Re: [Qemu-devel] E5-2620v2 - emulation stop error

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* Andrey Korolyov (andrey@xdel.ru) wrote:
> On Sat, Mar 7, 2015 at 3:00 AM, Andrey Korolyov <andrey@xdel.ru> wrote:
> > On Fri, Mar 6, 2015 at 7:57 PM, Bandan Das <bsd@redhat.com> wrote:
> >> Andrey Korolyov <andrey@xdel.ru> writes:
> >>
> >>> On Fri, Mar 6, 2015 at 1:14 AM, Andrey Korolyov <andrey@xdel.ru> wrote:
> >>>> Hello,
> >>>>
> >>>> recently I`ve got a couple of shiny new Intel 2620v2s for future
> >>>> replacement of the E5-2620v1, but I experienced relatively many events
> >>>> with emulation errors, all traces looks simular to the one below. I am
> >>>> running qemu-2.1 on x86 on top of 3.10 branch for testing purposes but
> >>>> can switch to some other versions if necessary. Most of crashes
> >>>> happened during reboot cycle or at the end of ACPI-based shutdown
> >>>> action, if this can help. I have zero clues of what can introduce such
> >>>> a mess inside same processor family using identical software, as
> >>>> 2620v1 has no simular problem ever. Please let me know if there can be
> >>>> some side measures for making entire story more clear.
> >>>>
> >>>> Thanks!
> >>>>
> >>>> KVM internal error. Suberror: 2
> >>>> extra data[0]: 800000d1
> >>>> extra data[1]: 80000b0d
> >>>> EAX=00000003 EBX=00000000 ECX=00000000 EDX=00000000
> >>>> ESI=00000000 EDI=00000000 EBP=00000000 ESP=00006cd4
> >>>> EIP=0000d3f9 EFL=00010202 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0
> >>>> ES =0000 00000000 0000ffff 00009300
> >>>> CS =f000 000f0000 0000ffff 00009b00
> >>>> SS =0000 00000000 0000ffff 00009300
> >>>> DS =0000 00000000 0000ffff 00009300
> >>>> FS =0000 00000000 0000ffff 00009300
> >>>> GS =0000 00000000 0000ffff 00009300
> >>>> LDT=0000 00000000 0000ffff 00008200
> >>>> TR =0000 00000000 0000ffff 00008b00
> >>>> GDT=     000f6e98 00000037
> >>>> IDT=     00000000 000003ff
> >>>> CR0=00000010 CR2=00000000 CR3=00000000 CR4=00000000
> >>>> DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000
> >>>> DR3=0000000000000000
> >>>> DR6=00000000ffff0ff0 DR7=0000000000000400
> >>>> EFER=0000000000000000
> >>>> Code=48 18 67 8c 00 8c d1 8e d9 66 5a 66 58 66 5d 66 c3 cd 02 cb <cd>
> >>>> 10 cb cd 13 cb cd 15 cb cd 16 cb cd 18 cb cd 19 cb cd 1c cb fa fc 66
> >>>> b8 00 e0 00 00 8e
> >>>
> >>>
> >>> It turns out that those errors are introduced by APICv, which gets
> >>> enabled due to different feature set. If anyone is interested in
> >>> reproducing/fixing this exactly on 3.10, it takes about one hundred of
> >>> migrations/power state changes for an issue to appear, guest OS can be
> >>> Linux or Win.
> >>
> >> Are you able to reproduce this on a more recent upstream kernel as well ?
> >>
> >> Bandan
> >
> > I`ll go through test cycle with 3.18 and 2603v2 around tomorrow and
> > follow up with any reproduceable results.
> 
> Heh.. issue is not triggered on 2603v2 at all, at least I am not able
> to hit this. The only difference with 2620v2 except lower frequency is
> an Intel Dynamic Acceleration feature. I`d appreciate any testing with
> higher CPU models with same or richer feature set. The testing itself
> can be done on both generic 3.10 or RH7 kernels, as both of them are
> experiencing this issue. I conducted all tests with disabled cstates
> so I advise to do the same for a first reproduction step.
> 
> Thanks!
> 
> model name      : Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz
> stepping        : 4
> microcode       : 0x416
> cpu MHz         : 2100.039
> cache size      : 15360 KB
> siblings        : 12
> apicid          : 43
> initial apicid  : 43
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 13
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
> mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe
> syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts
> rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq
> dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm pcid dca
> sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c
> rdrand lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi
> flexpriority ept vpid fsgsbase smep erms

I'm seeing something similar; it's very intermittent and generally
happening right at boot of the guest;   I'm running this on qemu
head+my postcopy world (but it's happening right at boot before postcopy
gets a chance), and I'm using a 3.19ish kernel. Xeon E5-2407 in my case
but hey maybe I'm seeing a different bug.

Dave
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK