lkml.org 
[lkml]   [2016]   [Feb]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v2 16/21] arm64: KVM: VHE: Add fpsimd enabling on guest access
On Mon, Jan 25, 2016 at 03:53:50PM +0000, Marc Zyngier wrote:
> Despite the fact that a VHE enabled kernel runs at EL2, it uses
> CPACR_EL1 to trap FPSIMD access. Add the required alternative
> code to re-enable guest FPSIMD access when it has trapped to
> EL2.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
> ---
> arch/arm64/kvm/hyp/entry.S | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
> index fd0fbe9..759a0ec 100644
> --- a/arch/arm64/kvm/hyp/entry.S
> +++ b/arch/arm64/kvm/hyp/entry.S
> @@ -130,9 +130,15 @@ ENDPROC(__guest_exit)
> ENTRY(__fpsimd_guest_restore)
> stp x4, lr, [sp, #-16]!
>
> +alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
> mrs x2, cptr_el2
> bic x2, x2, #CPTR_EL2_TFP
> msr cptr_el2, x2
> +alternative_else
> + mrs x2, cpacr_el1
> + orr x2, x2, #(3 << 20)

nit: bitfield definition again

> + msr cpacr_el1, x2
> +alternative_endif
> isb
>
> mrs x3, tpidr_el2
> --
> 2.1.4
>

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>

\
 
 \ /
  Last update: 2016-02-01 15:41    [W:0.340 / U:1.996 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site