On Wed, Sep 23, 2015 at 06:46:17PM +0200, Laurent Vivier wrote: > > > 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. > > > > 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. > > > > 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. > > > > spapr-pci-vfio-host-bridge does 3 additional things: > > > > 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. > > > > 2) It automatically configures the guest PHB's DMA window to match > > the capabilities of the host IOMMU, and advertises that to the > > guest. > > > > 3) It provides additional handling of EEH (Enhanced Error > > Handling) functions. > > > > This patch series: > > * Allows VFIO devices to be used on the spapr-pci-host-bridge by > > auto-switching the KVM TCE acceleration > > > > * Adds verification that the host IOMMU can handle the DMA windows > > used by guest PHBs > > > > * 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. > > > > * 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. > > > > * Makes a few related cleanups along the way > > > > 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. > > > > > > 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. > > > > 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. > > > > 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 > > > > 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(-) > > > > 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. > > <troll> > Please, use "vi" with "set ff=unix" > </troll> > > Stefan has a good tip to check automatically commits: > > http://blog.vmsplice.net/2011/03/how-to-automatically-run-checkpatchpl.html Nice, thanks. -- 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
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