Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-virtio

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-virtio:
  virtio: enhance id_matching for virtio drivers
  virtio: fix id_matching for virtio drivers
  virtio: handle short buffers in virtio_rng.
  virtio_blk: add missing __dev{init,exit} markings
  virtio: indirect ring entries (VIRTIO_RING_F_INDIRECT_DESC)
  virtio: teach virtio_has_feature() about transport features
  virtio: expose features in sysfs
  virtio_pci: optional MSI-X support
  virtio_pci: split up vp_interrupt
  virtio: find_vqs/del_vqs virtio operations
  virtio: add names to virtqueue struct, mapping from devices to queues.
  virtio: meet virtio spec by finalizing features before using device
  virtio: fix obsolete documentation on probe function

4 files changed, 64 insertions, 18 deletions

diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 06005fa9e982..4fca4f5440ba 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -10,14 +10,17 @@
 
 /**
  * virtqueue - a queue to register buffers for sending or receiving.
+ * @list: the chain of virtqueues for this device
  * @callback: the function to call when buffers are consumed (can be NULL).
+ * @name: the name of this virtqueue (mainly for debugging)
  * @vdev: the virtio device this queue was created for.
  * @vq_ops: the operations for this virtqueue (see below).
  * @priv: a pointer for the virtqueue implementation to use.
  */
-struct virtqueue
-{
+struct virtqueue {
+        struct list_head list;
         void (*callback)(struct virtqueue *vq);
+        const char *name;
         struct virtio_device *vdev;
         struct virtqueue_ops *vq_ops;
         void *priv;
@@ -76,15 +79,16 @@ struct virtqueue_ops {
  * @dev: underlying device.
  * @id: the device type identification (used to match it with a driver).
  * @config: the configuration ops for this device.
+ * @vqs: the list of virtqueues for this device.
  * @features: the features supported by both driver and device.
  * @priv: private pointer for the driver's use.
  */
-struct virtio_device
-{
+struct virtio_device {
         int index;
         struct device dev;
         struct virtio_device_id id;
         struct virtio_config_ops *config;
+        struct list_head vqs;
         /* Note that this is a Linux set_bit-style bitmap. */
         unsigned long features[1];
         void *priv;
@@ -99,8 +103,7 @@ void unregister_virtio_device(struct virtio_device *dev);
  * @id_table: the ids serviced by this driver.
  * @feature_table: an array of feature numbers supported by this device.
  * @feature_table_size: number of entries in the feature table array.
- * @probe: the function to call when a device is found.  Returns a token for
- *    remove, or PTR_ERR().
+ * @probe: the function to call when a device is found.  Returns 0 or -errno.
  * @remove: the function when a device is removed.
  * @config_changed: optional function to call when the device configuration
  *    changes; may be called in interrupt context.
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index bf8ec283b232..99f514575f6a 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -29,6 +29,7 @@
 #define VIRTIO_F_NOTIFY_ON_EMPTY        24
 
 #ifdef __KERNEL__
+#include <linux/err.h>
 #include <linux/virtio.h>
 
 /**
@@ -49,15 +50,26 @@
  * @set_status: write the status byte
  *      vdev: the virtio_device
  *      status: the new status byte
+ * @request_vqs: request the specified number of virtqueues
+ *      vdev: the virtio_device
+ *      max_vqs: the max number of virtqueues we want
+ *      If supplied, must call before any virtqueues are instantiated.
+ *      To modify the max number of virtqueues after request_vqs has been
+ *      called, call free_vqs and then request_vqs with a new value.
+ * @free_vqs: cleanup resources allocated by request_vqs
+ *      vdev: the virtio_device
+ *      If supplied, must call after all virtqueues have been deleted.
  * @reset: reset the device
  *      vdev: the virtio device
  *      After this, status and feature negotiation must be done again
- * @find_vq: find a virtqueue and instantiate it.
+ * @find_vqs: find virtqueues and instantiate them.
  *      vdev: the virtio_device
- *      index: the 0-based virtqueue number in case there's more than one.
- *      callback: the virqtueue callback
- *      Returns the new virtqueue or ERR_PTR() (eg. -ENOENT).
- * @del_vq: free a virtqueue found by find_vq().
+ *      nvqs: the number of virtqueues to find
+ *      vqs: on success, includes new virtqueues
+ *      callbacks: array of callbacks, for each virtqueue
+ *      names: array of virtqueue names (mainly for debugging)
+ *      Returns 0 on success or error status
+ * @del_vqs: free virtqueues found by find_vqs().
  * @get_features: get the array of feature bits for this device.
  *      vdev: the virtio_device
  *      Returns the first 32 feature bits (all we currently need).
@@ -66,6 +78,7 @@
  *      This gives the final feature bits for the device: it can change
  *      the dev->feature bits if it wants.
  */
+typedef void vq_callback_t(struct virtqueue *);
 struct virtio_config_ops
 {
         void (*get)(struct virtio_device *vdev, unsigned offset,
@@ -75,10 +88,11 @@ struct virtio_config_ops
         u8 (*get_status)(struct virtio_device *vdev);
         void (*set_status)(struct virtio_device *vdev, u8 status);
         void (*reset)(struct virtio_device *vdev);
-        struct virtqueue *(*find_vq)(struct virtio_device *vdev,
-                                     unsigned index,
-                                     void (*callback)(struct virtqueue *));
-        void (*del_vq)(struct virtqueue *vq);
+        int (*find_vqs)(struct virtio_device *, unsigned nvqs,
+                        struct virtqueue *vqs[],
+                        vq_callback_t *callbacks[],
+                        const char *names[]);
+        void (*del_vqs)(struct virtio_device *);
         u32 (*get_features)(struct virtio_device *vdev);
         void (*finalize_features)(struct virtio_device *vdev);
 };
@@ -99,7 +113,9 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev,
         if (__builtin_constant_p(fbit))
                 BUILD_BUG_ON(fbit >= 32);
 
-        virtio_check_driver_offered_feature(vdev, fbit);
+        if (fbit < VIRTIO_TRANSPORT_F_START)
+                virtio_check_driver_offered_feature(vdev, fbit);
+
         return test_bit(fbit, vdev->features);
 }
 
@@ -126,5 +142,18 @@ static inline int virtio_config_buf(struct virtio_device *vdev,
         vdev->config->get(vdev, offset, buf, len);
         return 0;
 }
+
+static inline
+struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
+                                        vq_callback_t *c, const char *n)
+{
+        vq_callback_t *callbacks[] = { c };
+        const char *names[] = { n };
+        struct virtqueue *vq;
+        int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
+        if (err < 0)
+                return ERR_PTR(err);
+        return vq;
+}
 #endif /* __KERNEL__ */
 #endif /* _LINUX_VIRTIO_CONFIG_H */
diff --git a/include/linux/virtio_pci.h b/include/linux/virtio_pci.h
index cd0fd5d181a6..9a3d7c48c622 100644
--- a/include/linux/virtio_pci.h
+++ b/include/linux/virtio_pci.h
@@ -47,9 +47,17 @@
 /* The bit of the ISR which indicates a device configuration change. */
 #define VIRTIO_PCI_ISR_CONFIG           0x2
 
+/* MSI-X registers: only enabled if MSI-X is enabled. */
+/* A 16-bit vector for configuration changes. */
+#define VIRTIO_MSI_CONFIG_VECTOR        20
+/* A 16-bit vector for selected queue notifications. */
+#define VIRTIO_MSI_QUEUE_VECTOR         22
+/* Vector value used to disable MSI for queue */
+#define VIRTIO_MSI_NO_VECTOR            0xffff
+
 /* The remaining space is defined by each driver as the per-driver
  * configuration space */
-#define VIRTIO_PCI_CONFIG               20
+#define VIRTIO_PCI_CONFIG(dev)          ((dev)->msix_enabled ? 24 : 20)
 
 /* Virtio ABI version, this must match exactly */
 #define VIRTIO_PCI_ABI_VERSION          0
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index 71e03722fb59..693e0ec5afa6 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -14,6 +14,8 @@
 #define VRING_DESC_F_NEXT       1
 /* This marks a buffer as write-only (otherwise read-only). */
 #define VRING_DESC_F_WRITE      2
+/* This means the buffer contains a list of buffer descriptors. */
+#define VRING_DESC_F_INDIRECT   4
 
 /* The Host uses this in used->flags to advise the Guest: don't kick me when
  * you add a buffer.  It's unreliable, so it's simply an optimization.  Guest
@@ -24,6 +26,9 @@
  * optimization.  */
 #define VRING_AVAIL_F_NO_INTERRUPT      1
 
+/* We support indirect buffer descriptors */
+#define VIRTIO_RING_F_INDIRECT_DESC     28
+
 /* Virtio ring descriptors: 16 bytes.  These can chain together via "next". */
 struct vring_desc
 {
@@ -119,7 +124,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
                                       struct virtio_device *vdev,
                                       void *pages,
                                       void (*notify)(struct virtqueue *vq),
-                                      void (*callback)(struct virtqueue *vq));
+                                      void (*callback)(struct virtqueue *vq),
+                                      const char *name);
 void vring_del_virtqueue(struct virtqueue *vq);
 /* Filter out transport-specific feature bits. */
 void vring_transport_features(struct virtio_device *vdev);