Re: [PATCH v3 2/2] arm: KVM: keep arm vfp/simd exit handling consistent with arm64

[Christoffer Dall <christoffer.dall@linaro.org>]

On Wed, Jun 24, 2015 at 05:04:12PM -0700, Mario Smarduch wrote:
> After enhancing arm64 FP/SIMD exit handling, ARMv7 VFP exit branch is moved
> to guest trap handling. This allows us to keep exit handling flow between both
> architectures consistent.
> 
> Signed-off-by: Mario Smarduch <m.smarduch@samsung.com>
> ---
>  arch/arm/kvm/interrupts.S |   14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
> index 79caf79..b245b4e 100644
> --- a/arch/arm/kvm/interrupts.S
> +++ b/arch/arm/kvm/interrupts.S
> @@ -363,10 +363,6 @@ hyp_hvc:
>  	@ Check syndrome register
>  	mrc	p15, 4, r1, c5, c2, 0	@ HSR
>  	lsr	r0, r1, #HSR_EC_SHIFT
> -#ifdef CONFIG_VFPv3
> -	cmp	r0, #HSR_EC_CP_0_13
> -	beq	switch_to_guest_vfp
> -#endif
>  	cmp	r0, #HSR_EC_HVC
>  	bne	guest_trap		@ Not HVC instr.
>  
> @@ -380,7 +376,10 @@ hyp_hvc:
>  	cmp     r2, #0
>  	bne	guest_trap		@ Guest called HVC
>  
> -host_switch_to_hyp:
> +	/*
> +	 * Getting here means host called HVC, we shift parameters and branch
> +	 * to Hyp function.
> +	 */
>  	pop	{r0, r1, r2}
>  
>  	/* Check for __hyp_get_vectors */
> @@ -411,6 +410,10 @@ guest_trap:
>  
>  	@ Check if we need the fault information
>  	lsr	r1, r1, #HSR_EC_SHIFT
> +#ifdef CONFIG_VFPv3
> +	cmp	r1, #HSR_EC_CP_0_13
> +	beq	switch_to_guest_vfp
> +#endif
>  	cmp	r1, #HSR_EC_IABT
>  	mrceq	p15, 4, r2, c6, c0, 2	@ HIFAR
>  	beq	2f
> @@ -479,7 +482,6 @@ guest_trap:
>   */
>  #ifdef CONFIG_VFPv3
>  switch_to_guest_vfp:
> -	load_vcpu			@ Load VCPU pointer to r0
>  	push	{r3-r7}
>  
>  	@ NEON/VFP used.  Turn on VFP access.
> -- 
> 1.7.9.5
> 

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