* [PATCH 1/2] virtio: abstract virtqueue related methods
@ 2023-05-12 9:46 ` zhenwei pi
0 siblings, 0 replies; 20+ messages in thread
From: zhenwei pi @ 2023-05-12 9:46 UTC (permalink / raw)
To: stefanha, mst, jasowang
Cc: xuanzhuo, virtualization, linux-kernel, zhenwei pi
There is already a virtqueue abstract structure in virtio subsystem
(see struct virtqueue in include/linux/virtio.h), however the vring
based virtqueue is used only in the past years, the virtqueue related
methods mix much with vring(just look like the codes, virtqueue_xxx
functions are implemented in virtio_ring.c).
Abstract virtqueue related methods(see struct virtqueue_ops), and
separate virtqueue_xxx symbols from vring. This allows a non-vring
based transport in the future. With this change, the following symbols
are exported from virtio.ko instead of virtio_ring.ko:
virtqueue_add_sgs
virtqueue_add_outbuf
virtqueue_add_inbuf
virtqueue_add_inbuf_ctx
virtqueue_kick_prepare
virtqueue_notify
virtqueue_kick
virtqueue_enable_cb_prepare
virtqueue_enable_cb
virtqueue_enable_cb_delayed
virtqueue_disable_cb
virtqueue_poll
virtqueue_get_buf_ctx
virtqueue_get_buf
virtqueue_detach_unused_buf
virtqueue_get_vring_size
virtqueue_resize
virtqueue_is_broken
virtio_break_device
__virtio_unbreak_device
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
drivers/virtio/virtio_ring.c | 282 +++++----------------------
include/linux/virtio.h | 29 +++
3 files changed, 443 insertions(+), 230 deletions(-)
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index 3893dc29eb26..8d8715a10f26 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
EXPORT_SYMBOL_GPL(virtio_device_restore);
#endif
+/**
+ * virtqueue_add_sgs - expose buffers to other end
+ * @vq: the struct virtqueue we're talking about.
+ * @sgs: array of terminated scatterlists.
+ * @out_sgs: the number of scatterlists readable by other side
+ * @in_sgs: the number of scatterlists which are writable (after readable ones)
+ * @data: the token identifying the buffer.
+ * @gfp: how to do memory allocations (if necessary).
+ *
+ * Caller must ensure we don't call this with other virtqueue operations
+ * at the same time (except where noted).
+ *
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
+ */
+int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
+ unsigned int out_sgs, unsigned int in_sgs,
+ void *data, gfp_t gfp)
+{
+ unsigned int i, total_sg = 0;
+
+ /* Count them first. */
+ for (i = 0; i < out_sgs + in_sgs; i++) {
+ struct scatterlist *sg;
+
+ for (sg = sgs[i]; sg; sg = sg_next(sg))
+ total_sg++;
+ }
+ return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
+ data, NULL, gfp);
+}
+EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
+
+/**
+ * virtqueue_add_outbuf - expose output buffers to other end
+ * @vq: the struct virtqueue we're talking about.
+ * @sg: scatterlist (must be well-formed and terminated!)
+ * @num: the number of entries in @sg readable by other side
+ * @data: the token identifying the buffer.
+ * @gfp: how to do memory allocations (if necessary).
+ *
+ * Caller must ensure we don't call this with other virtqueue operations
+ * at the same time (except where noted).
+ *
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
+ */
+int virtqueue_add_outbuf(struct virtqueue *vq, struct scatterlist *sg,
+ unsigned int num, void *data, gfp_t gfp)
+{
+ return vq->ops->add_sgs(vq, &sg, num, 1, 0, data, NULL, gfp);
+}
+EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
+
+/**
+ * virtqueue_add_inbuf - expose input buffers to other end
+ * @vq: the struct virtqueue we're talking about.
+ * @sg: scatterlist (must be well-formed and terminated!)
+ * @num: the number of entries in @sg writable by other side
+ * @data: the token identifying the buffer.
+ * @gfp: how to do memory allocations (if necessary).
+ *
+ * Caller must ensure we don't call this with other virtqueue operations
+ * at the same time (except where noted).
+ *
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
+ */
+int virtqueue_add_inbuf(struct virtqueue *vq, struct scatterlist *sg,
+ unsigned int num, void *data, gfp_t gfp)
+{
+ return vq->ops->add_sgs(vq, &sg, num, 0, 1, data, NULL, gfp);
+}
+EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
+
+/**
+ * virtqueue_add_inbuf_ctx - expose input buffers to other end
+ * @vq: the struct virtqueue we're talking about.
+ * @sg: scatterlist (must be well-formed and terminated!)
+ * @num: the number of entries in @sg writable by other side
+ * @data: the token identifying the buffer.
+ * @ctx: extra context for the token
+ * @gfp: how to do memory allocations (if necessary).
+ *
+ * Caller must ensure we don't call this with other virtqueue operations
+ * at the same time (except where noted).
+ *
+ * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
+ */
+int virtqueue_add_inbuf_ctx(struct virtqueue *vq, struct scatterlist *sg,
+ unsigned int num, void *data, void *ctx, gfp_t gfp)
+{
+ return vq->ops->add_sgs(vq, &sg, num, 0, 1, data, ctx, gfp);
+}
+EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
+
+/**
+ * virtqueue_kick_prepare - first half of split virtqueue_kick call.
+ * @vq: the struct virtqueue
+ *
+ * Instead of virtqueue_kick(), you can do:
+ * if (virtqueue_kick_prepare(vq))
+ * virtqueue_notify(vq);
+ *
+ * This is sometimes useful because the virtqueue_kick_prepare() needs
+ * to be serialized, but the actual virtqueue_notify() call does not.
+ */
+bool virtqueue_kick_prepare(struct virtqueue *vq)
+{
+ return vq->ops->kick_prepare(vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
+
+/**
+ * virtqueue_notify - second half of split virtqueue_kick call.
+ * @vq: the struct virtqueue
+ *
+ * This does not need to be serialized.
+ *
+ * Returns false if host notify failed or queue is broken, otherwise true.
+ */
+bool virtqueue_notify(struct virtqueue *vq)
+{
+ return vq->ops->notify(vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_notify);
+
+/**
+ * virtqueue_kick - update after add_buf
+ * @vq: the struct virtqueue
+ *
+ * After one or more virtqueue_add_* calls, invoke this to kick
+ * the other side.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ *
+ * Returns false if kick failed, otherwise true.
+ */
+bool virtqueue_kick(struct virtqueue *vq)
+{
+ if (virtqueue_kick_prepare(vq))
+ return virtqueue_notify(vq);
+ return true;
+}
+EXPORT_SYMBOL_GPL(virtqueue_kick);
+
+/**
+ * virtqueue_enable_cb_prepare - restart callbacks after disable_cb
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * This re-enables callbacks; it returns current queue state
+ * in an opaque unsigned value. This value should be later tested by
+ * virtqueue_poll, to detect a possible race between the driver checking for
+ * more work, and enabling callbacks.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ */
+unsigned int virtqueue_enable_cb_prepare(struct virtqueue *vq)
+{
+ return vq->ops->enable_cb_prepare(vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
+
+/**
+ * virtqueue_enable_cb - restart callbacks after disable_cb.
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * This re-enables callbacks; it returns "false" if there are pending
+ * buffers in the queue, to detect a possible race between the driver
+ * checking for more work, and enabling callbacks.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ */
+bool virtqueue_enable_cb(struct virtqueue *vq)
+{
+ unsigned int val = vq->ops->enable_cb_prepare(vq);
+
+ return !vq->ops->poll(vq, val);
+}
+EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
+
+/**
+ * virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * This re-enables callbacks but hints to the other side to delay
+ * interrupts until most of the available buffers have been processed;
+ * it returns "false" if there are many pending buffers in the queue,
+ * to detect a possible race between the driver checking for more work,
+ * and enabling callbacks.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ */
+bool virtqueue_enable_cb_delayed(struct virtqueue *vq)
+{
+ return vq->ops->enable_cb_delayed(vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
+
+/**
+ * virtqueue_disable_cb - disable callbacks
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * Note that this is not necessarily synchronous, hence unreliable and only
+ * useful as an optimization.
+ *
+ * Unlike other operations, this need not be serialized.
+ */
+void virtqueue_disable_cb(struct virtqueue *vq)
+{
+ vq->ops->disable_cb(vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
+
+/**
+ * virtqueue_poll - query pending used buffers
+ * @vq: the struct virtqueue we're talking about.
+ * @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
+ *
+ * Returns "true" if there are pending used buffers in the queue.
+ *
+ * This does not need to be serialized.
+ */
+bool virtqueue_poll(struct virtqueue *vq, unsigned int idx)
+{
+ return vq->ops->poll(vq, idx);
+}
+EXPORT_SYMBOL_GPL(virtqueue_poll);
+
+/**
+ * virtqueue_get_buf_ctx - get the next used buffer
+ * @vq: the struct virtqueue we're talking about.
+ * @len: the length written into the buffer
+ * @ctx: extra context for the token
+ *
+ * If the device wrote data into the buffer, @len will be set to the
+ * amount written. This means you don't need to clear the buffer
+ * beforehand to ensure there's no data leakage in the case of short
+ * writes.
+ *
+ * Caller must ensure we don't call this with other virtqueue
+ * operations at the same time (except where noted).
+ *
+ * Returns NULL if there are no used buffers, or the "data" token
+ * handed to virtqueue_add_*().
+ */
+void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
+ void **ctx)
+{
+ return vq->ops->get_buf_ctx(vq, len, ctx);
+}
+EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
+
+void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len)
+{
+ return vq->ops->get_buf_ctx(vq, len, NULL);
+}
+EXPORT_SYMBOL_GPL(virtqueue_get_buf);
+
+/**
+ * virtqueue_detach_unused_buf - detach first unused buffer
+ * @vq: the struct virtqueue we're talking about.
+ *
+ * Returns NULL or the "data" token handed to virtqueue_add_*().
+ * This is not valid on an active queue; it is useful for device
+ * shutdown or the reset queue.
+ */
+void *virtqueue_detach_unused_buf(struct virtqueue *vq)
+{
+ return vq->ops->detach_unused_buf(vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
+
+/**
+ * virtqueue_get_vring_size - return the size of the virtqueue's vring
+ * @vq: the struct virtqueue containing the vring of interest.
+ *
+ * Returns the size of the vring. This is mainly used for boasting to
+ * userspace. Unlike other operations, this need not be serialized.
+ */
+unsigned int virtqueue_get_vring_size(const struct virtqueue *vq)
+{
+ return vq->ops->get_vring_size(vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
+
+/**
+ * virtqueue_resize - resize the vring of vq
+ * @vq: the struct virtqueue we're talking about.
+ * @num: new ring num
+ * @recycle: callback for recycle the useless buffer
+ *
+ * When it is really necessary to create a new vring, it will set the current vq
+ * into the reset state. Then call the passed callback to recycle the buffer
+ * that is no longer used. Only after the new vring is successfully created, the
+ * old vring will be released.
+ *
+ * Caller must ensure we don't call this with other virtqueue operations
+ * at the same time (except where noted).
+ *
+ * Returns zero or a negative error.
+ * 0: success.
+ * -ENOMEM: Failed to allocate a new ring, fall back to the original ring size.
+ * vq can still work normally
+ * -EBUSY: Failed to sync with device, vq may not work properly
+ * -ENOENT: Transport or device not supported
+ * -E2BIG/-EINVAL: num error
+ * -EPERM: Operation not permitted
+ *
+ */
+int virtqueue_resize(struct virtqueue *vq, u32 num,
+ void (*recycle)(struct virtqueue *vq, void *buf))
+{
+ if (vq->ops->resize)
+ return vq->ops->resize(vq, num, recycle);
+
+ return -ENOENT;
+}
+EXPORT_SYMBOL_GPL(virtqueue_resize);
+
+bool virtqueue_is_broken(const struct virtqueue *vq)
+{
+ return vq->ops->is_broken(vq);
+}
+EXPORT_SYMBOL_GPL(virtqueue_is_broken);
+
+/*
+ * This should prevent the device from being used, allowing drivers to
+ * recover. You may need to grab appropriate locks to flush.
+ */
+void virtio_break_device(struct virtio_device *dev)
+{
+ struct virtqueue *vq;
+
+ spin_lock(&dev->vqs_list_lock);
+ list_for_each_entry(vq, &dev->vqs, list) {
+ vq->ops->__break(vq);
+ }
+ spin_unlock(&dev->vqs_list_lock);
+}
+EXPORT_SYMBOL_GPL(virtio_break_device);
+
+/*
+ * This should allow the device to be used by the driver. You may
+ * need to grab appropriate locks to flush the write to
+ * vq->broken. This should only be used in some specific case e.g
+ * (probing and restoring). This function should only be called by the
+ * core, not directly by the driver.
+ */
+void __virtio_unbreak_device(struct virtio_device *dev)
+{
+ struct virtqueue *vq;
+
+ spin_lock(&dev->vqs_list_lock);
+ list_for_each_entry(vq, &dev->vqs, list) {
+ vq->ops->__unbreak(vq);
+ }
+ spin_unlock(&dev->vqs_list_lock);
+}
+EXPORT_SYMBOL_GPL(__virtio_unbreak_device);
+
static int virtio_init(void)
{
if (bus_register(&virtio_bus) != 0)
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c5310eaf8b46..7b86417255db 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -227,6 +227,8 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num);
static void vring_free(struct virtqueue *_vq);
+static struct virtqueue_ops vring_ops;
+
/*
* Helpers.
*/
@@ -2041,6 +2043,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
vq->vq.name = name;
vq->vq.index = index;
vq->vq.reset = false;
+ vq->vq.ops = &vring_ops;
vq->we_own_ring = true;
vq->notify = notify;
vq->weak_barriers = weak_barriers;
@@ -2114,17 +2117,17 @@ static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num)
/*
- * Generic functions and exported symbols.
+ * Vring specific operation functions
*/
-static inline int virtqueue_add(struct virtqueue *_vq,
- struct scatterlist *sgs[],
- unsigned int total_sg,
- unsigned int out_sgs,
- unsigned int in_sgs,
- void *data,
- void *ctx,
- gfp_t gfp)
+static inline int vring_virtqueue_add_sgs(struct virtqueue *_vq,
+ struct scatterlist *sgs[],
+ unsigned int total_sg,
+ unsigned int out_sgs,
+ unsigned int in_sgs,
+ void *data,
+ void *ctx,
+ gfp_t gfp)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -2135,110 +2138,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
}
/**
- * virtqueue_add_sgs - expose buffers to other end
- * @_vq: the struct virtqueue we're talking about.
- * @sgs: array of terminated scatterlists.
- * @out_sgs: the number of scatterlists readable by other side
- * @in_sgs: the number of scatterlists which are writable (after readable ones)
- * @data: the token identifying the buffer.
- * @gfp: how to do memory allocations (if necessary).
- *
- * Caller must ensure we don't call this with other virtqueue operations
- * at the same time (except where noted).
- *
- * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
- */
-int virtqueue_add_sgs(struct virtqueue *_vq,
- struct scatterlist *sgs[],
- unsigned int out_sgs,
- unsigned int in_sgs,
- void *data,
- gfp_t gfp)
-{
- unsigned int i, total_sg = 0;
-
- /* Count them first. */
- for (i = 0; i < out_sgs + in_sgs; i++) {
- struct scatterlist *sg;
-
- for (sg = sgs[i]; sg; sg = sg_next(sg))
- total_sg++;
- }
- return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
- data, NULL, gfp);
-}
-EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
-
-/**
- * virtqueue_add_outbuf - expose output buffers to other end
- * @vq: the struct virtqueue we're talking about.
- * @sg: scatterlist (must be well-formed and terminated!)
- * @num: the number of entries in @sg readable by other side
- * @data: the token identifying the buffer.
- * @gfp: how to do memory allocations (if necessary).
- *
- * Caller must ensure we don't call this with other virtqueue operations
- * at the same time (except where noted).
- *
- * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
- */
-int virtqueue_add_outbuf(struct virtqueue *vq,
- struct scatterlist *sg, unsigned int num,
- void *data,
- gfp_t gfp)
-{
- return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
-}
-EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
-
-/**
- * virtqueue_add_inbuf - expose input buffers to other end
- * @vq: the struct virtqueue we're talking about.
- * @sg: scatterlist (must be well-formed and terminated!)
- * @num: the number of entries in @sg writable by other side
- * @data: the token identifying the buffer.
- * @gfp: how to do memory allocations (if necessary).
- *
- * Caller must ensure we don't call this with other virtqueue operations
- * at the same time (except where noted).
- *
- * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
- */
-int virtqueue_add_inbuf(struct virtqueue *vq,
- struct scatterlist *sg, unsigned int num,
- void *data,
- gfp_t gfp)
-{
- return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp);
-}
-EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
-
-/**
- * virtqueue_add_inbuf_ctx - expose input buffers to other end
- * @vq: the struct virtqueue we're talking about.
- * @sg: scatterlist (must be well-formed and terminated!)
- * @num: the number of entries in @sg writable by other side
- * @data: the token identifying the buffer.
- * @ctx: extra context for the token
- * @gfp: how to do memory allocations (if necessary).
- *
- * Caller must ensure we don't call this with other virtqueue operations
- * at the same time (except where noted).
- *
- * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
- */
-int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
- struct scatterlist *sg, unsigned int num,
- void *data,
- void *ctx,
- gfp_t gfp)
-{
- return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp);
-}
-EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
-
-/**
- * virtqueue_kick_prepare - first half of split virtqueue_kick call.
+ * vring_virtqueue_kick_prepare - first half of split virtqueue_kick call.
* @_vq: the struct virtqueue
*
* Instead of virtqueue_kick(), you can do:
@@ -2248,24 +2148,23 @@ EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
* This is sometimes useful because the virtqueue_kick_prepare() needs
* to be serialized, but the actual virtqueue_notify() call does not.
*/
-bool virtqueue_kick_prepare(struct virtqueue *_vq)
+static bool vring_virtqueue_kick_prepare(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
return vq->packed_ring ? virtqueue_kick_prepare_packed(_vq) :
virtqueue_kick_prepare_split(_vq);
}
-EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
/**
- * virtqueue_notify - second half of split virtqueue_kick call.
+ * vring_virtqueue_notify - second half of split virtqueue_kick call.
* @_vq: the struct virtqueue
*
* This does not need to be serialized.
*
* Returns false if host notify failed or queue is broken, otherwise true.
*/
-bool virtqueue_notify(struct virtqueue *_vq)
+static bool vring_virtqueue_notify(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -2279,30 +2178,9 @@ bool virtqueue_notify(struct virtqueue *_vq)
}
return true;
}
-EXPORT_SYMBOL_GPL(virtqueue_notify);
/**
- * virtqueue_kick - update after add_buf
- * @vq: the struct virtqueue
- *
- * After one or more virtqueue_add_* calls, invoke this to kick
- * the other side.
- *
- * Caller must ensure we don't call this with other virtqueue
- * operations at the same time (except where noted).
- *
- * Returns false if kick failed, otherwise true.
- */
-bool virtqueue_kick(struct virtqueue *vq)
-{
- if (virtqueue_kick_prepare(vq))
- return virtqueue_notify(vq);
- return true;
-}
-EXPORT_SYMBOL_GPL(virtqueue_kick);
-
-/**
- * virtqueue_get_buf_ctx - get the next used buffer
+ * vring_virtqueue_get_buf_ctx - get the next used buffer
* @_vq: the struct virtqueue we're talking about.
* @len: the length written into the buffer
* @ctx: extra context for the token
@@ -2318,7 +2196,7 @@ EXPORT_SYMBOL_GPL(virtqueue_kick);
* Returns NULL if there are no used buffers, or the "data" token
* handed to virtqueue_add_*().
*/
-void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
+static void *vring_virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
void **ctx)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -2326,15 +2204,9 @@ void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) :
virtqueue_get_buf_ctx_split(_vq, len, ctx);
}
-EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
-void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
-{
- return virtqueue_get_buf_ctx(_vq, len, NULL);
-}
-EXPORT_SYMBOL_GPL(virtqueue_get_buf);
/**
- * virtqueue_disable_cb - disable callbacks
+ * vring_virtqueue_disable_cb - disable callbacks
* @_vq: the struct virtqueue we're talking about.
*
* Note that this is not necessarily synchronous, hence unreliable and only
@@ -2342,7 +2214,7 @@ EXPORT_SYMBOL_GPL(virtqueue_get_buf);
*
* Unlike other operations, this need not be serialized.
*/
-void virtqueue_disable_cb(struct virtqueue *_vq)
+static void vring_virtqueue_disable_cb(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -2351,10 +2223,9 @@ void virtqueue_disable_cb(struct virtqueue *_vq)
else
virtqueue_disable_cb_split(_vq);
}
-EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
/**
- * virtqueue_enable_cb_prepare - restart callbacks after disable_cb
+ * vring_virtqueue_enable_cb_prepare - restart callbacks after disable_cb
* @_vq: the struct virtqueue we're talking about.
*
* This re-enables callbacks; it returns current queue state
@@ -2365,7 +2236,7 @@ EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
*/
-unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq)
+static unsigned int vring_virtqueue_enable_cb_prepare(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -2375,10 +2246,9 @@ unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq)
return vq->packed_ring ? virtqueue_enable_cb_prepare_packed(_vq) :
virtqueue_enable_cb_prepare_split(_vq);
}
-EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
/**
- * virtqueue_poll - query pending used buffers
+ * vring_virtqueue_poll - query pending used buffers
* @_vq: the struct virtqueue we're talking about.
* @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
*
@@ -2386,7 +2256,7 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
*
* This does not need to be serialized.
*/
-bool virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
+static bool vring_virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -2397,29 +2267,9 @@ bool virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
return vq->packed_ring ? virtqueue_poll_packed(_vq, last_used_idx) :
virtqueue_poll_split(_vq, last_used_idx);
}
-EXPORT_SYMBOL_GPL(virtqueue_poll);
/**
- * virtqueue_enable_cb - restart callbacks after disable_cb.
- * @_vq: the struct virtqueue we're talking about.
- *
- * This re-enables callbacks; it returns "false" if there are pending
- * buffers in the queue, to detect a possible race between the driver
- * checking for more work, and enabling callbacks.
- *
- * Caller must ensure we don't call this with other virtqueue
- * operations at the same time (except where noted).
- */
-bool virtqueue_enable_cb(struct virtqueue *_vq)
-{
- unsigned int last_used_idx = virtqueue_enable_cb_prepare(_vq);
-
- return !virtqueue_poll(_vq, last_used_idx);
-}
-EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
-
-/**
- * virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
+ * vring_virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
* @_vq: the struct virtqueue we're talking about.
*
* This re-enables callbacks but hints to the other side to delay
@@ -2431,7 +2281,7 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
* Caller must ensure we don't call this with other virtqueue
* operations at the same time (except where noted).
*/
-bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
+static bool vring_virtqueue_enable_cb_delayed(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
@@ -2441,24 +2291,22 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(_vq) :
virtqueue_enable_cb_delayed_split(_vq);
}
-EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
/**
- * virtqueue_detach_unused_buf - detach first unused buffer
+ * vring_virtqueue_detach_unused_buf - detach first unused buffer
* @_vq: the struct virtqueue we're talking about.
*
* Returns NULL or the "data" token handed to virtqueue_add_*().
* This is not valid on an active queue; it is useful for device
* shutdown or the reset queue.
*/
-void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
+static void *vring_virtqueue_detach_unused_buf(struct virtqueue *_vq)
{
struct vring_virtqueue *vq = to_vvq(_vq);
return vq->packed_ring ? virtqueue_detach_unused_buf_packed(_vq) :
virtqueue_detach_unused_buf_split(_vq);
}
-EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
static inline bool more_used(const struct vring_virtqueue *vq)
{
@@ -2531,6 +2379,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
vq->vq.name = name;
vq->vq.index = index;
vq->vq.reset = false;
+ vq->vq.ops = &vring_ops;
vq->we_own_ring = false;
vq->notify = notify;
vq->weak_barriers = weak_barriers;
@@ -2616,7 +2465,7 @@ struct virtqueue *vring_create_virtqueue_dma(
EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma);
/**
- * virtqueue_resize - resize the vring of vq
+ * vring_virtqueue_resize - resize the vring of vq
* @_vq: the struct virtqueue we're talking about.
* @num: new ring num
* @recycle: callback for recycle the useless buffer
@@ -2639,8 +2488,8 @@ EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma);
* -EPERM: Operation not permitted
*
*/
-int virtqueue_resize(struct virtqueue *_vq, u32 num,
- void (*recycle)(struct virtqueue *vq, void *buf))
+static int vring_virtqueue_resize(struct virtqueue *_vq, u32 num,
+ void (*recycle)(struct virtqueue *vq, void *buf))
{
struct vring_virtqueue *vq = to_vvq(_vq);
struct virtio_device *vdev = vq->vq.vdev;
@@ -2669,7 +2518,7 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
if (err)
return err;
- while ((buf = virtqueue_detach_unused_buf(_vq)) != NULL)
+ while ((buf = vring_virtqueue_detach_unused_buf(_vq)) != NULL)
recycle(_vq, buf);
if (vq->packed_ring)
@@ -2682,7 +2531,6 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
return err;
}
-EXPORT_SYMBOL_GPL(virtqueue_resize);
/* Only available for split ring */
struct virtqueue *vring_new_virtqueue(unsigned int index,
@@ -2809,20 +2657,19 @@ void vring_transport_features(struct virtio_device *vdev)
EXPORT_SYMBOL_GPL(vring_transport_features);
/**
- * virtqueue_get_vring_size - return the size of the virtqueue's vring
+ * vring_virtqueue_get_vring_size - return the size of the virtqueue's vring
* @_vq: the struct virtqueue containing the vring of interest.
*
* Returns the size of the vring. This is mainly used for boasting to
* userspace. Unlike other operations, this need not be serialized.
*/
-unsigned int virtqueue_get_vring_size(const struct virtqueue *_vq)
+static unsigned int vring_virtqueue_get_vring_size(const struct virtqueue *_vq)
{
const struct vring_virtqueue *vq = to_vvq(_vq);
return vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num;
}
-EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
/*
* This function should only be called by the core, not directly by the driver.
@@ -2848,54 +2695,29 @@ void __virtqueue_unbreak(struct virtqueue *_vq)
}
EXPORT_SYMBOL_GPL(__virtqueue_unbreak);
-bool virtqueue_is_broken(const struct virtqueue *_vq)
+static bool vring_virtqueue_is_broken(const struct virtqueue *_vq)
{
const struct vring_virtqueue *vq = to_vvq(_vq);
return READ_ONCE(vq->broken);
}
-EXPORT_SYMBOL_GPL(virtqueue_is_broken);
-
-/*
- * This should prevent the device from being used, allowing drivers to
- * recover. You may need to grab appropriate locks to flush.
- */
-void virtio_break_device(struct virtio_device *dev)
-{
- struct virtqueue *_vq;
-
- spin_lock(&dev->vqs_list_lock);
- list_for_each_entry(_vq, &dev->vqs, list) {
- struct vring_virtqueue *vq = to_vvq(_vq);
-
- /* Pairs with READ_ONCE() in virtqueue_is_broken(). */
- WRITE_ONCE(vq->broken, true);
- }
- spin_unlock(&dev->vqs_list_lock);
-}
-EXPORT_SYMBOL_GPL(virtio_break_device);
-
-/*
- * This should allow the device to be used by the driver. You may
- * need to grab appropriate locks to flush the write to
- * vq->broken. This should only be used in some specific case e.g
- * (probing and restoring). This function should only be called by the
- * core, not directly by the driver.
- */
-void __virtio_unbreak_device(struct virtio_device *dev)
-{
- struct virtqueue *_vq;
-
- spin_lock(&dev->vqs_list_lock);
- list_for_each_entry(_vq, &dev->vqs, list) {
- struct vring_virtqueue *vq = to_vvq(_vq);
- /* Pairs with READ_ONCE() in virtqueue_is_broken(). */
- WRITE_ONCE(vq->broken, false);
- }
- spin_unlock(&dev->vqs_list_lock);
-}
-EXPORT_SYMBOL_GPL(__virtio_unbreak_device);
+static struct virtqueue_ops vring_ops = {
+ .add_sgs = vring_virtqueue_add_sgs,
+ .kick_prepare = vring_virtqueue_kick_prepare,
+ .notify = vring_virtqueue_notify,
+ .enable_cb_prepare = vring_virtqueue_enable_cb_prepare,
+ .enable_cb_delayed = vring_virtqueue_enable_cb_delayed,
+ .disable_cb = vring_virtqueue_disable_cb,
+ .poll = vring_virtqueue_poll,
+ .get_buf_ctx = vring_virtqueue_get_buf_ctx,
+ .detach_unused_buf = vring_virtqueue_detach_unused_buf,
+ .get_vring_size = vring_virtqueue_get_vring_size,
+ .resize = vring_virtqueue_resize,
+ .__break = __virtqueue_break,
+ .__unbreak = __virtqueue_unbreak,
+ .is_broken = vring_virtqueue_is_broken,
+};
dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *_vq)
{
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index b93238db94e3..845858b8761e 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -10,6 +10,34 @@
#include <linux/mod_devicetable.h>
#include <linux/gfp.h>
+struct virtqueue;
+
+/**
+ * struct virtqueue_ops - abstract operations for a virtqueue.
+ *
+ * Descriptions of each field see the comments in virtio.c
+ */
+struct virtqueue_ops {
+ int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
+ unsigned int total_sg,
+ unsigned int out_sgs, unsigned int in_sgs,
+ void *data, void *ctx, gfp_t gfp);
+ bool (*kick_prepare)(struct virtqueue *vq);
+ bool (*notify)(struct virtqueue *vq);
+ unsigned int (*enable_cb_prepare)(struct virtqueue *vq);
+ bool (*enable_cb_delayed)(struct virtqueue *vq);
+ void (*disable_cb)(struct virtqueue *vq);
+ bool (*poll)(struct virtqueue *vq, unsigned int idx);
+ void *(*get_buf_ctx)(struct virtqueue *vq, unsigned int *len, void **ctx);
+ void *(*detach_unused_buf)(struct virtqueue *vq);
+ unsigned int (*get_vring_size)(const struct virtqueue *vq);
+ int (*resize)(struct virtqueue *vq, u32 num,
+ void (*recycle)(struct virtqueue *vq, void *buf));
+ void (*__break)(struct virtqueue *vq);
+ void (*__unbreak)(struct virtqueue *vq);
+ bool (*is_broken)(const struct virtqueue *vq);
+};
+
/**
* struct virtqueue - a queue to register buffers for sending or receiving.
* @list: the chain of virtqueues for this device
@@ -36,6 +64,7 @@ struct virtqueue {
unsigned int num_max;
bool reset;
void *priv;
+ struct virtqueue_ops *ops;
};
int virtqueue_add_outbuf(struct virtqueue *vq,
--
2.20.1
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PATCH 1/2] virtio: abstract virtqueue related methods
2023-05-12 9:46 ` zhenwei pi
@ 2023-05-12 10:46 ` Michael S. Tsirkin
-1 siblings, 0 replies; 20+ messages in thread
From: Michael S. Tsirkin @ 2023-05-12 10:46 UTC (permalink / raw)
To: zhenwei pi; +Cc: xuanzhuo, linux-kernel, stefanha, virtualization
On Fri, May 12, 2023 at 05:46:17PM +0800, zhenwei pi wrote:
> There is already a virtqueue abstract structure in virtio subsystem
> (see struct virtqueue in include/linux/virtio.h), however the vring
> based virtqueue is used only in the past years, the virtqueue related
> methods mix much with vring(just look like the codes, virtqueue_xxx
> functions are implemented in virtio_ring.c).
>
> Abstract virtqueue related methods(see struct virtqueue_ops), and
> separate virtqueue_xxx symbols from vring. This allows a non-vring
> based transport in the future. With this change, the following symbols
> are exported from virtio.ko instead of virtio_ring.ko:
> virtqueue_add_sgs
> virtqueue_add_outbuf
> virtqueue_add_inbuf
> virtqueue_add_inbuf_ctx
> virtqueue_kick_prepare
> virtqueue_notify
> virtqueue_kick
> virtqueue_enable_cb_prepare
> virtqueue_enable_cb
> virtqueue_enable_cb_delayed
> virtqueue_disable_cb
> virtqueue_poll
> virtqueue_get_buf_ctx
> virtqueue_get_buf
> virtqueue_detach_unused_buf
> virtqueue_get_vring_size
> virtqueue_resize
> virtqueue_is_broken
> virtio_break_device
> __virtio_unbreak_device
>
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
> drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
> drivers/virtio/virtio_ring.c | 282 +++++----------------------
> include/linux/virtio.h | 29 +++
> 3 files changed, 443 insertions(+), 230 deletions(-)
>
> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> index 3893dc29eb26..8d8715a10f26 100644
> --- a/drivers/virtio/virtio.c
> +++ b/drivers/virtio/virtio.c
> @@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
> EXPORT_SYMBOL_GPL(virtio_device_restore);
> #endif
>
> +/**
> + * virtqueue_add_sgs - expose buffers to other end
> + * @vq: the struct virtqueue we're talking about.
> + * @sgs: array of terminated scatterlists.
> + * @out_sgs: the number of scatterlists readable by other side
> + * @in_sgs: the number of scatterlists which are writable (after readable ones)
> + * @data: the token identifying the buffer.
> + * @gfp: how to do memory allocations (if necessary).
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> + */
> +int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
> + unsigned int out_sgs, unsigned int in_sgs,
> + void *data, gfp_t gfp)
> +{
> + unsigned int i, total_sg = 0;
> +
> + /* Count them first. */
> + for (i = 0; i < out_sgs + in_sgs; i++) {
> + struct scatterlist *sg;
> +
> + for (sg = sgs[i]; sg; sg = sg_next(sg))
> + total_sg++;
> + }
> + return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
> + data, NULL, gfp);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
Hmm this kind of indirection on data path is going to be costly
performance-wise especially when retpolines are in place.
Any data on this?
> +
> +/**
> + * virtqueue_add_outbuf - expose output buffers to other end
> + * @vq: the struct virtqueue we're talking about.
> + * @sg: scatterlist (must be well-formed and terminated!)
> + * @num: the number of entries in @sg readable by other side
> + * @data: the token identifying the buffer.
> + * @gfp: how to do memory allocations (if necessary).
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> + */
> +int virtqueue_add_outbuf(struct virtqueue *vq, struct scatterlist *sg,
> + unsigned int num, void *data, gfp_t gfp)
> +{
> + return vq->ops->add_sgs(vq, &sg, num, 1, 0, data, NULL, gfp);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
> +
> +/**
> + * virtqueue_add_inbuf - expose input buffers to other end
> + * @vq: the struct virtqueue we're talking about.
> + * @sg: scatterlist (must be well-formed and terminated!)
> + * @num: the number of entries in @sg writable by other side
> + * @data: the token identifying the buffer.
> + * @gfp: how to do memory allocations (if necessary).
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> + */
> +int virtqueue_add_inbuf(struct virtqueue *vq, struct scatterlist *sg,
> + unsigned int num, void *data, gfp_t gfp)
> +{
> + return vq->ops->add_sgs(vq, &sg, num, 0, 1, data, NULL, gfp);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
> +
> +/**
> + * virtqueue_add_inbuf_ctx - expose input buffers to other end
> + * @vq: the struct virtqueue we're talking about.
> + * @sg: scatterlist (must be well-formed and terminated!)
> + * @num: the number of entries in @sg writable by other side
> + * @data: the token identifying the buffer.
> + * @ctx: extra context for the token
> + * @gfp: how to do memory allocations (if necessary).
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> + */
> +int virtqueue_add_inbuf_ctx(struct virtqueue *vq, struct scatterlist *sg,
> + unsigned int num, void *data, void *ctx, gfp_t gfp)
> +{
> + return vq->ops->add_sgs(vq, &sg, num, 0, 1, data, ctx, gfp);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
> +
> +/**
> + * virtqueue_kick_prepare - first half of split virtqueue_kick call.
> + * @vq: the struct virtqueue
> + *
> + * Instead of virtqueue_kick(), you can do:
> + * if (virtqueue_kick_prepare(vq))
> + * virtqueue_notify(vq);
> + *
> + * This is sometimes useful because the virtqueue_kick_prepare() needs
> + * to be serialized, but the actual virtqueue_notify() call does not.
> + */
> +bool virtqueue_kick_prepare(struct virtqueue *vq)
> +{
> + return vq->ops->kick_prepare(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
> +
> +/**
> + * virtqueue_notify - second half of split virtqueue_kick call.
> + * @vq: the struct virtqueue
> + *
> + * This does not need to be serialized.
> + *
> + * Returns false if host notify failed or queue is broken, otherwise true.
> + */
> +bool virtqueue_notify(struct virtqueue *vq)
> +{
> + return vq->ops->notify(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_notify);
> +
> +/**
> + * virtqueue_kick - update after add_buf
> + * @vq: the struct virtqueue
> + *
> + * After one or more virtqueue_add_* calls, invoke this to kick
> + * the other side.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + *
> + * Returns false if kick failed, otherwise true.
> + */
> +bool virtqueue_kick(struct virtqueue *vq)
> +{
> + if (virtqueue_kick_prepare(vq))
> + return virtqueue_notify(vq);
> + return true;
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_kick);
> +
> +/**
> + * virtqueue_enable_cb_prepare - restart callbacks after disable_cb
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * This re-enables callbacks; it returns current queue state
> + * in an opaque unsigned value. This value should be later tested by
> + * virtqueue_poll, to detect a possible race between the driver checking for
> + * more work, and enabling callbacks.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + */
> +unsigned int virtqueue_enable_cb_prepare(struct virtqueue *vq)
> +{
> + return vq->ops->enable_cb_prepare(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
> +
> +/**
> + * virtqueue_enable_cb - restart callbacks after disable_cb.
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * This re-enables callbacks; it returns "false" if there are pending
> + * buffers in the queue, to detect a possible race between the driver
> + * checking for more work, and enabling callbacks.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + */
> +bool virtqueue_enable_cb(struct virtqueue *vq)
> +{
> + unsigned int val = vq->ops->enable_cb_prepare(vq);
> +
> + return !vq->ops->poll(vq, val);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
> +
> +/**
> + * virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * This re-enables callbacks but hints to the other side to delay
> + * interrupts until most of the available buffers have been processed;
> + * it returns "false" if there are many pending buffers in the queue,
> + * to detect a possible race between the driver checking for more work,
> + * and enabling callbacks.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + */
> +bool virtqueue_enable_cb_delayed(struct virtqueue *vq)
> +{
> + return vq->ops->enable_cb_delayed(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
> +
> +/**
> + * virtqueue_disable_cb - disable callbacks
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * Note that this is not necessarily synchronous, hence unreliable and only
> + * useful as an optimization.
> + *
> + * Unlike other operations, this need not be serialized.
> + */
> +void virtqueue_disable_cb(struct virtqueue *vq)
> +{
> + vq->ops->disable_cb(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
> +
> +/**
> + * virtqueue_poll - query pending used buffers
> + * @vq: the struct virtqueue we're talking about.
> + * @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
> + *
> + * Returns "true" if there are pending used buffers in the queue.
> + *
> + * This does not need to be serialized.
> + */
> +bool virtqueue_poll(struct virtqueue *vq, unsigned int idx)
> +{
> + return vq->ops->poll(vq, idx);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_poll);
> +
> +/**
> + * virtqueue_get_buf_ctx - get the next used buffer
> + * @vq: the struct virtqueue we're talking about.
> + * @len: the length written into the buffer
> + * @ctx: extra context for the token
> + *
> + * If the device wrote data into the buffer, @len will be set to the
> + * amount written. This means you don't need to clear the buffer
> + * beforehand to ensure there's no data leakage in the case of short
> + * writes.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + *
> + * Returns NULL if there are no used buffers, or the "data" token
> + * handed to virtqueue_add_*().
> + */
> +void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
> + void **ctx)
> +{
> + return vq->ops->get_buf_ctx(vq, len, ctx);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
> +
> +void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len)
> +{
> + return vq->ops->get_buf_ctx(vq, len, NULL);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_get_buf);
> +
> +/**
> + * virtqueue_detach_unused_buf - detach first unused buffer
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * Returns NULL or the "data" token handed to virtqueue_add_*().
> + * This is not valid on an active queue; it is useful for device
> + * shutdown or the reset queue.
> + */
> +void *virtqueue_detach_unused_buf(struct virtqueue *vq)
> +{
> + return vq->ops->detach_unused_buf(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
> +
> +/**
> + * virtqueue_get_vring_size - return the size of the virtqueue's vring
> + * @vq: the struct virtqueue containing the vring of interest.
> + *
> + * Returns the size of the vring. This is mainly used for boasting to
> + * userspace. Unlike other operations, this need not be serialized.
> + */
> +unsigned int virtqueue_get_vring_size(const struct virtqueue *vq)
> +{
> + return vq->ops->get_vring_size(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
> +
> +/**
> + * virtqueue_resize - resize the vring of vq
> + * @vq: the struct virtqueue we're talking about.
> + * @num: new ring num
> + * @recycle: callback for recycle the useless buffer
> + *
> + * When it is really necessary to create a new vring, it will set the current vq
> + * into the reset state. Then call the passed callback to recycle the buffer
> + * that is no longer used. Only after the new vring is successfully created, the
> + * old vring will be released.
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error.
> + * 0: success.
> + * -ENOMEM: Failed to allocate a new ring, fall back to the original ring size.
> + * vq can still work normally
> + * -EBUSY: Failed to sync with device, vq may not work properly
> + * -ENOENT: Transport or device not supported
> + * -E2BIG/-EINVAL: num error
> + * -EPERM: Operation not permitted
> + *
> + */
> +int virtqueue_resize(struct virtqueue *vq, u32 num,
> + void (*recycle)(struct virtqueue *vq, void *buf))
> +{
> + if (vq->ops->resize)
> + return vq->ops->resize(vq, num, recycle);
> +
> + return -ENOENT;
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_resize);
> +
> +bool virtqueue_is_broken(const struct virtqueue *vq)
> +{
> + return vq->ops->is_broken(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_is_broken);
> +
> +/*
> + * This should prevent the device from being used, allowing drivers to
> + * recover. You may need to grab appropriate locks to flush.
> + */
> +void virtio_break_device(struct virtio_device *dev)
> +{
> + struct virtqueue *vq;
> +
> + spin_lock(&dev->vqs_list_lock);
> + list_for_each_entry(vq, &dev->vqs, list) {
> + vq->ops->__break(vq);
> + }
> + spin_unlock(&dev->vqs_list_lock);
> +}
> +EXPORT_SYMBOL_GPL(virtio_break_device);
> +
> +/*
> + * This should allow the device to be used by the driver. You may
> + * need to grab appropriate locks to flush the write to
> + * vq->broken. This should only be used in some specific case e.g
> + * (probing and restoring). This function should only be called by the
> + * core, not directly by the driver.
> + */
> +void __virtio_unbreak_device(struct virtio_device *dev)
> +{
> + struct virtqueue *vq;
> +
> + spin_lock(&dev->vqs_list_lock);
> + list_for_each_entry(vq, &dev->vqs, list) {
> + vq->ops->__unbreak(vq);
> + }
> + spin_unlock(&dev->vqs_list_lock);
> +}
> +EXPORT_SYMBOL_GPL(__virtio_unbreak_device);
> +
> static int virtio_init(void)
> {
> if (bus_register(&virtio_bus) != 0)
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index c5310eaf8b46..7b86417255db 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -227,6 +227,8 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
> static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num);
> static void vring_free(struct virtqueue *_vq);
>
> +static struct virtqueue_ops vring_ops;
> +
> /*
> * Helpers.
> */
> @@ -2041,6 +2043,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
> vq->vq.name = name;
> vq->vq.index = index;
> vq->vq.reset = false;
> + vq->vq.ops = &vring_ops;
> vq->we_own_ring = true;
> vq->notify = notify;
> vq->weak_barriers = weak_barriers;
> @@ -2114,17 +2117,17 @@ static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num)
>
>
> /*
> - * Generic functions and exported symbols.
> + * Vring specific operation functions
> */
>
> -static inline int virtqueue_add(struct virtqueue *_vq,
> - struct scatterlist *sgs[],
> - unsigned int total_sg,
> - unsigned int out_sgs,
> - unsigned int in_sgs,
> - void *data,
> - void *ctx,
> - gfp_t gfp)
> +static inline int vring_virtqueue_add_sgs(struct virtqueue *_vq,
> + struct scatterlist *sgs[],
> + unsigned int total_sg,
> + unsigned int out_sgs,
> + unsigned int in_sgs,
> + void *data,
> + void *ctx,
> + gfp_t gfp)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2135,110 +2138,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
> }
>
> /**
> - * virtqueue_add_sgs - expose buffers to other end
> - * @_vq: the struct virtqueue we're talking about.
> - * @sgs: array of terminated scatterlists.
> - * @out_sgs: the number of scatterlists readable by other side
> - * @in_sgs: the number of scatterlists which are writable (after readable ones)
> - * @data: the token identifying the buffer.
> - * @gfp: how to do memory allocations (if necessary).
> - *
> - * Caller must ensure we don't call this with other virtqueue operations
> - * at the same time (except where noted).
> - *
> - * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> - */
> -int virtqueue_add_sgs(struct virtqueue *_vq,
> - struct scatterlist *sgs[],
> - unsigned int out_sgs,
> - unsigned int in_sgs,
> - void *data,
> - gfp_t gfp)
> -{
> - unsigned int i, total_sg = 0;
> -
> - /* Count them first. */
> - for (i = 0; i < out_sgs + in_sgs; i++) {
> - struct scatterlist *sg;
> -
> - for (sg = sgs[i]; sg; sg = sg_next(sg))
> - total_sg++;
> - }
> - return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
> - data, NULL, gfp);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
> -
> -/**
> - * virtqueue_add_outbuf - expose output buffers to other end
> - * @vq: the struct virtqueue we're talking about.
> - * @sg: scatterlist (must be well-formed and terminated!)
> - * @num: the number of entries in @sg readable by other side
> - * @data: the token identifying the buffer.
> - * @gfp: how to do memory allocations (if necessary).
> - *
> - * Caller must ensure we don't call this with other virtqueue operations
> - * at the same time (except where noted).
> - *
> - * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> - */
> -int virtqueue_add_outbuf(struct virtqueue *vq,
> - struct scatterlist *sg, unsigned int num,
> - void *data,
> - gfp_t gfp)
> -{
> - return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
> -
> -/**
> - * virtqueue_add_inbuf - expose input buffers to other end
> - * @vq: the struct virtqueue we're talking about.
> - * @sg: scatterlist (must be well-formed and terminated!)
> - * @num: the number of entries in @sg writable by other side
> - * @data: the token identifying the buffer.
> - * @gfp: how to do memory allocations (if necessary).
> - *
> - * Caller must ensure we don't call this with other virtqueue operations
> - * at the same time (except where noted).
> - *
> - * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> - */
> -int virtqueue_add_inbuf(struct virtqueue *vq,
> - struct scatterlist *sg, unsigned int num,
> - void *data,
> - gfp_t gfp)
> -{
> - return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
> -
> -/**
> - * virtqueue_add_inbuf_ctx - expose input buffers to other end
> - * @vq: the struct virtqueue we're talking about.
> - * @sg: scatterlist (must be well-formed and terminated!)
> - * @num: the number of entries in @sg writable by other side
> - * @data: the token identifying the buffer.
> - * @ctx: extra context for the token
> - * @gfp: how to do memory allocations (if necessary).
> - *
> - * Caller must ensure we don't call this with other virtqueue operations
> - * at the same time (except where noted).
> - *
> - * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> - */
> -int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
> - struct scatterlist *sg, unsigned int num,
> - void *data,
> - void *ctx,
> - gfp_t gfp)
> -{
> - return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
> -
> -/**
> - * virtqueue_kick_prepare - first half of split virtqueue_kick call.
> + * vring_virtqueue_kick_prepare - first half of split virtqueue_kick call.
> * @_vq: the struct virtqueue
> *
> * Instead of virtqueue_kick(), you can do:
> @@ -2248,24 +2148,23 @@ EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
> * This is sometimes useful because the virtqueue_kick_prepare() needs
> * to be serialized, but the actual virtqueue_notify() call does not.
> */
> -bool virtqueue_kick_prepare(struct virtqueue *_vq)
> +static bool vring_virtqueue_kick_prepare(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> return vq->packed_ring ? virtqueue_kick_prepare_packed(_vq) :
> virtqueue_kick_prepare_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
>
> /**
> - * virtqueue_notify - second half of split virtqueue_kick call.
> + * vring_virtqueue_notify - second half of split virtqueue_kick call.
> * @_vq: the struct virtqueue
> *
> * This does not need to be serialized.
> *
> * Returns false if host notify failed or queue is broken, otherwise true.
> */
> -bool virtqueue_notify(struct virtqueue *_vq)
> +static bool vring_virtqueue_notify(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2279,30 +2178,9 @@ bool virtqueue_notify(struct virtqueue *_vq)
> }
> return true;
> }
> -EXPORT_SYMBOL_GPL(virtqueue_notify);
>
> /**
> - * virtqueue_kick - update after add_buf
> - * @vq: the struct virtqueue
> - *
> - * After one or more virtqueue_add_* calls, invoke this to kick
> - * the other side.
> - *
> - * Caller must ensure we don't call this with other virtqueue
> - * operations at the same time (except where noted).
> - *
> - * Returns false if kick failed, otherwise true.
> - */
> -bool virtqueue_kick(struct virtqueue *vq)
> -{
> - if (virtqueue_kick_prepare(vq))
> - return virtqueue_notify(vq);
> - return true;
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_kick);
> -
> -/**
> - * virtqueue_get_buf_ctx - get the next used buffer
> + * vring_virtqueue_get_buf_ctx - get the next used buffer
> * @_vq: the struct virtqueue we're talking about.
> * @len: the length written into the buffer
> * @ctx: extra context for the token
> @@ -2318,7 +2196,7 @@ EXPORT_SYMBOL_GPL(virtqueue_kick);
> * Returns NULL if there are no used buffers, or the "data" token
> * handed to virtqueue_add_*().
> */
> -void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
> +static void *vring_virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
> void **ctx)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> @@ -2326,15 +2204,9 @@ void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
> return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) :
> virtqueue_get_buf_ctx_split(_vq, len, ctx);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
>
> -void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
> -{
> - return virtqueue_get_buf_ctx(_vq, len, NULL);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_get_buf);
> /**
> - * virtqueue_disable_cb - disable callbacks
> + * vring_virtqueue_disable_cb - disable callbacks
> * @_vq: the struct virtqueue we're talking about.
> *
> * Note that this is not necessarily synchronous, hence unreliable and only
> @@ -2342,7 +2214,7 @@ EXPORT_SYMBOL_GPL(virtqueue_get_buf);
> *
> * Unlike other operations, this need not be serialized.
> */
> -void virtqueue_disable_cb(struct virtqueue *_vq)
> +static void vring_virtqueue_disable_cb(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2351,10 +2223,9 @@ void virtqueue_disable_cb(struct virtqueue *_vq)
> else
> virtqueue_disable_cb_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
>
> /**
> - * virtqueue_enable_cb_prepare - restart callbacks after disable_cb
> + * vring_virtqueue_enable_cb_prepare - restart callbacks after disable_cb
> * @_vq: the struct virtqueue we're talking about.
> *
> * This re-enables callbacks; it returns current queue state
> @@ -2365,7 +2236,7 @@ EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
> * Caller must ensure we don't call this with other virtqueue
> * operations at the same time (except where noted).
> */
> -unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> +static unsigned int vring_virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2375,10 +2246,9 @@ unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> return vq->packed_ring ? virtqueue_enable_cb_prepare_packed(_vq) :
> virtqueue_enable_cb_prepare_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
>
> /**
> - * virtqueue_poll - query pending used buffers
> + * vring_virtqueue_poll - query pending used buffers
> * @_vq: the struct virtqueue we're talking about.
> * @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
> *
> @@ -2386,7 +2256,7 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
> *
> * This does not need to be serialized.
> */
> -bool virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
> +static bool vring_virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2397,29 +2267,9 @@ bool virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
> return vq->packed_ring ? virtqueue_poll_packed(_vq, last_used_idx) :
> virtqueue_poll_split(_vq, last_used_idx);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_poll);
>
> /**
> - * virtqueue_enable_cb - restart callbacks after disable_cb.
> - * @_vq: the struct virtqueue we're talking about.
> - *
> - * This re-enables callbacks; it returns "false" if there are pending
> - * buffers in the queue, to detect a possible race between the driver
> - * checking for more work, and enabling callbacks.
> - *
> - * Caller must ensure we don't call this with other virtqueue
> - * operations at the same time (except where noted).
> - */
> -bool virtqueue_enable_cb(struct virtqueue *_vq)
> -{
> - unsigned int last_used_idx = virtqueue_enable_cb_prepare(_vq);
> -
> - return !virtqueue_poll(_vq, last_used_idx);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
> -
> -/**
> - * virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
> + * vring_virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
> * @_vq: the struct virtqueue we're talking about.
> *
> * This re-enables callbacks but hints to the other side to delay
> @@ -2431,7 +2281,7 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
> * Caller must ensure we don't call this with other virtqueue
> * operations at the same time (except where noted).
> */
> -bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
> +static bool vring_virtqueue_enable_cb_delayed(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2441,24 +2291,22 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
> return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(_vq) :
> virtqueue_enable_cb_delayed_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
>
> /**
> - * virtqueue_detach_unused_buf - detach first unused buffer
> + * vring_virtqueue_detach_unused_buf - detach first unused buffer
> * @_vq: the struct virtqueue we're talking about.
> *
> * Returns NULL or the "data" token handed to virtqueue_add_*().
> * This is not valid on an active queue; it is useful for device
> * shutdown or the reset queue.
> */
> -void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
> +static void *vring_virtqueue_detach_unused_buf(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> return vq->packed_ring ? virtqueue_detach_unused_buf_packed(_vq) :
> virtqueue_detach_unused_buf_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
>
> static inline bool more_used(const struct vring_virtqueue *vq)
> {
> @@ -2531,6 +2379,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
> vq->vq.name = name;
> vq->vq.index = index;
> vq->vq.reset = false;
> + vq->vq.ops = &vring_ops;
> vq->we_own_ring = false;
> vq->notify = notify;
> vq->weak_barriers = weak_barriers;
> @@ -2616,7 +2465,7 @@ struct virtqueue *vring_create_virtqueue_dma(
> EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma);
>
> /**
> - * virtqueue_resize - resize the vring of vq
> + * vring_virtqueue_resize - resize the vring of vq
> * @_vq: the struct virtqueue we're talking about.
> * @num: new ring num
> * @recycle: callback for recycle the useless buffer
> @@ -2639,8 +2488,8 @@ EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma);
> * -EPERM: Operation not permitted
> *
> */
> -int virtqueue_resize(struct virtqueue *_vq, u32 num,
> - void (*recycle)(struct virtqueue *vq, void *buf))
> +static int vring_virtqueue_resize(struct virtqueue *_vq, u32 num,
> + void (*recycle)(struct virtqueue *vq, void *buf))
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> struct virtio_device *vdev = vq->vq.vdev;
> @@ -2669,7 +2518,7 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
> if (err)
> return err;
>
> - while ((buf = virtqueue_detach_unused_buf(_vq)) != NULL)
> + while ((buf = vring_virtqueue_detach_unused_buf(_vq)) != NULL)
> recycle(_vq, buf);
>
> if (vq->packed_ring)
> @@ -2682,7 +2531,6 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
>
> return err;
> }
> -EXPORT_SYMBOL_GPL(virtqueue_resize);
>
> /* Only available for split ring */
> struct virtqueue *vring_new_virtqueue(unsigned int index,
> @@ -2809,20 +2657,19 @@ void vring_transport_features(struct virtio_device *vdev)
> EXPORT_SYMBOL_GPL(vring_transport_features);
>
> /**
> - * virtqueue_get_vring_size - return the size of the virtqueue's vring
> + * vring_virtqueue_get_vring_size - return the size of the virtqueue's vring
> * @_vq: the struct virtqueue containing the vring of interest.
> *
> * Returns the size of the vring. This is mainly used for boasting to
> * userspace. Unlike other operations, this need not be serialized.
> */
> -unsigned int virtqueue_get_vring_size(const struct virtqueue *_vq)
> +static unsigned int vring_virtqueue_get_vring_size(const struct virtqueue *_vq)
> {
>
> const struct vring_virtqueue *vq = to_vvq(_vq);
>
> return vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num;
> }
> -EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
>
> /*
> * This function should only be called by the core, not directly by the driver.
> @@ -2848,54 +2695,29 @@ void __virtqueue_unbreak(struct virtqueue *_vq)
> }
> EXPORT_SYMBOL_GPL(__virtqueue_unbreak);
>
> -bool virtqueue_is_broken(const struct virtqueue *_vq)
> +static bool vring_virtqueue_is_broken(const struct virtqueue *_vq)
> {
> const struct vring_virtqueue *vq = to_vvq(_vq);
>
> return READ_ONCE(vq->broken);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_is_broken);
> -
> -/*
> - * This should prevent the device from being used, allowing drivers to
> - * recover. You may need to grab appropriate locks to flush.
> - */
> -void virtio_break_device(struct virtio_device *dev)
> -{
> - struct virtqueue *_vq;
> -
> - spin_lock(&dev->vqs_list_lock);
> - list_for_each_entry(_vq, &dev->vqs, list) {
> - struct vring_virtqueue *vq = to_vvq(_vq);
> -
> - /* Pairs with READ_ONCE() in virtqueue_is_broken(). */
> - WRITE_ONCE(vq->broken, true);
> - }
> - spin_unlock(&dev->vqs_list_lock);
> -}
> -EXPORT_SYMBOL_GPL(virtio_break_device);
> -
> -/*
> - * This should allow the device to be used by the driver. You may
> - * need to grab appropriate locks to flush the write to
> - * vq->broken. This should only be used in some specific case e.g
> - * (probing and restoring). This function should only be called by the
> - * core, not directly by the driver.
> - */
> -void __virtio_unbreak_device(struct virtio_device *dev)
> -{
> - struct virtqueue *_vq;
> -
> - spin_lock(&dev->vqs_list_lock);
> - list_for_each_entry(_vq, &dev->vqs, list) {
> - struct vring_virtqueue *vq = to_vvq(_vq);
>
> - /* Pairs with READ_ONCE() in virtqueue_is_broken(). */
> - WRITE_ONCE(vq->broken, false);
> - }
> - spin_unlock(&dev->vqs_list_lock);
> -}
> -EXPORT_SYMBOL_GPL(__virtio_unbreak_device);
> +static struct virtqueue_ops vring_ops = {
> + .add_sgs = vring_virtqueue_add_sgs,
> + .kick_prepare = vring_virtqueue_kick_prepare,
> + .notify = vring_virtqueue_notify,
> + .enable_cb_prepare = vring_virtqueue_enable_cb_prepare,
> + .enable_cb_delayed = vring_virtqueue_enable_cb_delayed,
> + .disable_cb = vring_virtqueue_disable_cb,
> + .poll = vring_virtqueue_poll,
> + .get_buf_ctx = vring_virtqueue_get_buf_ctx,
> + .detach_unused_buf = vring_virtqueue_detach_unused_buf,
> + .get_vring_size = vring_virtqueue_get_vring_size,
> + .resize = vring_virtqueue_resize,
> + .__break = __virtqueue_break,
> + .__unbreak = __virtqueue_unbreak,
> + .is_broken = vring_virtqueue_is_broken,
> +};
>
> dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *_vq)
> {
> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> index b93238db94e3..845858b8761e 100644
> --- a/include/linux/virtio.h
> +++ b/include/linux/virtio.h
> @@ -10,6 +10,34 @@
> #include <linux/mod_devicetable.h>
> #include <linux/gfp.h>
>
> +struct virtqueue;
> +
> +/**
> + * struct virtqueue_ops - abstract operations for a virtqueue.
> + *
> + * Descriptions of each field see the comments in virtio.c
> + */
> +struct virtqueue_ops {
> + int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
> + unsigned int total_sg,
> + unsigned int out_sgs, unsigned int in_sgs,
> + void *data, void *ctx, gfp_t gfp);
> + bool (*kick_prepare)(struct virtqueue *vq);
> + bool (*notify)(struct virtqueue *vq);
> + unsigned int (*enable_cb_prepare)(struct virtqueue *vq);
> + bool (*enable_cb_delayed)(struct virtqueue *vq);
> + void (*disable_cb)(struct virtqueue *vq);
> + bool (*poll)(struct virtqueue *vq, unsigned int idx);
> + void *(*get_buf_ctx)(struct virtqueue *vq, unsigned int *len, void **ctx);
> + void *(*detach_unused_buf)(struct virtqueue *vq);
> + unsigned int (*get_vring_size)(const struct virtqueue *vq);
> + int (*resize)(struct virtqueue *vq, u32 num,
> + void (*recycle)(struct virtqueue *vq, void *buf));
> + void (*__break)(struct virtqueue *vq);
> + void (*__unbreak)(struct virtqueue *vq);
> + bool (*is_broken)(const struct virtqueue *vq);
> +};
> +
> /**
> * struct virtqueue - a queue to register buffers for sending or receiving.
> * @list: the chain of virtqueues for this device
> @@ -36,6 +64,7 @@ struct virtqueue {
> unsigned int num_max;
> bool reset;
> void *priv;
> + struct virtqueue_ops *ops;
> };
>
> int virtqueue_add_outbuf(struct virtqueue *vq,
> --
> 2.20.1
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^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH 1/2] virtio: abstract virtqueue related methods
@ 2023-05-12 10:46 ` Michael S. Tsirkin
0 siblings, 0 replies; 20+ messages in thread
From: Michael S. Tsirkin @ 2023-05-12 10:46 UTC (permalink / raw)
To: zhenwei pi; +Cc: stefanha, jasowang, xuanzhuo, virtualization, linux-kernel
On Fri, May 12, 2023 at 05:46:17PM +0800, zhenwei pi wrote:
> There is already a virtqueue abstract structure in virtio subsystem
> (see struct virtqueue in include/linux/virtio.h), however the vring
> based virtqueue is used only in the past years, the virtqueue related
> methods mix much with vring(just look like the codes, virtqueue_xxx
> functions are implemented in virtio_ring.c).
>
> Abstract virtqueue related methods(see struct virtqueue_ops), and
> separate virtqueue_xxx symbols from vring. This allows a non-vring
> based transport in the future. With this change, the following symbols
> are exported from virtio.ko instead of virtio_ring.ko:
> virtqueue_add_sgs
> virtqueue_add_outbuf
> virtqueue_add_inbuf
> virtqueue_add_inbuf_ctx
> virtqueue_kick_prepare
> virtqueue_notify
> virtqueue_kick
> virtqueue_enable_cb_prepare
> virtqueue_enable_cb
> virtqueue_enable_cb_delayed
> virtqueue_disable_cb
> virtqueue_poll
> virtqueue_get_buf_ctx
> virtqueue_get_buf
> virtqueue_detach_unused_buf
> virtqueue_get_vring_size
> virtqueue_resize
> virtqueue_is_broken
> virtio_break_device
> __virtio_unbreak_device
>
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> ---
> drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
> drivers/virtio/virtio_ring.c | 282 +++++----------------------
> include/linux/virtio.h | 29 +++
> 3 files changed, 443 insertions(+), 230 deletions(-)
>
> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> index 3893dc29eb26..8d8715a10f26 100644
> --- a/drivers/virtio/virtio.c
> +++ b/drivers/virtio/virtio.c
> @@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
> EXPORT_SYMBOL_GPL(virtio_device_restore);
> #endif
>
> +/**
> + * virtqueue_add_sgs - expose buffers to other end
> + * @vq: the struct virtqueue we're talking about.
> + * @sgs: array of terminated scatterlists.
> + * @out_sgs: the number of scatterlists readable by other side
> + * @in_sgs: the number of scatterlists which are writable (after readable ones)
> + * @data: the token identifying the buffer.
> + * @gfp: how to do memory allocations (if necessary).
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> + */
> +int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
> + unsigned int out_sgs, unsigned int in_sgs,
> + void *data, gfp_t gfp)
> +{
> + unsigned int i, total_sg = 0;
> +
> + /* Count them first. */
> + for (i = 0; i < out_sgs + in_sgs; i++) {
> + struct scatterlist *sg;
> +
> + for (sg = sgs[i]; sg; sg = sg_next(sg))
> + total_sg++;
> + }
> + return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
> + data, NULL, gfp);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
Hmm this kind of indirection on data path is going to be costly
performance-wise especially when retpolines are in place.
Any data on this?
> +
> +/**
> + * virtqueue_add_outbuf - expose output buffers to other end
> + * @vq: the struct virtqueue we're talking about.
> + * @sg: scatterlist (must be well-formed and terminated!)
> + * @num: the number of entries in @sg readable by other side
> + * @data: the token identifying the buffer.
> + * @gfp: how to do memory allocations (if necessary).
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> + */
> +int virtqueue_add_outbuf(struct virtqueue *vq, struct scatterlist *sg,
> + unsigned int num, void *data, gfp_t gfp)
> +{
> + return vq->ops->add_sgs(vq, &sg, num, 1, 0, data, NULL, gfp);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
> +
> +/**
> + * virtqueue_add_inbuf - expose input buffers to other end
> + * @vq: the struct virtqueue we're talking about.
> + * @sg: scatterlist (must be well-formed and terminated!)
> + * @num: the number of entries in @sg writable by other side
> + * @data: the token identifying the buffer.
> + * @gfp: how to do memory allocations (if necessary).
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> + */
> +int virtqueue_add_inbuf(struct virtqueue *vq, struct scatterlist *sg,
> + unsigned int num, void *data, gfp_t gfp)
> +{
> + return vq->ops->add_sgs(vq, &sg, num, 0, 1, data, NULL, gfp);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
> +
> +/**
> + * virtqueue_add_inbuf_ctx - expose input buffers to other end
> + * @vq: the struct virtqueue we're talking about.
> + * @sg: scatterlist (must be well-formed and terminated!)
> + * @num: the number of entries in @sg writable by other side
> + * @data: the token identifying the buffer.
> + * @ctx: extra context for the token
> + * @gfp: how to do memory allocations (if necessary).
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> + */
> +int virtqueue_add_inbuf_ctx(struct virtqueue *vq, struct scatterlist *sg,
> + unsigned int num, void *data, void *ctx, gfp_t gfp)
> +{
> + return vq->ops->add_sgs(vq, &sg, num, 0, 1, data, ctx, gfp);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
> +
> +/**
> + * virtqueue_kick_prepare - first half of split virtqueue_kick call.
> + * @vq: the struct virtqueue
> + *
> + * Instead of virtqueue_kick(), you can do:
> + * if (virtqueue_kick_prepare(vq))
> + * virtqueue_notify(vq);
> + *
> + * This is sometimes useful because the virtqueue_kick_prepare() needs
> + * to be serialized, but the actual virtqueue_notify() call does not.
> + */
> +bool virtqueue_kick_prepare(struct virtqueue *vq)
> +{
> + return vq->ops->kick_prepare(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
> +
> +/**
> + * virtqueue_notify - second half of split virtqueue_kick call.
> + * @vq: the struct virtqueue
> + *
> + * This does not need to be serialized.
> + *
> + * Returns false if host notify failed or queue is broken, otherwise true.
> + */
> +bool virtqueue_notify(struct virtqueue *vq)
> +{
> + return vq->ops->notify(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_notify);
> +
> +/**
> + * virtqueue_kick - update after add_buf
> + * @vq: the struct virtqueue
> + *
> + * After one or more virtqueue_add_* calls, invoke this to kick
> + * the other side.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + *
> + * Returns false if kick failed, otherwise true.
> + */
> +bool virtqueue_kick(struct virtqueue *vq)
> +{
> + if (virtqueue_kick_prepare(vq))
> + return virtqueue_notify(vq);
> + return true;
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_kick);
> +
> +/**
> + * virtqueue_enable_cb_prepare - restart callbacks after disable_cb
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * This re-enables callbacks; it returns current queue state
> + * in an opaque unsigned value. This value should be later tested by
> + * virtqueue_poll, to detect a possible race between the driver checking for
> + * more work, and enabling callbacks.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + */
> +unsigned int virtqueue_enable_cb_prepare(struct virtqueue *vq)
> +{
> + return vq->ops->enable_cb_prepare(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
> +
> +/**
> + * virtqueue_enable_cb - restart callbacks after disable_cb.
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * This re-enables callbacks; it returns "false" if there are pending
> + * buffers in the queue, to detect a possible race between the driver
> + * checking for more work, and enabling callbacks.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + */
> +bool virtqueue_enable_cb(struct virtqueue *vq)
> +{
> + unsigned int val = vq->ops->enable_cb_prepare(vq);
> +
> + return !vq->ops->poll(vq, val);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
> +
> +/**
> + * virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * This re-enables callbacks but hints to the other side to delay
> + * interrupts until most of the available buffers have been processed;
> + * it returns "false" if there are many pending buffers in the queue,
> + * to detect a possible race between the driver checking for more work,
> + * and enabling callbacks.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + */
> +bool virtqueue_enable_cb_delayed(struct virtqueue *vq)
> +{
> + return vq->ops->enable_cb_delayed(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
> +
> +/**
> + * virtqueue_disable_cb - disable callbacks
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * Note that this is not necessarily synchronous, hence unreliable and only
> + * useful as an optimization.
> + *
> + * Unlike other operations, this need not be serialized.
> + */
> +void virtqueue_disable_cb(struct virtqueue *vq)
> +{
> + vq->ops->disable_cb(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
> +
> +/**
> + * virtqueue_poll - query pending used buffers
> + * @vq: the struct virtqueue we're talking about.
> + * @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
> + *
> + * Returns "true" if there are pending used buffers in the queue.
> + *
> + * This does not need to be serialized.
> + */
> +bool virtqueue_poll(struct virtqueue *vq, unsigned int idx)
> +{
> + return vq->ops->poll(vq, idx);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_poll);
> +
> +/**
> + * virtqueue_get_buf_ctx - get the next used buffer
> + * @vq: the struct virtqueue we're talking about.
> + * @len: the length written into the buffer
> + * @ctx: extra context for the token
> + *
> + * If the device wrote data into the buffer, @len will be set to the
> + * amount written. This means you don't need to clear the buffer
> + * beforehand to ensure there's no data leakage in the case of short
> + * writes.
> + *
> + * Caller must ensure we don't call this with other virtqueue
> + * operations at the same time (except where noted).
> + *
> + * Returns NULL if there are no used buffers, or the "data" token
> + * handed to virtqueue_add_*().
> + */
> +void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
> + void **ctx)
> +{
> + return vq->ops->get_buf_ctx(vq, len, ctx);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
> +
> +void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len)
> +{
> + return vq->ops->get_buf_ctx(vq, len, NULL);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_get_buf);
> +
> +/**
> + * virtqueue_detach_unused_buf - detach first unused buffer
> + * @vq: the struct virtqueue we're talking about.
> + *
> + * Returns NULL or the "data" token handed to virtqueue_add_*().
> + * This is not valid on an active queue; it is useful for device
> + * shutdown or the reset queue.
> + */
> +void *virtqueue_detach_unused_buf(struct virtqueue *vq)
> +{
> + return vq->ops->detach_unused_buf(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
> +
> +/**
> + * virtqueue_get_vring_size - return the size of the virtqueue's vring
> + * @vq: the struct virtqueue containing the vring of interest.
> + *
> + * Returns the size of the vring. This is mainly used for boasting to
> + * userspace. Unlike other operations, this need not be serialized.
> + */
> +unsigned int virtqueue_get_vring_size(const struct virtqueue *vq)
> +{
> + return vq->ops->get_vring_size(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
> +
> +/**
> + * virtqueue_resize - resize the vring of vq
> + * @vq: the struct virtqueue we're talking about.
> + * @num: new ring num
> + * @recycle: callback for recycle the useless buffer
> + *
> + * When it is really necessary to create a new vring, it will set the current vq
> + * into the reset state. Then call the passed callback to recycle the buffer
> + * that is no longer used. Only after the new vring is successfully created, the
> + * old vring will be released.
> + *
> + * Caller must ensure we don't call this with other virtqueue operations
> + * at the same time (except where noted).
> + *
> + * Returns zero or a negative error.
> + * 0: success.
> + * -ENOMEM: Failed to allocate a new ring, fall back to the original ring size.
> + * vq can still work normally
> + * -EBUSY: Failed to sync with device, vq may not work properly
> + * -ENOENT: Transport or device not supported
> + * -E2BIG/-EINVAL: num error
> + * -EPERM: Operation not permitted
> + *
> + */
> +int virtqueue_resize(struct virtqueue *vq, u32 num,
> + void (*recycle)(struct virtqueue *vq, void *buf))
> +{
> + if (vq->ops->resize)
> + return vq->ops->resize(vq, num, recycle);
> +
> + return -ENOENT;
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_resize);
> +
> +bool virtqueue_is_broken(const struct virtqueue *vq)
> +{
> + return vq->ops->is_broken(vq);
> +}
> +EXPORT_SYMBOL_GPL(virtqueue_is_broken);
> +
> +/*
> + * This should prevent the device from being used, allowing drivers to
> + * recover. You may need to grab appropriate locks to flush.
> + */
> +void virtio_break_device(struct virtio_device *dev)
> +{
> + struct virtqueue *vq;
> +
> + spin_lock(&dev->vqs_list_lock);
> + list_for_each_entry(vq, &dev->vqs, list) {
> + vq->ops->__break(vq);
> + }
> + spin_unlock(&dev->vqs_list_lock);
> +}
> +EXPORT_SYMBOL_GPL(virtio_break_device);
> +
> +/*
> + * This should allow the device to be used by the driver. You may
> + * need to grab appropriate locks to flush the write to
> + * vq->broken. This should only be used in some specific case e.g
> + * (probing and restoring). This function should only be called by the
> + * core, not directly by the driver.
> + */
> +void __virtio_unbreak_device(struct virtio_device *dev)
> +{
> + struct virtqueue *vq;
> +
> + spin_lock(&dev->vqs_list_lock);
> + list_for_each_entry(vq, &dev->vqs, list) {
> + vq->ops->__unbreak(vq);
> + }
> + spin_unlock(&dev->vqs_list_lock);
> +}
> +EXPORT_SYMBOL_GPL(__virtio_unbreak_device);
> +
> static int virtio_init(void)
> {
> if (bus_register(&virtio_bus) != 0)
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index c5310eaf8b46..7b86417255db 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -227,6 +227,8 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
> static struct vring_desc_extra *vring_alloc_desc_extra(unsigned int num);
> static void vring_free(struct virtqueue *_vq);
>
> +static struct virtqueue_ops vring_ops;
> +
> /*
> * Helpers.
> */
> @@ -2041,6 +2043,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
> vq->vq.name = name;
> vq->vq.index = index;
> vq->vq.reset = false;
> + vq->vq.ops = &vring_ops;
> vq->we_own_ring = true;
> vq->notify = notify;
> vq->weak_barriers = weak_barriers;
> @@ -2114,17 +2117,17 @@ static int virtqueue_resize_packed(struct virtqueue *_vq, u32 num)
>
>
> /*
> - * Generic functions and exported symbols.
> + * Vring specific operation functions
> */
>
> -static inline int virtqueue_add(struct virtqueue *_vq,
> - struct scatterlist *sgs[],
> - unsigned int total_sg,
> - unsigned int out_sgs,
> - unsigned int in_sgs,
> - void *data,
> - void *ctx,
> - gfp_t gfp)
> +static inline int vring_virtqueue_add_sgs(struct virtqueue *_vq,
> + struct scatterlist *sgs[],
> + unsigned int total_sg,
> + unsigned int out_sgs,
> + unsigned int in_sgs,
> + void *data,
> + void *ctx,
> + gfp_t gfp)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2135,110 +2138,7 @@ static inline int virtqueue_add(struct virtqueue *_vq,
> }
>
> /**
> - * virtqueue_add_sgs - expose buffers to other end
> - * @_vq: the struct virtqueue we're talking about.
> - * @sgs: array of terminated scatterlists.
> - * @out_sgs: the number of scatterlists readable by other side
> - * @in_sgs: the number of scatterlists which are writable (after readable ones)
> - * @data: the token identifying the buffer.
> - * @gfp: how to do memory allocations (if necessary).
> - *
> - * Caller must ensure we don't call this with other virtqueue operations
> - * at the same time (except where noted).
> - *
> - * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> - */
> -int virtqueue_add_sgs(struct virtqueue *_vq,
> - struct scatterlist *sgs[],
> - unsigned int out_sgs,
> - unsigned int in_sgs,
> - void *data,
> - gfp_t gfp)
> -{
> - unsigned int i, total_sg = 0;
> -
> - /* Count them first. */
> - for (i = 0; i < out_sgs + in_sgs; i++) {
> - struct scatterlist *sg;
> -
> - for (sg = sgs[i]; sg; sg = sg_next(sg))
> - total_sg++;
> - }
> - return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
> - data, NULL, gfp);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
> -
> -/**
> - * virtqueue_add_outbuf - expose output buffers to other end
> - * @vq: the struct virtqueue we're talking about.
> - * @sg: scatterlist (must be well-formed and terminated!)
> - * @num: the number of entries in @sg readable by other side
> - * @data: the token identifying the buffer.
> - * @gfp: how to do memory allocations (if necessary).
> - *
> - * Caller must ensure we don't call this with other virtqueue operations
> - * at the same time (except where noted).
> - *
> - * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> - */
> -int virtqueue_add_outbuf(struct virtqueue *vq,
> - struct scatterlist *sg, unsigned int num,
> - void *data,
> - gfp_t gfp)
> -{
> - return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
> -
> -/**
> - * virtqueue_add_inbuf - expose input buffers to other end
> - * @vq: the struct virtqueue we're talking about.
> - * @sg: scatterlist (must be well-formed and terminated!)
> - * @num: the number of entries in @sg writable by other side
> - * @data: the token identifying the buffer.
> - * @gfp: how to do memory allocations (if necessary).
> - *
> - * Caller must ensure we don't call this with other virtqueue operations
> - * at the same time (except where noted).
> - *
> - * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> - */
> -int virtqueue_add_inbuf(struct virtqueue *vq,
> - struct scatterlist *sg, unsigned int num,
> - void *data,
> - gfp_t gfp)
> -{
> - return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
> -
> -/**
> - * virtqueue_add_inbuf_ctx - expose input buffers to other end
> - * @vq: the struct virtqueue we're talking about.
> - * @sg: scatterlist (must be well-formed and terminated!)
> - * @num: the number of entries in @sg writable by other side
> - * @data: the token identifying the buffer.
> - * @ctx: extra context for the token
> - * @gfp: how to do memory allocations (if necessary).
> - *
> - * Caller must ensure we don't call this with other virtqueue operations
> - * at the same time (except where noted).
> - *
> - * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> - */
> -int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
> - struct scatterlist *sg, unsigned int num,
> - void *data,
> - void *ctx,
> - gfp_t gfp)
> -{
> - return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
> -
> -/**
> - * virtqueue_kick_prepare - first half of split virtqueue_kick call.
> + * vring_virtqueue_kick_prepare - first half of split virtqueue_kick call.
> * @_vq: the struct virtqueue
> *
> * Instead of virtqueue_kick(), you can do:
> @@ -2248,24 +2148,23 @@ EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
> * This is sometimes useful because the virtqueue_kick_prepare() needs
> * to be serialized, but the actual virtqueue_notify() call does not.
> */
> -bool virtqueue_kick_prepare(struct virtqueue *_vq)
> +static bool vring_virtqueue_kick_prepare(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> return vq->packed_ring ? virtqueue_kick_prepare_packed(_vq) :
> virtqueue_kick_prepare_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
>
> /**
> - * virtqueue_notify - second half of split virtqueue_kick call.
> + * vring_virtqueue_notify - second half of split virtqueue_kick call.
> * @_vq: the struct virtqueue
> *
> * This does not need to be serialized.
> *
> * Returns false if host notify failed or queue is broken, otherwise true.
> */
> -bool virtqueue_notify(struct virtqueue *_vq)
> +static bool vring_virtqueue_notify(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2279,30 +2178,9 @@ bool virtqueue_notify(struct virtqueue *_vq)
> }
> return true;
> }
> -EXPORT_SYMBOL_GPL(virtqueue_notify);
>
> /**
> - * virtqueue_kick - update after add_buf
> - * @vq: the struct virtqueue
> - *
> - * After one or more virtqueue_add_* calls, invoke this to kick
> - * the other side.
> - *
> - * Caller must ensure we don't call this with other virtqueue
> - * operations at the same time (except where noted).
> - *
> - * Returns false if kick failed, otherwise true.
> - */
> -bool virtqueue_kick(struct virtqueue *vq)
> -{
> - if (virtqueue_kick_prepare(vq))
> - return virtqueue_notify(vq);
> - return true;
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_kick);
> -
> -/**
> - * virtqueue_get_buf_ctx - get the next used buffer
> + * vring_virtqueue_get_buf_ctx - get the next used buffer
> * @_vq: the struct virtqueue we're talking about.
> * @len: the length written into the buffer
> * @ctx: extra context for the token
> @@ -2318,7 +2196,7 @@ EXPORT_SYMBOL_GPL(virtqueue_kick);
> * Returns NULL if there are no used buffers, or the "data" token
> * handed to virtqueue_add_*().
> */
> -void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
> +static void *vring_virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
> void **ctx)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> @@ -2326,15 +2204,9 @@ void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
> return vq->packed_ring ? virtqueue_get_buf_ctx_packed(_vq, len, ctx) :
> virtqueue_get_buf_ctx_split(_vq, len, ctx);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
>
> -void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
> -{
> - return virtqueue_get_buf_ctx(_vq, len, NULL);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_get_buf);
> /**
> - * virtqueue_disable_cb - disable callbacks
> + * vring_virtqueue_disable_cb - disable callbacks
> * @_vq: the struct virtqueue we're talking about.
> *
> * Note that this is not necessarily synchronous, hence unreliable and only
> @@ -2342,7 +2214,7 @@ EXPORT_SYMBOL_GPL(virtqueue_get_buf);
> *
> * Unlike other operations, this need not be serialized.
> */
> -void virtqueue_disable_cb(struct virtqueue *_vq)
> +static void vring_virtqueue_disable_cb(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2351,10 +2223,9 @@ void virtqueue_disable_cb(struct virtqueue *_vq)
> else
> virtqueue_disable_cb_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
>
> /**
> - * virtqueue_enable_cb_prepare - restart callbacks after disable_cb
> + * vring_virtqueue_enable_cb_prepare - restart callbacks after disable_cb
> * @_vq: the struct virtqueue we're talking about.
> *
> * This re-enables callbacks; it returns current queue state
> @@ -2365,7 +2236,7 @@ EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
> * Caller must ensure we don't call this with other virtqueue
> * operations at the same time (except where noted).
> */
> -unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> +static unsigned int vring_virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2375,10 +2246,9 @@ unsigned int virtqueue_enable_cb_prepare(struct virtqueue *_vq)
> return vq->packed_ring ? virtqueue_enable_cb_prepare_packed(_vq) :
> virtqueue_enable_cb_prepare_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
>
> /**
> - * virtqueue_poll - query pending used buffers
> + * vring_virtqueue_poll - query pending used buffers
> * @_vq: the struct virtqueue we're talking about.
> * @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
> *
> @@ -2386,7 +2256,7 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
> *
> * This does not need to be serialized.
> */
> -bool virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
> +static bool vring_virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2397,29 +2267,9 @@ bool virtqueue_poll(struct virtqueue *_vq, unsigned int last_used_idx)
> return vq->packed_ring ? virtqueue_poll_packed(_vq, last_used_idx) :
> virtqueue_poll_split(_vq, last_used_idx);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_poll);
>
> /**
> - * virtqueue_enable_cb - restart callbacks after disable_cb.
> - * @_vq: the struct virtqueue we're talking about.
> - *
> - * This re-enables callbacks; it returns "false" if there are pending
> - * buffers in the queue, to detect a possible race between the driver
> - * checking for more work, and enabling callbacks.
> - *
> - * Caller must ensure we don't call this with other virtqueue
> - * operations at the same time (except where noted).
> - */
> -bool virtqueue_enable_cb(struct virtqueue *_vq)
> -{
> - unsigned int last_used_idx = virtqueue_enable_cb_prepare(_vq);
> -
> - return !virtqueue_poll(_vq, last_used_idx);
> -}
> -EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
> -
> -/**
> - * virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
> + * vring_virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
> * @_vq: the struct virtqueue we're talking about.
> *
> * This re-enables callbacks but hints to the other side to delay
> @@ -2431,7 +2281,7 @@ EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
> * Caller must ensure we don't call this with other virtqueue
> * operations at the same time (except where noted).
> */
> -bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
> +static bool vring_virtqueue_enable_cb_delayed(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> @@ -2441,24 +2291,22 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
> return vq->packed_ring ? virtqueue_enable_cb_delayed_packed(_vq) :
> virtqueue_enable_cb_delayed_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
>
> /**
> - * virtqueue_detach_unused_buf - detach first unused buffer
> + * vring_virtqueue_detach_unused_buf - detach first unused buffer
> * @_vq: the struct virtqueue we're talking about.
> *
> * Returns NULL or the "data" token handed to virtqueue_add_*().
> * This is not valid on an active queue; it is useful for device
> * shutdown or the reset queue.
> */
> -void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
> +static void *vring_virtqueue_detach_unused_buf(struct virtqueue *_vq)
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
>
> return vq->packed_ring ? virtqueue_detach_unused_buf_packed(_vq) :
> virtqueue_detach_unused_buf_split(_vq);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
>
> static inline bool more_used(const struct vring_virtqueue *vq)
> {
> @@ -2531,6 +2379,7 @@ static struct virtqueue *__vring_new_virtqueue(unsigned int index,
> vq->vq.name = name;
> vq->vq.index = index;
> vq->vq.reset = false;
> + vq->vq.ops = &vring_ops;
> vq->we_own_ring = false;
> vq->notify = notify;
> vq->weak_barriers = weak_barriers;
> @@ -2616,7 +2465,7 @@ struct virtqueue *vring_create_virtqueue_dma(
> EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma);
>
> /**
> - * virtqueue_resize - resize the vring of vq
> + * vring_virtqueue_resize - resize the vring of vq
> * @_vq: the struct virtqueue we're talking about.
> * @num: new ring num
> * @recycle: callback for recycle the useless buffer
> @@ -2639,8 +2488,8 @@ EXPORT_SYMBOL_GPL(vring_create_virtqueue_dma);
> * -EPERM: Operation not permitted
> *
> */
> -int virtqueue_resize(struct virtqueue *_vq, u32 num,
> - void (*recycle)(struct virtqueue *vq, void *buf))
> +static int vring_virtqueue_resize(struct virtqueue *_vq, u32 num,
> + void (*recycle)(struct virtqueue *vq, void *buf))
> {
> struct vring_virtqueue *vq = to_vvq(_vq);
> struct virtio_device *vdev = vq->vq.vdev;
> @@ -2669,7 +2518,7 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
> if (err)
> return err;
>
> - while ((buf = virtqueue_detach_unused_buf(_vq)) != NULL)
> + while ((buf = vring_virtqueue_detach_unused_buf(_vq)) != NULL)
> recycle(_vq, buf);
>
> if (vq->packed_ring)
> @@ -2682,7 +2531,6 @@ int virtqueue_resize(struct virtqueue *_vq, u32 num,
>
> return err;
> }
> -EXPORT_SYMBOL_GPL(virtqueue_resize);
>
> /* Only available for split ring */
> struct virtqueue *vring_new_virtqueue(unsigned int index,
> @@ -2809,20 +2657,19 @@ void vring_transport_features(struct virtio_device *vdev)
> EXPORT_SYMBOL_GPL(vring_transport_features);
>
> /**
> - * virtqueue_get_vring_size - return the size of the virtqueue's vring
> + * vring_virtqueue_get_vring_size - return the size of the virtqueue's vring
> * @_vq: the struct virtqueue containing the vring of interest.
> *
> * Returns the size of the vring. This is mainly used for boasting to
> * userspace. Unlike other operations, this need not be serialized.
> */
> -unsigned int virtqueue_get_vring_size(const struct virtqueue *_vq)
> +static unsigned int vring_virtqueue_get_vring_size(const struct virtqueue *_vq)
> {
>
> const struct vring_virtqueue *vq = to_vvq(_vq);
>
> return vq->packed_ring ? vq->packed.vring.num : vq->split.vring.num;
> }
> -EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
>
> /*
> * This function should only be called by the core, not directly by the driver.
> @@ -2848,54 +2695,29 @@ void __virtqueue_unbreak(struct virtqueue *_vq)
> }
> EXPORT_SYMBOL_GPL(__virtqueue_unbreak);
>
> -bool virtqueue_is_broken(const struct virtqueue *_vq)
> +static bool vring_virtqueue_is_broken(const struct virtqueue *_vq)
> {
> const struct vring_virtqueue *vq = to_vvq(_vq);
>
> return READ_ONCE(vq->broken);
> }
> -EXPORT_SYMBOL_GPL(virtqueue_is_broken);
> -
> -/*
> - * This should prevent the device from being used, allowing drivers to
> - * recover. You may need to grab appropriate locks to flush.
> - */
> -void virtio_break_device(struct virtio_device *dev)
> -{
> - struct virtqueue *_vq;
> -
> - spin_lock(&dev->vqs_list_lock);
> - list_for_each_entry(_vq, &dev->vqs, list) {
> - struct vring_virtqueue *vq = to_vvq(_vq);
> -
> - /* Pairs with READ_ONCE() in virtqueue_is_broken(). */
> - WRITE_ONCE(vq->broken, true);
> - }
> - spin_unlock(&dev->vqs_list_lock);
> -}
> -EXPORT_SYMBOL_GPL(virtio_break_device);
> -
> -/*
> - * This should allow the device to be used by the driver. You may
> - * need to grab appropriate locks to flush the write to
> - * vq->broken. This should only be used in some specific case e.g
> - * (probing and restoring). This function should only be called by the
> - * core, not directly by the driver.
> - */
> -void __virtio_unbreak_device(struct virtio_device *dev)
> -{
> - struct virtqueue *_vq;
> -
> - spin_lock(&dev->vqs_list_lock);
> - list_for_each_entry(_vq, &dev->vqs, list) {
> - struct vring_virtqueue *vq = to_vvq(_vq);
>
> - /* Pairs with READ_ONCE() in virtqueue_is_broken(). */
> - WRITE_ONCE(vq->broken, false);
> - }
> - spin_unlock(&dev->vqs_list_lock);
> -}
> -EXPORT_SYMBOL_GPL(__virtio_unbreak_device);
> +static struct virtqueue_ops vring_ops = {
> + .add_sgs = vring_virtqueue_add_sgs,
> + .kick_prepare = vring_virtqueue_kick_prepare,
> + .notify = vring_virtqueue_notify,
> + .enable_cb_prepare = vring_virtqueue_enable_cb_prepare,
> + .enable_cb_delayed = vring_virtqueue_enable_cb_delayed,
> + .disable_cb = vring_virtqueue_disable_cb,
> + .poll = vring_virtqueue_poll,
> + .get_buf_ctx = vring_virtqueue_get_buf_ctx,
> + .detach_unused_buf = vring_virtqueue_detach_unused_buf,
> + .get_vring_size = vring_virtqueue_get_vring_size,
> + .resize = vring_virtqueue_resize,
> + .__break = __virtqueue_break,
> + .__unbreak = __virtqueue_unbreak,
> + .is_broken = vring_virtqueue_is_broken,
> +};
>
> dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *_vq)
> {
> diff --git a/include/linux/virtio.h b/include/linux/virtio.h
> index b93238db94e3..845858b8761e 100644
> --- a/include/linux/virtio.h
> +++ b/include/linux/virtio.h
> @@ -10,6 +10,34 @@
> #include <linux/mod_devicetable.h>
> #include <linux/gfp.h>
>
> +struct virtqueue;
> +
> +/**
> + * struct virtqueue_ops - abstract operations for a virtqueue.
> + *
> + * Descriptions of each field see the comments in virtio.c
> + */
> +struct virtqueue_ops {
> + int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
> + unsigned int total_sg,
> + unsigned int out_sgs, unsigned int in_sgs,
> + void *data, void *ctx, gfp_t gfp);
> + bool (*kick_prepare)(struct virtqueue *vq);
> + bool (*notify)(struct virtqueue *vq);
> + unsigned int (*enable_cb_prepare)(struct virtqueue *vq);
> + bool (*enable_cb_delayed)(struct virtqueue *vq);
> + void (*disable_cb)(struct virtqueue *vq);
> + bool (*poll)(struct virtqueue *vq, unsigned int idx);
> + void *(*get_buf_ctx)(struct virtqueue *vq, unsigned int *len, void **ctx);
> + void *(*detach_unused_buf)(struct virtqueue *vq);
> + unsigned int (*get_vring_size)(const struct virtqueue *vq);
> + int (*resize)(struct virtqueue *vq, u32 num,
> + void (*recycle)(struct virtqueue *vq, void *buf));
> + void (*__break)(struct virtqueue *vq);
> + void (*__unbreak)(struct virtqueue *vq);
> + bool (*is_broken)(const struct virtqueue *vq);
> +};
> +
> /**
> * struct virtqueue - a queue to register buffers for sending or receiving.
> * @list: the chain of virtqueues for this device
> @@ -36,6 +64,7 @@ struct virtqueue {
> unsigned int num_max;
> bool reset;
> void *priv;
> + struct virtqueue_ops *ops;
> };
>
> int virtqueue_add_outbuf(struct virtqueue *vq,
> --
> 2.20.1
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: Re: [PATCH 1/2] virtio: abstract virtqueue related methods
2023-05-12 10:46 ` Michael S. Tsirkin
@ 2023-05-12 11:09 ` zhenwei pi
-1 siblings, 0 replies; 20+ messages in thread
From: zhenwei pi via Virtualization @ 2023-05-12 11:09 UTC (permalink / raw)
To: Michael S. Tsirkin; +Cc: xuanzhuo, linux-kernel, stefanha, virtualization
On 5/12/23 18:46, Michael S. Tsirkin wrote:
> On Fri, May 12, 2023 at 05:46:17PM +0800, zhenwei pi wrote:
>> There is already a virtqueue abstract structure in virtio subsystem
>> (see struct virtqueue in include/linux/virtio.h), however the vring
>> based virtqueue is used only in the past years, the virtqueue related
>> methods mix much with vring(just look like the codes, virtqueue_xxx
>> functions are implemented in virtio_ring.c).
>>
>> Abstract virtqueue related methods(see struct virtqueue_ops), and
>> separate virtqueue_xxx symbols from vring. This allows a non-vring
>> based transport in the future. With this change, the following symbols
>> are exported from virtio.ko instead of virtio_ring.ko:
>> virtqueue_add_sgs
>> virtqueue_add_outbuf
>> virtqueue_add_inbuf
>> virtqueue_add_inbuf_ctx
>> virtqueue_kick_prepare
>> virtqueue_notify
>> virtqueue_kick
>> virtqueue_enable_cb_prepare
>> virtqueue_enable_cb
>> virtqueue_enable_cb_delayed
>> virtqueue_disable_cb
>> virtqueue_poll
>> virtqueue_get_buf_ctx
>> virtqueue_get_buf
>> virtqueue_detach_unused_buf
>> virtqueue_get_vring_size
>> virtqueue_resize
>> virtqueue_is_broken
>> virtio_break_device
>> __virtio_unbreak_device
>>
>> Cc: Stefan Hajnoczi <stefanha@redhat.com>
>> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
>> ---
>> drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
>> drivers/virtio/virtio_ring.c | 282 +++++----------------------
>> include/linux/virtio.h | 29 +++
>> 3 files changed, 443 insertions(+), 230 deletions(-)
>>
>> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
>> index 3893dc29eb26..8d8715a10f26 100644
>> --- a/drivers/virtio/virtio.c
>> +++ b/drivers/virtio/virtio.c
>> @@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
>> EXPORT_SYMBOL_GPL(virtio_device_restore);
>> #endif
>>
>> +/**
>> + * virtqueue_add_sgs - expose buffers to other end
>> + * @vq: the struct virtqueue we're talking about.
>> + * @sgs: array of terminated scatterlists.
>> + * @out_sgs: the number of scatterlists readable by other side
>> + * @in_sgs: the number of scatterlists which are writable (after readable ones)
>> + * @data: the token identifying the buffer.
>> + * @gfp: how to do memory allocations (if necessary).
>> + *
>> + * Caller must ensure we don't call this with other virtqueue operations
>> + * at the same time (except where noted).
>> + *
>> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
>> + */
>> +int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
>> + unsigned int out_sgs, unsigned int in_sgs,
>> + void *data, gfp_t gfp)
>> +{
>> + unsigned int i, total_sg = 0;
>> +
>> + /* Count them first. */
>> + for (i = 0; i < out_sgs + in_sgs; i++) {
>> + struct scatterlist *sg;
>> +
>> + for (sg = sgs[i]; sg; sg = sg_next(sg))
>> + total_sg++;
>> + }
>> + return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
>> + data, NULL, gfp);
>> +}
>> +EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
>
>
> Hmm this kind of indirection on data path is going to be costly
> performance-wise especially when retpolines are in place.
>
> Any data on this?
>
Hi,
1, What about moving these functions into virtio.h and declare them as
static inline?
2, what about moving method fields into struct virtqueue?
Then we have struct like:
struct virtqueue {
struct list_head list;
...
void *priv;
/* virtqueue specific operations */
int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
unsigned int total_sg,
unsigned int out_sgs, unsigned int in_sgs,
void *data, void *ctx, gfp_t gfp);
...
}
and functions like:
static inline int virtqueue_add_sgs(...)
{
unsigned int i, total_sg = 0;
/* Count them first. */
for (i = 0; i < out_sgs + in_sgs; i++) {
struct scatterlist *sg;
for (sg = sgs[i]; sg; sg = sg_next(sg))
total_sg++;
}
return vq->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
data, NULL, gfp);
}
If [1] is acceptable, we can also reduce changes in patch 'tools/virtio:
implement virtqueue in test'.
--
zhenwei pi
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^ permalink raw reply [flat|nested] 20+ messages in thread* Re: Re: [PATCH 1/2] virtio: abstract virtqueue related methods
@ 2023-05-12 11:09 ` zhenwei pi
0 siblings, 0 replies; 20+ messages in thread
From: zhenwei pi @ 2023-05-12 11:09 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: stefanha, jasowang, xuanzhuo, virtualization, linux-kernel
On 5/12/23 18:46, Michael S. Tsirkin wrote:
> On Fri, May 12, 2023 at 05:46:17PM +0800, zhenwei pi wrote:
>> There is already a virtqueue abstract structure in virtio subsystem
>> (see struct virtqueue in include/linux/virtio.h), however the vring
>> based virtqueue is used only in the past years, the virtqueue related
>> methods mix much with vring(just look like the codes, virtqueue_xxx
>> functions are implemented in virtio_ring.c).
>>
>> Abstract virtqueue related methods(see struct virtqueue_ops), and
>> separate virtqueue_xxx symbols from vring. This allows a non-vring
>> based transport in the future. With this change, the following symbols
>> are exported from virtio.ko instead of virtio_ring.ko:
>> virtqueue_add_sgs
>> virtqueue_add_outbuf
>> virtqueue_add_inbuf
>> virtqueue_add_inbuf_ctx
>> virtqueue_kick_prepare
>> virtqueue_notify
>> virtqueue_kick
>> virtqueue_enable_cb_prepare
>> virtqueue_enable_cb
>> virtqueue_enable_cb_delayed
>> virtqueue_disable_cb
>> virtqueue_poll
>> virtqueue_get_buf_ctx
>> virtqueue_get_buf
>> virtqueue_detach_unused_buf
>> virtqueue_get_vring_size
>> virtqueue_resize
>> virtqueue_is_broken
>> virtio_break_device
>> __virtio_unbreak_device
>>
>> Cc: Stefan Hajnoczi <stefanha@redhat.com>
>> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
>> ---
>> drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
>> drivers/virtio/virtio_ring.c | 282 +++++----------------------
>> include/linux/virtio.h | 29 +++
>> 3 files changed, 443 insertions(+), 230 deletions(-)
>>
>> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
>> index 3893dc29eb26..8d8715a10f26 100644
>> --- a/drivers/virtio/virtio.c
>> +++ b/drivers/virtio/virtio.c
>> @@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
>> EXPORT_SYMBOL_GPL(virtio_device_restore);
>> #endif
>>
>> +/**
>> + * virtqueue_add_sgs - expose buffers to other end
>> + * @vq: the struct virtqueue we're talking about.
>> + * @sgs: array of terminated scatterlists.
>> + * @out_sgs: the number of scatterlists readable by other side
>> + * @in_sgs: the number of scatterlists which are writable (after readable ones)
>> + * @data: the token identifying the buffer.
>> + * @gfp: how to do memory allocations (if necessary).
>> + *
>> + * Caller must ensure we don't call this with other virtqueue operations
>> + * at the same time (except where noted).
>> + *
>> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
>> + */
>> +int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
>> + unsigned int out_sgs, unsigned int in_sgs,
>> + void *data, gfp_t gfp)
>> +{
>> + unsigned int i, total_sg = 0;
>> +
>> + /* Count them first. */
>> + for (i = 0; i < out_sgs + in_sgs; i++) {
>> + struct scatterlist *sg;
>> +
>> + for (sg = sgs[i]; sg; sg = sg_next(sg))
>> + total_sg++;
>> + }
>> + return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
>> + data, NULL, gfp);
>> +}
>> +EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
>
>
> Hmm this kind of indirection on data path is going to be costly
> performance-wise especially when retpolines are in place.
>
> Any data on this?
>
Hi,
1, What about moving these functions into virtio.h and declare them as
static inline?
2, what about moving method fields into struct virtqueue?
Then we have struct like:
struct virtqueue {
struct list_head list;
...
void *priv;
/* virtqueue specific operations */
int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
unsigned int total_sg,
unsigned int out_sgs, unsigned int in_sgs,
void *data, void *ctx, gfp_t gfp);
...
}
and functions like:
static inline int virtqueue_add_sgs(...)
{
unsigned int i, total_sg = 0;
/* Count them first. */
for (i = 0; i < out_sgs + in_sgs; i++) {
struct scatterlist *sg;
for (sg = sgs[i]; sg; sg = sg_next(sg))
total_sg++;
}
return vq->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
data, NULL, gfp);
}
If [1] is acceptable, we can also reduce changes in patch 'tools/virtio:
implement virtqueue in test'.
--
zhenwei pi
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: Re: [PATCH 1/2] virtio: abstract virtqueue related methods
2023-05-12 11:09 ` zhenwei pi
@ 2023-05-12 11:35 ` Michael S. Tsirkin
-1 siblings, 0 replies; 20+ messages in thread
From: Michael S. Tsirkin @ 2023-05-12 11:35 UTC (permalink / raw)
To: zhenwei pi; +Cc: xuanzhuo, linux-kernel, stefanha, virtualization
On Fri, May 12, 2023 at 07:09:40PM +0800, zhenwei pi wrote:
> On 5/12/23 18:46, Michael S. Tsirkin wrote:
> > On Fri, May 12, 2023 at 05:46:17PM +0800, zhenwei pi wrote:
> > > There is already a virtqueue abstract structure in virtio subsystem
> > > (see struct virtqueue in include/linux/virtio.h), however the vring
> > > based virtqueue is used only in the past years, the virtqueue related
> > > methods mix much with vring(just look like the codes, virtqueue_xxx
> > > functions are implemented in virtio_ring.c).
> > >
> > > Abstract virtqueue related methods(see struct virtqueue_ops), and
> > > separate virtqueue_xxx symbols from vring. This allows a non-vring
> > > based transport in the future. With this change, the following symbols
> > > are exported from virtio.ko instead of virtio_ring.ko:
> > > virtqueue_add_sgs
> > > virtqueue_add_outbuf
> > > virtqueue_add_inbuf
> > > virtqueue_add_inbuf_ctx
> > > virtqueue_kick_prepare
> > > virtqueue_notify
> > > virtqueue_kick
> > > virtqueue_enable_cb_prepare
> > > virtqueue_enable_cb
> > > virtqueue_enable_cb_delayed
> > > virtqueue_disable_cb
> > > virtqueue_poll
> > > virtqueue_get_buf_ctx
> > > virtqueue_get_buf
> > > virtqueue_detach_unused_buf
> > > virtqueue_get_vring_size
> > > virtqueue_resize
> > > virtqueue_is_broken
> > > virtio_break_device
> > > __virtio_unbreak_device
> > >
> > > Cc: Stefan Hajnoczi <stefanha@redhat.com>
> > > Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> > > ---
> > > drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
> > > drivers/virtio/virtio_ring.c | 282 +++++----------------------
> > > include/linux/virtio.h | 29 +++
> > > 3 files changed, 443 insertions(+), 230 deletions(-)
> > >
> > > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> > > index 3893dc29eb26..8d8715a10f26 100644
> > > --- a/drivers/virtio/virtio.c
> > > +++ b/drivers/virtio/virtio.c
> > > @@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
> > > EXPORT_SYMBOL_GPL(virtio_device_restore);
> > > #endif
> > > +/**
> > > + * virtqueue_add_sgs - expose buffers to other end
> > > + * @vq: the struct virtqueue we're talking about.
> > > + * @sgs: array of terminated scatterlists.
> > > + * @out_sgs: the number of scatterlists readable by other side
> > > + * @in_sgs: the number of scatterlists which are writable (after readable ones)
> > > + * @data: the token identifying the buffer.
> > > + * @gfp: how to do memory allocations (if necessary).
> > > + *
> > > + * Caller must ensure we don't call this with other virtqueue operations
> > > + * at the same time (except where noted).
> > > + *
> > > + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> > > + */
> > > +int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
> > > + unsigned int out_sgs, unsigned int in_sgs,
> > > + void *data, gfp_t gfp)
> > > +{
> > > + unsigned int i, total_sg = 0;
> > > +
> > > + /* Count them first. */
> > > + for (i = 0; i < out_sgs + in_sgs; i++) {
> > > + struct scatterlist *sg;
> > > +
> > > + for (sg = sgs[i]; sg; sg = sg_next(sg))
> > > + total_sg++;
> > > + }
> > > + return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
> > > + data, NULL, gfp);
> > > +}
> > > +EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
> >
> >
> > Hmm this kind of indirection on data path is going to be costly
> > performance-wise especially when retpolines are in place.
> >
> > Any data on this?
> >
>
> Hi,
>
> 1, What about moving these functions into virtio.h and declare them as
> static inline?
This will do nothing to remove indirection.
> 2, what about moving method fields into struct virtqueue?
This gets rid of one level of indirection but the big problem
is indirect function call due to retpolines, this remains.
> Then we have struct like:
> struct virtqueue {
> struct list_head list;
> ...
> void *priv;
>
> /* virtqueue specific operations */
> int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
> unsigned int total_sg,
> unsigned int out_sgs, unsigned int in_sgs,
> void *data, void *ctx, gfp_t gfp);
> ...
> }
>
> and functions like:
> static inline int virtqueue_add_sgs(...)
> {
> unsigned int i, total_sg = 0;
>
> /* Count them first. */
> for (i = 0; i < out_sgs + in_sgs; i++) {
> struct scatterlist *sg;
>
> for (sg = sgs[i]; sg; sg = sg_next(sg))
> total_sg++;
> }
> return vq->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
> data, NULL, gfp);
> }
Maybe a flag in vq:
bool abstract; /* use ops to add/get bufs and kick */
and then
if (unlikely(vq->abstract))
return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
data, NULL, gfp);
transport then just sets the ops if it wants abstract vqs,
and core then skips the vring.
> If [1] is acceptable, we can also reduce changes in patch 'tools/virtio:
> implement virtqueue in test'.
Yea that one shouldn't be there.
> --
> zhenwei pi
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: Re: [PATCH 1/2] virtio: abstract virtqueue related methods
@ 2023-05-12 11:35 ` Michael S. Tsirkin
0 siblings, 0 replies; 20+ messages in thread
From: Michael S. Tsirkin @ 2023-05-12 11:35 UTC (permalink / raw)
To: zhenwei pi; +Cc: stefanha, jasowang, xuanzhuo, virtualization, linux-kernel
On Fri, May 12, 2023 at 07:09:40PM +0800, zhenwei pi wrote:
> On 5/12/23 18:46, Michael S. Tsirkin wrote:
> > On Fri, May 12, 2023 at 05:46:17PM +0800, zhenwei pi wrote:
> > > There is already a virtqueue abstract structure in virtio subsystem
> > > (see struct virtqueue in include/linux/virtio.h), however the vring
> > > based virtqueue is used only in the past years, the virtqueue related
> > > methods mix much with vring(just look like the codes, virtqueue_xxx
> > > functions are implemented in virtio_ring.c).
> > >
> > > Abstract virtqueue related methods(see struct virtqueue_ops), and
> > > separate virtqueue_xxx symbols from vring. This allows a non-vring
> > > based transport in the future. With this change, the following symbols
> > > are exported from virtio.ko instead of virtio_ring.ko:
> > > virtqueue_add_sgs
> > > virtqueue_add_outbuf
> > > virtqueue_add_inbuf
> > > virtqueue_add_inbuf_ctx
> > > virtqueue_kick_prepare
> > > virtqueue_notify
> > > virtqueue_kick
> > > virtqueue_enable_cb_prepare
> > > virtqueue_enable_cb
> > > virtqueue_enable_cb_delayed
> > > virtqueue_disable_cb
> > > virtqueue_poll
> > > virtqueue_get_buf_ctx
> > > virtqueue_get_buf
> > > virtqueue_detach_unused_buf
> > > virtqueue_get_vring_size
> > > virtqueue_resize
> > > virtqueue_is_broken
> > > virtio_break_device
> > > __virtio_unbreak_device
> > >
> > > Cc: Stefan Hajnoczi <stefanha@redhat.com>
> > > Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
> > > ---
> > > drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
> > > drivers/virtio/virtio_ring.c | 282 +++++----------------------
> > > include/linux/virtio.h | 29 +++
> > > 3 files changed, 443 insertions(+), 230 deletions(-)
> > >
> > > diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
> > > index 3893dc29eb26..8d8715a10f26 100644
> > > --- a/drivers/virtio/virtio.c
> > > +++ b/drivers/virtio/virtio.c
> > > @@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
> > > EXPORT_SYMBOL_GPL(virtio_device_restore);
> > > #endif
> > > +/**
> > > + * virtqueue_add_sgs - expose buffers to other end
> > > + * @vq: the struct virtqueue we're talking about.
> > > + * @sgs: array of terminated scatterlists.
> > > + * @out_sgs: the number of scatterlists readable by other side
> > > + * @in_sgs: the number of scatterlists which are writable (after readable ones)
> > > + * @data: the token identifying the buffer.
> > > + * @gfp: how to do memory allocations (if necessary).
> > > + *
> > > + * Caller must ensure we don't call this with other virtqueue operations
> > > + * at the same time (except where noted).
> > > + *
> > > + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
> > > + */
> > > +int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
> > > + unsigned int out_sgs, unsigned int in_sgs,
> > > + void *data, gfp_t gfp)
> > > +{
> > > + unsigned int i, total_sg = 0;
> > > +
> > > + /* Count them first. */
> > > + for (i = 0; i < out_sgs + in_sgs; i++) {
> > > + struct scatterlist *sg;
> > > +
> > > + for (sg = sgs[i]; sg; sg = sg_next(sg))
> > > + total_sg++;
> > > + }
> > > + return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
> > > + data, NULL, gfp);
> > > +}
> > > +EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
> >
> >
> > Hmm this kind of indirection on data path is going to be costly
> > performance-wise especially when retpolines are in place.
> >
> > Any data on this?
> >
>
> Hi,
>
> 1, What about moving these functions into virtio.h and declare them as
> static inline?
This will do nothing to remove indirection.
> 2, what about moving method fields into struct virtqueue?
This gets rid of one level of indirection but the big problem
is indirect function call due to retpolines, this remains.
> Then we have struct like:
> struct virtqueue {
> struct list_head list;
> ...
> void *priv;
>
> /* virtqueue specific operations */
> int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
> unsigned int total_sg,
> unsigned int out_sgs, unsigned int in_sgs,
> void *data, void *ctx, gfp_t gfp);
> ...
> }
>
> and functions like:
> static inline int virtqueue_add_sgs(...)
> {
> unsigned int i, total_sg = 0;
>
> /* Count them first. */
> for (i = 0; i < out_sgs + in_sgs; i++) {
> struct scatterlist *sg;
>
> for (sg = sgs[i]; sg; sg = sg_next(sg))
> total_sg++;
> }
> return vq->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
> data, NULL, gfp);
> }
Maybe a flag in vq:
bool abstract; /* use ops to add/get bufs and kick */
and then
if (unlikely(vq->abstract))
return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
data, NULL, gfp);
transport then just sets the ops if it wants abstract vqs,
and core then skips the vring.
> If [1] is acceptable, we can also reduce changes in patch 'tools/virtio:
> implement virtqueue in test'.
Yea that one shouldn't be there.
> --
> zhenwei pi
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: Re: Re: [PATCH 1/2] virtio: abstract virtqueue related methods
2023-05-12 11:35 ` Michael S. Tsirkin
@ 2023-05-12 11:53 ` zhenwei pi
-1 siblings, 0 replies; 20+ messages in thread
From: zhenwei pi via Virtualization @ 2023-05-12 11:53 UTC (permalink / raw)
To: Michael S. Tsirkin; +Cc: xuanzhuo, linux-kernel, stefanha, virtualization
On 5/12/23 19:35, Michael S. Tsirkin wrote:
> On Fri, May 12, 2023 at 07:09:40PM +0800, zhenwei pi wrote:
>> On 5/12/23 18:46, Michael S. Tsirkin wrote:
>>> On Fri, May 12, 2023 at 05:46:17PM +0800, zhenwei pi wrote:
>>>> There is already a virtqueue abstract structure in virtio subsystem
>>>> (see struct virtqueue in include/linux/virtio.h), however the vring
>>>> based virtqueue is used only in the past years, the virtqueue related
>>>> methods mix much with vring(just look like the codes, virtqueue_xxx
>>>> functions are implemented in virtio_ring.c).
>>>>
>>>> Abstract virtqueue related methods(see struct virtqueue_ops), and
>>>> separate virtqueue_xxx symbols from vring. This allows a non-vring
>>>> based transport in the future. With this change, the following symbols
>>>> are exported from virtio.ko instead of virtio_ring.ko:
>>>> virtqueue_add_sgs
>>>> virtqueue_add_outbuf
>>>> virtqueue_add_inbuf
>>>> virtqueue_add_inbuf_ctx
>>>> virtqueue_kick_prepare
>>>> virtqueue_notify
>>>> virtqueue_kick
>>>> virtqueue_enable_cb_prepare
>>>> virtqueue_enable_cb
>>>> virtqueue_enable_cb_delayed
>>>> virtqueue_disable_cb
>>>> virtqueue_poll
>>>> virtqueue_get_buf_ctx
>>>> virtqueue_get_buf
>>>> virtqueue_detach_unused_buf
>>>> virtqueue_get_vring_size
>>>> virtqueue_resize
>>>> virtqueue_is_broken
>>>> virtio_break_device
>>>> __virtio_unbreak_device
>>>>
>>>> Cc: Stefan Hajnoczi <stefanha@redhat.com>
>>>> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
>>>> ---
>>>> drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
>>>> drivers/virtio/virtio_ring.c | 282 +++++----------------------
>>>> include/linux/virtio.h | 29 +++
>>>> 3 files changed, 443 insertions(+), 230 deletions(-)
>>>>
>>>> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
>>>> index 3893dc29eb26..8d8715a10f26 100644
>>>> --- a/drivers/virtio/virtio.c
>>>> +++ b/drivers/virtio/virtio.c
>>>> @@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
>>>> EXPORT_SYMBOL_GPL(virtio_device_restore);
>>>> #endif
>>>> +/**
>>>> + * virtqueue_add_sgs - expose buffers to other end
>>>> + * @vq: the struct virtqueue we're talking about.
>>>> + * @sgs: array of terminated scatterlists.
>>>> + * @out_sgs: the number of scatterlists readable by other side
>>>> + * @in_sgs: the number of scatterlists which are writable (after readable ones)
>>>> + * @data: the token identifying the buffer.
>>>> + * @gfp: how to do memory allocations (if necessary).
>>>> + *
>>>> + * Caller must ensure we don't call this with other virtqueue operations
>>>> + * at the same time (except where noted).
>>>> + *
>>>> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
>>>> + */
>>>> +int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
>>>> + unsigned int out_sgs, unsigned int in_sgs,
>>>> + void *data, gfp_t gfp)
>>>> +{
>>>> + unsigned int i, total_sg = 0;
>>>> +
>>>> + /* Count them first. */
>>>> + for (i = 0; i < out_sgs + in_sgs; i++) {
>>>> + struct scatterlist *sg;
>>>> +
>>>> + for (sg = sgs[i]; sg; sg = sg_next(sg))
>>>> + total_sg++;
>>>> + }
>>>> + return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
>>>> + data, NULL, gfp);
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
>>>
>>>
>>> Hmm this kind of indirection on data path is going to be costly
>>> performance-wise especially when retpolines are in place.
>>>
>>> Any data on this?
>>>
>>
>> Hi,
>>
>> 1, What about moving these functions into virtio.h and declare them as
>> static inline?
>
> This will do nothing to remove indirection.
>
>> 2, what about moving method fields into struct virtqueue?
>
> This gets rid of one level of indirection but the big problem
> is indirect function call due to retpolines, this remains.
>
>
>> Then we have struct like:
>> struct virtqueue {
>> struct list_head list;
>> ...
>> void *priv;
>>
>> /* virtqueue specific operations */
>> int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
>> unsigned int total_sg,
>> unsigned int out_sgs, unsigned int in_sgs,
>> void *data, void *ctx, gfp_t gfp);
>> ...
>> }
>>
>> and functions like:
>> static inline int virtqueue_add_sgs(...)
>> {
>> unsigned int i, total_sg = 0;
>>
>> /* Count them first. */
>> for (i = 0; i < out_sgs + in_sgs; i++) {
>> struct scatterlist *sg;
>>
>> for (sg = sgs[i]; sg; sg = sg_next(sg))
>> total_sg++;
>> }
>> return vq->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
>> data, NULL, gfp);
>> }
>
> Maybe a flag in vq:
> bool abstract; /* use ops to add/get bufs and kick */
> and then
> if (unlikely(vq->abstract))
> return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
> data, NULL, gfp);
>
> transport then just sets the ops if it wants abstract vqs,
> and core then skips the vring.
>
>
>> If [1] is acceptable, we can also reduce changes in patch 'tools/virtio:
>> implement virtqueue in test'.
>
> Yea that one shouldn't be there.
>
>> --
>> zhenwei pi
>
OK, I'll try and send a next version a few days later. Thanks!
--
zhenwei pi
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: Re: Re: [PATCH 1/2] virtio: abstract virtqueue related methods
@ 2023-05-12 11:53 ` zhenwei pi
0 siblings, 0 replies; 20+ messages in thread
From: zhenwei pi @ 2023-05-12 11:53 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: stefanha, jasowang, xuanzhuo, virtualization, linux-kernel
On 5/12/23 19:35, Michael S. Tsirkin wrote:
> On Fri, May 12, 2023 at 07:09:40PM +0800, zhenwei pi wrote:
>> On 5/12/23 18:46, Michael S. Tsirkin wrote:
>>> On Fri, May 12, 2023 at 05:46:17PM +0800, zhenwei pi wrote:
>>>> There is already a virtqueue abstract structure in virtio subsystem
>>>> (see struct virtqueue in include/linux/virtio.h), however the vring
>>>> based virtqueue is used only in the past years, the virtqueue related
>>>> methods mix much with vring(just look like the codes, virtqueue_xxx
>>>> functions are implemented in virtio_ring.c).
>>>>
>>>> Abstract virtqueue related methods(see struct virtqueue_ops), and
>>>> separate virtqueue_xxx symbols from vring. This allows a non-vring
>>>> based transport in the future. With this change, the following symbols
>>>> are exported from virtio.ko instead of virtio_ring.ko:
>>>> virtqueue_add_sgs
>>>> virtqueue_add_outbuf
>>>> virtqueue_add_inbuf
>>>> virtqueue_add_inbuf_ctx
>>>> virtqueue_kick_prepare
>>>> virtqueue_notify
>>>> virtqueue_kick
>>>> virtqueue_enable_cb_prepare
>>>> virtqueue_enable_cb
>>>> virtqueue_enable_cb_delayed
>>>> virtqueue_disable_cb
>>>> virtqueue_poll
>>>> virtqueue_get_buf_ctx
>>>> virtqueue_get_buf
>>>> virtqueue_detach_unused_buf
>>>> virtqueue_get_vring_size
>>>> virtqueue_resize
>>>> virtqueue_is_broken
>>>> virtio_break_device
>>>> __virtio_unbreak_device
>>>>
>>>> Cc: Stefan Hajnoczi <stefanha@redhat.com>
>>>> Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
>>>> ---
>>>> drivers/virtio/virtio.c | 362 +++++++++++++++++++++++++++++++++++
>>>> drivers/virtio/virtio_ring.c | 282 +++++----------------------
>>>> include/linux/virtio.h | 29 +++
>>>> 3 files changed, 443 insertions(+), 230 deletions(-)
>>>>
>>>> diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
>>>> index 3893dc29eb26..8d8715a10f26 100644
>>>> --- a/drivers/virtio/virtio.c
>>>> +++ b/drivers/virtio/virtio.c
>>>> @@ -553,6 +553,368 @@ int virtio_device_restore(struct virtio_device *dev)
>>>> EXPORT_SYMBOL_GPL(virtio_device_restore);
>>>> #endif
>>>> +/**
>>>> + * virtqueue_add_sgs - expose buffers to other end
>>>> + * @vq: the struct virtqueue we're talking about.
>>>> + * @sgs: array of terminated scatterlists.
>>>> + * @out_sgs: the number of scatterlists readable by other side
>>>> + * @in_sgs: the number of scatterlists which are writable (after readable ones)
>>>> + * @data: the token identifying the buffer.
>>>> + * @gfp: how to do memory allocations (if necessary).
>>>> + *
>>>> + * Caller must ensure we don't call this with other virtqueue operations
>>>> + * at the same time (except where noted).
>>>> + *
>>>> + * Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
>>>> + */
>>>> +int virtqueue_add_sgs(struct virtqueue *vq, struct scatterlist *sgs[],
>>>> + unsigned int out_sgs, unsigned int in_sgs,
>>>> + void *data, gfp_t gfp)
>>>> +{
>>>> + unsigned int i, total_sg = 0;
>>>> +
>>>> + /* Count them first. */
>>>> + for (i = 0; i < out_sgs + in_sgs; i++) {
>>>> + struct scatterlist *sg;
>>>> +
>>>> + for (sg = sgs[i]; sg; sg = sg_next(sg))
>>>> + total_sg++;
>>>> + }
>>>> + return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
>>>> + data, NULL, gfp);
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
>>>
>>>
>>> Hmm this kind of indirection on data path is going to be costly
>>> performance-wise especially when retpolines are in place.
>>>
>>> Any data on this?
>>>
>>
>> Hi,
>>
>> 1, What about moving these functions into virtio.h and declare them as
>> static inline?
>
> This will do nothing to remove indirection.
>
>> 2, what about moving method fields into struct virtqueue?
>
> This gets rid of one level of indirection but the big problem
> is indirect function call due to retpolines, this remains.
>
>
>> Then we have struct like:
>> struct virtqueue {
>> struct list_head list;
>> ...
>> void *priv;
>>
>> /* virtqueue specific operations */
>> int (*add_sgs)(struct virtqueue *vq, struct scatterlist *sgs[],
>> unsigned int total_sg,
>> unsigned int out_sgs, unsigned int in_sgs,
>> void *data, void *ctx, gfp_t gfp);
>> ...
>> }
>>
>> and functions like:
>> static inline int virtqueue_add_sgs(...)
>> {
>> unsigned int i, total_sg = 0;
>>
>> /* Count them first. */
>> for (i = 0; i < out_sgs + in_sgs; i++) {
>> struct scatterlist *sg;
>>
>> for (sg = sgs[i]; sg; sg = sg_next(sg))
>> total_sg++;
>> }
>> return vq->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
>> data, NULL, gfp);
>> }
>
> Maybe a flag in vq:
> bool abstract; /* use ops to add/get bufs and kick */
> and then
> if (unlikely(vq->abstract))
> return vq->ops->add_sgs(vq, sgs, total_sg, out_sgs, in_sgs,
> data, NULL, gfp);
>
> transport then just sets the ops if it wants abstract vqs,
> and core then skips the vring.
>
>
>> If [1] is acceptable, we can also reduce changes in patch 'tools/virtio:
>> implement virtqueue in test'.
>
> Yea that one shouldn't be there.
>
>> --
>> zhenwei pi
>
OK, I'll try and send a next version a few days later. Thanks!
--
zhenwei pi
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] virtio: abstract virtqueue related methods
2023-05-12 9:46 ` zhenwei pi
@ 2023-05-12 16:40 ` kernel test robot
-1 siblings, 0 replies; 20+ messages in thread
From: kernel test robot @ 2023-05-12 16:40 UTC (permalink / raw)
To: zhenwei pi, stefanha, mst, jasowang
Cc: oe-kbuild-all, xuanzhuo, virtualization, linux-kernel, zhenwei pi
Hi zhenwei,
kernel test robot noticed the following build errors:
[auto build test ERROR on mst-vhost/linux-next]
[also build test ERROR on linus/master v6.4-rc1 next-20230512]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/zhenwei-pi/virtio-abstract-virtqueue-related-methods/20230512-174928
base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link: https://lore.kernel.org/r/20230512094618.433707-2-pizhenwei%40bytedance.com
patch subject: [PATCH 1/2] virtio: abstract virtqueue related methods
config: loongarch-allyesconfig (https://download.01.org/0day-ci/archive/20230513/202305130012.LQ2KTO5C-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/372bc1a0371968752fe0f5ec6e81edee6f9c44dd
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review zhenwei-pi/virtio-abstract-virtqueue-related-methods/20230512-174928
git checkout 372bc1a0371968752fe0f5ec6e81edee6f9c44dd
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash drivers/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305130012.LQ2KTO5C-lkp@intel.com/
All errors (new ones prefixed by >>):
drivers/virtio/virtio.c: In function 'virtio_break_device':
>> drivers/virtio/virtio.c:893:24: error: 'struct virtqueue_ops' has no member named '__builtin_loongarch_break'
893 | vq->ops->__break(vq);
| ^~
vim +893 drivers/virtio/virtio.c
882
883 /*
884 * This should prevent the device from being used, allowing drivers to
885 * recover. You may need to grab appropriate locks to flush.
886 */
887 void virtio_break_device(struct virtio_device *dev)
888 {
889 struct virtqueue *vq;
890
891 spin_lock(&dev->vqs_list_lock);
892 list_for_each_entry(vq, &dev->vqs, list) {
> 893 vq->ops->__break(vq);
894 }
895 spin_unlock(&dev->vqs_list_lock);
896 }
897 EXPORT_SYMBOL_GPL(virtio_break_device);
898
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH 1/2] virtio: abstract virtqueue related methods
@ 2023-05-12 16:40 ` kernel test robot
0 siblings, 0 replies; 20+ messages in thread
From: kernel test robot @ 2023-05-12 16:40 UTC (permalink / raw)
To: zhenwei pi, stefanha, mst, jasowang
Cc: xuanzhuo, virtualization, linux-kernel, zhenwei pi, oe-kbuild-all
Hi zhenwei,
kernel test robot noticed the following build errors:
[auto build test ERROR on mst-vhost/linux-next]
[also build test ERROR on linus/master v6.4-rc1 next-20230512]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/zhenwei-pi/virtio-abstract-virtqueue-related-methods/20230512-174928
base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link: https://lore.kernel.org/r/20230512094618.433707-2-pizhenwei%40bytedance.com
patch subject: [PATCH 1/2] virtio: abstract virtqueue related methods
config: loongarch-allyesconfig (https://download.01.org/0day-ci/archive/20230513/202305130012.LQ2KTO5C-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/372bc1a0371968752fe0f5ec6e81edee6f9c44dd
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review zhenwei-pi/virtio-abstract-virtqueue-related-methods/20230512-174928
git checkout 372bc1a0371968752fe0f5ec6e81edee6f9c44dd
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash drivers/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305130012.LQ2KTO5C-lkp@intel.com/
All errors (new ones prefixed by >>):
drivers/virtio/virtio.c: In function 'virtio_break_device':
>> drivers/virtio/virtio.c:893:24: error: 'struct virtqueue_ops' has no member named '__builtin_loongarch_break'
893 | vq->ops->__break(vq);
| ^~
vim +893 drivers/virtio/virtio.c
882
883 /*
884 * This should prevent the device from being used, allowing drivers to
885 * recover. You may need to grab appropriate locks to flush.
886 */
887 void virtio_break_device(struct virtio_device *dev)
888 {
889 struct virtqueue *vq;
890
891 spin_lock(&dev->vqs_list_lock);
892 list_for_each_entry(vq, &dev->vqs, list) {
> 893 vq->ops->__break(vq);
894 }
895 spin_unlock(&dev->vqs_list_lock);
896 }
897 EXPORT_SYMBOL_GPL(virtio_break_device);
898
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PATCH 1/2] virtio: abstract virtqueue related methods
2023-05-12 9:46 ` zhenwei pi
@ 2023-05-13 17:22 ` kernel test robot
-1 siblings, 0 replies; 20+ messages in thread
From: kernel test robot @ 2023-05-13 17:22 UTC (permalink / raw)
To: zhenwei pi, stefanha, mst, jasowang
Cc: oe-kbuild-all, xuanzhuo, virtualization, linux-kernel, zhenwei pi
Hi zhenwei,
kernel test robot noticed the following build warnings:
[auto build test WARNING on mst-vhost/linux-next]
[also build test WARNING on linus/master v6.4-rc1 next-20230512]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/zhenwei-pi/virtio-abstract-virtqueue-related-methods/20230512-174928
base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link: https://lore.kernel.org/r/20230512094618.433707-2-pizhenwei%40bytedance.com
patch subject: [PATCH 1/2] virtio: abstract virtqueue related methods
reproduce:
# https://github.com/intel-lab-lkp/linux/commit/372bc1a0371968752fe0f5ec6e81edee6f9c44dd
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review zhenwei-pi/virtio-abstract-virtqueue-related-methods/20230512-174928
git checkout 372bc1a0371968752fe0f5ec6e81edee6f9c44dd
make menuconfig
# enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
make htmldocs
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305140142.c0QQq9wZ-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_add_inbuf' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_add_outbuf' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_add_sgs' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_get_buf_ctx' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_disable_cb' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_enable_cb' not found
vim +/virtqueue_add_inbuf +1 ./drivers/virtio/virtio_ring.c
fd534e9b5fdcf9 Thomas Gleixner 2019-05-23 @1 // SPDX-License-Identifier: GPL-2.0-or-later
0a8a69dd77ddbd Rusty Russell 2007-10-22 2 /* Virtio ring implementation.
0a8a69dd77ddbd Rusty Russell 2007-10-22 3 *
0a8a69dd77ddbd Rusty Russell 2007-10-22 4 * Copyright 2007 Rusty Russell IBM Corporation
0a8a69dd77ddbd Rusty Russell 2007-10-22 5 */
0a8a69dd77ddbd Rusty Russell 2007-10-22 6 #include <linux/virtio.h>
0a8a69dd77ddbd Rusty Russell 2007-10-22 7 #include <linux/virtio_ring.h>
e34f87256794b8 Rusty Russell 2008-07-25 8 #include <linux/virtio_config.h>
0a8a69dd77ddbd Rusty Russell 2007-10-22 9 #include <linux/device.h>
5a0e3ad6af8660 Tejun Heo 2010-03-24 10 #include <linux/slab.h>
b5a2c4f1996d1d Paul Gortmaker 2011-07-03 11 #include <linux/module.h>
e93300b1afc7cd Rusty Russell 2012-01-12 12 #include <linux/hrtimer.h>
780bc7903a32ed Andy Lutomirski 2016-02-02 13 #include <linux/dma-mapping.h>
88938359e2dfe1 Alexander Potapenko 2022-09-15 14 #include <linux/kmsan.h>
f8ce72632fa7ed Michael S. Tsirkin 2021-08-10 15 #include <linux/spinlock.h>
78fe39872378b0 Andy Lutomirski 2016-02-02 16 #include <xen/xen.h>
0a8a69dd77ddbd Rusty Russell 2007-10-22 17
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PATCH 1/2] virtio: abstract virtqueue related methods
@ 2023-05-13 17:22 ` kernel test robot
0 siblings, 0 replies; 20+ messages in thread
From: kernel test robot @ 2023-05-13 17:22 UTC (permalink / raw)
To: zhenwei pi, stefanha, mst, jasowang
Cc: xuanzhuo, virtualization, linux-kernel, zhenwei pi, oe-kbuild-all
Hi zhenwei,
kernel test robot noticed the following build warnings:
[auto build test WARNING on mst-vhost/linux-next]
[also build test WARNING on linus/master v6.4-rc1 next-20230512]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/zhenwei-pi/virtio-abstract-virtqueue-related-methods/20230512-174928
base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next
patch link: https://lore.kernel.org/r/20230512094618.433707-2-pizhenwei%40bytedance.com
patch subject: [PATCH 1/2] virtio: abstract virtqueue related methods
reproduce:
# https://github.com/intel-lab-lkp/linux/commit/372bc1a0371968752fe0f5ec6e81edee6f9c44dd
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review zhenwei-pi/virtio-abstract-virtqueue-related-methods/20230512-174928
git checkout 372bc1a0371968752fe0f5ec6e81edee6f9c44dd
make menuconfig
# enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
make htmldocs
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305140142.c0QQq9wZ-lkp@intel.com/
All warnings (new ones prefixed by >>):
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_add_inbuf' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_add_outbuf' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_add_sgs' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_get_buf_ctx' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_disable_cb' not found
>> ./drivers/virtio/virtio_ring.c:1: warning: 'virtqueue_enable_cb' not found
vim +/virtqueue_add_inbuf +1 ./drivers/virtio/virtio_ring.c
fd534e9b5fdcf9 Thomas Gleixner 2019-05-23 @1 // SPDX-License-Identifier: GPL-2.0-or-later
0a8a69dd77ddbd Rusty Russell 2007-10-22 2 /* Virtio ring implementation.
0a8a69dd77ddbd Rusty Russell 2007-10-22 3 *
0a8a69dd77ddbd Rusty Russell 2007-10-22 4 * Copyright 2007 Rusty Russell IBM Corporation
0a8a69dd77ddbd Rusty Russell 2007-10-22 5 */
0a8a69dd77ddbd Rusty Russell 2007-10-22 6 #include <linux/virtio.h>
0a8a69dd77ddbd Rusty Russell 2007-10-22 7 #include <linux/virtio_ring.h>
e34f87256794b8 Rusty Russell 2008-07-25 8 #include <linux/virtio_config.h>
0a8a69dd77ddbd Rusty Russell 2007-10-22 9 #include <linux/device.h>
5a0e3ad6af8660 Tejun Heo 2010-03-24 10 #include <linux/slab.h>
b5a2c4f1996d1d Paul Gortmaker 2011-07-03 11 #include <linux/module.h>
e93300b1afc7cd Rusty Russell 2012-01-12 12 #include <linux/hrtimer.h>
780bc7903a32ed Andy Lutomirski 2016-02-02 13 #include <linux/dma-mapping.h>
88938359e2dfe1 Alexander Potapenko 2022-09-15 14 #include <linux/kmsan.h>
f8ce72632fa7ed Michael S. Tsirkin 2021-08-10 15 #include <linux/spinlock.h>
78fe39872378b0 Andy Lutomirski 2016-02-02 16 #include <xen/xen.h>
0a8a69dd77ddbd Rusty Russell 2007-10-22 17
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
^ permalink raw reply [flat|nested] 20+ messages in thread