From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59964) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zjqsg-0001Lx-00 for qemu-devel@nongnu.org; Wed, 07 Oct 2015 11:43:54 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zjqsb-0006YJ-Qt for qemu-devel@nongnu.org; Wed, 07 Oct 2015 11:43:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58411) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zjqsb-0006YB-Ky for qemu-devel@nongnu.org; Wed, 07 Oct 2015 11:43:45 -0400 From: Alex Williamson Date: Wed, 07 Oct 2015 09:43:44 -0600 Message-ID: <20151007154344.22135.547.stgit@gimli.home> In-Reply-To: <20151007153840.22135.78451.stgit@gimli.home> References: <20151007153840.22135.78451.stgit@gimli.home> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] [PULL 9/9] vfio: Allow hotplug of containers onto existing guest IOMMU mappings List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: David Gibson From: 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 Signed-off-by: Alex Williamson --- 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 f666de2..6797208 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 +374,16 @@ 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; }