From mboxrd@z Thu Jan  1 00:00:00 1970
From: Roland Dreier <rdreier@cisco.com>
Subject: Re: [PATCH 2/4 v2] PCI: support ARI capability
Date: Wed, 10 Sep 2008 11:42:18 -0700
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References: <7A25B56E4BE99C4283EB931CD1A40E110177EB6E@pdsmsx414.ccr.corp.intel.com>
	<20080901152734.GC16796@ldl.fc.hp.com> <ada3akjj268.fsf@cisco.com>
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Cc: "Alex Chiang" <achiang@hp.com>,
	"Jesse Barnes" <jbarnes@virtuousgeek.org>,
	<linux-pci@vger.kernel.org>,
	"Randy Dunlap" <randy.dunlap@oracle.com>,
	"Greg KH" <greg@kroah.com>,
	"Grant Grundler" <grundler@parisc-linux.org>,
	"Matthew Wilcox" <matthew@wil.cx>, <linux-kernel@vger.kernel.org>,
	<kvm@vger.kernel.org>, <virtualization@lists.linux-foundation.org>,
	<xen-devel@lists.xensource.com>
To: "Zhao\, Yu" <yu.zhao@intel.com>
Return-path: <linux-pci-owner@vger.kernel.org>
In-Reply-To: <7A25B56E4BE99C4283EB931CD1A40E110181CAF7@pdsmsx414.ccr.corp.intel.com>
	(Yu Zhao's message of "Wed, 10 Sep 2008 15:48:04 +0800")
Sender: linux-pci-owner@vger.kernel.org
List-Id: kvm.vger.kernel.org

 > ARI is an independent PCI Express extended capability. Multi-function
 > devices supporting this capability may use it to track dependency
 > between different functions and assign function group numbers to
 > these functions.

 > Another reason to keep this separated with SR-IOV is that after ARI
 > is enabled, PCI Express Endpoint may have non-zero slot number
 > (device number), which is different from traditional PCI Express
 > Endpoint.

OK, I guess.  Although I still don't see why we need a user-visible
option to control ARI independent of SR-IOV.  When would a user want to
enable CONFIG_PCI_ARI=y but not select CONFIG_PCI_IOV?  (Also, by the
way, why PCI_IOV instead of PCI_SR_IOV -- I assume in the future we may
have PCI_MR_IOV, and matching the PCI terminology is probably easier for
people to understand).

 - R.