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From: Paul Brook <paul@codesourcery.com>
To: Avi Kivity <avi@redhat.com>
Cc: Cam Macdonell <cam@cs.ualberta.ca>,
	qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] [PATCH] Inter-VM shared memory PCI device
Date: Wed, 10 Mar 2010 11:13:10 +0000	[thread overview]
Message-ID: <201003101113.11974.paul@codesourcery.com> (raw)
In-Reply-To: <4B97668C.3060203@redhat.com>

> >> As of March 2009[1] Intel guarantees that memory reads occur in order
> >> (they may only be reordered relative to writes). It appears AMD do not
> >> provide this guarantee, which could be an interesting problem for
> >> heterogeneous migration..
> >
> > Interesting, but what ordering would cause problems that AMD would do
> > but Intel wouldn't?  Wouldn't that ordering cause the same problems
> > for POSIX shared memory in general (regardless of Qemu) on AMD?
> 
> If some code was written for the Intel guarantees it would break if
> migrated to AMD.  Of course, it would also break if run on AMD in the
> first place.

Right. This is independent of shared memory, and is a case where reporting an 
Intel CPUID on and AMD host might get you into trouble.

Paul

  reply	other threads:[~2010-03-10 11:13 UTC|newest]

Thread overview: 48+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-05 23:52 [Qemu-devel] [PATCH] Support adding a file to qemu's ram allocation Cam Macdonell
2010-03-05 23:52 ` [Qemu-devel] [PATCH] Inter-VM shared memory PCI device Cam Macdonell
2010-03-07 22:53   ` Paul Brook
2010-03-08  1:45     ` Jamie Lokier
2010-03-08  9:48       ` Alexander Graf
2010-03-08  9:54         ` Jamie Lokier
2010-03-08 10:57           ` Alexander Graf
2010-03-09 21:41           ` Anthony Liguori
2010-03-08 13:04       ` Paul Brook
2010-03-09 19:00         ` Jamie Lokier
2010-03-08  9:52     ` Avi Kivity
2010-03-08 13:03       ` Paul Brook
2010-03-08 13:16         ` Avi Kivity
2010-03-09 20:11           ` Jamie Lokier
2010-03-09 21:44           ` Anthony Liguori
2010-03-10  9:25             ` Avi Kivity
2010-03-10 17:13               ` Anthony Liguori
2010-03-10 17:30                 ` Avi Kivity
2010-03-10 17:41                   ` Paul Brook
2010-03-11  6:33                     ` Avi Kivity
2010-03-11 12:21                       ` Paul Brook
2010-03-09 20:12         ` Jamie Lokier
2010-03-10  0:03           ` Paul Brook
2010-03-10  4:38             ` Cam Macdonell
2010-03-10  9:29               ` Avi Kivity
2010-03-10 11:13                 ` Paul Brook [this message]
2010-03-11  3:10             ` Jamie Lokier
2010-03-11  4:37               ` Nick Piggin
2010-03-11 14:38                 ` malc
2010-03-08  9:56   ` [Qemu-devel] " Avi Kivity
2010-03-08 17:57     ` Cam Macdonell
2010-03-09 10:29       ` Avi Kivity
     [not found]         ` <8286e4ee1003090724m1ef0b571g8b705a24e36e1753@mail.gmail.com>
2010-03-09 15:27           ` [Qemu-devel] " Cam Macdonell
2010-03-09 17:28             ` [Qemu-devel] " Avi Kivity
2010-03-09 17:34               ` Anthony Liguori
2010-03-09 18:34               ` Cam Macdonell
2010-03-10  9:21                 ` Avi Kivity
2010-03-10 16:36                   ` Cam Macdonell
2010-03-11  6:49                     ` Avi Kivity
2010-03-09 12:49       ` Arnd Bergmann
2010-03-09 13:03         ` Avi Kivity
2010-03-09 16:44           ` Cam Macdonell
2010-03-10 14:04             ` Arnd Bergmann
2010-03-11  6:50               ` Avi Kivity
2010-03-11 12:57                 ` Arnd Bergmann
2010-03-11 13:07                   ` Avi Kivity
2010-03-11 14:32                     ` Arnd Bergmann
2010-03-08  9:53 ` [Qemu-devel] Re: [PATCH] Support adding a file to qemu's ram allocation Avi Kivity

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