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

Pull virtio fixes from Michael S Tsirkin:
 "virtio 1.0 related fixes

  Most importantly, this fixes using virtio_pci as a module.

  Further, the big virtio 1.0 conversion missed a couple of places.
  This fixes them up.

  This isn't 100% sparse-clean yet because on many architectures
  get_user triggers sparse warnings when used with __bitwise tag (when
  same tag is on both pointer and value read).

  I posted a patchset to fix it up by adding __force on all arches that
  don't already have it (many do), when that's merged these warnings
  will go away"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_pci: restore module attributes
  mic/host: fix up virtio 1.0 APIs
  vringh: update for virtio 1.0 APIs
  vringh: 64 bit features
  tools/virtio: add virtio 1.0 in vringh_test
  tools/virtio: add virtio 1.0 in virtio_test
  tools/virtio: enable -Werror
  tools/virtio: 64 bit features
  tools/virtio: fix vringh test
  tools/virtio: more stubs
  virtio: core support for config generation
  virtio_pci: add VIRTIO_PCI_NO_LEGACY
  virtio_pci: move probe to common file
  virtio_pci_common.h: drop VIRTIO_PCI_NO_LEGACY
  virtio_config: fix virtio_cread_bytes
  virtio: set VIRTIO_CONFIG_S_FEATURES_OK on restore

2 files changed, 63 insertions, 3 deletions

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 7979f850e7a..ca3ed78e5ec 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -19,6 +19,9 @@
  *	offset: the offset of the configuration field
  *	buf: the buffer to read the field value from.
  *	len: the length of the buffer
+ * @generation: config generation counter
+ *	vdev: the virtio_device
+ *	Returns the config generation counter
  * @get_status: read the status byte
  *	vdev: the virtio_device
  *	Returns the status byte
@@ -60,6 +63,7 @@ struct virtio_config_ops {
 		    void *buf, unsigned len);
 	void (*set)(struct virtio_device *vdev, unsigned offset,
 		    const void *buf, unsigned len);
+	u32 (*generation)(struct virtio_device *vdev);
 	u8 (*get_status)(struct virtio_device *vdev);
 	void (*set_status)(struct virtio_device *vdev, u8 status);
 	void (*reset)(struct virtio_device *vdev);
@@ -301,11 +305,33 @@ static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
 	return ret;
 }
 
+/* Read @count fields, @bytes each. */
+static inline void __virtio_cread_many(struct virtio_device *vdev,
+				       unsigned int offset,
+				       void *buf, size_t count, size_t bytes)
+{
+	u32 old, gen = vdev->config->generation ?
+		vdev->config->generation(vdev) : 0;
+	int i;
+
+	do {
+		old = gen;
+
+		for (i = 0; i < count; i++)
+			vdev->config->get(vdev, offset + bytes * i,
+					  buf + i * bytes, bytes);
+
+		gen = vdev->config->generation ?
+			vdev->config->generation(vdev) : 0;
+	} while (gen != old);
+}
+
+
 static inline void virtio_cread_bytes(struct virtio_device *vdev,
 				      unsigned int offset,
 				      void *buf, size_t len)
 {
-	vdev->config->get(vdev, offset, buf, len);
+	__virtio_cread_many(vdev, offset, buf, len, 1);
 }
 
 static inline void virtio_cwrite8(struct virtio_device *vdev,
@@ -349,6 +375,7 @@ static inline u64 virtio_cread64(struct virtio_device *vdev,
 {
 	u64 ret;
 	vdev->config->get(vdev, offset, &ret, sizeof(ret));
+	__virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret));
 	return virtio64_to_cpu(vdev, (__force __virtio64)ret);
 }
 
diff --git a/include/linux/vringh.h b/include/linux/vringh.h
index 749cde28728..a3fa537e717 100644
--- a/include/linux/vringh.h
+++ b/include/linux/vringh.h
@@ -24,12 +24,16 @@
 #ifndef _LINUX_VRINGH_H
 #define _LINUX_VRINGH_H
 #include <uapi/linux/virtio_ring.h>
+#include <linux/virtio_byteorder.h>
 #include <linux/uio.h>
 #include <linux/slab.h>
 #include <asm/barrier.h>
 
 /* virtio_ring with information needed for host access. */
 struct vringh {
+	/* Everything is little endian */
+	bool little_endian;
+
 	/* Guest publishes used event idx (note: we always do). */
 	bool event_indices;
 
@@ -105,7 +109,7 @@ struct vringh_kiov {
 #define VRINGH_IOV_ALLOCATED 0x8000000
 
 /* Helpers for userspace vrings. */
-int vringh_init_user(struct vringh *vrh, u32 features,
+int vringh_init_user(struct vringh *vrh, u64 features,
 		     unsigned int num, bool weak_barriers,
 		     struct vring_desc __user *desc,
 		     struct vring_avail __user *avail,
@@ -167,7 +171,7 @@ bool vringh_notify_enable_user(struct vringh *vrh);
 void vringh_notify_disable_user(struct vringh *vrh);
 
 /* Helpers for kernelspace vrings. */
-int vringh_init_kern(struct vringh *vrh, u32 features,
+int vringh_init_kern(struct vringh *vrh, u64 features,
 		     unsigned int num, bool weak_barriers,
 		     struct vring_desc *desc,
 		     struct vring_avail *avail,
@@ -222,4 +226,33 @@ static inline void vringh_notify(struct vringh *vrh)
 		vrh->notify(vrh);
 }
 
+static inline u16 vringh16_to_cpu(const struct vringh *vrh, __virtio16 val)
+{
+	return __virtio16_to_cpu(vrh->little_endian, val);
+}
+
+static inline __virtio16 cpu_to_vringh16(const struct vringh *vrh, u16 val)
+{
+	return __cpu_to_virtio16(vrh->little_endian, val);
+}
+
+static inline u32 vringh32_to_cpu(const struct vringh *vrh, __virtio32 val)
+{
+	return __virtio32_to_cpu(vrh->little_endian, val);
+}
+
+static inline __virtio32 cpu_to_vringh32(const struct vringh *vrh, u32 val)
+{
+	return __cpu_to_virtio32(vrh->little_endian, val);
+}
+
+static inline u64 vringh64_to_cpu(const struct vringh *vrh, __virtio64 val)
+{
+	return __virtio64_to_cpu(vrh->little_endian, val);
+}
+
+static inline __virtio64 cpu_to_vringh64(const struct vringh *vrh, u64 val)
+{
+	return __cpu_to_virtio64(vrh->little_endian, val);
+}
 #endif /* _LINUX_VRINGH_H */