On Wed, Feb 13, 2013 at 2:21 AM, H. Peter Anvin <hpa@xxxxxxxxx> wrote: >>> + rdmsrl(MSR_AMD64_BU_CFG2, value); >>> + value &= ~(1ULL << 24); >>> + wrmsrl(MSR_AMD64_BU_CFG2, value); >>> + } >>> } >>> >>> rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy); >> >> >> However, the more serious issue is that that same kernel #GPs when >> booted in kvm. It seems it cannot stomach that specific MSR, see the >> second "<-- trapping instruction" below and that BU_CFG2 MSR landing in >> %ecx in the line before that. >> >> Oh, and this happens only with the kvm executable (/usr/bin/kvm) in >> debian testing. If I use qemu from git, it passes over init_amd just >> fine. >> >> Hmmm.. > > It #GPs on an MSR, which tends to be a bug in the VMM; RDMSR/WRMSR generally > kick out to the VMM. There isn't a huge lot of work we can do about that... > > I think Qemu defaults to ignoring unknown-to-it MSRs whereas maybe kvmtool > croaks? Pekka? I think we should also be fine. Cyrillos? -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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