On Fri, Apr 17, 2009 at 10:22 AM, Glauber Costa <glommer@xxxxxxxxx> wrote: >> Even on sunny days, this collides with QEMU commit #7048. :) >> >> Does Intel specify what non-existent MSRs should return, ie. is your >> version still correct if !s->apicbase means that there is actually no >> APIC? And does kvm depend on the default base? If so, I would say: >> provide a patch against upstream. > > hummm, I missed this one going in. > But sadly, your patch also breaks cpu hotplug. Not a segfault anymore, but the > VM will freeze instead of shutting down, if we ask too. It does not even respond > to ^C anymore. > > By leaving your patch as is, and changing the apic base return to > > return s ? s->apicbase : (0xfee00000 | MSR_IA32_APICBASE_ENABLE); > > fixes the issue. > After reading the manual, my understanding is that only the flag must be set. I tried, and in fact: return s ? s->apicbase : MSR_IA32_APICBASE_ENABLE; still fixes it. If it works for you, I believe this is a good solution, and will send a descriptive patch. If we ever read the apic as disabled, we will have problems enabling it again. So for my test case, kvm should never see a disabled apic. For yours, you'll still see the apic base address as zero. what do you think? -- Glauber Costa. "Free as in Freedom" http://glommer.net "The less confident you are, the more serious you have to act." -- 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
