From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Tiejun" Subject: Re: [v6][PATCH 2/2] xen:vtd: missing RMRR mapping while share EPT Date: Wed, 30 Jul 2014 18:40:00 +0800 Message-ID: <53D8CB80.1000606@intel.com> References: <1406684186-12788-1-git-send-email-tiejun.chen@intel.com> <1406684186-12788-2-git-send-email-tiejun.chen@intel.com> <53D8CAC402000078000278E9@mail.emea.novell.com> <53D8B408.1010409@intel.com> <53D8D5A0020000780002792A@mail.emea.novell.com> <53D8BD70.7040905@intel.com> <53D8E4370200007800027986@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <53D8E4370200007800027986@mail.emea.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Jan Beulich Cc: yang.z.zhang@intel.com, kevin.tian@intel.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On 2014/7/30 18:25, Jan Beulich wrote: >>>> On 30.07.14 at 11:40, wrote: >> From what those codes mean, it just return regardless whether they >> really conflict. And this is just a good assumption, so if I'm >> understanding this properly, actually our patches do this thing >> precisely because we further check if this assumption is true, then take >> necessary actions. > > Except that the pointed out check prevents the code you modify > from being reached at all, i.e. as long as that check is there it > doesn't matter (for any passed through USB device) what action > rmrr_identity_mapping() takes. > Sorry, what do you mean? From my point of view these two patches should be better than drop simply RMRR for any PT USB device no matter if its really necessary. Thanks Tiejun