kvm: irqchip: Break up high order allocations of kvm_irq_routing_table

[firefly-linux-kernel-4.4.55.git] / virt / kvm / irqchip.c

diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index 1d56a901e791788d9f2c855dcf3e96a9b650df77..21c14244f4c4fd1c3c8ffade7f3265df91c89efb 100644 (file)
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -33,7 +33,6 @@
 
 struct kvm_irq_routing_table {
        int chip[KVM_NR_IRQCHIPS][KVM_IRQCHIP_NUM_PINS];
-       struct kvm_kernel_irq_routing_entry *rt_entries;
        u32 nr_rt_entries;
        /*
         * Array indexed by gsi. Each entry contains list of irq chips
@@ -118,11 +117,32 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level,
        return ret;
 }
 
+static void free_irq_routing_table(struct kvm_irq_routing_table *rt)
+{
+       int i;
+
+       if (!rt)
+               return;
+
+       for (i = 0; i < rt->nr_rt_entries; ++i) {
+               struct kvm_kernel_irq_routing_entry *e;
+               struct hlist_node *n;
+
+               hlist_for_each_entry_safe(e, n, &rt->map[i], link) {
+                       hlist_del(&e->link);
+                       kfree(e);
+               }
+       }
+
+       kfree(rt);
+}
+
 void kvm_free_irq_routing(struct kvm *kvm)
 {
        /* Called only during vm destruction. Nobody can use the pointer
           at this stage */
-       kfree(kvm->irq_routing);
+       struct kvm_irq_routing_table *rt = rcu_access_pointer(kvm->irq_routing);
+       free_irq_routing_table(rt);
 }
 
 static int setup_routing_entry(struct kvm_irq_routing_table *rt,
@@ -173,25 +193,29 @@ int kvm_set_irq_routing(struct kvm *kvm,
 
        nr_rt_entries += 1;
 
-       new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
-                     + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
+       new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head)),
                      GFP_KERNEL);
 
        if (!new)
                return -ENOMEM;
 
-       new->rt_entries = (void *)&new->map[nr_rt_entries];
-
        new->nr_rt_entries = nr_rt_entries;
        for (i = 0; i < KVM_NR_IRQCHIPS; i++)
                for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)
                        new->chip[i][j] = -1;
 
        for (i = 0; i < nr; ++i) {
+               struct kvm_kernel_irq_routing_entry *e;
+
+               r = -ENOMEM;
+               e = kzalloc(sizeof(*e), GFP_KERNEL);
+               if (!e)
+                       goto out;
+
                r = -EINVAL;
                if (ue->flags)
                        goto out;
-               r = setup_routing_entry(new, &new->rt_entries[i], ue);
+               r = setup_routing_entry(new, e, ue);
                if (r)
                        goto out;
                ++ue;
@@ -209,6 +233,7 @@ int kvm_set_irq_routing(struct kvm *kvm,
        r = 0;
 
 out:
-       kfree(new);
+       free_irq_routing_table(new);
+
        return r;
 }