From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: Re: Summary of LPC guest MSI discussion in Santa Fe Date: Thu, 10 Nov 2016 16:18:48 +0100 Message-ID: <20161110151848.GE2078@8bytes.org> References: <1478209178-3009-1-git-send-email-eric.auger@redhat.com> <20161103220205.37715b49@t450s.home> <20161108024559.GA20591@arm.com> <20161108202922.GC15676@cbox> <20161108163508.1bcae0c2@t450s.home> <58228F71.6020108@redhat.com> <20161109170326.GG17771@arm.com> <582371FB.2040808@redhat.com> 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: Robin Murphy Cc: arnd-r2nGTMty4D4@public.gmane.org, drjones-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, marc.zyngier-5wv7dgnIgG8@public.gmane.org, benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org, punit.agrawal-5wv7dgnIgG8@public.gmane.org, Will Deacon , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, pranav.sawargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, jcm-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, dwmw-vV1OtcyAfmbQXOPxS62xeg@public.gmane.org, Christoffer Dall , eric.auger.pro-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: iommu@lists.linux-foundation.org On Wed, Nov 09, 2016 at 08:11:16PM +0000, Robin Murphy wrote: > When we *are* in full control of the IOVA space, we just carve out what > we can find as best we can - see iova_reserve_pci_windows() in > dma-iommu.c, which isn't really all that different to what x86 does > (e.g. init_reserved_iova_ranges() in amd-iommu.c). Yeah, that code was actually written with a look at what the Intel driver does. I don't really like that it goes over all resources and reserves them individually (not only because it is not hotplug-safe). I have to check whether there is a nice and generic way to find out the root-bridge windows and just reserve them in the iova-space. That would be easier and more reliable. Joerg