[PATCH v3 0/2] Misc cleanup for iommu/vt-d

[PATCH v3 0/2] Misc cleanup for iommu/vt-d

[Yanfei Xu]

No functional changes intended

v1->v2:
1.Change to use check and return for dmar_reenable_qi()
2.Remove WARN_ON of 'table' instead of using BUG_ON
3.Also remove useless WARN_ON of domain id

v2->v3:
Move check for 'ret' value to correct conditional statement.
(For patch2. Pointed out by Robin)

Yanfei Xu (2):
  iommu/vt-d: Handle the failure case of dmar_reenable_qi()
  iommu/vt-d: Remove two WARN_ON in domain_context_mapping_one()

 drivers/iommu/intel/iommu.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

-- 
2.34.1

[PATCH v3 1/2] iommu/vt-d: Handle the failure case of dmar_reenable_qi()

[Yanfei Xu]

dmar_reenable_qi() may not succeed. Check and return when it fails.

Signed-off-by: Yanfei Xu <yanfei.xu@intel.com>
---
 drivers/iommu/intel/iommu.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 8096273b034c..c13c6475b626 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -2967,10 +2967,15 @@ static int init_iommu_hw(void)
 {
 	struct dmar_drhd_unit *drhd;
 	struct intel_iommu *iommu = NULL;
+	int ret;
 
-	for_each_active_iommu(iommu, drhd)
-		if (iommu->qi)
-			dmar_reenable_qi(iommu);
+	for_each_active_iommu(iommu, drhd) {
+		if (iommu->qi) {
+			ret = dmar_reenable_qi(iommu);
+			if (ret)
+				return ret;
+		}
+	}
 
 	for_each_iommu(iommu, drhd) {
 		if (drhd->ignored) {
-- 
2.34.1

[PATCH v3 2/2] iommu/vt-d: Remove two WARN_ON in domain_context_mapping_one()

[Yanfei Xu]

Remove the WARN_ON(did == 0) as the domain id 0 is reserved and
set once the domain_ids is allocated. So iommu_init_domains will
never return 0.

Remvoe the WARN_ON(!table) as this pointer will be accessed in
the following code, if empty "table" really happens, the kernel
will report a NULL pointer reference warning at the first place.

Signed-off-by: Yanfei Xu <yanfei.xu@intel.com>
---
 drivers/iommu/intel/iommu.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index c13c6475b626..cd9e01a0aa1d 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1897,8 +1897,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 	struct context_entry *context;
 	int ret;
 
-	WARN_ON(did == 0);
-
 	if (hw_pass_through && domain_type_is_si(domain))
 		translation = CONTEXT_TT_PASS_THROUGH;
 
@@ -1944,8 +1942,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
 	if (sm_supported(iommu)) {
 		unsigned long pds;
 
-		WARN_ON(!table);
-
 		/* Setup the PASID DIR pointer: */
 		pds = context_get_sm_pds(table);
 		context->lo = (u64)virt_to_phys(table->table) |
-- 
2.34.1