linux-kernel - Re: [PATCH v9 06/30] KVM: arm64: Pay attention to FFR parameter in SVE save and load

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CA+EHjTznG=6+bYW+mmmBs_QqZ2rXkKTzNxA5KSh3S67H_BBaHg@mail.gmail.com>
Date: Thu, 8 Jan 2026 14:09:41 +0000
From: Fuad Tabba <tabba@...gle.com>
To: Mark Brown <broonie@...nel.org>
Cc: Marc Zyngier <maz@...nel.org>, Joey Gouly <joey.gouly@....com>, 
	Catalin Marinas <catalin.marinas@....com>, Suzuki K Poulose <suzuki.poulose@....com>, 
	Will Deacon <will@...nel.org>, Paolo Bonzini <pbonzini@...hat.com>, Jonathan Corbet <corbet@....net>, 
	Shuah Khan <shuah@...nel.org>, Oliver Upton <oupton@...nel.org>, Dave Martin <Dave.Martin@....com>, 
	Mark Rutland <mark.rutland@....com>, Ben Horgan <ben.horgan@....com>, 
	linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev, 
	linux-kernel@...r.kernel.org, kvm@...r.kernel.org, linux-doc@...r.kernel.org, 
	linux-kselftest@...r.kernel.org, Peter Maydell <peter.maydell@...aro.org>, 
	Eric Auger <eric.auger@...hat.com>
Subject: Re: [PATCH v9 06/30] KVM: arm64: Pay attention to FFR parameter in
 SVE save and load

On Tue, 23 Dec 2025 at 01:22, Mark Brown <broonie@...nel.org> wrote:
>
> The hypervisor copies of the SVE save and load functions are prototyped
> with third arguments specifying FFR should be accessed but the assembly
> functions overwrite whatever is supplied to unconditionally access FFR.
> Remove this and use the supplied parameter.
>
> This has no effect currently since FFR is always present for SVE but will
> be important for SME.
>
> Signed-off-by: Mark Brown <broonie@...nel.org>

Reviewed-by: Fuad Tabba <tabba@...gle.com>

Cheers,
/fuad


> ---
>  arch/arm64/kvm/hyp/fpsimd.S | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/fpsimd.S b/arch/arm64/kvm/hyp/fpsimd.S
> index e950875e31ce..6e16cbfc5df2 100644
> --- a/arch/arm64/kvm/hyp/fpsimd.S
> +++ b/arch/arm64/kvm/hyp/fpsimd.S
> @@ -21,13 +21,11 @@ SYM_FUNC_START(__fpsimd_restore_state)
>  SYM_FUNC_END(__fpsimd_restore_state)
>
>  SYM_FUNC_START(__sve_restore_state)
> -       mov     x2, #1
>         sve_load 0, x1, x2, 3
>         ret
>  SYM_FUNC_END(__sve_restore_state)
>
>  SYM_FUNC_START(__sve_save_state)
> -       mov     x2, #1
>         sve_save 0, x1, x2, 3
>         ret
>  SYM_FUNC_END(__sve_save_state)
>
> --
> 2.47.3
>