KVM: mark memory slots as rcu

we access the memslots array via srcu. Mark it as such and
use the right access functions also for the freeing of
memory slots.

Found by sparse:
./include/linux/kvm_host.h:565:16: error: incompatible types in
comparison expression (different address spaces)

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6a164f9..b3ca77a 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -390,7 +390,7 @@ struct kvm {
        spinlock_t mmu_lock;
        struct mutex slots_lock;
        struct mm_struct *mm; /* userspace tied to this vm */
-       struct kvm_memslots *memslots[KVM_ADDRESS_SPACE_NUM];
+       struct kvm_memslots __rcu *memslots[KVM_ADDRESS_SPACE_NUM];
        struct kvm_vcpu *vcpus[KVM_MAX_VCPUS];
 
        /*

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d76e822..6e6d4ed 100644 (file)
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -707,7 +707,8 @@ out_err_no_disable:
        for (i = 0; i < KVM_NR_BUSES; i++)
                kfree(rcu_access_pointer(kvm->buses[i]));
        for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
-               kvm_free_memslots(kvm, kvm->memslots[i]);
+               kvm_free_memslots(kvm,
+                       rcu_dereference_protected(kvm->memslots[i], 1));
        kvm_arch_free_vm(kvm);
        mmdrop(current->mm);
        return ERR_PTR(r);
@@ -756,7 +757,8 @@ static void kvm_destroy_vm(struct kvm *kvm)
        kvm_arch_destroy_vm(kvm);
        kvm_destroy_devices(kvm);
        for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
-               kvm_free_memslots(kvm, kvm->memslots[i]);
+               kvm_free_memslots(kvm,
+                       rcu_dereference_protected(kvm->memslots[i], 1));
        cleanup_srcu_struct(&kvm->irq_srcu);
        cleanup_srcu_struct(&kvm->srcu);
        kvm_arch_free_vm(kvm);