intel-iommu: set iommu_superpage on VM domains to lowest common denominator

set dmar->iommu_superpage field to the smallest common denominator
of super page sizes supported by all active VT-d engines.  Initialize
this field in intel_iommu_domain_init() API so intel_iommu_map() API
will be able to use iommu_superpage field to determine the appropriate
super page size to use.

Signed-off-by: Allen Kay <allen.m.kay@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 237ef52c8c7684e15077568b25f3d7637b607f2d..e5883602cb359cd246921ded93ef0df18200b985 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -580,17 +580,18 @@ static void domain_update_iommu_snooping(struct dmar_domain *domain)
 
 static void domain_update_iommu_superpage(struct dmar_domain *domain)
 {
-       int i, mask = 0xf;
+       struct dmar_drhd_unit *drhd;
+       struct intel_iommu *iommu = NULL;
+       int mask = 0xf;
 
        if (!intel_iommu_superpage) {
                domain->iommu_superpage = 0;
                return;
        }
 
-       domain->iommu_superpage = 4; /* 1TiB */
-
-       for_each_set_bit(i, &domain->iommu_bmp, g_num_of_iommus) {
-               mask |= cap_super_page_val(g_iommus[i]->cap);
+       /* set iommu_superpage to the smallest common denominator */
+       for_each_active_iommu(iommu, drhd) {
+               mask &= cap_super_page_val(iommu->cap);
                if (!mask) {
                        break;
                }
@@ -3748,6 +3749,7 @@ static int intel_iommu_domain_init(struct iommu_domain *domain)
                vm_domain_exit(dmar_domain);
                return -ENOMEM;
        }
+       domain_update_iommu_cap(dmar_domain);
        domain->priv = dmar_domain;
 
        return 0;