On 16/06/15 22:50, Mario Smarduch wrote:
> After enhancing arm64 FP/SIMD exit handling, FP/SIMD exit branch is moved
> to guest trap handling. This keeps exiting handling flow between both
> architectures consistent.
>
> Signed-off-by: Mario Smarduch <[email protected]>
> ---
> arch/arm/kvm/interrupts.S | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
> index 79caf79..fca2c56 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.
>
> @@ -406,6 +402,12 @@ THUMB( orr lr, #1)
> 1: eret
>
> guest_trap:
> +#ifdef CONFIG_VFPv3
> + /* Guest accessed VFP/SIMD registers, save host, restore Guest */
> + cmp r0, #HSR_EC_CP_0_13
> + beq switch_to_guest_fpsimd
> +#endif
> +
> load_vcpu @ Load VCPU pointer to r0
> str r1, [vcpu, #VCPU_HSR]
>
> @@ -478,7 +480,7 @@ guest_trap:
> * inject an undefined exception to the guest.
> */
> #ifdef CONFIG_VFPv3
> -switch_to_guest_vfp:
> +switch_to_guest_fpsimd:
Ah, I think I managed to confuse you in my previous comment.
On ARMv7, we call the floating point stuff VFP.
On ARMv8, we call it FP/SIMD.
Not very consistent, I know...
> load_vcpu @ Load VCPU pointer to r0
It would be interesting to find out if we can make this load_vcpu part
of the common sequence (without spilling another register, of course).
Probably involves moving the exception class to r2.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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