From mboxrd@z Thu Jan 1 00:00:00 1970 From: Weidong Han Subject: Re: [PATCH] VT-d: improve RMRR validity checking Date: Mon, 25 Jan 2010 22:12:40 +0800 Message-ID: <4B5DA6D8.5090901@intel.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: Sander Eikelenboom , "Cihula, Joseph" , "xen-devel@lists.xensource.com" , Noboru Iwamatsu , "Kay, Allen M" List-Id: xen-devel@lists.xenproject.org Keir Fraser wrote: > On 25/01/2010 10:45, "Sander Eikelenboom" wrote: > > >> a) Could be discussed if panic should be default instead of disabling iommu or >> not, although there seem to be a lot of broken bioses, so that would lead to a >> lot of machines not booting. >> > > Absolutely not acceptable. Warn and completely disable IOMMU is the correct > default causing least pain to the most end users. > > -- Keir > > > Agree. It should not crash Xen by default due to BIOS issues. warn-and-disable is better. It won't impact common Xen users, and if a user really wants to use VT-d, he can try iommu=workaround_bogus_bios, or directly report to OEM vendor to get it fixed in BIOS. As VT-d is used more and more widely, I think the BIOS issues will be found and fixed more quickly than before, thus the situation should be better. Regards, Weidong