2 files changed, 107 insertions, 2 deletions

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index d5c0057196ae..5523f0a1cddc 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1838,13 +1838,89 @@ static int vgic_its_restore_device_tables(struct vgic_its *its)
 	return -ENXIO;
 }
 
+static int vgic_its_save_cte(struct vgic_its *its,
+			     struct its_collection *collection,
+			     gpa_t gpa, int esz)
+{
+	u64 val;
+
+	val = (1ULL << KVM_ITS_CTE_VALID_SHIFT |
+	       ((u64)collection->target_addr << KVM_ITS_CTE_RDBASE_SHIFT) |
+	       collection->collection_id);
+	val = cpu_to_le64(val);
+	return kvm_write_guest(its->dev->kvm, gpa, &val, esz);
+}
+
+static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz)
+{
+	struct its_collection *collection;
+	struct kvm *kvm = its->dev->kvm;
+	u32 target_addr, coll_id;
+	u64 val;
+	int ret;
+
+	BUG_ON(esz > sizeof(val));
+	ret = kvm_read_guest(kvm, gpa, &val, esz);
+	if (ret)
+		return ret;
+	val = le64_to_cpu(val);
+	if (!(val & KVM_ITS_CTE_VALID_MASK))
+		return 0;
+
+	target_addr = (u32)(val >> KVM_ITS_CTE_RDBASE_SHIFT);
+	coll_id = val & KVM_ITS_CTE_ICID_MASK;
+
+	if (target_addr >= atomic_read(&kvm->online_vcpus))
+		return -EINVAL;
+
+	collection = find_collection(its, coll_id);
+	if (collection)
+		return -EEXIST;
+	ret = vgic_its_alloc_collection(its, &collection, coll_id);
+	if (ret)
+		return ret;
+	collection->target_addr = target_addr;
+	return 1;
+}
+
 /**
  * vgic_its_save_collection_table - Save the collection table into
  * guest RAM
  */
 static int vgic_its_save_collection_table(struct vgic_its *its)
 {
-	return -ENXIO;
+	const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+	struct its_collection *collection;
+	u64 val;
+	gpa_t gpa;
+	size_t max_size, filled = 0;
+	int ret, cte_esz = abi->cte_esz;
+
+	gpa = BASER_ADDRESS(its->baser_coll_table);
+	if (!gpa)
+		return 0;
+
+	max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K;
+
+	list_for_each_entry(collection, &its->collection_list, coll_list) {
+		ret = vgic_its_save_cte(its, collection, gpa, cte_esz);
+		if (ret)
+			return ret;
+		gpa += cte_esz;
+		filled += cte_esz;
+	}
+
+	if (filled == max_size)
+		return 0;
+
+	/*
+	 * table is not fully filled, add a last dummy element
+	 * with valid bit unset
+	 */
+	val = 0;
+	BUG_ON(cte_esz > sizeof(val));
+	ret = kvm_write_guest(its->dev->kvm, gpa, &val, cte_esz);
+	return ret;
 }
 
 /**
@@ -1854,7 +1930,27 @@ static int vgic_its_save_collection_table(struct vgic_its *its)
  */
 static int vgic_its_restore_collection_table(struct vgic_its *its)
 {
-	return -ENXIO;
+	const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+	int cte_esz = abi->cte_esz;
+	size_t max_size, read = 0;
+	gpa_t gpa;
+	int ret;
+
+	if (!(its->baser_coll_table & GITS_BASER_VALID))
+		return 0;
+
+	gpa = BASER_ADDRESS(its->baser_coll_table);
+
+	max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K;
+
+	while (read < max_size) {
+		ret = vgic_its_restore_cte(its, gpa, cte_esz);
+		if (ret <= 0)
+			break;
+		gpa += cte_esz;
+		read += cte_esz;
+	}
+	return ret;
 }
 
 /**
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 79768c801863..757de7a2bdc3 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -73,6 +73,15 @@
 				      KVM_REG_ARM_VGIC_SYSREG_CRM_MASK | \
 				      KVM_REG_ARM_VGIC_SYSREG_OP2_MASK)
 
+/*
+ * As per Documentation/virtual/kvm/devices/arm-vgic-its.txt,
+ * below macros are defined for ITS table entry encoding.
+ */
+#define KVM_ITS_CTE_VALID_SHIFT		63
+#define KVM_ITS_CTE_VALID_MASK		BIT_ULL(63)
+#define KVM_ITS_CTE_RDBASE_SHIFT	16
+#define KVM_ITS_CTE_ICID_MASK		GENMASK_ULL(15, 0)
+
 static inline bool irq_is_pending(struct vgic_irq *irq)
 {
 	if (irq->config == VGIC_CONFIG_EDGE)