[v1] KVM: arm64: Making BT Field in ID_AA64PFR1_EL1 writable

[PATCH v1 0/2] KVM: arm64: Making BT Field in ID_AA64PFR1_EL1 writable

Posted by Shaoqin Huang 1 year, 6 months ago

In this patch series, we try to make more register fields writable like
ID_AA64PFR1_EL1.BT since this can benifit the migration between some of the
machines which have different BT values.

Changelog:
----------
RFCv1 -> v1:
  * Fix the compilation error.
  * Delete the machine specific information and make the description more
    generable.

RFCv1: https://lore.kernel.org/all/20240612023553.127813-1-shahuang@redhat.com/

Shaoqin Huang (2):
  KVM: arm64: Allow BT field in ID_AA64PFR1_EL1 writable
  KVM: selftests: aarch64: Add writable test for ID_AA64PFR1_EL1

 arch/arm64/kvm/sys_regs.c                         | 2 +-
 tools/testing/selftests/kvm/aarch64/set_id_regs.c | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

-- 
2.40.1

Re: [PATCH v1 0/2] KVM: arm64: Making BT Field in ID_AA64PFR1_EL1 writable

Posted by Oliver Upton 1 year, 6 months ago

On Mon, Jun 17, 2024 at 03:51:29AM -0400, Shaoqin Huang wrote:
> In this patch series, we try to make more register fields writable like
> ID_AA64PFR1_EL1.BT since this can benifit the migration between some of the
> machines which have different BT values.
> 
> Changelog:
> ----------
> RFCv1 -> v1:
>   * Fix the compilation error.
>   * Delete the machine specific information and make the description more
>     generable.

Can you please address Marc's feedback?

If we only make things writable a field at a time it's going to take
forever to catch up w/ the architecture.

https://lore.kernel.org/kvmarm/86zfrpjkt6.wl-maz@kernel.org/

-- 
Thanks,
Oliver

Re: [PATCH v1 0/2] KVM: arm64: Making BT Field in ID_AA64PFR1_EL1 writable

Posted by Shaoqin Huang 1 year, 6 months ago

Hi Oliver,

On 6/18/24 01:40, Oliver Upton wrote:
> On Mon, Jun 17, 2024 at 03:51:29AM -0400, Shaoqin Huang wrote:
>> In this patch series, we try to make more register fields writable like
>> ID_AA64PFR1_EL1.BT since this can benifit the migration between some of the
>> machines which have different BT values.
>>
>> Changelog:
>> ----------
>> RFCv1 -> v1:
>>    * Fix the compilation error.
>>    * Delete the machine specific information and make the description more
>>      generable.
> 
> Can you please address Marc's feedback?
> 
> If we only make things writable a field at a time it's going to take
> forever to catch up w/ the architecture.
> 
> https://lore.kernel.org/kvmarm/86zfrpjkt6.wl-maz@kernel.org/

Ok. I will update the patch series again with tackling the full register.

Thanks,
Shaoqin

> 

-- 
Shaoqin