From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: [PATCH 5/5] iommu: Allow default domain type to be set on the kernel command line Date: Thu, 26 Jan 2017 18:15:55 +0100 Message-ID: <20170126171555.GD27598@8bytes.org> References: <1484849955-1871-1-git-send-email-will.deacon@arm.com> <1484849955-1871-6-git-send-email-will.deacon@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1484849955-1871-6-git-send-email-will.deacon-5wv7dgnIgG8@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Will Deacon Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Thu, Jan 19, 2017 at 06:19:15PM +0000, Will Deacon wrote: > Rather than modify each IOMMU driver to provide different semantics for > DMA domains, instead we introduce a command line parameter that can be > used to change the type of the default domain. Passthrough can then be > specified using "iommu.default_domain=identity" on the kernel command > line. I like the general idea of this, but the above is a terrible name for a kernel commandline-parameter. The x86 iommus support iommu=pt which is pretty much the same as this patch does. How about something like "iommu.passthrough=0/1"? And please add the parameter to the kernel documentation too. Joerg