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 7979f850e7ac..ca3ed78e5ec7 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 749cde28728b..a3fa537e717a 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 */