Re: [PATCH v2 1/1] migration: skip poisoned memory pages on "ram saving" phase

[William Roche <william.roche@oracle.com>]

Thank you Zhijian for your feedback.

So I'll try to push this change today.

Cheers,
William.


On 9/20/23 12:04, Zhijian Li (Fujitsu) wrote:
> 
> 
> On 15/09/2023 19:31, William Roche wrote:
>> On 9/15/23 05:13, Zhijian Li (Fujitsu) wrote:
>>>
>>>
>>> I'm okay with "RDMA isn't touched".
>>> BTW, could you share your reproducing program/hacking to poison the page, so that
>>> i am able to take a look the RDMA part later when i'm free.
>>>
>>> Not sure it's suitable to acknowledge a not touched part. Anyway
>>> Acked-by: Li Zhijian <lizhijian@fujitsu.com> # RDMA
>>>
>>
>> Thanks.
>> As you asked for a procedure to inject memory errors into a running VM,
>> I've attached to this email the source code (mce_process_react.c) of a
>> program that will help to target the error injection in the VM.
> 
> 
> I just tried you hwpoison program and do RDMA migration. Migration failed, but fortunately
> the source side is still alive :).
> 
> (qemu) Failed to register chunk!: Bad address
> Chunk details: block: 0 chunk index 671 start 139955096518656 end 139955097567232 host 139955096518656 local 139954392924160 registrations: 636
> qemu-system-x86_64: cannot get lkey
> qemu-system-x86_64: rdma migration: write error! -22
> qemu-system-x86_64: RDMA is in an error state waiting migration to abort!
> qemu-system-x86_64: failed to save SaveStateEntry with id(name): 2(ram): -22
> qemu-system-x86_64: Early error. Sending error.
> 
> 
> Since current RDMA migration transfers guest memory in a chunk size(1M) by default, we may need to
> 
> option 1: reduce all chunk size to 1 page
> option 2: handle the hwpoison chunk specially
> 
> However, because there may be a chance to use another protocol, it's also possible to temporarily not fix the issue.
> 
> Tested-by: Li Zhijian <lizhijian@fujitsu.com>
> 
> Thanks
> Zhijian