iommu/vt-d: Fix dead-locks in disable_dmar_iommu() path

It turns out that the disable_dmar_iommu() code-path tried
to get the device_domain_lock recursivly, which will
dead-lock when this code runs on dmar removal. Fix both
code-paths that could lead to the dead-lock.

Fixes: 55d940430ab9 ('iommu/vt-d: Get rid of domain->iommu_lock')
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a4407eabf0e6..3965e73db51c 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1711,6 +1711,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
         if (!iommu->domains || !iommu->domain_ids)
                 return;
 
+again:
         spin_lock_irqsave(&device_domain_lock, flags);
         list_for_each_entry_safe(info, tmp, &device_domain_list, global) {
                 struct dmar_domain *domain;
@@ -1723,10 +1724,19 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
 
                 domain = info->domain;
 
-                dmar_remove_one_dev_info(domain, info->dev);
+                __dmar_remove_one_dev_info(info);
 
-                if (!domain_type_is_vm_or_si(domain))
+                if (!domain_type_is_vm_or_si(domain)) {
+                        /*
+                         * The domain_exit() function  can't be called under
+                         * device_domain_lock, as it takes this lock itself.
+                         * So release the lock here and re-run the loop
+                         * afterwards.
+                         */
+                        spin_unlock_irqrestore(&device_domain_lock, flags);
                         domain_exit(domain);
+                        goto again;
+                }
         }
         spin_unlock_irqrestore(&device_domain_lock, flags);