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From: Anthony Liguori <aliguori@us.ibm.com>
To: Avi Kivity <avi@qumranet.com>
Cc: Carsten Otte <cotte@de.ibm.com>,
	Andrea Arcangeli <andrea@qumranet.com>,
	Hollis Blanchard <hollisb@us.ibm.com>,
	kvm-devel@lists.sourceforge.net,
	Ben-Ami Yassour <benami@il.ibm.com>,
	"Zhang,  Xiantao" <xiantao.zhang@intel.com>
Subject: Re: [PATCH] Handle vma regions with no backing page (v2)
Date: Tue, 29 Apr 2008 17:51:46 -0500	[thread overview]
Message-ID: <4817A682.3090308@us.ibm.com> (raw)
In-Reply-To: <4817A44D.5080808@qumranet.com>

Avi Kivity wrote:
> It depends on what's going on?  Does a page table point to mmio?  Or 
> the glommerclock?
>
> Not sure there is a single answer.
>
>> Perhaps we should be replacing consumers of gfn_to_page() with 
>> copy_to_user() instead?
>
> Indeed we should.  The problem is access in atomic contexts.  It's 
> easy to detect failure, but not always easy to handle it.

So I think we should replace it with a rate limited printk and returning 
bad_page.  That way the guest can't exploit it and we'll still hopefully 
get printk()s to track down instances of things going bad.

Regards,

Anthony Liguori


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  reply	other threads:[~2008-04-29 22:51 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-04-29 19:09 [PATCH] Handle vma regions with no backing page (v2) Anthony Liguori
2008-04-29 22:17 ` Avi Kivity
2008-04-29 22:25   ` Anthony Liguori
2008-04-29 22:42     ` Avi Kivity
2008-04-29 22:51       ` Anthony Liguori [this message]
2008-04-29 22:52         ` Avi Kivity
2008-04-29 22:57   ` Hollis Blanchard
2008-04-29 23:12     ` Anthony Liguori
2008-04-30  7:00       ` Andrea Arcangeli
2008-04-30 15:37         ` Anthony Liguori
2008-04-30 15:11       ` Hollis Blanchard
2008-04-30  7:59   ` Carsten Otte
2008-04-30  6:11 ` Muli Ben-Yehuda
2008-04-30  8:59   ` Avi Kivity
2008-04-30  9:13     ` Andrea Arcangeli
2008-04-30  9:15       ` Avi Kivity
2008-04-30 12:24   ` Anthony Liguori

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