Message-ID: <4B541D08.9040802@zytor.com>
Date: Mon, 18 Jan 2010 00:34:16 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Gleb Natapov <gleb@redhat.com>
CC: Peter Zijlstra <peterz@infradead.org>, kvm@vger.kernel.org,
       linux-mm@kvack.org, linux-kernel@vger.kernel.org, avi@redhat.com,
       mingo@elte.hu, tglx@linutronix.de, riel@redhat.com,
       cl@linux-foundation.org
Subject: Re: [PATCH v3 04/12] Add "handle page fault" PV helper.
References: <1262700774-1808-1-git-send-email-gleb@redhat.com> <1262700774-1808-5-git-send-email-gleb@redhat.com> <1263490267.4244.340.camel@laptop> <20100117144411.GI31692@redhat.com>
In-Reply-To: <20100117144411.GI31692@redhat.com>
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On 01/17/2010 06:44 AM, Gleb Natapov wrote:
> On Thu, Jan 14, 2010 at 06:31:07PM +0100, Peter Zijlstra wrote:
>> On Tue, 2010-01-05 at 16:12 +0200, Gleb Natapov wrote:
>>> Allow paravirtualized guest to do special handling for some page faults.
>>>
>>> The patch adds one 'if' to do_page_fault() function. The call is patched
>>> out when running on physical HW. I ran kernbech on the kernel with and
>>> without that additional 'if' and result were rawly the same:
>>
>> So why not program a different handler address for the #PF/#GP faults
>> and avoid the if all together?
> I would gladly use fault vector reserved by x86 architecture, but I am
> not sure Intel will be happy about it.
>

That's what it's there for... see Peter Z.'s response.

	-hpa
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