Re: [Qemu-devel] 答复: [PATCH RESEND v15 10/10] target-arm: kvm64: handle SIGBUS signal from kernel or KVM

[Peter Maydell <peter.maydell@linaro.org>]

On 22 November 2018 at 10:28, Peter Maydell <peter.maydell@linaro.org> wrote:
> On 22 November 2018 at 03:05, gengdongjiu <gengdongjiu@huawei.com> wrote:
>>> >
>>> Shouldn't there be something in here to say "only report this error to the guest if we are actually reporting RAS errors to the guest" ?
>>
>> Yes, We can say something that such as "report this error to the guest", because this error is indeed triggered by guest, which is guest error.
>
> I'm afraid I don't really understand what you mean. Could you
> try rephrasing it?
>
> My understanding was:
>  * we get this signal if there is a RAS error in the host memory
>  * if we are exposing RAS errors to the guest (ie we have
>    told it that in the ACPI table we passed it at startup)
>    then we should pass on this error to the guest
>
> but that these are two different conditions.
>
> If the host hardware detects a RAS error in memory used
> by the guest but the guest is not being told about RAS
> errors, then we cannot report the error: we have no mechanism
> to do so, and the guest is not expecting it.

If you look at the x86 version of this function you can see that
it tests (env->mcg_cap & MCG_SER_P), which I think is the
equivalent x86 "is the guest CPU/config one we can report
these errors to" test.

thanks
-- PMM