On 29.06.2017 16:57, Christian Borntraeger wrote: > On 06/28/2017 09:16 PM, Christian Borntraeger wrote: >> On 06/28/2017 09:08 PM, David Hildenbrand wrote: >>> On 28.06.2017 20:59, Christian Borntraeger wrote: >>>> On 06/28/2017 08:06 PM, David Hildenbrand wrote: >>>>> On 28.06.2017 19:30, Christian Borntraeger wrote: >>>>>> From: QingFeng Hao <haoqf@xxxxxxxxxxxxxxxxxx> >>>>>> >>>>>> With vsie feature enabled, kvm can support nested guests (guest-3). >>>>>> So inject machine check to the guest-2 if it happens when the nested >>>>>> guest is running. And guest-2 will detect the machine check belongs >>>>>> to guest-3 and reinject it into guest-3. >>>>>> The host (guest-1) tries to inject the machine check to the picked >>>>>> destination vcpu if it's a floating machine check. >>>>> >>>>> The subject is confusing. We don't inject anything into the nested guest >>>>> here. We just catch machine checks during vsie and inject it into the >>>>> ordinary kvm guest. >>>> >>>> Agreed, it is confusing and maybe a leftover from an early rework due to internal >>>> feedback. We inject in guest-2 and rely on guest-2 to reinject to guest-3 would >>>> be a better wording. >>>> >>>> >>>> >>>> >>>>> Are there any SIE specific things to consider here, that may have to be >>>>> translated? >>>> >>>> As HW exits SIE before delivering the machine check, the SIE control block >>>> contains all saved guest3 registers and the host (guest1) registers contain >>>> the lazy registers (as we have already restored them) just like a normal exit. >>> >>> As mentioned in the other mail, e.g. vector register validity should >>> only be set if vector registers are enabled for the nested guest >>> (execution control enabled). >> >> Yes, but sInce we inject in the base guest (non-nested) we have to check the base guest >> execution control. > > While we drag the vector validity along, it looks like __write_machine_check is already > doing the right thing for vector and guarded storage before writing the mcic to the > guest, no? (sorry for the delay, I'm currently visiting a rural part of Slovakia) Yes, perfect. So the only thing that could actually happen is an under indication, which can be easily added later. Thanks! -- Thanks, David
