Re: [RFC PATCH V2] kvm: arm64: export memory error recovery capability to user space

[gengdongjiu]

On 2019/5/13 17:44, Peter Maydell wrote:
> On Mon, 13 May 2019 at 07:32, Dongjiu Geng <gengdongjiu@xxxxxxxxxx> wrote:
>>
>> When user space do memory recovery, it will check whether KVM and
>> guest support the error recovery, only when both of them support,
>> user space will do the error recovery. This patch exports this
>> capability of KVM to user space.
>>
>> Cc: Peter Maydell <peter.maydell@xxxxxxxxxx>
>> Signed-off-by: Dongjiu Geng <gengdongjiu@xxxxxxxxxx>
>> ---
>> v1->v2:
>> 1. check whether host support memory failure instead of RAS capability
>>    https://patchwork.kernel.org/patch/10730827/
>>
>> v1:
>> 1. User space needs to check this capability of host is suggested by Peter[1],
>> this patch as RFC tag because user space patches are still under review,
>> so this kernel patch is firstly sent out for review.
>>
>> [1]: https://patchwork.codeaurora.org/patch/652261/
>> ---
> 
> I thought the conclusion of the thread on the v1 patch was that
> userspace doesn't need to specifically ask the host kernel if
> it has support for this -- if it does not, then the host kernel
> will just never deliver userspace any SIGBUS with MCEERR code,
> which is fine. Or am I still confused?

thanks Peter's quick reply.
yes, I think so, if it does not support,  then the host kernel
will just never deliver userspace any SIGBUS with MCEERR code.

so maybe we do not need this patch.

> 
> thanks
> -- PMM
> .
>