From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58129) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmZbB-0004W9-TK for qemu-devel@nongnu.org; Wed, 21 Sep 2016 00:57:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bmZb7-0003J2-Nn for qemu-devel@nongnu.org; Wed, 21 Sep 2016 00:57:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45476) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmZb7-0003Iq-Hn for qemu-devel@nongnu.org; Wed, 21 Sep 2016 00:57:29 -0400 Date: Wed, 21 Sep 2016 12:57:22 +0800 From: Peter Xu Message-ID: <20160921045722.GG5134@pxdev.xzpeter.org> References: <1473841548-26742-1-git-send-email-peterx@redhat.com> <1473841548-26742-4-git-send-email-peterx@redhat.com> <20160920061409.GX20488@umbus> <20160920072808.GE5134@pxdev.xzpeter.org> <20160921034910.GX20488@umbus> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160921034910.GX20488@umbus> Subject: Re: [Qemu-devel] [PATCH v5 3/3] intel_iommu: allow UNMAP notifiers List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson Cc: qemu-devel@nongnu.org, mst@redhat.com, jasowang@redhat.com, vkaplans@redhat.com, alex.williamson@redhat.com, wexu@redhat.com, pbonzini@redhat.com, cornelia.huck@de.ibm.com, dgibson@redhat.com On Wed, Sep 21, 2016 at 01:49:10PM +1000, David Gibson wrote: > On Tue, Sep 20, 2016 at 03:28:08PM +0800, Peter Xu wrote: > > On Tue, Sep 20, 2016 at 04:14:09PM +1000, David Gibson wrote: > > > On Wed, Sep 14, 2016 at 04:25:48PM +0800, Peter Xu wrote: > > > > Intel vIOMMU is still lacking of a complete IOMMU notifier mechanism. > > > > Before that is achieved, let's open a door for vhost DMAR support, which > > > > only requires cache invalidations (UNMAP operations). > > > > > > > > Meanwhile, converting hw_error() to error_report() and exit(1), to make > > > > the error messages clean and obvious (so no CPU registers will be > > > > dumped). > > > > > > Erm... AIUI currently the intel iommu driver doesn't do any > > > notifications. Surely it's only valid to allow this once you've > > > implemented unmap side notifications. > > > > Yes, I suppose vhost DMAR patches will be based upon this one. I can > > postpone this patch until Jason wants to pick it up, but it actually > > does not hurt if we just enable it now, anyway no one is using it. > > Even so, I think it's misleading to implicitly advertise a capability > that's not yet implemented. Changing this warning should happen after > or at the same time as implementing the notifications in the vIOMMU > model. Sure. Then I'll post v6, and I'm okay with either way to merge it. Thanks. -- peterx