From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60098) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZeuvF-0004EI-66 for qemu-devel@nongnu.org; Wed, 23 Sep 2015 21:02:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZeuvD-00058g-E4 for qemu-devel@nongnu.org; Wed, 23 Sep 2015 21:02:05 -0400 Date: Thu, 24 Sep 2015 11:02:19 +1000 From: David Gibson Message-ID: <20150924010219.GJ15944@voom.fritz.box> References: <1442495357-26547-1-git-send-email-david@gibson.dropbear.id.au> <5602D759.1020201@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="KjX7LgAomYr70Ka9" Content-Disposition: inline In-Reply-To: <5602D759.1020201@redhat.com> Subject: Re: [Qemu-devel] [RFC PATCH 00/10] pseries: Allow VFIO devices on spapr-pci-host-bridge List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Laurent Vivier Cc: thuth@redhat.com, aik@ozlabs.ru, gwshan@linux.vnet.ibm.com, qemu-devel@nongnu.org, alex.williamson@redhat.com, qemu-ppc@nongnu.org, pbonzini@redhat.com --KjX7LgAomYr70Ka9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Sep 23, 2015 at 06:46:17PM +0200, Laurent Vivier wrote: >=20 >=20 > On 17/09/2015 15:09, David Gibson wrote: > > Currently the pseries machine type uses two types of PCI Host Bridge > > (PHB) devices: "spapr-pci-host-bridge" the 'normal' variant intended > > for emulated PCI devices, and "spapr-pci-vfio-host-bridge" intended > > for VFIO devices. > >=20 > > When using VFIO with pseries, a separate spapr-pci-vfio-host-bridge > > device is needed for every host IOMMU group from which you're using > > VFIO devices. This is quite awkward for the user and/or management > > tools. It's especially awkward since the current code makes > > essentially no attempt to detect and warn the user if the wrong sorts > > of devices are connected to the wrong PHB. > >=20 > > It turns out that the VFIO core code is actually general enough that > > VFIO devices almost work on the normal spapr-pci-host-bridge device. > > In fact with the right combination of circumstances they *can* work > > right now. > >=20 > > spapr-pci-vfio-host-bridge does 3 additional things: > >=20 > > 1) It disables KVM acceleration of the guest IOMMU. That > > acceleration breaks VFIO because it means guest IOMMU updates > > bypass the VFIO infrastructure which keeps the host IOMMU in > > sync. > >=20 > > 2) It automatically configures the guest PHB's DMA window to match > > the capabilities of the host IOMMU, and advertises that to the > > guest. > >=20 > > 3) It provides additional handling of EEH (Enhanced Error > > Handling) functions. > >=20 > > This patch series: > > * Allows VFIO devices to be used on the spapr-pci-host-bridge by > > auto-switching the KVM TCE acceleration > >=20 > > * Adds verification that the host IOMMU can handle the DMA windows > > used by guest PHBs > >=20 > > * Allows the DMA window on the guest PHB to be configured with > > device properties. This can be used to make sure it matches a > > host window, but in practice the default setting will already > > work with the host IOMMU on all current systems. > >=20 > > * Adds support to the VFIO core to allow a VFIO device to be > > hotplugged onto a bus which doesn't yet have VFIO devices. This > > already worked for systems without a guest-visible IOMMU > > (i.e. x86), this series makes it work even with a guest visible > > IOMMU. > >=20 > > * Makes a few related cleanups along the way > >=20 > > This series does NOT allow EEH operations on VFIO devices on the > > spapr-pci-host-bridge device, so the spapr-pci-vfio-host-bridge device > > is left in for now. It turns out there are some serious existing > > problems in both the qemu EEH implementation and (worse) in the > > EEH/VFIO kernel interface. Fixing those is a problem for another day. > > Maybe tomorrow. > >=20 > >=20 > > I've tested basic assignment of an xHCI to a pseries guest, both at > > startup and with hotplug. I haven't (yet) tested VFIO on x86 with > > this series. > >=20 > > This series probably needs to be merged via several different trees. > > I'm intending to split up as necessary once it's had some review. > >=20 > > David Gibson (10): > > vfio: Remove unneeded union from VFIOContainer > > vfio: Generalize vfio_listener_region_add failure path > > vfio: Check guest IOVA ranges against host IOMMU capabilities > > vfio: Record host IOMMU's available IO page sizes > > memory: Allow replay of IOMMU mapping notifications > > vfio: Allow hotplug of containers onto existing guest IOMMU mappings > > spapr_pci: Allow PCI host bridge DMA window to be configured > > spapr_iommu: Rename vfio_accel parameter > > spapr_iommu: Provide a function to switch a TCE table to allowing VFIO > > spapr_pci: Allow VFIO devices to work on the normal PCI host bridge > >=20 > > hw/ppc/spapr_iommu.c | 25 ++++++- > > hw/ppc/spapr_pci.c | 13 +++- > > hw/vfio/common.c | 152 +++++++++++++++++++++++++++-------= -------- > > include/exec/memory.h | 16 +++++ > > include/hw/pci-host/spapr.h | 3 +- > > include/hw/ppc/spapr.h | 6 +- > > include/hw/vfio/vfio-common.h | 21 +++--- > > memory.c | 18 +++++ > > target-ppc/kvm.c | 4 +- > > target-ppc/kvm_ppc.h | 2 +- > > 10 files changed, 184 insertions(+), 76 deletions(-) > >=20 >=20 > Just a comment on the form: checkpatch.pl vociferates because of "DOS > line endings", "trailing whitespace" and "line over 80 characters". Hmm.. I see the trailing whitespace and over 80 characters warnings along with a few others. Nothing about DOS line endings though. Wondering if that could be something that's come from your mailer. >=20 > > Please, use "vi" with "set ff=3Dunix" > >=20 > Stefan has a good tip to check automatically commits: >=20 > http://blog.vmsplice.net/2011/03/how-to-automatically-run-checkpatchpl.ht= ml Nice, thanks. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --KjX7LgAomYr70Ka9 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJWA0ubAAoJEGw4ysog2bOSla0QALxMSArK3udum1ZLOAcP8/6F IF70TRPd1IjhldjjO/8kzO2mEGae+gdFOtiq3B+9J/rSMuIfDVRm+NmXIvBS4Ewj aA9j8wviqEn4eQUsnAef29PqF9nQpoZfy9DVFnRVz9SavgBkDJMFh4RPLiPlas0l devkzKX5dVoeeK94h++tyIwNQJ9B5vb/tD9660Nk7biVwJ93GT4V0y9uAu1iS93w Vt2csAXMlFDge7jCJcQhTmIi3yg2PsMU5rHgOYwuicNG3zy9hC6nU4cNgw8Akoqp ccxyJ6+ukbgUHbwStjt5H+FHljKpGR8H55y/vau8BKP1ZOVzobWke/71T8yTharZ U/rBTuCgpZ+dXDo1w01xE5Fj5DBs3SpEHWxinpWKr/qGHN7fuk9R6vUTjVVtlFQ5 63+M0Z+D0Yeldmgeql09LxBNLeXuhqrZ2Ikks2pK9iHl46ChRWUbfDLZgE9UZiCZ nyZ5PY6KjAiBMEv5V5Ymo5MDbck4GsvUbDLQ5+5xC2zgxBipoNKwqvC1ft/Dzo5R rIFMjoBrX3qb7dCcrMhqI9LbdPN+0eLPUJH23KLo6stiL1au7uJs8C7WHNRQ+bgt dfKEkiQJsl5B6JubI1KpfM8YAjgRXQOEx4oyLWwae6VRCA1JvGEcPXVcvFP1HOr3 cszxFGzf6qYtVefrEAqg =cSZN -----END PGP SIGNATURE----- --KjX7LgAomYr70Ka9--