On 06/28/2017 08:20 PM, David Hildenbrand wrote: > On 28.06.2017 19:30, Christian Borntraeger wrote: >> From: QingFeng Hao <haoqf@xxxxxxxxxxxxxxxxxx> >> >> When a machine check happens in the guest, related mcck info (mcic, >> external damage code, ...) is stored in the vcpu's lowcore on the host. >> Then the machine check handler's low-level part is executed, followed >> by the high-level part. >> >> If the high-level part's execution is interrupted by a new machine check >> happening on the same vcpu on the host, the mcck info in the lowcore is >> overwritten with the new machine check's data. >> >> If the high-level part's execution is scheduled to a different cpu, >> the mcck info in the lowcore is uncertain. >> >> Therefore, for both cases, the further reinjection to the guest will use >> the wrong data. >> Let's backup the mcck info in the lowcore to the sie page >> for further reinjection, so that the right data will be used. >> >> Add new member into struct sie_page to store related machine check's >> info of mcic, failing storage address and external damage code. >> > > > When this happens while the guest is running, there will be some > registers written into the low core save area (gprs, cr etc.) during the > machine check. Are these always host registers? Or can these be guest > registers? Always host registers (the machine will exit SIE before presenting the machine check). > > Also, do the "valid" flags always refer to guest or host bits? The host bits. > > If they can be guest bits, I think we would have to do more translation. > And most likely treat vSIE special. > > Or will something like that always lead to a host crash and real machine > errors will still take the host down, and not the guest? > >
