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authorGregory Haskins <ghaskins@novell.com>2009-07-07 17:08:44 -0400
committerAvi Kivity <avi@redhat.com>2009-09-10 08:33:12 +0300
commit090b7aff27120cdae76a346a70db394844fea598 (patch)
tree4676410f57a44d7c0fba9d791fc77d7850ad1d51 /virt
parentfef07aae9cd9ed82f94228c311b35360f1f38902 (diff)
downloadlinux-2.6.34-ux500-090b7aff27120cdae76a346a70db394844fea598.tar.gz
KVM: make io_bus interface more robust
Today kvm_io_bus_regsiter_dev() returns void and will internally BUG_ON if it fails. We want to create dynamic MMIO/PIO entries driven from userspace later in the series, so we need to enhance the code to be more robust with the following changes: 1) Add a return value to the registration function 2) Fix up all the callsites to check the return code, handle any failures, and percolate the error up to the caller. 3) Add an unregister function that collapses holes in the array Signed-off-by: Gregory Haskins <ghaskins@novell.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/coalesced_mmio.c8
-rw-r--r--virt/kvm/ioapic.c8
-rw-r--r--virt/kvm/kvm_main.c39
3 files changed, 46 insertions, 9 deletions
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 0352f81ecc0..04d69cd7049 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -92,6 +92,7 @@ static const struct kvm_io_device_ops coalesced_mmio_ops = {
int kvm_coalesced_mmio_init(struct kvm *kvm)
{
struct kvm_coalesced_mmio_dev *dev;
+ int ret;
dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
if (!dev)
@@ -100,9 +101,12 @@ int kvm_coalesced_mmio_init(struct kvm *kvm)
kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
dev->kvm = kvm;
kvm->coalesced_mmio_dev = dev;
- kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev);
- return 0;
+ ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev);
+ if (ret < 0)
+ kfree(dev);
+
+ return ret;
}
int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index b91fbb21544..fa05f67423a 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -342,6 +342,7 @@ static const struct kvm_io_device_ops ioapic_mmio_ops = {
int kvm_ioapic_init(struct kvm *kvm)
{
struct kvm_ioapic *ioapic;
+ int ret;
ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
if (!ioapic)
@@ -350,7 +351,10 @@ int kvm_ioapic_init(struct kvm *kvm)
kvm_ioapic_reset(ioapic);
kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
ioapic->kvm = kvm;
- kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &ioapic->dev);
- return 0;
+ ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &ioapic->dev);
+ if (ret < 0)
+ kfree(ioapic);
+
+ return ret;
}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fc1b58a7275..9c2fd025b8a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2533,21 +2533,50 @@ int kvm_io_bus_read(struct kvm_io_bus *bus, gpa_t addr, int len, void *val)
return -EOPNOTSUPP;
}
-void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus,
+int kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus,
struct kvm_io_device *dev)
{
+ int ret;
+
down_write(&kvm->slots_lock);
- __kvm_io_bus_register_dev(bus, dev);
+ ret = __kvm_io_bus_register_dev(bus, dev);
up_write(&kvm->slots_lock);
+
+ return ret;
}
/* An unlocked version. Caller must have write lock on slots_lock. */
-void __kvm_io_bus_register_dev(struct kvm_io_bus *bus,
- struct kvm_io_device *dev)
+int __kvm_io_bus_register_dev(struct kvm_io_bus *bus,
+ struct kvm_io_device *dev)
{
- BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
+ if (bus->dev_count > NR_IOBUS_DEVS-1)
+ return -ENOSPC;
bus->devs[bus->dev_count++] = dev;
+
+ return 0;
+}
+
+void kvm_io_bus_unregister_dev(struct kvm *kvm,
+ struct kvm_io_bus *bus,
+ struct kvm_io_device *dev)
+{
+ down_write(&kvm->slots_lock);
+ __kvm_io_bus_unregister_dev(bus, dev);
+ up_write(&kvm->slots_lock);
+}
+
+/* An unlocked version. Caller must have write lock on slots_lock. */
+void __kvm_io_bus_unregister_dev(struct kvm_io_bus *bus,
+ struct kvm_io_device *dev)
+{
+ int i;
+
+ for (i = 0; i < bus->dev_count; i++)
+ if (bus->devs[i] == dev) {
+ bus->devs[i] = bus->devs[--bus->dev_count];
+ break;
+ }
}
static struct notifier_block kvm_cpu_notifier = {