[PATCHv5 2/6] kvm: switch coalesced mmio changes to slots_lock

Michael S. Tsirkin
2009-06-29T19:25:23Z

switch coalesced mmio slots_lock. slots_lock is already taken for read
everywhere, so we only need to take it for write when changing zones.
This is in preparation to removing in_range and kvm->lock around it.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
virt/kvm/coalesced_mmio.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 397f419..7b7cc9f 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -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;
}
@@ -115,16 +115,16 @@ int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
if (dev == NULL)
return -EINVAL;

- mutex_lock(&kvm->lock);
+ down_write(&kvm->slots_lock);
if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) {
- mutex_unlock(&kvm->lock);
+ up_write(&kvm->slots_lock);
return -ENOBUFS;
}

dev->zone[dev->nb_zones] = *zone;
dev->nb_zones++;

- mutex_unlock(&kvm->lock);
+ up_write(&kvm->slots_lock);
return 0;
}

@@ -138,7 +138,7 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
if (dev == NULL)
return -EINVAL;

- mutex_lock(&kvm->lock);
+ down_write(&kvm->slots_lock);

i = dev->nb_zones;
while(i) {
@@ -156,7 +156,7 @@ int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
i--;
}

- mutex_unlock(&kvm->lock);