Date: Thu, 10 Nov 2016 16:18:48 +0100
From: Joerg Roedel <joro@8bytes.org>
To: Robin Murphy <robin.murphy@arm.com>
Cc: Don Dutile <ddutile@redhat.com>, Will Deacon <will.deacon@arm.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Christoffer Dall <christoffer.dall@linaro.org>,
        Eric Auger <eric.auger@redhat.com>, eric.auger.pro@gmail.com,
        marc.zyngier@arm.com, tglx@linutronix.de, jason@lakedaemon.net,
        linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org,
        drjones@redhat.com, linux-kernel@vger.kernel.org,
        pranav.sawargaonkar@gmail.com, iommu@lists.linux-foundation.org,
        punit.agrawal@arm.com, diana.craciun@nxp.com, benh@kernel.crashing.org,
        arnd@arndb.de, jcm@redhat.com, dwmw@amazon.co.uk
Subject: Re: Summary of LPC guest MSI discussion in Santa Fe
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>
 <e59e9a17-e943-a227-5ea4-d028232155a8@arm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <e59e9a17-e943-a227-5ea4-d028232155a8@arm.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 714
Lines: 16

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