On 09/03/12 07:20, Marcelo Tosatti wrote:
On Thu, Mar 08, 2012 at 10:03:55AM +0800, Amos Kong wrote:
This patch makes the kvm_io_range array can be resized dynamically.
Signed-off-by: Amos Kong<akong@xxxxxxxxxx>
---
include/linux/kvm_host.h | 5 +++--
virt/kvm/kvm_main.c | 38 ++++++++++++++++++--------------------
2 files changed, 21 insertions(+), 22 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index e42d85a..8a6c1a3 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -67,10 +67,11 @@ struct kvm_io_range {
struct kvm_io_device *dev;
};
+#define NR_IOBUS_DEVS 300
+
struct kvm_io_bus {
int dev_count;
-#define NR_IOBUS_DEVS 300
- struct kvm_io_range range[NR_IOBUS_DEVS];
+ struct kvm_io_range range[];
};
enum kvm_bus {
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 94e148e..f6ee1e2 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2393,9 +2393,6 @@ int kvm_io_bus_sort_cmp(const void *p1, const void *p2)
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 @@ int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
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 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,
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) {
Hi Marcelo,
the deleted dev is found here.
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;
+
+ new_bus->dev_count--;
Was just zeroed above?
+ memcpy(new_bus->range, bus->range, i * sizeof(struct kvm_io_range));
Oh, dev_count memory needs to be copied.
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));
Did you mean "i" as an indice for ->range[] ?
'i' is the index of deleted dev in bus->range[]
--
Amos.
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
