Re: [PATCH v3 0/7] Fix setting SVE and SME traps in (h)VHE

[Marc Zyngier <maz@kernel.org>]

On Mon, 24 Jul 2023 13:38:21 +0100,
Fuad Tabba <tabba@google.com> wrote:
> 
> Hi,
> 
> Changes from V2:
> - Rebased onto Linux 6.5-rc3
> - s/__check_e2h/__check_hvhe/g (Oliver)
> - Fixed bug in calculating CPACR_EL1 reset value for hVHE in
> trapping SVE
> 
> Changes from V1:
> - Expanded the cover letter to clarify the reasoning behind being
> consistent in writing to the architectural trap register based on
> the KVM mode (Marc)
> - Factored out the code for checking E2H into a macro (Oliver)
> - Factored out the code that selects which register to write to
> into a function (Oliver)
> 
> The (re)setting and disabling of SVE/SME trap handling (mostly)
> done for the hVHE work [*] misses a couple of cases.
> 
> This patch series ensures that these traps are disabled on setup
> and reset. Moreover, it makes the code consistent in using
> CPACR_EL1 or CPTR_EL2, depending on the mode.
> 
> CPACR_EL1 aliases to CPTR_EL2 when HCR_EL2.E2H == 1, but by being
> consistent we don't need to issue a synchronisation when
> alternating between one or the other accessor. Moreover, when
> running hVHE under NV, we don't trap unnecessarily on accessing
> CPTR_EL2, while CPACR_EL1 can be used directly without any trap.
> 
> Based on Linux 6.5-rc3.

Reviewed-by: Marc Zyngier <maz@kernel.org>

	M.

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