[PATCH 42/47] KVM: switch coalesced mmio changes to slots_lock

[Avi Kivity]

From: Michael S. Tsirkin <m...@redhat.com>

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.

[avi: fix build]

Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
Signed-off-by: Avi Kivity <a...@redhat.com>
---
 virt/kvm/coalesced_mmio.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
index 397f419..b40946c 100644
--- a/virt/kvm/coalesced_mmio.c
+++ b/virt/kvm/coalesced_mmio.c
@@ -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);
+       up_write(&kvm->slots_lock);
 
        return 0;
 }
-- 
1.6.3.3

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