KVM: PPC: Book3S: Fix some RCU-list locks

[platform/kernel/linux-rpi.git] / arch / powerpc / kvm / book3s_64_vio.c

diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
index 5834db0..03b9474 100644 (file)
--- a/arch/powerpc/kvm/book3s_64_vio.c
+++ b/arch/powerpc/kvm/book3s_64_vio.c
@@ -74,6 +74,7 @@ extern void kvm_spapr_tce_release_iommu_group(struct kvm *kvm,
        struct kvmppc_spapr_tce_iommu_table *stit, *tmp;
        struct iommu_table_group *table_group = NULL;
 
+       rcu_read_lock();
        list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
 
                table_group = iommu_group_get_iommudata(grp);
@@ -88,7 +89,9 @@ extern void kvm_spapr_tce_release_iommu_group(struct kvm *kvm,
                                kref_put(&stit->kref, kvm_spapr_tce_liobn_put);
                        }
                }
+               cond_resched_rcu();
        }
+       rcu_read_unlock();
 }
 
 extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
@@ -106,12 +109,14 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
        if (!f.file)
                return -EBADF;
 
+       rcu_read_lock();
        list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
                if (stt == f.file->private_data) {
                        found = true;
                        break;
                }
        }
+       rcu_read_unlock();
 
        fdput(f);
 
@@ -144,6 +149,7 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
        if (!tbl)
                return -EINVAL;
 
+       rcu_read_lock();
        list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
                if (tbl != stit->tbl)
                        continue;
@@ -151,14 +157,17 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
                if (!kref_get_unless_zero(&stit->kref)) {
                        /* stit is being destroyed */
                        iommu_tce_table_put(tbl);
+                       rcu_read_unlock();
                        return -ENOTTY;
                }
                /*
                 * The table is already known to this KVM, we just increased
                 * its KVM reference counter and can return.
                 */
+               rcu_read_unlock();
                return 0;
        }
+       rcu_read_unlock();
 
        stit = kzalloc(sizeof(*stit), GFP_KERNEL);
        if (!stit) {
@@ -364,18 +373,19 @@ static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt,
        if (kvmppc_tce_to_ua(stt->kvm, tce, &ua))
                return H_TOO_HARD;
 
+       rcu_read_lock();
        list_for_each_entry_rcu(stit, &stt->iommu_tables, next) {
                unsigned long hpa = 0;
                struct mm_iommu_table_group_mem_t *mem;
                long shift = stit->tbl->it_page_shift;
 
                mem = mm_iommu_lookup(stt->kvm->mm, ua, 1ULL << shift);
-               if (!mem)
-                       return H_TOO_HARD;
-
-               if (mm_iommu_ua_to_hpa(mem, ua, shift, &hpa))
+               if (!mem || mm_iommu_ua_to_hpa(mem, ua, shift, &hpa)) {
+                       rcu_read_unlock();
                        return H_TOO_HARD;
+               }
        }
+       rcu_read_unlock();
 
        return H_SUCCESS;
 }