Re: [Xen-devel] [PATCH v2 07/19] xen/arm: Introduce a virtual abort injection helper

[Wei Chen <Wei.Chen@xxxxxxx>]

On 2017/3/31 1:20, Julien Grall wrote:
> Hi Wei,
>
> On 30/03/17 10:13, Wei Chen wrote:
>> When guest triggers async aborts, in most platform, such aborts
>> will be routed to hypervisor. But we don't want the hypervisor
>> to handle such aborts, so we have to route such aborts back to
>> the guest.
>>
>> This helper is using the HCR_EL2.VSE (HCR.VA for aarch32) bit to
>> route such aborts back to the guest. If the guest PC had been
>> advanced by SVC/HVC/SMC instructions before we caught the SError
>> in hypervisor, we have to adjust the guest PC to exact address
>> while the SError generated.
>>
>> About HSR_EC_SVC32/64, even thought we don't trap SVC32/64 today,
>> we would like them to be handled here. This would be useful when
>> VM introspection will gain support of SVC32/64 trapping.
>>
>> This helper will be used by the later patches in this series, we
>> use #if 0 to disable it in this patch temporarily to remove the
>> warning message of unused function from compiler.
>>
>> Signed-off-by: Wei Chen <Wei.Chen@xxxxxxx>
>> Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
>> ---
>> v1->v2:
>> 1. After updating HCR_EL2.VSE bit of vCPU HCR_EL2, write the value
>>    to HCR_EL2 immediately. In this case we don't need to move the
>>    restoration of HCR_EL2 to leave_hypervisor_tail, and it worked
>>    regardless of whether we get preempted.
>
> This should have been explained in the commit message and ...

Ok.

>
>> 2. Add Stefano's Acked-by.
>
> I would not keep Acked-by/Reviewed-by with a change like above. Or at
> least, I would ask whether they are fine with this change.

Thanks, I understand now.

>
> Cheers,
>


-- 
Regards,
Wei Chen

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