Re: [RFC 00/12] arm64: Add support for TLBI domains

[Marc Zyngier <maz@kernel.org>]

On Mon, 19 Oct 2026 09:52:04 +0100,
Jinqian Yang <yangjinqian1@huawei.com> wrote:
> 
> Hi,
> 
> On 2026/10/1 19:06, Kristina Martšenko wrote:
> > Hi,
> > 
> > This series allows the kernel to use TLBI domains. TLBI domains (FEAT_TLBID) is
> > an Arm architecture feature that enables a TLB invalidation to target a subset
> > of CPUs instead of the whole system. It can improve performance on systems with
> > many CPUs. TLBID is not yet part of the Arm Architecture Reference Manual but
> > some of it is described in the latest XML [1].
> > 
> > The goal of this series is to send TLBI commands only to the CPUs where a
> > process has run (i.e. where its page tables have been installed). The last
> > patch explains a bit about how it works. This is an RFC since I'm not familiar
> > with the kernel's TLB/mm code and I'd like feedback on whether the general
> > approach is correct.
> > 
> 
> Thanks for posting this series.
> 
> I'm working on the KVM side of TLBID, and have a series that
> virtualizes TLBI domains for guests. It includes:
> 
>  - per-vCPU vDomain configuration via a new capability and
>    two ioctls
>  - VTLBID_EL2 programming at vCPU load/put, mapping vDomains
>    to physical domains
>  - a guest visible TLBIDIDR_EL1 with virtual domain counts,
>    and conditional exposure of ID_AA64MMFR4_EL1.TLBID
> 
> You mentioned you planned to look at KVM support in your next
> version. Would it be OK for us to post this as an RFC on top
> of your series? :)

It is always OK to post patches, but don't expect much reviewing to
take place until things have settled on the host side of things.

Thanks,

	M.

-- 
Without deviation from the norm, progress is not possible.