From: Keir Fraser <keir@xen.org>
To: Jan Beulich <JBeulich@novell.com>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>,
Christoph Egger <Christoph.Egger@amd.com>,
"xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: regression from c/s 22071:c5aed2e049bc (ept: Put locks around ept_get_entry) ?
Date: Thu, 16 Dec 2010 17:03:11 +0000 [thread overview]
Message-ID: <C92FF6CF.295FC%keir@xen.org> (raw)
In-Reply-To: <4D0A516B0200007800028755@vpn.id2.novell.com>
On 16/12/2010 16:50, "Jan Beulich" <JBeulich@novell.com> wrote:
>>>> On 16.12.10 at 17:42, Keir Fraser <keir@xen.org> wrote:
>> The issue is not one of serialisation or code ordering. It is one of
>> memory-access atomicity. Thus it seems to me that volatile is the correct
>
> Indeed, I agree.
>
>> approach therefore. Perhaps *(volatile type *)px = x or, really, even better
>> I should define some {read,write}_atomic{8,16,32,64} accessor functions
>> which use inline asm to absolutely definitely emit a single atomic 'mov'
>> instruction.
>>
>> Make sense?
>
> Yes.
Excellent. I will lay groundwork and fix pte_{read,write}_atomic directly in
-unstable and -4.0-testing. I will then post a proposed fix for EPT to the
list. I don't know that code so well and I may not otherwise catch all
places that require use of the new accessor macros.
-- Keir
> Jan
>
next prev parent reply other threads:[~2010-12-16 17:03 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-14 8:39 regression from c/s 22071:c5aed2e049bc (ept: Put locks around ept_get_entry) ? Jan Beulich
2010-12-14 10:47 ` George Dunlap
2010-12-14 10:48 ` George Dunlap
2010-12-14 12:37 ` Jan Beulich
2010-12-14 14:32 ` George Dunlap
2010-12-14 14:34 ` George Dunlap
2010-12-14 14:50 ` Jan Beulich
2010-12-16 15:51 ` Jan Beulich
2010-12-16 16:12 ` Keir Fraser
2010-12-16 16:22 ` Jan Beulich
2010-12-16 16:42 ` Keir Fraser
2010-12-16 16:50 ` Jan Beulich
2010-12-16 17:03 ` Keir Fraser [this message]
2010-12-16 20:34 ` Keir Fraser
2010-12-17 11:15 ` Tim Deegan
2010-12-20 16:24 ` George Dunlap
2010-12-17 14:03 ` Olaf Hering
2010-12-17 14:18 ` Keir Fraser
2010-12-16 16:59 ` Keir Fraser
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