KVM: remove the usage of the mmap_sem for the protection of the memory slots.

This patch replaces the mmap_sem lock for the memory slots with a new
kvm private lock, it is needed beacuse untill now there were cases where
kvm accesses user memory while holding the mmap semaphore.

Signed-off-by: Izik Eidus <izike@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ea4764b0a2f..928b0d59e9b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -107,6 +107,7 @@ struct kvm_memory_slot {
 struct kvm {
         struct mutex lock; /* protects the vcpus array and APIC accesses */
         spinlock_t mmu_lock;
+        struct rw_semaphore slots_lock;
         struct mm_struct *mm; /* userspace tied to this vm */
         int nmemslots;
         struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS +