From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: Any side effect if turn off amd_iommu Date: Tue, 5 May 2015 17:13:19 +0200 Message-ID: <20150505151319.GO15736@8bytes.org> References: <20150325140410.GS4441@8bytes.org> <20150326120547.GU4441@8bytes.org> <20150330160910.GZ4441@8bytes.org> <20150504110802.GE15736@8bytes.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: 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: AceLan Kao Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: iommu@lists.linux-foundation.org Hi, On Tue, May 05, 2015 at 03:30:41PM +0800, AceLan Kao wrote: > There is no easy way to check whether this BIOS bug is present, so we > have to list them explicitly. > I think we can do just like what platform drivers(ex. asus_quirks[1]) > do, check the system vendor and product name to identify those > machines, and give them a working ioapic value. Problem here is that system vendor and platform name is not enough, the version of the BIOS is also important. To make things worse, the problem could be introduced into one BIOS version and fixes in another later version. My feeling is that trying to make guesses here will open a can of worms we better keep closed. The strategy for now has been to search for broken configurations and disable interrupt remapping when they are detected. Joerg