Re: paravirtualization structure

Omar Khan
2007-02-19T20:29:34Z

Avi Kivity <avi@...> writes:

> The hypercall sequence does not avoid a vmexit. The guest issues a
> vmcall instruction, which is trapped and processed by the host.
>

Thanks for replying Avi. In your response
(http://article.gmane.org/gmane.linux.kernel/481457) to the announcement of the
KVM paravirtualization patch you said about the cr3 related hypercall that:

"The gain probably comes not only from avoiding the vmentry/vmexit, but also
from avoiding the flushing of the global page tlb entries."

Is the vmexit caused by the vmcall more efficient/different than the vmexit that
is caused by writing to the cr3 register say.

Thanks

Omar Khan