iommu/vt-d: Fix issue in computing domain's iommu_snooping flag

IOMMU units may dynamically attached to/detached from domains,
so we should scan all active IOMMU units when computing iommu_snooping
flag for a domain instead of only scanning IOMMU units associated
with the domain.

Also check snooping and superpage capabilities when hot-adding DMAR units.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

1 files changed, 24 insertions, 18 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index cd1ba24c766a..58cc2b75d7ae 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -633,50 +633,56 @@ static void domain_update_iommu_coherency(struct dmar_domain *domain)
         rcu_read_unlock();
 }
 
-static void domain_update_iommu_snooping(struct dmar_domain *domain)
+static int domain_update_iommu_snooping(struct intel_iommu *skip)
 {
-        int i;
-
-        domain->iommu_snooping = 1;
+        struct dmar_drhd_unit *drhd;
+        struct intel_iommu *iommu;
+        int ret = 1;
 
-        for_each_set_bit(i, domain->iommu_bmp, g_num_of_iommus) {
-                if (!ecap_sc_support(g_iommus[i]->ecap)) {
-                        domain->iommu_snooping = 0;
-                        break;
+        rcu_read_lock();
+        for_each_active_iommu(iommu, drhd) {
+                if (iommu != skip) {
+                        if (!ecap_sc_support(iommu->ecap)) {
+                                ret = 0;
+                                break;
+                        }
                 }
         }
+        rcu_read_unlock();
+
+        return ret;
 }
 
-static void domain_update_iommu_superpage(struct dmar_domain *domain)
+static int domain_update_iommu_superpage(struct intel_iommu *skip)
 {
         struct dmar_drhd_unit *drhd;
-        struct intel_iommu *iommu = NULL;
+        struct intel_iommu *iommu;
         int mask = 0xf;
 
         if (!intel_iommu_superpage) {
-                domain->iommu_superpage = 0;
-                return;
+                return 0;
         }
 
         /* set iommu_superpage to the smallest common denominator */
         rcu_read_lock();
         for_each_active_iommu(iommu, drhd) {
-                mask &= cap_super_page_val(iommu->cap);
-                if (!mask) {
-                        break;
+                if (iommu != skip) {
+                        mask &= cap_super_page_val(iommu->cap);
+                        if (!mask)
+                                break;
                 }
         }
         rcu_read_unlock();
 
-        domain->iommu_superpage = fls(mask);
+        return fls(mask);
 }
 
 /* Some capabilities may be different across iommus */
 static void domain_update_iommu_cap(struct dmar_domain *domain)
 {
         domain_update_iommu_coherency(domain);
-        domain_update_iommu_snooping(domain);
-        domain_update_iommu_superpage(domain);
+        domain->iommu_snooping = domain_update_iommu_snooping(NULL);
+        domain->iommu_superpage = domain_update_iommu_superpage(NULL);
 }
 
 static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn)