Re: [RESEND RFC PATCH v2 1/2] target/arm: Allow to inject SError interrupt

[Gavin Shan <gshan@redhat.com>]

On 2/13/20 4:39 PM, Richard Henderson wrote:
> On 2/12/20 7:49 PM, Gavin Shan wrote:
>> On 2/12/20 10:34 PM, Peter Maydell wrote:
>>> Yeah, this is on my list to look at; Richard Henderson also could
>>> have a look at it. From a quick scan I suspect you may be missing
>>> handling for AArch32.
>>>
>>
>> [Thanks for copying Richard Henderson]
>>
>> Yes, the functionality is only supported on aarch64 currently by intention
>> because the next patch enables it on "max" and "host" CPU models and both
>> of them are running in aarch64 mode.
> 
> We shouldn't leave the aarch32 exception entry paths unimplemented though.  C.f.
> 
> AArch32.TakePhysicalSErrorException()
> AArch32.TakeVirtualSErrorException()
> 
> It really shouldn't be more than a couple of lines, just like
> arm_cpu_do_interrupt_aarch64.  Remember both arm_cpu_do_interrupt_aarch32 and
> arm_cpu_do_interrupt_aarch32_hyp.
> 

Thanks for the details. The SError injection for aarch32 will be included in v3.

>> However, it seems there is a long list of aarch32 CPU models, defined
>> in target/arm/cpu.c::arm_cpus. so which CPU models you prefer to see with
>> this supported? I think we might choose one or two popular CPU models if
>> you agree.
> 
> Even qemu-system-aarch64 -cpu max can exercise this path when EL1 is running in
> aarch32 mode.  Admittedly it would be easier if we had the rest of the plumbing
> so that -cpu max,aarch64=off worked.
> 
> FWIW, the rest of the patch looks good.
> 

I think "-cpu max,aarch64=off" is only valid when KVM is enabled? If that's true,
the ioctl(cpu, KVM_SET_VCPU_EVENTS, &events) already worked for aarch32 or aarch64
guest if I'm correct enough. But yes, I need to test it because I never tested this
series on aarch32 guest :)

Thanks,
Gavin