[libvirt] [Qemu-devel] [Question] why x2apic's set by default without host support(on Nehalem CPU).

[Peter Huang(Peng)]

> libvirt's "host-passthrough" uses "-cpu host', and it "-cpu host"
> enables every feature that can be enabled on the host.
>From my test results, I found that even when use host-passthrough mode, VM's
cpu features are very different from host, this doesn't match what host-passthrough
mode's explanation.

libvirt's option exlanation:
With this mode, the CPU visible to the guest should be exactly  the  same as  the host 
CPU even in  the aspects  that libvirt  does not understand.
> If the behavior of "-cpu host" doesn't match libvirt expectations, we
> need to clarify what are the requirements, and maybe have a "try to be
> close to host CPU mode" as opposed to the current "enable everything
> that can be enabled" mode.
Does the results above indicates what you mean to do? or the current way doesn't work
as we expect.

Thanks!