Greg Kurz's on March 17, 2020 9:02 pm:
> On Tue, 17 Mar 2020 15:02:11 +1000
> Nicholas Piggin <npig...@gmail.com> wrote:
>
>> The KVM FWNMI capability should be enabled with the "ibm,nmi-register"
>> rtas call. Although MCEs from KVM will be delivered as architected
>> interrupts to the guest before "ibm,nmi-register" is called, KVM has
>> different behaviour depending on whether the guest has enabled FWNMI
>> (it attempts to do more recovery on behalf of a non-FWNMI guest).
>>
>> Signed-off-by: Nicholas Piggin <npig...@gmail.com>
>> ---
>> hw/ppc/spapr_caps.c | 5 +++--
>> hw/ppc/spapr_rtas.c | 7 +++++++
>> target/ppc/kvm.c | 7 +++++++
>> target/ppc/kvm_ppc.h | 6 ++++++
>> 4 files changed, 23 insertions(+), 2 deletions(-)
>>
>> diff --git a/hw/ppc/spapr_caps.c b/hw/ppc/spapr_caps.c
>> index 679ae7959f..eb5521d0c2 100644
>> --- a/hw/ppc/spapr_caps.c
>> +++ b/hw/ppc/spapr_caps.c
>> @@ -517,9 +517,10 @@ static void cap_fwnmi_apply(SpaprMachineState *spapr,
>> uint8_t val,
>> }
>>
>> if (kvm_enabled()) {
>> - if (kvmppc_set_fwnmi() < 0) {
>> + if (!kvmppc_get_fwnmi()) {
>> error_setg(errp, "Firmware Assisted Non-Maskable
>> Interrupts(FWNMI) "
>> - "not supported by KVM");
>> + "not supported by KVM, "
>> + "try appending -machine cap-fwnmi=off");
>
> It is usually preferred to keep error message strings on one
> line for easier grepping. Also hints should be specified with
> error_append_hint() because they are treated differently by
> QMP (ie. not printed).
>
> Something like:
>
> if (!kvmppc_get_fwnmi()) {
> error_setg(errp,
> "Firmware Assisted Non-Maskable Interrupts(FWNMI) not supported by
> KVM");
> error_append_hint(errp, "Try appending -machine cap-fwnmi=off\n");
> }
Hmm, okay.
>
> Note that the current error handling code has an issue that
> prevents hints to be printed when errp == &error_fatal, which
> is exactly what spapr_caps_apply() does. Since this affects
> a lot of locations in the code base, there's an on-going
> effort to fix that globally:
>
> https://patchwork.ozlabs.org/project/qemu-devel/list/?series=163907
>
> I don't know if this will make it for 5.0, but in any case I
> think you should call error_append_hint() in this patch anyway
> and the code will just work at some later point.
>
> Rest looks good.
Thanks will do,
Nick
