KVM: resize kvm_io_range array dynamically
This patch makes the kvm_io_range array can be resized dynamically.
Signed-off-by: Amos Kong <akong@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 42b7393..a9565e2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2393,9 +2393,6 @@
int kvm_io_bus_insert_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev,
gpa_t addr, int len)
{
- if (bus->dev_count == NR_IOBUS_DEVS)
- return -ENOSPC;
-
bus->range[bus->dev_count++] = (struct kvm_io_range) {
.addr = addr,
.len = len,
@@ -2495,12 +2492,15 @@
struct kvm_io_bus *new_bus, *bus;
bus = kvm->buses[bus_idx];
- if (bus->dev_count > NR_IOBUS_DEVS-1)
+ if (bus->dev_count > NR_IOBUS_DEVS - 1)
return -ENOSPC;
- new_bus = kmemdup(bus, sizeof(struct kvm_io_bus), GFP_KERNEL);
+ new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count + 1) *
+ sizeof(struct kvm_io_range)), GFP_KERNEL);
if (!new_bus)
return -ENOMEM;
+ memcpy(new_bus, bus, sizeof(*bus) + (bus->dev_count *
+ sizeof(struct kvm_io_range)));
kvm_io_bus_insert_dev(new_bus, dev, addr, len);
rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
synchronize_srcu_expedited(&kvm->srcu);
@@ -2517,27 +2517,25 @@
struct kvm_io_bus *new_bus, *bus;
bus = kvm->buses[bus_idx];
-
- new_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL);
- if (!new_bus)
- return -ENOMEM;
-
r = -ENOENT;
- for (i = 0; i < new_bus->dev_count; i++)
- if (new_bus->range[i].dev == dev) {
+ for (i = 0; i < bus->dev_count; i++)
+ if (bus->range[i].dev == dev) {
r = 0;
- new_bus->dev_count--;
- new_bus->range[i] = new_bus->range[new_bus->dev_count];
- sort(new_bus->range, new_bus->dev_count,
- sizeof(struct kvm_io_range),
- kvm_io_bus_sort_cmp, NULL);
break;
}
- if (r) {
- kfree(new_bus);
+ if (r)
return r;
- }
+
+ new_bus = kzalloc(sizeof(*bus) + ((bus->dev_count - 1) *
+ sizeof(struct kvm_io_range)), GFP_KERNEL);
+ if (!new_bus)
+ return -ENOMEM;
+
+ memcpy(new_bus, bus, sizeof(*bus) + i * sizeof(struct kvm_io_range));
+ new_bus->dev_count--;
+ memcpy(new_bus->range + i, bus->range + i + 1,
+ (new_bus->dev_count - i) * sizeof(struct kvm_io_range));
rcu_assign_pointer(kvm->buses[bus_idx], new_bus);
synchronize_srcu_expedited(&kvm->srcu);