From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joerg Roedel <joro@8bytes.org>
Subject: Re: [PATCH] VFIO driver: Non-privileged user level PCI drivers
Date: Wed, 2 Jun 2010 11:53:54 +0200
Message-ID: <20100602095354.GE964@8bytes.org>
References: <20100530121944.GH27611@redhat.com> <4C04E0E0.3070006@redhat.com> <1275452987.16980.24.camel@x201> <201006012159.41344.pugs@lyon-about.com>
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Cc: Alex Williamson <alex.williamson@redhat.com>,
	Avi Kivity <avi@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	chrisw@sous-sol.org, hjk@linutronix.de, gregkh@suse.de,
	aafabbri@cisco.com, scofeldm@cisco.com
To: Tom Lyon <pugs@lyon-about.com>
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On Tue, Jun 01, 2010 at 09:59:40PM -0700, Tom Lyon wrote:
> This is just what I was thinking.  But rather than a get/set, just use two fds.
> 
> 	ioctl(vfio_fd1, VFIO_SET_DOMAIN, vfio_fd2);
> 
> This may fail if there are really 2 different IOMMUs, so user code must be
> prepared for failure,  In addition, this is strictlyupwards compatible with 
> what is there now, so maybe we can add it later.

How can this fail with multiple IOMMUs? This should be handled
transparently by the IOMMU driver.

	Joerg