Re: [PATCH v2 3/5] KVM: arm64: Add context-switch of ACCDATA_EL1

[Catalin Marinas]

On Sun, Oct 25, 2026 at 07:51:36AM +0000, Fuad Tabba wrote:
> From: Marc Zyngier <maz@xxxxxxxxxx>
> 
> Add ACCDATA_EL1 save/restore as part of the EL0 context. This is
> conditioned on the guest's view of ID_AA64ISAR1_EL1.LS64 reporting
> that this register is supported.
> 
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> Fixes: 58ce78667a641 ("arm64: Add support for FEAT_{LS64, LS64_V}")
> Link: https://lore.kernel.org/r/20240815125959.2097734-5-maz@xxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx
> [Fuad: rebased; switch ACCDATA_EL1 for guests only, as the host never
>  uses it; gate it on a new ARM64_HAS_LS64_ACCDATA capability, since
>  in pKVM the host controls a non-protected guest's ID registers, and
>  an EL2 access to ACCDATA_EL1 on a CPU without the feature is UNDEFINED]
> Signed-off-by: Fuad Tabba <fuad.tabba@xxxxxxxxx>

Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>