From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50275) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZfRHA-0005DH-Qv for qemu-devel@nongnu.org; Fri, 25 Sep 2015 07:34:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZfRH8-00027y-NF for qemu-devel@nongnu.org; Fri, 25 Sep 2015 07:34:52 -0400 From: David Gibson Date: Fri, 25 Sep 2015 21:35:07 +1000 Message-Id: <1443180908-19911-7-git-send-email-david@gibson.dropbear.id.au> In-Reply-To: <1443180908-19911-1-git-send-email-david@gibson.dropbear.id.au> References: <1443180908-19911-1-git-send-email-david@gibson.dropbear.id.au> Subject: [Qemu-devel] [PATCHv2 6/7] vfio: Allow hotplug of containers onto existing guest IOMMU mappings List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: alex.williamson@redhat.com, pbonzini@redhat.com Cc: lvivier@redhat.com, thuth@redhat.com, abologna@redhat.com, qemu-devel@nongnu.org, qemu-ppc@nongnu.org, David Gibson 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 --- hw/vfio/common.c | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) diff --git a/hw/vfio/common.c b/hw/vfio/common.c index f666de2..a1bd078 100644 --- a/hw/vfio/common.c +++ b/hw/vfio/common.c @@ -312,6 +312,11 @@ out: rcu_read_unlock(); } +static hwaddr vfio_container_granularity(VFIOContainer *container) +{ + return (hwaddr)1 << ctz64(container->iova_pgsizes); +} + static void vfio_listener_region_add(MemoryListener *listener, MemoryRegionSection *section) { @@ -369,26 +374,14 @@ 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_register_iommu_notifier_replay(giommu->iommu, &giommu->n, + vfio_container_granularity(container), false); return; } -- 2.4.3