KVM: convert bus to slots_lock

Use slots_lock to protect device list on the bus.  slots_lock is already
taken for read everywhere, so we only need to take it for write when
registering devices.  This is in preparation to removing in_range and
kvm->lock around it.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2009-06-29 22:24:26 +03:00 committed by Avi Kivity
parent 108b56690f
commit 6c47469453
6 changed files with 21 additions and 7 deletions

View file

@ -583,6 +583,7 @@ static const struct kvm_io_device_ops speaker_dev_ops = {
.in_range = speaker_in_range,
};
/* Caller must have writers lock on slots_lock */
struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags)
{
struct kvm_pit *pit;
@ -621,11 +622,11 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags)
kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
kvm_iodevice_init(&pit->dev, &pit_dev_ops);
kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev);
__kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev);
if (flags & KVM_PIT_SPEAKER_DUMMY) {
kvm_iodevice_init(&pit->speaker_dev, &speaker_dev_ops);
kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev);
__kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev);
}
return pit;

View file

@ -548,6 +548,6 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm)
* Initialize PIO device
*/
kvm_iodevice_init(&s->dev, &picdev_ops);
kvm_io_bus_register_dev(&kvm->pio_bus, &s->dev);
kvm_io_bus_register_dev(kvm, &kvm->pio_bus, &s->dev);
return s;
}

View file

@ -42,6 +42,7 @@
#define KVM_USERSPACE_IRQ_SOURCE_ID 0
struct kvm;
struct kvm_vcpu;
extern struct kmem_cache *kvm_vcpu_cache;
@ -61,7 +62,9 @@ void kvm_io_bus_init(struct kvm_io_bus *bus);
void kvm_io_bus_destroy(struct kvm_io_bus *bus);
struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
gpa_t addr, int len, int is_write);
void kvm_io_bus_register_dev(struct kvm_io_bus *bus,
void __kvm_io_bus_register_dev(struct kvm_io_bus *bus,
struct kvm_io_device *dev);
void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus,
struct kvm_io_device *dev);
struct kvm_vcpu {

View file

@ -102,7 +102,7 @@ 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->mmio_bus, &dev->dev);
kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev);
return 0;
}

View file

@ -343,7 +343,7 @@ 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->mmio_bus, &ioapic->dev);
kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &ioapic->dev);
return 0;
}

View file

@ -2527,7 +2527,17 @@ struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
return NULL;
}
void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
void kvm_io_bus_register_dev(struct kvm *kvm, struct kvm_io_bus *bus,
struct kvm_io_device *dev)
{
down_write(&kvm->slots_lock);
__kvm_io_bus_register_dev(bus, dev);
up_write(&kvm->slots_lock);
}
/* 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)
{
BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));