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

[David Hildenbrand]

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.

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

-- 
Thanks,

David / dhildenb