3 files changed, 45 insertions, 0 deletions
diff --git a/tools/virtio/linux/compiler.h b/tools/virtio/linux/compiler.h
index 1f3a15b954b9..204ef0e9f542 100644
--- a/tools/virtio/linux/compiler.h
+++ b/tools/virtio/linux/compiler.h
@@ -10,4 +10,29 @@
 #define READ_ONCE(var) (*((volatile typeof(var) *)(&(var))))
 
 #define __aligned(x) __attribute((__aligned__(x)))
+
+/**
+ * data_race - mark an expression as containing intentional data races
+ *
+ * This data_race() macro is useful for situations in which data races
+ * should be forgiven.  One example is diagnostic code that accesses
+ * shared variables but is not a part of the core synchronization design.
+ * For example, if accesses to a given variable are protected by a lock,
+ * except for diagnostic code, then the accesses under the lock should
+ * be plain C-language accesses and those in the diagnostic code should
+ * use data_race().  This way, KCSAN will complain if buggy lockless
+ * accesses to that variable are introduced, even if the buggy accesses
+ * are protected by READ_ONCE() or WRITE_ONCE().
+ *
+ * This macro *does not* affect normal code generation, but is a hint
+ * to tooling that data races here are to be ignored.  If the access must
+ * be atomic *and* KCSAN should ignore the access, use both data_race()
+ * and READ_ONCE(), for example, data_race(READ_ONCE(x)).
+ */
+#define data_race(expr)							\
+({									\
+	__auto_type __v = (expr);					\
+	__v;								\
+})
+
 #endif
diff --git a/tools/virtio/linux/dma-mapping.h b/tools/virtio/linux/dma-mapping.h
index 822ecaa8e4df..095958461788 100644
--- a/tools/virtio/linux/dma-mapping.h
+++ b/tools/virtio/linux/dma-mapping.h
@@ -31,6 +31,7 @@ enum dma_data_direction {
 #define dma_unmap_page(d, a, s, r) do { (void)(d); (void)(a); (void)(s); (void)(r); } while (0)
 
 #define sg_dma_address(sg) (0)
+#define sg_dma_len(sg) (0)
 #define dma_need_sync(v, a) (0)
 #define dma_unmap_single_attrs(d, a, s, r, t) do { \
 	(void)(d); (void)(a); (void)(s); (void)(r); (void)(t); \
@@ -43,4 +44,16 @@ enum dma_data_direction {
 } while (0)
 #define dma_max_mapping_size(...) SIZE_MAX
 
+/*
+ * A dma_addr_t can hold any valid DMA or bus address for the platform.  It can
+ * be given to a device to use as a DMA source or target.  It is specific to a
+ * given device and there may be a translation between the CPU physical address
+ * space and the bus address space.
+ *
+ * DMA_MAPPING_ERROR is the magic error code if a mapping failed.  It should not
+ * be used directly in drivers, but checked for using dma_mapping_error()
+ * instead.
+ */
+#define DMA_MAPPING_ERROR		(~(dma_addr_t)0)
+
 #endif
diff --git a/tools/virtio/linux/module.h b/tools/virtio/linux/module.h
index 9dfa96fea2b2..b91681fc1571 100644
--- a/tools/virtio/linux/module.h
+++ b/tools/virtio/linux/module.h
@@ -5,3 +5,10 @@
 	static __attribute__((unused)) const char *__MODULE_LICENSE_name = \
 		__MODULE_LICENSE_value
 
+#ifndef MODULE_AUTHOR
+#define MODULE_AUTHOR(x)
+#endif
+
+#ifndef MODULE_DESCRIPTION
+#define MODULE_DESCRIPTION(x)
+#endif