Re: [PATCH v3 2/4] s390x: Add missing vcpu reset functions

[David Hildenbrand]

On 04.12.19 16:07, David Hildenbrand wrote:
> On 04.12.19 15:59, Cornelia Huck wrote:
>> On Tue,  3 Dec 2019 08:28:11 -0500
>> Janosch Frank <address@hidden> wrote:
>>
>>> Up to now we only had an ioctl to reset vcpu data QEMU couldn't reach
>>> for the initial reset, and that was also called for the clear
>>> reset. To be architecture compliant, we also need to clear local
>>> interrupts on a normal reset.
>>
>> Do we also need to do something like that for tcg? David?
>>
> 
> So, we have
> 
> /* Fields up to this point are not cleared by initial CPU reset */
> struct {} start_initial_reset_fields;
> [...]
> int pending_int
> uint16_t external_call_addr;
> DECLARE_BITMAP(emergency_signals, S390_MAX_CPUS);
> [...]
> /* Fields up to this point are cleared by a CPU reset */
> struct {} end_reset_fields;
> 
> This means, local interrupts will be cleared by everything that zeroes
> "start_initial_reset_fields->end_reset_fields"
> 
> So, they will get cleared by S390_CPU_RESET_INITIAL only if I am not
> wrong. In order to clear them on S390_CPU_RESET_NORMAL, we have to
> manually set them to zero.

Sorry, by S390_CPU_RESET_INITIAL and S390_CPU_RESET_CLEAR.

> 
> (we really should wrap TCG-only fields by ifdefs)
> 


-- 
Thanks,

David / dhildenb