iommu/vt-d: Make sure RMRRs are mapped before domain goes public

When a domain is allocated through the get_valid_domain_for_dev
path, it will be context-mapped before the RMRR regions are
mapped in the page-table. This opens a short time window
where device-accesses to these regions fail and causing DMAR
faults.

Fix this by mapping the RMRR regions before the domain is
context-mapped.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 20 insertions, 7 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index bcdbe9de7560..a4407eabf0e6 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3428,17 +3428,18 @@ static unsigned long intel_alloc_iova(struct device *dev,
 
 static struct dmar_domain *__get_valid_domain_for_dev(struct device *dev)
 {
+        struct dmar_domain *domain, *tmp;
         struct dmar_rmrr_unit *rmrr;
-        struct dmar_domain *domain;
         struct device *i_dev;
         int i, ret;
 
-        domain = get_domain_for_dev(dev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
-        if (!domain) {
-                pr_err("Allocating domain for %s failed\n",
-                       dev_name(dev));
-                return NULL;
-        }
+        domain = find_domain(dev);
+        if (domain)
+                goto out;
+
+        domain = find_or_alloc_domain(dev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
+        if (!domain)
+                goto out;
 
         /* We have a new domain - setup possible RMRRs for the device */
         rcu_read_lock();
@@ -3457,6 +3458,18 @@ static struct dmar_domain *__get_valid_domain_for_dev(struct device *dev)
         }
         rcu_read_unlock();
 
+        tmp = set_domain_for_dev(dev, domain);
+        if (!tmp || domain != tmp) {
+                domain_exit(domain);
+                domain = tmp;
+        }
+
+out:
+
+        if (!domain)
+                pr_err("Allocating domain for %s failed\n", dev_name(dev));
+
+
         return domain;
 }