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From: Omar Khan <okhan-e94Sedi4moU@public.gmane.org>
To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org
Subject: Re: paravirtualization structure
Date: Mon, 19 Feb 2007 20:29:34 +0000 (UTC)	[thread overview]
Message-ID: <loom.20070219T211655-267@post.gmane.org> (raw)
In-Reply-To: 45D9C127.9050201@qumranet.com

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





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  reply	other threads:[~2007-02-19 20:29 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-19 15:17 paravirtualization structure Omar Khan
     [not found] ` <loom.20070219T155153-393-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2007-02-19 15:24   ` Avi Kivity
2007-02-19 20:29     ` Omar Khan [this message]
     [not found]       ` <loom.20070219T211655-267-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2007-02-19 21:18         ` Dor Laor
2007-02-20  0:47           ` Omar Khan
     [not found]             ` <loom.20070220T011441-39-eS7Uydv5nfjZ+VzJOa5vwg@public.gmane.org>
2007-02-20  7:14               ` Avi Kivity
2007-02-20  8:18               ` Arjan van de Ven

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