The core VFIO infrastructure more or less allows VFIO devices to work on any normal guest PCI host bridge (PHB) without extra logic. However, the "spapr-pci-host-bridge" device (as opposed to the special "spapr-pci-vfio-host-bridge" device) breaks this by using a partially KVM accelerated implementation of the guest kernel IOMMU which won't work with VFIO devices, without additional kernel support.
This patch allows VFIO devices to work on the spapr-pci-host-bridge, by having it switch off KVM TCE acceleration when a VFIO device is added to the PHB (either on startup, or by hotplug). Signed-off-by: David Gibson <da...@gibson.dropbear.id.au> --- hw/ppc/spapr_pci.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c index 622c4ac..a0cca22 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -1090,6 +1090,12 @@ static void spapr_phb_add_pci_device(sPAPRDRConnector *drc, void *fdt = NULL; int fdt_start_offset = 0, fdt_size; + if (object_dynamic_cast(OBJECT(pdev), "vfio-pci")) { + sPAPRTCETable *tcet = spapr_tce_find_by_liobn(phb->dma_liobn); + + spapr_tce_need_vfio(tcet); + } + if (dev->hotplugged) { fdt = create_device_tree(&fdt_size); fdt_start_offset = spapr_create_pci_child_dt(phb, pdev, fdt, 0); -- 2.4.3