(re-adding cc) On 11/09/2011 09:35 PM, Walter Haidinger wrote: > Am 09.11.2011 14:40, schrieb Avi Kivity: > > Actually, it looks like an OpenBSD bug. According to the AMD > > documentation: > > Well, the OpenBSD developers are very confident that is > a bug in the KVM cpu emulation and _not_ in OpenBSD. > > Basically they say that [despite -cpu host], the emulated > cpu does not look like a real, but _non-existant_ cpu. > Virtualization should look like _existing_ hardware. That is true. But OpenBSD is not following the vendor's recommendation for how software should access the hardware. > Since the list archive at > http://marc.info/?l=openbsd-misc&m=132077741910464&w=2 > lags a bit, I'm attaching some parts of the thread below: > > However, please remember it's OpenBSD, so the tone is, let's just > say, rough. Less than expected, actually. > > The panic you hit is for an msr read, not a write. I'm aware those > > registers are read-only. The CPUID check isn't done, it matches on > > all family 10 and/or higher AMD processors. They're pretending to be > > an AMD K10 processor. On all real hardware I've tested this works > > fine. If you wish to be pedantic, patches are welcome. So they're actually open to adding the cpuid check. > They sent me a patch as a workaround, which: > > > The previous patch avoids touching the msr at all if ACPI indicates > > speed scaling is unavailable, this should prevent your panic. > > with -cpu host, OpenBSD dmesg showed the 1100T: > >> cpu0: AMD Phenom(tm) II X6 1100T Processor ("AuthenticAMD" 686-class, 512KB L2 cache) 3.31 GHz cpu0: > >> FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,MMX,FXSR,SSE,SSE2,SSE3,CX16,POPCNT > >> ... > >> bios0: vendor Bochs version "Bochs" date 01/01/2007 bios0: Bochs > >> Bochs > > They shouldn't be pretending to be AMD, especially if that emulation > > is very incompatible. > > but the bug is in the Linux KVM: > > >> They're pretending to be an AMD K10 processor. > >> > > Exactly. What they are doing is wrong. They are pretending to be a > > AMD K10 processor _badly_, and then they think they can say "oh, but > > you need to check all these other registers too". A machine with that > > setup has never physically existed. > > Is this all because I used -cpu host? > -cpu host is not to blame, you could get the same result from other combinations of cpu model and family. I'll look at adding support for this MSR; should be simple. But in general processor features need to be qualified by cpuid, not by model. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
