On 06/18/2015 10:27 AM, Marc Zyngier wrote:
> 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 <m.smarduch@xxxxxxxxxxx>
>> ---
>> 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.
Ah I see, I'll update.
>
> Not very consistent, I know...
>
>> load_vcpu @ Load VCPU pointer to r0
How about move it here - then it does not stick out like
before.
guest_trap:
load_vcpu @ Load VCPU pointer to r0
str r1, [vcpu, #VCPU_HSR]
@ Check if we need the fault information
lsr r1, r1, #HSR_EC_SHIFT
#ifdef CONFIG_VFPv3
/* Guest accessed VFP/SIMD registers, save host, restore Guest */
cmp r1, #HSR_EC_CP_0_13
beq switch_to_guest_vfp
#endif
Regarding "host_switch_to_hyp:" it has no reference but appears
like a clean separator, that's on purpose?
Thanks
>
> 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.
>
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