On Thu, 2011-02-03 at 00:50 +0200, Timo Juhani Lindfors wrote: > Ben Hutchings <ben@decadent.org.uk> writes: > > Which version of qemu are you using in the host? If you are using > > kvm-qemu, which kernel version are you using in the host? > > The host is a xen domU: So this is ordinary qemu, not using hardware virtualisation? > lindi1:~$ qemu-system-x86_64 --version > QEMU PC emulator version 0.12.5 (Debian 0.12.5+dfsg-3), Copyright (c) 2003-2008 Fabrice Bellard > lindi1:~$ dpkg-query -W qemu > qemu 0.12.5+dfsg-3 > lindi1:~$ dmesg|head -n3 > [ 0.000000] Initializing cgroup subsys cpuset > [ 0.000000] Initializing cgroup subsys cpu > [ 0.000000] Linux version 2.6.32-5-amd64 (Debian 2.6.32-30) (ben@decadent.org.uk) (gcc version 4.3.5 (Debian 4.3.5-4) ) #1 SMP Wed Jan 12 03:40:32 UTC 2011 > > >> 0x0000000000600889 <f+41>: 57 push %rdi > >> 0x000000000060088a <f+42>: 9d popfq > >> 0x000000000060088b <f+43>: 66 66 90 xchg %ax,%ax > >> 0x000000000060088e <f+46>: 66 90 xchg %ax,%ax > > > > This looks like deliberate patching by the PV-alternatives mechanism. > > Is this PV-alternatives a linux or qemu feature or are they both > cooperating? > > I tried to look around but couldn't find the code yet. It's a kernel feature to be more efficient when running in a recognised virtual machine implementation (PV = paravirtualisation). Ben. -- Ben Hutchings Once a job is fouled up, anything done to improve it makes it worse.
Attachment:
signature.asc
Description: This is a digitally signed message part