[PATCH 1/2] iommu/vt-d: Avoid iova flush queue in strict mode

[Lu Baolu]

If Intel IOMMU strict mode is enabled by users, it's unnecessary
to create the iova flush queue.

Signed-off-by: Lu Baolu <baolu...@linux.intel.com>
---
 drivers/iommu/intel-iommu.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0726705d2d89..93e1d7c3ac7c 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1858,10 +1858,12 @@ static int domain_init(struct dmar_domain *domain, 
struct intel_iommu *iommu,
 
        init_iova_domain(&domain->iovad, VTD_PAGE_SIZE, IOVA_START_PFN);
 
-       err = init_iova_flush_queue(&domain->iovad,
-                                   iommu_flush_iova, iova_entry_free);
-       if (err)
-               return err;
+       if (!intel_iommu_strict) {
+               err = init_iova_flush_queue(&domain->iovad,
+                                           iommu_flush_iova, iova_entry_free);
+               if (err)
+                       return err;
+       }
 
        domain_reserve_special_ranges(domain);
 
@@ -5199,6 +5201,7 @@ static struct iommu_domain 
*intel_iommu_domain_alloc(unsigned type)
 {
        struct dmar_domain *dmar_domain;
        struct iommu_domain *domain;
+       int ret;
 
        switch (type) {
        case IOMMU_DOMAIN_DMA:
@@ -5215,11 +5218,14 @@ static struct iommu_domain 
*intel_iommu_domain_alloc(unsigned type)
                        return NULL;
                }
 
-               if (type == IOMMU_DOMAIN_DMA &&
-                   init_iova_flush_queue(&dmar_domain->iovad,
-                                         iommu_flush_iova, iova_entry_free)) {
-                       pr_warn("iova flush queue initialization failed\n");
-                       intel_iommu_strict = 1;
+               if (!intel_iommu_strict && type == IOMMU_DOMAIN_DMA) {
+                       ret = init_iova_flush_queue(&dmar_domain->iovad,
+                                                   iommu_flush_iova,
+                                                   iova_entry_free);
+                       if (ret) {
+                               pr_warn("iova flush queue initialization 
failed\n");
+                               intel_iommu_strict = 1;
+                       }
                }
 
                domain_update_iommu_cap(dmar_domain);
-- 
2.17.1

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