"Denis V. Lunev" <den@xxxxxxxxxxxxx> writes: > On 11/10/2015 06:55 PM, Dmitry Andreev wrote: >> Paolo, Jiri, can I do something more for this patch to be accepted? >> >> On 05.11.2015 17:32, Paolo Bonzini wrote: >>> >>> On 05/11/2015 14:54, Dmitry Andreev wrote: >>>>>> Add crash CPU feature for Hyper-V. Hyper-V crash MSR's can be used >>>>>> by Hyper-V based guests to notify about occurred guest crash. >>>>>> >>>>>> XML: >>>>>> <features> >>>>>> <hyperv> >>>>>> <crash state='on'/> >>>>>> </hyperv> >>>>>> </features> >>>>> Sounds like this is related to an existing panic device we already >>>>> support. So what does enabling hv_crash do in QEMU? Is it an >>>>> additional >>>>> channel to a panic device or is the panic device still needed even if >>>>> hv_crash is enabled? In any case, I think we should map this >>>>> somehow to >>>>> the panic device instead of copying 1:1 the way QEMU enables hv_crash. >>>> pvpanic and Hyper-V crash are independent ways for guest to notify >>>> about >>>> OS crash. Both ways rise the 'qemu guest panicked' event. Domain can >>>> have both hv_crash and pvpanic enabled at the same time. >>>> >>>> pvpanic is in <devices> section in domain configuration because it >>>> is an >>>> ISA device. Hyper-V crash is a hypervisor's feature, which enables >>>> a set >>>> of model-specific registers. Guest can use this registers to send >>>> notification and store additional information about a crash. This is a >>>> part of Microsoft hypervisor interface. >>>> >>>> That's why I think hv_crash should be in <features> section. >>> I agree. >>> >>> Paolo >> > Please. > > This feature is very interesting for us for guest debugging > especially during guest installation where specific drivers > are not available or not ready or not that easy to supply. +1 while I think it would make more sense to propagate crash information (HV_X64_MSR_CRASH_P0..P4 MSR) all the way up to libvirt (and even further to libvirt users) instead of just triggering 'guest panic', enabling the feature for Windows guests looks like a good starting point. -- Vitaly -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list