Merge branch 'kvm-lockdep-common' into HEAD

Introduce new mutex locking functions mutex_trylock_nest_lock() and
mutex_lock_killable_nest_lock() and use them to clean up locking
of all vCPUs for a VM.

For x86, this removes some complex code that was used instead
of lockdep's "nest_lock" feature.

For ARM and RISC-V, this removes a lockdep warning when the VM is
configured to have more than MAX_LOCK_DEPTH vCPUs, and removes a fair
amount of duplicate code by sharing the logic across all architectures.

Signed-off-by: Paolo BOnzini <pbonzini@redhat.com>

2 files changed, 32 insertions, 4 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c685fb417e92..3bde4fb5c6aa 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1015,6 +1015,10 @@ static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
 
 void kvm_destroy_vcpus(struct kvm *kvm);
 
+int kvm_trylock_all_vcpus(struct kvm *kvm);
+int kvm_lock_all_vcpus(struct kvm *kvm);
+void kvm_unlock_all_vcpus(struct kvm *kvm);
+
 void vcpu_load(struct kvm_vcpu *vcpu);
 void vcpu_put(struct kvm_vcpu *vcpu);
 
diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index 2143d05116be..a039fa8c1780 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -156,16 +156,15 @@ static inline int __devm_mutex_init(struct device *dev, struct mutex *lock)
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass);
 extern void _mutex_lock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
-
 extern int __must_check mutex_lock_interruptible_nested(struct mutex *lock,
 					unsigned int subclass);
-extern int __must_check mutex_lock_killable_nested(struct mutex *lock,
-					unsigned int subclass);
+extern int __must_check _mutex_lock_killable(struct mutex *lock,
+		unsigned int subclass, struct lockdep_map *nest_lock);
 extern void mutex_lock_io_nested(struct mutex *lock, unsigned int subclass);
 
 #define mutex_lock(lock) mutex_lock_nested(lock, 0)
 #define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0)
-#define mutex_lock_killable(lock) mutex_lock_killable_nested(lock, 0)
+#define mutex_lock_killable(lock) _mutex_lock_killable(lock, 0, NULL)
 #define mutex_lock_io(lock) mutex_lock_io_nested(lock, 0)
 
 #define mutex_lock_nest_lock(lock, nest_lock)				\
@@ -174,6 +173,15 @@ do {									\
 	_mutex_lock_nest_lock(lock, &(nest_lock)->dep_map);		\
 } while (0)
 
+#define mutex_lock_killable_nest_lock(lock, nest_lock)			\
+(									\
+	typecheck(struct lockdep_map *, &(nest_lock)->dep_map),		\
+	_mutex_lock_killable(lock, 0, &(nest_lock)->dep_map)		\
+)
+
+#define mutex_lock_killable_nested(lock, subclass) \
+	_mutex_lock_killable(lock, subclass, NULL)
+
 #else
 extern void mutex_lock(struct mutex *lock);
 extern int __must_check mutex_lock_interruptible(struct mutex *lock);
@@ -183,6 +191,7 @@ extern void mutex_lock_io(struct mutex *lock);
 # define mutex_lock_nested(lock, subclass) mutex_lock(lock)
 # define mutex_lock_interruptible_nested(lock, subclass) mutex_lock_interruptible(lock)
 # define mutex_lock_killable_nested(lock, subclass) mutex_lock_killable(lock)
+# define mutex_lock_killable_nest_lock(lock, nest_lock) mutex_lock_killable(lock)
 # define mutex_lock_nest_lock(lock, nest_lock) mutex_lock(lock)
 # define mutex_lock_io_nested(lock, subclass) mutex_lock_io(lock)
 #endif
@@ -193,7 +202,22 @@ extern void mutex_lock_io(struct mutex *lock);
  *
  * Returns 1 if the mutex has been acquired successfully, and 0 on contention.
  */
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+extern int _mutex_trylock_nest_lock(struct mutex *lock, struct lockdep_map *nest_lock);
+
+#define mutex_trylock_nest_lock(lock, nest_lock)		\
+(								\
+	typecheck(struct lockdep_map *, &(nest_lock)->dep_map),	\
+	_mutex_trylock_nest_lock(lock, &(nest_lock)->dep_map)	\
+)
+
+#define mutex_trylock(lock) _mutex_trylock_nest_lock(lock, NULL)
+#else
 extern int mutex_trylock(struct mutex *lock);
+#define mutex_trylock_nest_lock(lock, nest_lock) mutex_trylock(lock)
+#endif
+
 extern void mutex_unlock(struct mutex *lock);
 
 extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);