Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

Pull virtio fixes from Michael Tsirkin:
 "Just a bunch of fixes, mostly trivial ones in tools/virtio"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost/vsock: improve RCU read sections around vhost_vsock_get()
  tools/virtio: add device, device_driver stubs
  tools/virtio: fix up oot build
  virtio_features: make it self-contained
  tools/virtio: switch to kernel's virtio_config.h
  tools/virtio: stub might_sleep and synchronize_rcu
  tools/virtio: add struct cpumask to cpumask.h
  tools/virtio: pass KCFLAGS to module build
  tools/virtio: add ucopysize.h stub
  tools/virtio: add dev_WARN_ONCE and is_vmalloc_addr stubs
  tools/virtio: stub DMA mapping functions
  tools/virtio: add struct module forward declaration
  tools/virtio: use kernel's virtio.h
  virtio: make it self-contained
  tools/virtio: fix up compiler.h stub

drivers/vhost/vsock.c

@@ -66,14 +66,15 @@ static u32 vhost_transport_get_local_cid(void)
 	return VHOST_VSOCK_DEFAULT_HOST_CID;
 }
 
-/* Callers that dereference the return value must hold vhost_vsock_mutex or the
+/* Callers must be in an RCU read section or hold the vhost_vsock_mutex.
- * RCU read lock.
+ * The return value can only be dereferenced while within the section.
  */
 static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
 {
 	struct vhost_vsock *vsock;
 
-	hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid) {
+	hash_for_each_possible_rcu(vhost_vsock_hash, vsock, hash, guest_cid,
+				   lockdep_is_held(&vhost_vsock_mutex)) {
 		u32 other_cid = vsock->guest_cid;
 
 		/* Skip instances that have no CID yet */
@@ -709,9 +710,15 @@ static void vhost_vsock_reset_orphans(struct sock *sk)
 	 * executing.
 	 */
 
+	rcu_read_lock();
+
 	/* If the peer is still valid, no need to reset connection */
-	if (vhost_vsock_get(vsk->remote_addr.svm_cid))
+	if (vhost_vsock_get(vsk->remote_addr.svm_cid)) {
+		rcu_read_unlock();
 		return;
+	}
+
+	rcu_read_unlock();
 
 	/* If the close timeout is pending, let it expire.  This avoids races
 	 * with the timeout callback.

include/linux/virtio.h

@@ -13,6 +13,8 @@
 #include <linux/completion.h>
 #include <linux/virtio_features.h>
 
+struct module;
+
 /**
  * struct virtqueue - a queue to register buffers for sending or receiving.
  * @list: the chain of virtqueues for this device

include/linux/virtio_features.h

@@ -3,6 +3,8 @@
 #define _LINUX_VIRTIO_FEATURES_H
 
 #include <linux/bits.h>
+#include <linux/bug.h>
+#include <linux/string.h>
 
 #define VIRTIO_FEATURES_U64S	2
 #define VIRTIO_FEATURES_BITS	(VIRTIO_FEATURES_U64S * 64)

tools/virtio/Makefile

@@ -20,8 +20,9 @@ CFLAGS += -g -O2 -Werror -Wno-maybe-uninitialized -Wall -I. -I../include/ -I ../
 CFLAGS += -pthread
 LDFLAGS += -pthread
 vpath %.c ../../drivers/virtio ../../drivers/vhost
+BUILD=KCFLAGS="-I "`pwd`/../../drivers/vhost ${MAKE} -C `pwd`/../.. V=${V}
 mod:
-	${MAKE} -C `pwd`/../.. M=`pwd`/vhost_test V=${V}
+	${BUILD} M=`pwd`/vhost_test
 
 #oot: build vhost as an out of tree module for a distro kernel
 #no effort is taken to make it actually build or work, but tends to mostly work
@@ -37,8 +38,9 @@ OOT_CONFIGS=\
 	CONFIG_VHOST_NET=n \
 	CONFIG_VHOST_SCSI=n \
 	CONFIG_VHOST_VSOCK=n \
-	CONFIG_VHOST_RING=n
+	CONFIG_VHOST_RING=n \
-OOT_BUILD=KCFLAGS="-I "${OOT_VHOST} ${MAKE} -C ${OOT_KSRC} V=${V}
+	CONFIG_VHOST_VDPA=n
+OOT_BUILD=KCFLAGS="-include "`pwd`"/oot-stubs.h -I "${OOT_VHOST} ${MAKE} -C ${OOT_KSRC} V=${V}
 oot-build:
 	echo "UNSUPPORTED! Don't use the resulting modules in production!"
 	${OOT_BUILD} M=`pwd`/vhost_test

tools/virtio/linux/compiler.h

@@ -2,7 +2,11 @@
 #ifndef LINUX_COMPILER_H
 #define LINUX_COMPILER_H
 
+/* Avoid redefinition warnings */
+#undef __user
 #include "../../../include/linux/compiler_types.h"
+#undef __user
+#define __user
 
 #define WRITE_ONCE(var, val) \
 	(*((volatile typeof(val) *)(&(var))) = (val))
@@ -35,4 +39,6 @@
 	__v;								\
 })
 
+#define __must_check
+
 #endif

tools/virtio/linux/cpumask.h

@@ -4,4 +4,8 @@
 
 #include <linux/kernel.h>
 
+struct cpumask {
+	unsigned long bits[1];
+};
+
 #endif /* _LINUX_CPUMASK_H */

tools/virtio/linux/device.h

@@ -1,2 +1,10 @@
 #ifndef LINUX_DEVICE_H
+
+struct device {
+	void *parent;
+};
+
+struct device_driver {
+	const char *name;
+};
 #endif

tools/virtio/linux/dma-mapping.h

@@ -22,6 +22,7 @@ enum dma_data_direction {
 #define dma_free_coherent(d, s, p, h) kfree(p)
 
 #define dma_map_page(d, p, o, s, dir) (page_to_phys(p) + (o))
+#define dma_map_page_attrs(d, p, o, s, dir, a) (page_to_phys(p) + (o))
 
 #define dma_map_single(d, p, s, dir) (virt_to_phys(p))
 #define dma_map_single_attrs(d, p, s, dir, a) (virt_to_phys(p))
@@ -29,6 +30,9 @@ enum dma_data_direction {
 
 #define dma_unmap_single(d, a, s, r) do { (void)(d); (void)(a); (void)(s); (void)(r); } while (0)
 #define dma_unmap_page(d, a, s, r) do { (void)(d); (void)(a); (void)(s); (void)(r); } while (0)
+#define dma_unmap_page_attrs(d, a, s, r, t) do { \
+	(void)(d); (void)(a); (void)(s); (void)(r); (void)(t); \
+} while (0)
 
 #define sg_dma_address(sg) (0)
 #define sg_dma_len(sg) (0)

tools/virtio/linux/kernel.h

@@ -14,6 +14,7 @@
 #include <linux/log2.h>
 #include <linux/types.h>
 #include <linux/overflow.h>
+#include <linux/limits.h>
 #include <linux/list.h>
 #include <linux/printk.h>
 #include <linux/bug.h>
@@ -135,6 +136,21 @@ static inline void *krealloc_array(void *p, size_t new_n, size_t new_size, gfp_t
 #define dev_warn(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 #define dev_warn_once(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
 
+#define dev_WARN_ONCE(dev, condition, format...) \
+	WARN_ONCE(condition, format)
+
+static inline bool is_vmalloc_addr(const void *x)
+{
+	return false;
+}
+
+#define might_sleep() do { } while (0)
+
+static inline void synchronize_rcu(void)
+{
+	assert(0);
+}
+
 #define min(x, y) ({				\
 	typeof(x) _min1 = (x);			\
 	typeof(y) _min2 = (y);			\

tools/virtio/linux/module.h

@@ -1,6 +1,8 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #include <linux/export.h>
 
+struct module;
+
 #define MODULE_LICENSE(__MODULE_LICENSE_value) \
 	static __attribute__((unused)) const char *__MODULE_LICENSE_name = \
 		__MODULE_LICENSE_value

tools/virtio/linux/ucopysize.h

@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_UCOPYSIZE_H__
+#define __LINUX_UCOPYSIZE_H__
+
+#include <linux/bug.h>
+
+static inline void check_object_size(const void *ptr, unsigned long n,
+				     bool to_user)
+{ }
+
+static inline void copy_overflow(int size, unsigned long count)
+{
+}
+
+static __always_inline __must_check bool
+check_copy_size(const void *addr, size_t bytes, bool is_source)
+{
+	return true;
+}
+
+#endif /* __LINUX_UCOPYSIZE_H__ */

tools/virtio/linux/virtio.h

@@ -1,72 +1 @@
-/* SPDX-License-Identifier: GPL-2.0 */
+#include <../../include/linux/virtio.h>
-#ifndef LINUX_VIRTIO_H
-#define LINUX_VIRTIO_H
-#include <linux/scatterlist.h>
-#include <linux/kernel.h>
-#include <linux/spinlock.h>
-
-struct device {
-	void *parent;
-};
-
-struct virtio_device {
-	struct device dev;
-	u64 features;
-	struct list_head vqs;
-	spinlock_t vqs_list_lock;
-	const struct virtio_config_ops *config;
-};
-
-struct virtqueue {
-	struct list_head list;
-	void (*callback)(struct virtqueue *vq);
-	const char *name;
-	struct virtio_device *vdev;
-        unsigned int index;
-        unsigned int num_free;
-	unsigned int num_max;
-	void *priv;
-	bool reset;
-};
-
-/* Interfaces exported by virtio_ring. */
-int virtqueue_add_sgs(struct virtqueue *vq,
-		      struct scatterlist *sgs[],
-		      unsigned int out_sgs,
-		      unsigned int in_sgs,
-		      void *data,
-		      gfp_t gfp);
-
-int virtqueue_add_outbuf(struct virtqueue *vq,
-			 struct scatterlist sg[], unsigned int num,
-			 void *data,
-			 gfp_t gfp);
-
-int virtqueue_add_inbuf(struct virtqueue *vq,
-			struct scatterlist sg[], unsigned int num,
-			void *data,
-			gfp_t gfp);
-
-bool virtqueue_kick(struct virtqueue *vq);
-
-void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
-
-void virtqueue_disable_cb(struct virtqueue *vq);
-
-bool virtqueue_enable_cb(struct virtqueue *vq);
-bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
-
-void *virtqueue_detach_unused_buf(struct virtqueue *vq);
-struct virtqueue *vring_new_virtqueue(unsigned int index,
-				      unsigned int num,
-				      unsigned int vring_align,
-				      struct virtio_device *vdev,
-				      bool weak_barriers,
-				      bool ctx,
-				      void *pages,
-				      bool (*notify)(struct virtqueue *vq),
-				      void (*callback)(struct virtqueue *vq),
-				      const char *name);
-void vring_del_virtqueue(struct virtqueue *vq);
-
-#endif

tools/virtio/linux/virtio_config.h

@@ -1,101 +1 @@
-/* SPDX-License-Identifier: GPL-2.0 */
+#include "../../include/linux/virtio_config.h"
-#ifndef LINUX_VIRTIO_CONFIG_H
-#define LINUX_VIRTIO_CONFIG_H
-#include <linux/virtio_byteorder.h>
-#include <linux/virtio.h>
-#include <uapi/linux/virtio_config.h>
-
-struct virtio_config_ops {
-	int (*disable_vq_and_reset)(struct virtqueue *vq);
-	int (*enable_vq_after_reset)(struct virtqueue *vq);
-};
-
-/*
- * __virtio_test_bit - helper to test feature bits. For use by transports.
- *                     Devices should normally use virtio_has_feature,
- *                     which includes more checks.
- * @vdev: the device
- * @fbit: the feature bit
- */
-static inline bool __virtio_test_bit(const struct virtio_device *vdev,
-				     unsigned int fbit)
-{
-	return vdev->features & (1ULL << fbit);
-}
-
-/**
- * __virtio_set_bit - helper to set feature bits. For use by transports.
- * @vdev: the device
- * @fbit: the feature bit
- */
-static inline void __virtio_set_bit(struct virtio_device *vdev,
-				    unsigned int fbit)
-{
-	vdev->features |= (1ULL << fbit);
-}
-
-/**
- * __virtio_clear_bit - helper to clear feature bits. For use by transports.
- * @vdev: the device
- * @fbit: the feature bit
- */
-static inline void __virtio_clear_bit(struct virtio_device *vdev,
-				      unsigned int fbit)
-{
-	vdev->features &= ~(1ULL << fbit);
-}
-
-#define virtio_has_feature(dev, feature) \
-	(__virtio_test_bit((dev), feature))
-
-/**
- * virtio_has_dma_quirk - determine whether this device has the DMA quirk
- * @vdev: the device
- */
-static inline bool virtio_has_dma_quirk(const struct virtio_device *vdev)
-{
-	/*
-	 * Note the reverse polarity of the quirk feature (compared to most
-	 * other features), this is for compatibility with legacy systems.
-	 */
-	return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
-}
-
-static inline bool virtio_is_little_endian(struct virtio_device *vdev)
-{
-	return virtio_has_feature(vdev, VIRTIO_F_VERSION_1) ||
-		virtio_legacy_is_little_endian();
-}
-
-/* Memory accessors */
-static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
-{
-	return __virtio16_to_cpu(virtio_is_little_endian(vdev), val);
-}
-
-static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
-{
-	return __cpu_to_virtio16(virtio_is_little_endian(vdev), val);
-}
-
-static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
-{
-	return __virtio32_to_cpu(virtio_is_little_endian(vdev), val);
-}
-
-static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
-{
-	return __cpu_to_virtio32(virtio_is_little_endian(vdev), val);
-}
-
-static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
-{
-	return __virtio64_to_cpu(virtio_is_little_endian(vdev), val);
-}
-
-static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
-{
-	return __cpu_to_virtio64(virtio_is_little_endian(vdev), val);
-}
-
-#endif

tools/virtio/oot-stubs.h

@@ -0,0 +1,10 @@
+#include <linux/bug.h>
+#include <linux/string.h>
+#include <linux/virtio_features.h>
+
+#ifndef VIRTIO_FEATURES_BITS
+#define VIRTIO_FEATURES_BITS 128
+#endif
+#ifndef VIRTIO_U64
+#define VIRTIO_U64(b)           ((b) >> 6)
+#endif