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 6a164f9eb02c159bb03558bf9bbf5293406f83ad..b3ca77a96b2d7520f37007f3ab0746e229d4616e 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 d76e822f89291a00002cd2f5ff83afe6777584a5..6e6d4edf0e92311d7c48ca18aab53603d56fe3bc 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);