Re: [PATCH v2 0/4] KVM: arm64: Fix underallocation of storage for SVE state

Catalin Marinas
2024-07-04T14:20:59Z

On Thu, Jun 06, 2024 at 04:21:42PM +0100, Mark Brown wrote:
> As observed during review the pKVM support for saving host SVE state is
> broken if an asymmetric system has VLs larger than the maximum shared
> VL, fix this by discovering then using the maximum VL for allocations
> and using RDVL during the save/restore process.
>
> Signed-off-by: Mark Brown <broonie@kernel.org>
> ---
> Changes in v2:
> - Downgrade check for a late CPU increasing maximum VL to a warning only
> but do it unconditionally since pKVM prevents late CPUs anyway.
> - Commit log tweaks.
> - Link to v1: https://lore.kernel.org/r/20240605-kvm-arm64-fix-pkvm-sve-vl-v1-0-680d6b43b4c1@kernel.org
>
> ---
> Mark Brown (4):
> arm64/fpsimd: Introduce __bit_to_vl() helper
> arm64/fpsimd: Discover maximum vector length implemented by any CPU
> KVM: arm64: Fix FFR offset calculation for pKVM host state save and restore
> KVM: arm64: Avoid underallocating storage for host SVE state

Since the patches address a KVM issue, I think it should go via
Oliver/Marc's tree. But happy to queue it via the arm64 tree if people
think otherwise.

Thanks.

--
Catalin