Re: 2.6.31.5 x86-64 KVM: 'emulation failed (pagetable) rip 7fb49335da7b 66 0f 7f 07'

Avi Kivity
2009-11-29T10:43:26Z

On 11/27/2009 11:56 PM, Nix wrote:
> So I installed my first KVM guest image (a prerelease of Ubuntu 9.10
> that I had lying around) this morning (through virt-manager, as it
> happens). Everything worked fine, the install was searingly fast
> compared to the UML virtual machines I'm used to.
>
> I got back to it this evening, restarted the VM, and found that it had
> suddenly slowed right down again, with one CPU being saturated with work
> even when nothing was happening. Looking at the syslog shows (what would
> be but for ratelimit) incredible numbers of these messages being logged:
>
> Nov 27 21:44:00 spindle info: [444857.792205] device vnet0 entered promiscuous mode
> Nov 27 21:44:00 spindle info: [444857.794347] linux-net: port 2(vnet0) entering learning state
> Nov 27 21:44:03 spindle warning: [444860.856640] __ratelimit: 928705 callbacks suppressed
> Nov 27 21:44:03 spindle err: [444860.856729] emulation failed (pagetable) rip 7f3845f36a7b 66 0f 7f 07
>

66 0f 7f 07 movdqa %xmm0,(%rdi)

which we don't emulate.

Can you, using the qemu monitor, see where the guest is trying to write?

(qemu) info registers
(qemu) x/30i $eip - 20

--
error compiling committee.c: too many arguments to function