] 
>> https://lore.kernel.org/linux-arm-kernel/20240815125959.2097734-1-maz@kernel.org/
> 
> The patches all look reasonable to me, but I notice that you forgot
> to add your signoff below Yicong's, so the Arm maintainers won't be
> able to merge the series.>
> If nobody else has any comments on this version, please resend in
> a couple of days with your signoff added to each patch.

I will add my signoff in next version. In fact, comparing with v5, there is little
change, so I did not add my signoff.

Best,
Zhou

> 
>      Arnd
> .