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From: Muli Ben-Yehuda <muli@il.ibm.com>
To: Eric Liu <ericliu2008@hotmail.com>
Cc: kvm@vger.kernel.org
Subject: Re: IOMMU setting
Date: Sat, 4 Apr 2009 21:18:23 +0300	[thread overview]
Message-ID: <20090404181823.GC9168@il.ibm.com> (raw)
In-Reply-To: <BAY132-W82612B25C0E9E73D5DAB1A8860@phx.gbl>

On Sat, Apr 04, 2009 at 12:16:50AM +0000, Eric Liu wrote:
> 
> Is there a quick way to check if system has IOMMU enabled in Linux?
>  
> I saw the following messages in /var/log/messages:
>  
> Apr  3 21:03:16 kernel: PCI-DMA: Disabling AGP.
> Apr  3 21:03:16 kernel: PCI-DMA: aperture base @ f4000000 size 65536 KB
> Apr  3 21:03:16 kernel: init_memory_mapping: 00000000f4000000-00000000f8000000
> Apr  3 21:03:16 kernel: last_map_addr: f8000000 end: f8000000
> Apr  3 21:03:16 kernel: PCI-DMA: using GART IOMMU.
> Apr  3 21:03:16 kernel: PCI-DMA: Reserving 64MB of IOMMU area in the AGP aperture
>  
> Does this mean IOMMU is enabed? And i don't need anything like
> iommu=force in boot option, right?

It means that you are running on an AMD system, and that this system
has a GART. You need an isolation-capable IOMMU such as Intel's VT-d
for KVM in-tree device passthrough.

Cheers,
Muli
-- 
Muli Ben-Yehuda | muli@il.ibm.com | +972-4-8281080
Manager, Virtualization and Systems Architecture
Master Inventor, IBM Haifa Research Laboratory

SYSTOR 2009---The Israeli Experimental Systems Conference
http://www.haifa.il.ibm.com/conferences/systor2009/

  reply	other threads:[~2009-04-04 18:20 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-04  0:16 IOMMU setting Eric Liu
2009-04-04 18:18 ` Muli Ben-Yehuda [this message]
2009-04-05 17:14   ` Eric Liu
2009-04-05 17:31     ` Muli Ben-Yehuda

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