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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 Signed-off-by: zhenwei pi --- 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 #include +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,