Re: [PATCH v6 2/2] s390: diagnose 318 info reset and migration support

[Collin Walling]

On 1/27/20 12:35 PM, Cornelia Huck wrote:
> On Mon, 27 Jan 2020 11:39:02 -0500
> Collin Walling <address@hidden> wrote:
> 
>> On 1/27/20 6:47 AM, Cornelia Huck wrote:
>>> On Fri, 24 Jan 2020 17:14:04 -0500
>>> Collin Walling <address@hidden> wrote:
>>>   
>>>> DIAGNOSE 0x318 (diag318) is a privileged s390x instruction that must
>>>> be intercepted by SIE and handled via KVM. Let's introduce some
>>>> functions to communicate between QEMU and KVM via ioctls. These
>>>> will be used to get/set the diag318 information.  
>>>
>>> Do you want to give a hint what diag 318 actually does?
>>>   
>>
>> For the sake of completeness, I'll have to get back to you on this.
>>

The DIAGNOSE 318 instruction allows the guest to store diagnostic data
that is collected by the firmware in the case of hardware/firmware
service events. The instruction is invoked in the Linux kernel and
intercepted in KVM. QEMU needs to collect this data for migration
so that this data is consistent on the destination host.

Perhaps I should add this to the patch description as well? :)

[...]


-- 
Respectfully,
- Collin Walling