From 8d2b67c3a0e61cdefd2cb60924f0fb4265846ca9 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 30 Sep 2015 06:43:14 +0200 Subject: [PATCH 06/10] vfio: Allow hotplug of containers onto existing guest IOMMU mappings Message-id: <1443595398-20898-7-git-send-email-dgibson@redhat.com> Patchwork-id: 67990 O-Subject: [RHEL7.2 qemu-kvm-rhev PATCHv4 06/10] vfio: Allow hotplug of containers onto existing guest IOMMU mappings Bugzilla: 1259556 RH-Acked-by: Alex Williamson RH-Acked-by: Laurent Vivier RH-Acked-by: Thomas Huth At present the memory listener used by vfio to keep host IOMMU mappings in sync with the guest memory image assumes that if a guest IOMMU appears, then it has no existing mappings. This may not be true if a VFIO device is hotplugged onto a guest bus which didn't previously include a VFIO device, and which has existing guest IOMMU mappings. Therefore, use the memory_region_register_iommu_notifier_replay() function in order to fix this case, replaying existing guest IOMMU mappings, bringing the host IOMMU into sync with the guest IOMMU. Signed-off-by: David Gibson Upstream: 508ce5eb00070809f0d19917a1b2960dfcf5a64b Signed-off-by: David Gibson Signed-off-by: Miroslav Rezanina --- hw/vfio/common.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 26a5a14..197cd11 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -309,6 +309,11 @@ static void vfio_iommu_map_notify(Notifier *n, void *data) } } +static hwaddr vfio_container_granularity(VFIOContainer *container) +{ + return (hwaddr)1 << ctz64(container->iova_pgsizes); +} + static void vfio_listener_region_add(MemoryListener *listener, MemoryRegionSection *section) { @@ -366,26 +371,16 @@ static void vfio_listener_region_add(MemoryListener *listener, * would be the right place to wire that up (tell the KVM * device emulation the VFIO iommu handles to use). */ - /* - * This assumes that the guest IOMMU is empty of - * mappings at this point. - * - * One way of doing this is: - * 1. Avoid sharing IOMMUs between emulated devices or different - * IOMMU groups. - * 2. Implement VFIO_IOMMU_ENABLE in the host kernel to fail if - * there are some mappings in IOMMU. - * - * VFIO on SPAPR does that. Other IOMMU models may do that different, - * they must make sure there are no existing mappings or - * loop through existing mappings to map them into VFIO. - */ giommu = g_malloc0(sizeof(*giommu)); giommu->iommu = section->mr; giommu->container = container; giommu->n.notify = vfio_iommu_map_notify; QLIST_INSERT_HEAD(&container->giommu_list, giommu, giommu_next); + memory_region_register_iommu_notifier(giommu->iommu, &giommu->n); + memory_region_iommu_replay(giommu->iommu, &giommu->n, + vfio_container_granularity(container), + false); return; } -- 1.8.3.1