From e7f9fa5498d91fcdc63d93007ba43f36b1a30538 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Tue, 5 Aug 2014 12:55:45 +0200 Subject: [PATCH] iommu/vt-d: Defer domain removal if device is assigned to a driver When the BUS_NOTIFY_DEL_DEVICE event is received the device might still be attached to a driver. In this case the domain can't be released as the mappings might still be in use. Defer the domain removal in this case until we receivce the BUS_NOTIFY_UNBOUND_DRIVER event. Cc: Jiang Liu Cc: David Woodhouse Cc: stable@vger.kernel.org # v3.15, v3.16 Signed-off-by: Joerg Roedel --- drivers/iommu/intel-iommu.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index d1f5caa..5619f26 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -3869,6 +3869,14 @@ static int device_notifier(struct notifier_block *nb, action != BUS_NOTIFY_DEL_DEVICE) return 0; + /* + * If the device is still attached to a device driver we can't + * tear down the domain yet as DMA mappings may still be in use. + * Wait for the BUS_NOTIFY_UNBOUND_DRIVER event to do that. + */ + if (action == BUS_NOTIFY_DEL_DEVICE && dev->driver != NULL) + return 0; + domain = find_domain(dev); if (!domain) return 0; -- 2.7.4