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Xuan Zhuo

2022-Jan-26 07:35 UTC

[PATCH v3 00/17] virtio pci support VIRTIO_F_RING_RESET

===============================================================================The
virtio spec already supports the virtio queue reset function. This patch set
is to add this function to the kernel. The relevant virtio spec information is
here:

    https://github.com/oasis-tcs/virtio-spec/issues/124

Also regarding MMIO support for queue reset, I plan to support it after this
patch is passed.

#14-#17 is the disable/enable function of rx/tx pair implemented by virtio-net
using the new helper. This function is not currently referenced by other
functions. It is more to show the usage of the new helper, I not sure if they
are going to be merged together.

Please review. Thanks.

v3:
  1. keep vq, irq unreleased

Xuan Zhuo (17):
  virtio_pci: struct virtio_pci_common_cfg add queue_notify_data
  virtio: queue_reset: add VIRTIO_F_RING_RESET
  virtio: queue_reset: struct virtio_config_ops add callbacks for
    queue_reset
  virtio: queue_reset: add helper
  vritio_ring: queue_reset: extract the release function of the vq ring
  virtio_ring: queue_reset: split: add __vring_init_virtqueue()
  virtio_ring: queue_reset: split: support enable reset queue
  virtio_ring: queue_reset: packed: support enable reset queue
  virtio_ring: queue_reset: add vring_reset_virtqueue()
  virtio_pci: queue_reset: update struct virtio_pci_common_cfg and
    option functions
  virtio_pci: queue_reset: release vq by vp_dev->vqs
  virtio_pci: queue_reset: setup_vq use vring_setup_virtqueue()
  virtio_pci: queue_reset: support VIRTIO_F_RING_RESET
  virtio_net: virtnet_tx_timeout() fix style
  virtio_net: virtnet_tx_timeout() stop ref sq->vq
  virtio_net: split free_unused_bufs()
  virtio_net: support pair disable/enable

 drivers/net/virtio_net.c               | 220 ++++++++++++++++++++++---
 drivers/virtio/virtio_pci_common.c     |  62 ++++---
 drivers/virtio/virtio_pci_common.h     |  11 +-
 drivers/virtio/virtio_pci_legacy.c     |   5 +-
 drivers/virtio/virtio_pci_modern.c     | 120 +++++++++++++-
 drivers/virtio/virtio_pci_modern_dev.c |  28 ++++
 drivers/virtio/virtio_ring.c           | 144 +++++++++++-----
 include/linux/virtio.h                 |   1 +
 include/linux/virtio_config.h          |  75 ++++++++-
 include/linux/virtio_pci_modern.h      |   2 +
 include/linux/virtio_ring.h            |  42 +++--
 include/uapi/linux/virtio_config.h     |   7 +-
 include/uapi/linux/virtio_pci.h        |   2 +
 13 files changed, 618 insertions(+), 101 deletions(-)

--
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 01/17] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data

Add queue_notify_data in struct virtio_pci_common_cfg, which comes from
here https://github.com/oasis-tcs/virtio-spec/issues/89

Since I want to add queue_reset after it, I submitted this patch first.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 include/uapi/linux/virtio_pci.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 3a86f36d7e3d..492c89f56c6a 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -164,6 +164,7 @@ struct virtio_pci_common_cfg {
 	__le32 queue_avail_hi;		/* read-write */
 	__le32 queue_used_lo;		/* read-write */
 	__le32 queue_used_hi;		/* read-write */
+	__le16 queue_notify_data;	/* read-write */
 };
 
 /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 02/17] virtio: queue_reset: add VIRTIO_F_RING_RESET

Added VIRTIO_F_RING_RESET, it came from here
https://github.com/oasis-tcs/virtio-spec/issues/124

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 include/uapi/linux/virtio_config.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/virtio_config.h
b/include/uapi/linux/virtio_config.h
index b5eda06f0d57..0862be802ff8 100644
--- a/include/uapi/linux/virtio_config.h
+++ b/include/uapi/linux/virtio_config.h
@@ -52,7 +52,7 @@
  * rest are per-device feature bits.
  */
 #define VIRTIO_TRANSPORT_F_START	28
-#define VIRTIO_TRANSPORT_F_END		38
+#define VIRTIO_TRANSPORT_F_END		41
 
 #ifndef VIRTIO_CONFIG_NO_LEGACY
 /* Do we get callbacks when the ring is completely used, even if we've
@@ -92,4 +92,9 @@
  * Does the device support Single Root I/O Virtualization?
  */
 #define VIRTIO_F_SR_IOV			37
+
+/*
+ * This feature indicates that the driver can reset a queue individually.
+ */
+#define VIRTIO_F_RING_RESET		40
 #endif /* _UAPI_LINUX_VIRTIO_CONFIG_H */
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 03/17] virtio: queue_reset: struct virtio_config_ops add callbacks for queue_reset

Performing reset on a queue is divided into two steps:

1. reset_vq: reset one vq
2. enable_reset_vq: re-enable the reset queue

In the first step, these tasks will be completed:
    1. notify the hardware queue to reset
    2. recycle the buffer from vq
    3. release the ring of the vq

The second step is similar to find vqs, passing parameters callback and
name, etc. Based on the original vq, the ring is re-allocated and
configured to the backend.

So add two callbacks reset_vq, enable_reset_vq to struct
virtio_config_ops.

Add a structure for passing parameters. This will facilitate subsequent
expansion of the parameters of enable reset vq.
There is currently only one default extended parameter ring_num.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 include/linux/virtio_config.h | 43 ++++++++++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 4d107ad31149..51dd8461d1b6 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -16,6 +16,44 @@ struct virtio_shm_region {
 	u64 len;
 };
 
+typedef void vq_callback_t(struct virtqueue *);
+
+/* virtio_reset_vq: specify parameters for queue_reset
+ *
+ *	vdev: the device
+ *	queue_index: the queue index
+ *
+ *	free_unused_cb: callback to free unused bufs
+ *	data: used by free_unused_cb
+ *
+ *	callback: callback for the virtqueue, NULL for vq that do not need a
+ *	          callback
+ *	name: virtqueue names (mainly for debugging), NULL for vq unused by
+ *	      driver
+ *	ctx: ctx
+ *
+ *	ring_num: specify ring num for the vq to be re-enabled. 0 means use the
+ *	          default value. MUST be a power of 2.
+ */
+struct virtio_reset_vq;
+typedef void vq_reset_callback_t(struct virtio_reset_vq *param, void *buf);
+struct virtio_reset_vq {
+	struct virtio_device *vdev;
+	u16 queue_index;
+
+	/* reset vq param */
+	vq_reset_callback_t *free_unused_cb;
+	void *data;
+
+	/* enable reset vq param */
+	vq_callback_t *callback;
+	const char *name;
+	const bool *ctx;
+
+	/* ext enable reset vq param */
+	u16 ring_num;
+};
+
 /**
  * virtio_config_ops - operations for configuring a virtio device
  * Note: Do not assume that a transport implements all of the operations
@@ -74,8 +112,9 @@ struct virtio_shm_region {
  * @set_vq_affinity: set the affinity for a virtqueue (optional).
  * @get_vq_affinity: get the affinity for a virtqueue (optional).
  * @get_shm_region: get a shared memory region based on the index.
+ * @reset_vq: reset a queue individually
+ * @enable_reset_vq: enable a reset queue
  */
-typedef void vq_callback_t(struct virtqueue *);
 struct virtio_config_ops {
 	void (*enable_cbs)(struct virtio_device *vdev);
 	void (*get)(struct virtio_device *vdev, unsigned offset,
@@ -100,6 +139,8 @@ struct virtio_config_ops {
 			int index);
 	bool (*get_shm_region)(struct virtio_device *vdev,
 			       struct virtio_shm_region *region, u8 id);
+	int (*reset_vq)(struct virtio_reset_vq *param);
+	struct virtqueue *(*enable_reset_vq)(struct virtio_reset_vq *param);
 };
 
 /* If driver didn't advertise the feature, it will never appear. */
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 04/17] virtio: queue_reset: add helper

Add helper for virtio queue reset.

* virtio_reset_vq: reset a queue individually
* virtio_enable_resetq: enable a reset queue

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 include/linux/virtio_config.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 51dd8461d1b6..3c971d9a0a59 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -260,6 +260,38 @@ int virtio_find_vqs_ctx(struct virtio_device *vdev,
unsigned nvqs,
 				      desc);
 }
 
+/**
+ * virtio_reset_vq - reset a queue individually
+ * @param: struct virtio_reset_vq
+ *
+ * returns 0 on success or error status
+ *
+ */
+static inline
+int virtio_reset_vq(struct virtio_reset_vq *param)
+{
+	if (!param->vdev->config->reset_vq)
+		return -ENOENT;
+
+	return param->vdev->config->reset_vq(param);
+}
+
+/**
+ * virtio_enable_resetq - enable a reset queue
+ * @param: struct virtio_reset_vq
+ *
+ * returns vq on success or error status
+ *
+ */
+static inline
+struct virtqueue *virtio_enable_resetq(struct virtio_reset_vq *param)
+{
+	if (!param->vdev->config->enable_reset_vq)
+		return ERR_PTR(-ENOENT);
+
+	return param->vdev->config->enable_reset_vq(param);
+}
+
 /**
  * virtio_device_ready - enable vq use in probe function
  * @vdev: the device
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 05/17] vritio_ring: queue_reset: extract the release function of the vq ring

Extract a function __vring_del_virtqueue() from vring_del_virtqueue() to
handle releasing vq's ring.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 028b05d44546..b6434e36c447 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2300,12 +2300,10 @@ struct virtqueue *vring_new_virtqueue(unsigned int
index,
 }
 EXPORT_SYMBOL_GPL(vring_new_virtqueue);
 
-void vring_del_virtqueue(struct virtqueue *_vq)
+static void __vring_del_virtqueue(struct vring_virtqueue *vq)
 {
-	struct vring_virtqueue *vq = to_vvq(_vq);
-
 	spin_lock(&vq->vq.vdev->vqs_list_lock);
-	list_del(&_vq->list);
+	list_del(&vq->vq.list);
 	spin_unlock(&vq->vq.vdev->vqs_list_lock);
 
 	if (vq->we_own_ring) {
@@ -2338,6 +2336,13 @@ void vring_del_virtqueue(struct virtqueue *_vq)
 		kfree(vq->split.desc_state);
 		kfree(vq->split.desc_extra);
 	}
+}
+
+void vring_del_virtqueue(struct virtqueue *_vq)
+{
+	struct vring_virtqueue *vq = to_vvq(_vq);
+
+	__vring_del_virtqueue(vq);
 	kfree(vq);
 }
 EXPORT_SYMBOL_GPL(vring_del_virtqueue);
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 06/17] virtio_ring: queue_reset: split: add __vring_init_virtqueue()

Extract vq's initialization function __vring_init_virtqueue() from
__vring_new_virtqueue()

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 61 +++++++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 19 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index b6434e36c447..4e1d345b0557 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2167,23 +2167,17 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
 EXPORT_SYMBOL_GPL(vring_interrupt);
 
 /* Only available for split ring */
-struct virtqueue *__vring_new_virtqueue(unsigned int index,
-					struct vring vring,
-					struct virtio_device *vdev,
-					bool weak_barriers,
-					bool context,
-					bool (*notify)(struct virtqueue *),
-					void (*callback)(struct virtqueue *),
-					const char *name)
+static int __vring_init_virtqueue(struct virtqueue *_vq,
+				  unsigned int index,
+				  struct vring vring,
+				  struct virtio_device *vdev,
+				  bool weak_barriers,
+				  bool context,
+				  bool (*notify)(struct virtqueue *),
+				  void (*callback)(struct virtqueue *),
+				  const char *name)
 {
-	struct vring_virtqueue *vq;
-
-	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
-		return NULL;
-
-	vq = kmalloc(sizeof(*vq), GFP_KERNEL);
-	if (!vq)
-		return NULL;
+	struct vring_virtqueue *vq = to_vvq(_vq);
 
 	vq->packed_ring = false;
 	vq->vq.callback = callback;
@@ -2243,13 +2237,42 @@ struct virtqueue *__vring_new_virtqueue(unsigned int
index,
 	spin_lock(&vdev->vqs_list_lock);
 	list_add_tail(&vq->vq.list, &vdev->vqs);
 	spin_unlock(&vdev->vqs_list_lock);
-	return &vq->vq;
+	return 0;
 
 err_extra:
 	kfree(vq->split.desc_state);
 err_state:
-	kfree(vq);
-	return NULL;
+	return -ENOMEM;
+}
+
+struct virtqueue *__vring_new_virtqueue(unsigned int index,
+					struct vring vring,
+					struct virtio_device *vdev,
+					bool weak_barriers,
+					bool context,
+					bool (*notify)(struct virtqueue *),
+					void (*callback)(struct virtqueue *),
+					const char *name)
+{
+	struct vring_virtqueue *vq;
+	int err;
+
+	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
+		return NULL;
+
+	vq = kmalloc(sizeof(*vq), GFP_KERNEL);
+	if (!vq)
+		return NULL;
+
+	err = __vring_init_virtqueue(&vq->vq, index, vring, vdev,
weak_barriers,
+				     context, notify, callback, name);
+
+	if (err) {
+		kfree(vq);
+		return NULL;
+	}
+
+	return &vq->vq;
 }
 EXPORT_SYMBOL_GPL(__vring_new_virtqueue);
 
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 07/17] virtio_ring: queue_reset: split: support enable reset queue

The purpose of this patch is to make vring split support re-enable reset
vq.

The core idea is that when calling vring_create_virtqueue_split, use the
existing vq instead of re-allocating vq. vq is passed in through
function parameters.

Modify vring_create_virtqueue() to vring_setup_virtqueue(), and add a
new parameter vq. At the same time, add a new inline function, the
definition of the function is exactly the same as the original
vring_create_virtqueue().

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 41 ++++++++++++++++++++++++++----------
 include/linux/virtio.h       |  1 +
 include/linux/virtio_ring.h  | 37 +++++++++++++++++++++++---------
 3 files changed, 58 insertions(+), 21 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 4e1d345b0557..a93a677008ba 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -198,6 +198,15 @@ struct vring_virtqueue {
 #endif
 };
 
+static int __vring_init_virtqueue(struct virtqueue *_vq,
+				  unsigned int index,
+				  struct vring vring,
+				  struct virtio_device *vdev,
+				  bool weak_barriers,
+				  bool context,
+				  bool (*notify)(struct virtqueue *),
+				  void (*callback)(struct virtqueue *),
+				  const char *name);
 
 /*
  * Helpers.
@@ -925,9 +934,9 @@ static struct virtqueue *vring_create_virtqueue_split(
 	bool context,
 	bool (*notify)(struct virtqueue *),
 	void (*callback)(struct virtqueue *),
-	const char *name)
+	const char *name,
+	struct virtqueue *vq)
 {
-	struct virtqueue *vq;
 	void *queue = NULL;
 	dma_addr_t dma_addr;
 	size_t queue_size_in_bytes;
@@ -964,12 +973,17 @@ static struct virtqueue *vring_create_virtqueue_split(
 	queue_size_in_bytes = vring_size(num, vring_align);
 	vring_init(&vring, num, queue, vring_align);
 
-	vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
-				   notify, callback, name);
 	if (!vq) {
-		vring_free_queue(vdev, queue_size_in_bytes, queue,
-				 dma_addr);
-		return NULL;
+		vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers,
+					   context, notify, callback, name);
+		if (!vq)
+			goto err;
+
+	} else {
+		if (__vring_init_virtqueue(vq, index, vring, vdev,
+					   weak_barriers, context, notify,
+					   callback, name))
+			goto err;
 	}
 
 	to_vvq(vq)->split.queue_dma_addr = dma_addr;
@@ -977,6 +991,9 @@ static struct virtqueue *vring_create_virtqueue_split(
 	to_vvq(vq)->we_own_ring = true;
 
 	return vq;
+err:
+	vring_free_queue(vdev, queue_size_in_bytes, queue, dma_addr);
+	return NULL;
 }
 
 
@@ -2185,6 +2202,7 @@ static int __vring_init_virtqueue(struct virtqueue *_vq,
 	vq->vq.name = name;
 	vq->vq.num_free = vring.num;
 	vq->vq.index = index;
+	vq->vq.reset = false;
 	vq->we_own_ring = false;
 	vq->notify = notify;
 	vq->weak_barriers = weak_barriers;
@@ -2276,7 +2294,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int
index,
 }
 EXPORT_SYMBOL_GPL(__vring_new_virtqueue);
 
-struct virtqueue *vring_create_virtqueue(
+struct virtqueue *vring_setup_virtqueue(
 	unsigned int index,
 	unsigned int num,
 	unsigned int vring_align,
@@ -2286,7 +2304,8 @@ struct virtqueue *vring_create_virtqueue(
 	bool context,
 	bool (*notify)(struct virtqueue *),
 	void (*callback)(struct virtqueue *),
-	const char *name)
+	const char *name,
+	struct virtqueue *vq)
 {
 
 	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
@@ -2296,9 +2315,9 @@ struct virtqueue *vring_create_virtqueue(
 
 	return vring_create_virtqueue_split(index, num, vring_align,
 			vdev, weak_barriers, may_reduce_num,
-			context, notify, callback, name);
+			context, notify, callback, name, vq);
 }
-EXPORT_SYMBOL_GPL(vring_create_virtqueue);
+EXPORT_SYMBOL_GPL(vring_setup_virtqueue);
 
 /* Only available for split ring */
 struct virtqueue *vring_new_virtqueue(unsigned int index,
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 41edbc01ffa4..98c89cbeafa1 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -32,6 +32,7 @@ struct virtqueue {
 	unsigned int index;
 	unsigned int num_free;
 	void *priv;
+	bool reset;
 };
 
 int virtqueue_add_outbuf(struct virtqueue *vq,
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index b485b13fa50b..e90323fce4bf 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -65,16 +65,33 @@ struct virtqueue;
  * expected.  The caller should query virtqueue_get_vring_size to learn
  * the actual size of the ring.
  */
-struct virtqueue *vring_create_virtqueue(unsigned int index,
-					 unsigned int num,
-					 unsigned int vring_align,
-					 struct virtio_device *vdev,
-					 bool weak_barriers,
-					 bool may_reduce_num,
-					 bool ctx,
-					 bool (*notify)(struct virtqueue *vq),
-					 void (*callback)(struct virtqueue *vq),
-					 const char *name);
+struct virtqueue *vring_setup_virtqueue(unsigned int index,
+					unsigned int num,
+					unsigned int vring_align,
+					struct virtio_device *vdev,
+					bool weak_barriers,
+					bool may_reduce_num,
+					bool ctx,
+					bool (*notify)(struct virtqueue *vq),
+					void (*callback)(struct virtqueue *vq),
+					const char *name,
+					struct virtqueue *vq);
+
+static inline struct virtqueue *vring_create_virtqueue(unsigned int index,
+						       unsigned int num,
+						       unsigned int vring_align,
+						       struct virtio_device *vdev,
+						       bool weak_barriers,
+						       bool may_reduce_num,
+						       bool ctx,
+						       bool (*notify)(struct virtqueue *vq),
+						       void (*callback)(struct virtqueue *vq),
+						       const char *name)
+{
+	return vring_setup_virtqueue(index, num, vring_align, vdev,
+				     weak_barriers, may_reduce_num, ctx,
+				     notify, callback, name, NULL);
+}
 
 /* Creates a virtqueue with a custom layout. */
 struct virtqueue *__vring_new_virtqueue(unsigned int index,
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 08/17] virtio_ring: queue_reset: packed: support enable reset queue

The purpose of this patch is to make vring packed support re-enable reset
vq.

The core idea is that when calling vring_create_virtqueue_packed, use the
existing vq instead of re-allocating vq. vq is passed in through
function parameters.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index a93a677008ba..4beb7c7127c1 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1680,7 +1680,8 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	bool context,
 	bool (*notify)(struct virtqueue *),
 	void (*callback)(struct virtqueue *),
-	const char *name)
+	const char *name,
+	struct virtqueue *_vq)
 {
 	struct vring_virtqueue *vq;
 	struct vring_packed_desc *ring;
@@ -1710,15 +1711,20 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	if (!device)
 		goto err_device;
 
-	vq = kmalloc(sizeof(*vq), GFP_KERNEL);
-	if (!vq)
-		goto err_vq;
+	if (_vq) {
+		vq = to_vvq(_vq);
+	} else {
+		vq = kmalloc(sizeof(*vq), GFP_KERNEL);
+		if (!vq)
+			goto err_vq;
+	}
 
 	vq->vq.callback = callback;
 	vq->vq.vdev = vdev;
 	vq->vq.name = name;
 	vq->vq.num_free = num;
 	vq->vq.index = index;
+	vq->vq.reset = false;
 	vq->we_own_ring = true;
 	vq->notify = notify;
 	vq->weak_barriers = weak_barriers;
@@ -1789,7 +1795,8 @@ static struct virtqueue *vring_create_virtqueue_packed(
 err_desc_extra:
 	kfree(vq->packed.desc_state);
 err_desc_state:
-	kfree(vq);
+	if (!_vq)
+		kfree(vq);
 err_vq:
 	vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr);
 err_device:
@@ -2311,7 +2318,7 @@ struct virtqueue *vring_setup_virtqueue(
 	if (virtio_has_feature(vdev, VIRTIO_F_RING_PACKED))
 		return vring_create_virtqueue_packed(index, num, vring_align,
 				vdev, weak_barriers, may_reduce_num,
-				context, notify, callback, name);
+				context, notify, callback, name, vq);
 
 	return vring_create_virtqueue_split(index, num, vring_align,
 			vdev, weak_barriers, may_reduce_num,
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 09/17] virtio_ring: queue_reset: add vring_reset_virtqueue()

Added vring_reset_virtqueue() for reset vring_virtqueue.

In this process, vq is removed from the vdev->vqs queue. And the memory
of the ring is released

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 12 +++++++++++-
 include/linux/virtio_ring.h  |  5 +++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 4beb7c7127c1..bba9f3c67b33 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2391,11 +2391,21 @@ void vring_del_virtqueue(struct virtqueue *_vq)
 {
 	struct vring_virtqueue *vq = to_vvq(_vq);
 
-	__vring_del_virtqueue(vq);
+	if (!_vq->reset)
+		__vring_del_virtqueue(vq);
 	kfree(vq);
 }
 EXPORT_SYMBOL_GPL(vring_del_virtqueue);
 
+void vring_reset_virtqueue(struct virtqueue *_vq)
+{
+	struct vring_virtqueue *vq = to_vvq(_vq);
+
+	__vring_del_virtqueue(vq);
+	_vq->reset = true;
+}
+EXPORT_SYMBOL_GPL(vring_reset_virtqueue);
+
 /* Manipulates transport-specific feature bits. */
 void vring_transport_features(struct virtio_device *vdev)
 {
diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h
index e90323fce4bf..84b55fb8686d 100644
--- a/include/linux/virtio_ring.h
+++ b/include/linux/virtio_ring.h
@@ -124,6 +124,11 @@ struct virtqueue *vring_new_virtqueue(unsigned int index,
  */
 void vring_del_virtqueue(struct virtqueue *vq);
 
+/*
+ * Resets a virtqueue. Just frees the ring, not free vq.
+ */
+void vring_reset_virtqueue(struct virtqueue *vq);
+
 /* Filter out transport-specific feature bits. */
 void vring_transport_features(struct virtio_device *vdev);
 
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 10/17] virtio_pci: queue_reset: update struct virtio_pci_common_cfg and option functions

Add queue_reset in virtio_pci_common_cfg, and add related operation
functions.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_pci_modern_dev.c | 28 ++++++++++++++++++++++++++
 include/linux/virtio_pci_modern.h      |  2 ++
 include/uapi/linux/virtio_pci.h        |  1 +
 3 files changed, 31 insertions(+)

diff --git a/drivers/virtio/virtio_pci_modern_dev.c
b/drivers/virtio/virtio_pci_modern_dev.c
index e11ed748e661..be02f812a2f6 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -463,6 +463,34 @@ void vp_modern_set_status(struct virtio_pci_modern_device
*mdev,
 }
 EXPORT_SYMBOL_GPL(vp_modern_set_status);
 
+/*
+ * vp_modern_get_queue_reset - get the queue reset status
+ * @mdev: the modern virtio-pci device
+ * @index: queue index
+ */
+int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
+{
+	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
+
+	vp_iowrite16(index, &cfg->queue_select);
+	return vp_ioread16(&cfg->queue_reset);
+}
+EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
+
+/*
+ * vp_modern_set_queue_reset - reset the queue
+ * @mdev: the modern virtio-pci device
+ * @index: queue index
+ */
+void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16
index)
+{
+	struct virtio_pci_common_cfg __iomem *cfg = mdev->common;
+
+	vp_iowrite16(index, &cfg->queue_select);
+	vp_iowrite16(1, &cfg->queue_reset);
+}
+EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
+
 /*
  * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
  * @mdev: the modern virtio-pci device
diff --git a/include/linux/virtio_pci_modern.h
b/include/linux/virtio_pci_modern.h
index eb2bd9b4077d..cc4154dd7b28 100644
--- a/include/linux/virtio_pci_modern.h
+++ b/include/linux/virtio_pci_modern.h
@@ -106,4 +106,6 @@ void __iomem * vp_modern_map_vq_notify(struct
virtio_pci_modern_device *mdev,
 				       u16 index, resource_size_t *pa);
 int vp_modern_probe(struct virtio_pci_modern_device *mdev);
 void vp_modern_remove(struct virtio_pci_modern_device *mdev);
+int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16
index);
+void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16
index);
 #endif
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 492c89f56c6a..bf10f349087f 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -165,6 +165,7 @@ struct virtio_pci_common_cfg {
 	__le32 queue_used_lo;		/* read-write */
 	__le32 queue_used_hi;		/* read-write */
 	__le16 queue_notify_data;	/* read-write */
+	__le16 queue_reset;		/* read-write */
 };
 
 /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 11/17] virtio_pci: queue_reset: release vq by vp_dev->vqs

In the process of queue reset, vq leaves vdev->vqs, so the original
processing logic may miss some vq. So modify the processing method of
releasing vq. Release vq by listing vqs.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_pci_common.c | 22 ++++++++++++++++++----
 drivers/virtio/virtio_pci_common.h |  2 ++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index fdbde1db5ec5..6b2573ec1ae8 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -260,12 +260,20 @@ static void vp_del_vq(struct virtqueue *vq)
 void vp_del_vqs(struct virtio_device *vdev)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	struct virtqueue *vq, *n;
-	int i;
+	struct virtio_pci_vq_info *info;
+	struct virtqueue *vq;
+	int i, v;
+
+	for (i = 0; i < vp_dev->nvqs; ++i) {
+
+		info = vp_dev->vqs[i];
+		if (!info)
+			continue;
+
+		vq = info->vq;
 
-	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
 		if (vp_dev->per_vq_vectors) {
-			int v = vp_dev->vqs[vq->index]->msix_vector;
+			v = info->msix_vector;
 
 			if (v != VIRTIO_MSI_NO_VECTOR) {
 				int irq = pci_irq_vector(vp_dev->pci_dev, v);
@@ -275,6 +283,7 @@ void vp_del_vqs(struct virtio_device *vdev)
 			}
 		}
 		vp_del_vq(vq);
+		vp_dev->vqs[i] = NULL;
 	}
 	vp_dev->per_vq_vectors = false;
 
@@ -308,6 +317,7 @@ void vp_del_vqs(struct virtio_device *vdev)
 	vp_dev->msix_affinity_masks = NULL;
 	kfree(vp_dev->vqs);
 	vp_dev->vqs = NULL;
+	vp_dev->nvqs = 0;
 }
 
 static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
@@ -324,6 +334,8 @@ static int vp_find_vqs_msix(struct virtio_device *vdev,
unsigned nvqs,
 	if (!vp_dev->vqs)
 		return -ENOMEM;
 
+	vp_dev->nvqs = nvqs;
+
 	if (per_vq_vectors) {
 		/* Best option: one for change interrupt, one per vq. */
 		nvectors = 1;
@@ -395,6 +407,8 @@ static int vp_find_vqs_intx(struct virtio_device *vdev,
unsigned nvqs,
 	if (!vp_dev->vqs)
 		return -ENOMEM;
 
+	vp_dev->nvqs = nvqs;
+
 	err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
 			dev_name(&vdev->dev), vp_dev);
 	if (err)
diff --git a/drivers/virtio/virtio_pci_common.h
b/drivers/virtio/virtio_pci_common.h
index 23f6c5c678d5..392d990b7c73 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -60,6 +60,8 @@ struct virtio_pci_device {
 	/* array of all queues for house-keeping */
 	struct virtio_pci_vq_info **vqs;
 
+	u32 nvqs;
+
 	/* MSI-X support */
 	int msix_enabled;
 	int intx_enabled;
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 12/17] virtio_pci: queue_reset: setup_vq use vring_setup_virtqueue()

setup_vq replaces vring_create_virtuque() with vring_setup_virtqueue() to
support the need to enable reset vq.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_pci_common.c |  8 ++++----
 drivers/virtio/virtio_pci_common.h |  4 +++-
 drivers/virtio/virtio_pci_legacy.c |  5 +++--
 drivers/virtio/virtio_pci_modern.c | 20 ++++++++++++++------
 4 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index 6b2573ec1ae8..c02936d29a31 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -209,7 +209,7 @@ static struct virtqueue *vp_setup_vq(struct virtio_device
*vdev, unsigned index,
 				     void (*callback)(struct virtqueue *vq),
 				     const char *name,
 				     bool ctx,
-				     u16 msix_vec)
+				     u16 msix_vec, u16 num)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
 	struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL);
@@ -221,7 +221,7 @@ static struct virtqueue *vp_setup_vq(struct virtio_device
*vdev, unsigned index,
 		return ERR_PTR(-ENOMEM);
 
 	vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx,
-			      msix_vec);
+			      msix_vec, NULL, num);
 	if (IS_ERR(vq))
 		goto out_info;
 
@@ -368,7 +368,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev,
unsigned nvqs,
 			msix_vec = VP_MSIX_VQ_VECTOR;
 		vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
 				     ctx ? ctx[i] : false,
-				     msix_vec);
+				     msix_vec, 0);
 		if (IS_ERR(vqs[i])) {
 			err = PTR_ERR(vqs[i]);
 			goto error_find;
@@ -423,7 +423,7 @@ static int vp_find_vqs_intx(struct virtio_device *vdev,
unsigned nvqs,
 		}
 		vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
 				     ctx ? ctx[i] : false,
-				     VIRTIO_MSI_NO_VECTOR);
+				     VIRTIO_MSI_NO_VECTOR, 0);
 		if (IS_ERR(vqs[i])) {
 			err = PTR_ERR(vqs[i]);
 			goto out_del_vqs;
diff --git a/drivers/virtio/virtio_pci_common.h
b/drivers/virtio/virtio_pci_common.h
index 392d990b7c73..65db92245e41 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -84,7 +84,9 @@ struct virtio_pci_device {
 				      void (*callback)(struct virtqueue *vq),
 				      const char *name,
 				      bool ctx,
-				      u16 msix_vec);
+				      u16 msix_vec,
+				      struct virtqueue *vq,
+				      u16 num);
 	void (*del_vq)(struct virtio_pci_vq_info *info);
 
 	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
diff --git a/drivers/virtio/virtio_pci_legacy.c
b/drivers/virtio/virtio_pci_legacy.c
index b3f8128b7983..9bc41b764624 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -113,9 +113,10 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 				  void (*callback)(struct virtqueue *vq),
 				  const char *name,
 				  bool ctx,
-				  u16 msix_vec)
+				  u16 msix_vec,
+				  struct virtqueue *vq,
+				  u16 ring_num)
 {
-	struct virtqueue *vq;
 	u16 num;
 	int err;
 	u64 q_pfn;
diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index 5455bc041fb6..2ce58de549de 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -187,11 +187,12 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 				  void (*callback)(struct virtqueue *vq),
 				  const char *name,
 				  bool ctx,
-				  u16 msix_vec)
+				  u16 msix_vec,
+				  struct virtqueue *vq,
+				  u16 ring_num)
 {
 
 	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
-	struct virtqueue *vq;
 	u16 num;
 	int err;
 
@@ -203,6 +204,13 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 	if (!num || vp_modern_get_queue_enable(mdev, index))
 		return ERR_PTR(-ENOENT);
 
+	if (ring_num) {
+		if (ring_num > num)
+			return ERR_PTR(-ENOENT);
+
+		num = ring_num;
+	}
+
 	if (num & (num - 1)) {
 		dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u",
num);
 		return ERR_PTR(-EINVAL);
@@ -211,10 +219,10 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 	info->msix_vector = msix_vec;
 
 	/* create the vring */
-	vq = vring_create_virtqueue(index, num,
-				    SMP_CACHE_BYTES, &vp_dev->vdev,
-				    true, true, ctx,
-				    vp_notify, callback, name);
+	vq = vring_setup_virtqueue(index, num,
+				   SMP_CACHE_BYTES, &vp_dev->vdev,
+				   true, true, ctx,
+				   vp_notify, callback, name, vq);
 	if (!vq)
 		return ERR_PTR(-ENOMEM);
 
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 13/17] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET

This patch implements virtio pci support for QUEUE RESET.

Performing reset on a queue is divided into two steps:

1. reset_vq: reset one vq
2. enable_reset_vq: re-enable the reset queue

In the first step, these tasks will be completed:
   1. notify the hardware queue to reset
   2. recycle the buffer from vq
   3. release the ring of the vq

The process of enable reset vq:
    vp_modern_enable_reset_vq()
    vp_enable_reset_vq()
    __vp_setup_vq()
    setup_vq()
    vring_setup_virtqueue()

In this process, we added two parameters, vq and num, and finally passed
them to vring_setup_virtqueue().  And reuse the original info and vq.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_pci_common.c |  36 +++++++----
 drivers/virtio/virtio_pci_common.h |   5 ++
 drivers/virtio/virtio_pci_modern.c | 100 +++++++++++++++++++++++++++++
 3 files changed, 128 insertions(+), 13 deletions(-)

diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index c02936d29a31..ad21638fbf66 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -205,23 +205,28 @@ static int vp_request_msix_vectors(struct virtio_device
*vdev, int nvectors,
 	return err;
 }
 
-static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned
index,
-				     void (*callback)(struct virtqueue *vq),
-				     const char *name,
-				     bool ctx,
-				     u16 msix_vec, u16 num)
+struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
+			      void (*callback)(struct virtqueue *vq),
+			      const char *name,
+			      bool ctx,
+			      u16 msix_vec, u16 num)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL);
+	struct virtio_pci_vq_info *info;
 	struct virtqueue *vq;
 	unsigned long flags;
 
-	/* fill out our structure that represents an active queue */
-	if (!info)
-		return ERR_PTR(-ENOMEM);
+	info = vp_dev->vqs[index];
+	if (!info) {
+		info = kzalloc(sizeof *info, GFP_KERNEL);
+
+		/* fill out our structure that represents an active queue */
+		if (!info)
+			return ERR_PTR(-ENOMEM);
+	}
 
 	vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx,
-			      msix_vec, NULL, num);
+			      msix_vec, info->vq, num);
 	if (IS_ERR(vq))
 		goto out_info;
 
@@ -238,6 +243,9 @@ static struct virtqueue *vp_setup_vq(struct virtio_device
*vdev, unsigned index,
 	return vq;
 
 out_info:
+	if (info->vq && info->vq->reset)
+		return vq;
+
 	kfree(info);
 	return vq;
 }
@@ -248,9 +256,11 @@ static void vp_del_vq(struct virtqueue *vq)
 	struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
 	unsigned long flags;
 
-	spin_lock_irqsave(&vp_dev->lock, flags);
-	list_del(&info->node);
-	spin_unlock_irqrestore(&vp_dev->lock, flags);
+	if (!vq->reset) {
+		spin_lock_irqsave(&vp_dev->lock, flags);
+		list_del(&info->node);
+		spin_unlock_irqrestore(&vp_dev->lock, flags);
+	}
 
 	vp_dev->del_vq(info);
 	kfree(info);
diff --git a/drivers/virtio/virtio_pci_common.h
b/drivers/virtio/virtio_pci_common.h
index 65db92245e41..c1d15f7c0be4 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -119,6 +119,11 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 		struct virtqueue *vqs[], vq_callback_t *callbacks[],
 		const char * const names[], const bool *ctx,
 		struct irq_affinity *desc);
+struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
+			      void (*callback)(struct virtqueue *vq),
+			      const char *name,
+			      bool ctx,
+			      u16 msix_vec, u16 num);
 const char *vp_bus_name(struct virtio_device *vdev);
 
 /* Setup the affinity for a virtqueue:
diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index 2ce58de549de..6789411169e4 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -34,6 +34,9 @@ static void vp_transport_features(struct virtio_device *vdev,
u64 features)
 	if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
 			pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
 		__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
+
+	if (features & BIT_ULL(VIRTIO_F_RING_RESET))
+		__virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
 }
 
 /* virtio config->finalize_features() implementation */
@@ -176,6 +179,94 @@ static void vp_reset(struct virtio_device *vdev)
 	vp_disable_cbs(vdev);
 }
 
+static int vp_modern_reset_vq(struct virtio_reset_vq *param)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(param->vdev);
+	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+	struct virtio_pci_vq_info *info;
+	u16 msix_vec, queue_index;
+	unsigned long flags;
+	void *buf;
+
+	if (!virtio_has_feature(param->vdev, VIRTIO_F_RING_RESET))
+		return -ENOENT;
+
+	queue_index = param->queue_index;
+
+	vp_modern_set_queue_reset(mdev, queue_index);
+
+	/* After write 1 to queue reset, the driver MUST wait for a read of
+	 * queue reset to return 1.
+	 */
+	while (vp_modern_get_queue_reset(mdev, queue_index) != 1)
+		msleep(1);
+
+	info = vp_dev->vqs[queue_index];
+	msix_vec = info->msix_vector;
+
+	/* Disable VQ callback. */
+	if (vp_dev->per_vq_vectors && msix_vec != VIRTIO_MSI_NO_VECTOR)
+		disable_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec));
+
+	while ((buf = virtqueue_detach_unused_buf(info->vq)) != NULL)
+		param->free_unused_cb(param, buf);
+
+	/* delete vq */
+	spin_lock_irqsave(&vp_dev->lock, flags);
+	list_del(&info->node);
+	spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+	INIT_LIST_HEAD(&info->node);
+
+	if (vp_dev->msix_enabled)
+		vp_modern_queue_vector(mdev, info->vq->index,
+				       VIRTIO_MSI_NO_VECTOR);
+
+	if (!mdev->notify_base)
+		pci_iounmap(mdev->pci_dev,
+			    (void __force __iomem *)info->vq->priv);
+
+	vring_reset_virtqueue(info->vq);
+
+	return 0;
+}
+
+static struct virtqueue *vp_modern_enable_reset_vq(struct virtio_reset_vq
*param)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(param->vdev);
+	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+	struct virtio_pci_vq_info *info;
+	u16 msix_vec, queue_index;
+	struct virtqueue *vq;
+
+	if (!virtio_has_feature(param->vdev, VIRTIO_F_RING_RESET))
+		return ERR_PTR(-ENOENT);
+
+	queue_index = param->queue_index;
+
+	info = vp_dev->vqs[queue_index];
+
+	if (!info->vq->reset)
+		return ERR_PTR(-EPERM);
+
+	/* check queue reset status */
+	if (vp_modern_get_queue_reset(mdev, queue_index) != 1)
+		return ERR_PTR(-EBUSY);
+
+	vq = vp_setup_vq(param->vdev, queue_index, param->callback,
param->name,
+			 param->ctx, info->msix_vector, param->ring_num);
+	if (IS_ERR(vq))
+		return vq;
+
+	vp_modern_set_queue_enable(&vp_dev->mdev, vq->index, true);
+
+	msix_vec = vp_dev->vqs[queue_index]->msix_vector;
+	if (vp_dev->per_vq_vectors && msix_vec != VIRTIO_MSI_NO_VECTOR)
+		enable_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec));
+
+	return vq;
+}
+
 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
 {
 	return vp_modern_config_vector(&vp_dev->mdev, vector);
@@ -284,6 +375,11 @@ static void del_vq(struct virtio_pci_vq_info *info)
 	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
 
+	if (vq->reset) {
+		vring_del_virtqueue(vq);
+		return;
+	}
+
 	if (vp_dev->msix_enabled)
 		vp_modern_queue_vector(mdev, vq->index,
 				       VIRTIO_MSI_NO_VECTOR);
@@ -403,6 +499,8 @@ static const struct virtio_config_ops
virtio_pci_config_nodev_ops = {
 	.set_vq_affinity = vp_set_vq_affinity,
 	.get_vq_affinity = vp_get_vq_affinity,
 	.get_shm_region  = vp_get_shm_region,
+	.reset_vq	 = vp_modern_reset_vq,
+	.enable_reset_vq = vp_modern_enable_reset_vq,
 };
 
 static const struct virtio_config_ops virtio_pci_config_ops = {
@@ -421,6 +519,8 @@ static const struct virtio_config_ops virtio_pci_config_ops
= {
 	.set_vq_affinity = vp_set_vq_affinity,
 	.get_vq_affinity = vp_get_vq_affinity,
 	.get_shm_region  = vp_get_shm_region,
+	.reset_vq	 = vp_modern_reset_vq,
+	.enable_reset_vq = vp_modern_enable_reset_vq,
 };
 
 /* the PCI probing function */
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 14/17] virtio_net: virtnet_tx_timeout() fix style

Replace priv with vi which is commonly used in the virtio-net module.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 569eecfbc2cd..97eb4dddba1f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2683,8 +2683,8 @@ static int virtnet_set_features(struct net_device *dev,
 
 static void virtnet_tx_timeout(struct net_device *dev, unsigned int txqueue)
 {
-	struct virtnet_info *priv = netdev_priv(dev);
-	struct send_queue *sq = &priv->sq[txqueue];
+	struct virtnet_info *vi = netdev_priv(dev);
+	struct send_queue *sq = &vi->sq[txqueue];
 	struct netdev_queue *txq = netdev_get_tx_queue(dev, txqueue);
 
 	u64_stats_update_begin(&sq->stats.syncp);
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 15/17] virtio_net: virtnet_tx_timeout() stop ref sq->vq

Make virtnet_tx_timeout() no longer refer to vq directly. Because sq->vq
may be equal to NULL after implementing rx/tx queue disable/enable.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 97eb4dddba1f..2add7fe749b8 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2692,7 +2692,7 @@ static void virtnet_tx_timeout(struct net_device *dev,
unsigned int txqueue)
 	u64_stats_update_end(&sq->stats.syncp);
 
 	netdev_err(dev, "TX timeout on queue: %u, sq: %s, vq: 0x%x, name: %s, %u
usecs ago\n",
-		   txqueue, sq->name, sq->vq->index, sq->vq->name,
+		   txqueue, sq->name, txq2vq(sq - vi->sq), sq->name,
 		   jiffies_to_usecs(jiffies - READ_ONCE(txq->trans_start)));
 }
 
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 16/17] virtio_net: split free_unused_bufs()

This patch separates two functions for freeing sq buf and rq buf from
free_unused_bufs().

When supporting the enable/disable tx/rq queue in the future, it is
necessary to support separate recovery of a sq buf or a rq buf.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c | 46 ++++++++++++++++++++++++----------------
 1 file changed, 28 insertions(+), 18 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 2add7fe749b8..ea90a1a57c9e 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2804,33 +2804,43 @@ static void free_receive_page_frags(struct virtnet_info
*vi)
 			put_page(vi->rq[i].alloc_frag.page);
 }
 
+static void virtnet_sq_free_unused_buf(struct virtnet_info *vi,
+				       struct send_queue *sq, void *buf)
+{
+	if (!is_xdp_frame(buf))
+		dev_kfree_skb(buf);
+	else
+		xdp_return_frame(ptr_to_xdp(buf));
+}
+
+static void virtnet_rq_free_unused_buf(struct virtnet_info *vi,
+				       struct receive_queue *rq, void *buf)
+{
+	if (vi->mergeable_rx_bufs)
+		put_page(virt_to_head_page(buf));
+	else if (vi->big_packets)
+		give_pages(rq, buf);
+	else
+		put_page(virt_to_head_page(buf));
+}
+
 static void free_unused_bufs(struct virtnet_info *vi)
 {
+	struct receive_queue *rq;
+	struct send_queue *sq;
 	void *buf;
 	int i;
 
 	for (i = 0; i < vi->max_queue_pairs; i++) {
-		struct virtqueue *vq = vi->sq[i].vq;
-		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
-			if (!is_xdp_frame(buf))
-				dev_kfree_skb(buf);
-			else
-				xdp_return_frame(ptr_to_xdp(buf));
-		}
+		sq = &vi->sq[i];
+		while ((buf = virtqueue_detach_unused_buf(sq->vq)) != NULL)
+			virtnet_sq_free_unused_buf(vi, sq, buf);
 	}
 
 	for (i = 0; i < vi->max_queue_pairs; i++) {
-		struct virtqueue *vq = vi->rq[i].vq;
-
-		while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) {
-			if (vi->mergeable_rx_bufs) {
-				put_page(virt_to_head_page(buf));
-			} else if (vi->big_packets) {
-				give_pages(&vi->rq[i], buf);
-			} else {
-				put_page(virt_to_head_page(buf));
-			}
-		}
+		rq = &vi->rq[i];
+		while ((buf = virtqueue_detach_unused_buf(rq->vq)) != NULL)
+			virtnet_rq_free_unused_buf(vi, rq, buf);
 	}
 }
 
-- 
2.31.0

Xuan Zhuo

2022-Jan-26 07:35 UTC

head link

[PATCH v3 17/17] virtio_net: support pair disable/enable

This patch implements virtio-net rx/tx pair disable/enable functionality
based on virtio queue reset. The purpose of the current implementation
is to quickly recycle the buffer submitted to vq.

In the process of pair disable, in theory, as long as virtio supports
queue reset, there will be no exceptions.

However, in the process of pari enable, there may be exceptions due to
memory allocation. In this case, vq == NULL, but napi will still
be enabled. Because napi_disable is similar to a lock, napi_enable must
be called after calling napi_disable.

Since enable fails, the driver will not receive an interrupt from the
device to wake up napi, so the driver is safe. But we still need to add
vq checks in some places to ensure safety, such as refill_work().

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c | 168 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 168 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ea90a1a57c9e..cf77ef1bad1c 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1369,6 +1369,9 @@ static void virtnet_napi_enable(struct virtqueue *vq,
struct napi_struct *napi)
 {
 	napi_enable(napi);
 
+	if (!vq)
+		return;
+
 	/* If all buffers were filled by other side before we napi_enabled, we
 	 * won't get another interrupt, so process any outstanding packets now.
 	 * Call local_bh_enable after to trigger softIRQ processing.
@@ -1413,6 +1416,10 @@ static void refill_work(struct work_struct *work)
 		struct receive_queue *rq = &vi->rq[i];
 
 		napi_disable(&rq->napi);
+		if (!rq->vq) {
+			virtnet_napi_enable(rq->vq, &rq->napi);
+			continue;
+		}
 		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
 		virtnet_napi_enable(rq->vq, &rq->napi);
 
@@ -2871,6 +2878,167 @@ static unsigned int mergeable_min_buf_len(struct
virtnet_info *vi, struct virtqu
 		   (unsigned int)GOOD_PACKET_LEN);
 }
 
+static void virtnet_rq_free_unused_buf_cb(struct virtio_reset_vq *param,
+					  void *buf)
+{
+	virtnet_rq_free_unused_buf(param->vdev->priv, param->data, buf);
+}
+
+static void virtnet_sq_free_unused_buf_cb(struct virtio_reset_vq *param,
+					  void *buf)
+{
+	virtnet_rq_free_unused_buf(param->vdev->priv, param->data, buf);
+}
+
+static int __virtnet_rx_vq_disable(struct virtnet_info *vi,
+				   struct receive_queue *rq)
+{
+	struct virtio_reset_vq param = {0};
+	int err, qnum;
+
+	qnum = rxq2vq(rq - vi->rq);
+
+	napi_disable(&rq->napi);
+
+	param.vdev = vi->vdev;
+	param.queue_index = qnum;
+	param.free_unused_cb = virtnet_rq_free_unused_buf_cb;
+	param.data = rq;
+
+	err = virtio_reset_vq(&param);
+	if (err) {
+		virtnet_napi_enable(rq->vq, &rq->napi);
+		return err;
+	}
+
+	rq->vq = NULL;
+
+	return err;
+}
+
+static int __virtnet_tx_vq_disable(struct virtnet_info *vi,
+				   struct send_queue *sq)
+{
+	struct virtio_reset_vq param = {0};
+	struct netdev_queue *txq;
+	int err, qnum;
+
+	qnum = txq2vq(sq - vi->sq);
+
+	netif_stop_subqueue(vi->dev, sq - vi->sq);
+	virtnet_napi_tx_disable(&sq->napi);
+
+	/* wait xmit done */
+	txq = netdev_get_tx_queue(vi->dev, qnum);
+	__netif_tx_lock(txq, raw_smp_processor_id());
+	__netif_tx_unlock(txq);
+
+	param.vdev = vi->vdev;
+	param.queue_index = qnum;
+	param.free_unused_cb = virtnet_sq_free_unused_buf_cb;
+	param.data = sq;
+
+	err = virtio_reset_vq(&param);
+	if (err) {
+		virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
+		netif_start_subqueue(vi->dev, sq - vi->sq);
+		return err;
+	}
+
+	sq->vq = NULL;
+
+	return err;
+}
+
+static int virtnet_pair_disable(struct virtnet_info *vi, int i)
+{
+	int err;
+
+	err = __virtnet_rx_vq_disable(vi, vi->rq + i);
+	if (err)
+		return err;
+
+	return __virtnet_tx_vq_disable(vi, vi->sq + i);
+}
+
+static int virtnet_enable_resetq(struct virtnet_info *vi,
+				 struct receive_queue *rq,
+				 struct send_queue *sq)
+{
+	struct virtio_reset_vq param = {0};
+	vq_callback_t *callback;
+	struct virtqueue *vq;
+	const char *name;
+	int vq_idx;
+	bool ctx;
+
+	if (rq) {
+		vq = rq->vq;
+		vq_idx = rxq2vq(rq - vi->rq);
+		callback = skb_recv_done;
+		name = rq->name;
+
+	} else {
+		vq = sq->vq;
+		vq_idx = txq2vq(sq - vi->sq);
+		callback = skb_xmit_done;
+		name = sq->name;
+	}
+
+	if (vq)
+		return -EBUSY;
+
+	if (!vi->big_packets || vi->mergeable_rx_bufs)
+		ctx = true;
+	else
+		ctx = false;
+
+	param.vdev = vi->vdev;
+	param.queue_index = vq_idx;
+	param.callback = callback;
+	param.name = name;
+	param.ctx = &ctx;
+	param.ring_num = 0;
+
+	vq = virtio_enable_resetq(&param);
+	if (IS_ERR(vq))
+		return PTR_ERR(vq);
+
+	if (rq)
+		rq->vq = vq;
+	else
+		sq->vq = vq;
+
+	return 0;
+}
+
+static int virtnet_pair_enable(struct virtnet_info *vi, int i)
+{
+	struct receive_queue *rq;
+	struct send_queue *sq;
+	int err;
+
+	rq = vi->rq + i;
+	sq = vi->sq + i;
+
+	/* tx */
+	err = virtnet_enable_resetq(vi, NULL, sq);
+	if (err)
+		goto err;
+	else
+		netif_start_subqueue(vi->dev, sq - vi->sq);
+
+	/* rx */
+	err = virtnet_enable_resetq(vi, rq, NULL);
+	if (err)
+		return err;
+
+err:
+	virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
+	virtnet_napi_enable(rq->vq, &rq->napi);
+	return 0;
+}
+
 static int virtnet_find_vqs(struct virtnet_info *vi)
 {
 	vq_callback_t **callbacks;
-- 
2.31.0

Jason Wang

2022-Feb-07 03:39 UTC

head link

[PATCH v3 00/17] virtio pci support VIRTIO_F_RING_RESET

On Wed, Jan 26, 2022 at 3:35 PM Xuan Zhuo <xuanzhuo at linux.alibaba.com>
wrote:>
>
===============================================================================>
The virtio spec already supports the virtio queue reset function. This patch set
> is to add this function to the kernel. The relevant virtio spec information
is
> here:
>
>     https://github.com/oasis-tcs/virtio-spec/issues/124
>
> Also regarding MMIO support for queue reset, I plan to support it after
this
> patch is passed.
>
> #14-#17 is the disable/enable function of rx/tx pair implemented by
virtio-net
> using the new helper.
One thing that came to mind is the steering. E.g if we disable an RX,
should we stop steering packets to that queue?

Thanks
> This function is not currently referenced by other
> functions. It is more to show the usage of the new helper, I not sure if
they
> are going to be merged together.
>
> Please review. Thanks.
>
> v3:
>   1. keep vq, irq unreleased
>
> Xuan Zhuo (17):
>   virtio_pci: struct virtio_pci_common_cfg add queue_notify_data
>   virtio: queue_reset: add VIRTIO_F_RING_RESET
>   virtio: queue_reset: struct virtio_config_ops add callbacks for
>     queue_reset
>   virtio: queue_reset: add helper
>   vritio_ring: queue_reset: extract the release function of the vq ring
>   virtio_ring: queue_reset: split: add __vring_init_virtqueue()
>   virtio_ring: queue_reset: split: support enable reset queue
>   virtio_ring: queue_reset: packed: support enable reset queue
>   virtio_ring: queue_reset: add vring_reset_virtqueue()
>   virtio_pci: queue_reset: update struct virtio_pci_common_cfg and
>     option functions
>   virtio_pci: queue_reset: release vq by vp_dev->vqs
>   virtio_pci: queue_reset: setup_vq use vring_setup_virtqueue()
>   virtio_pci: queue_reset: support VIRTIO_F_RING_RESET
>   virtio_net: virtnet_tx_timeout() fix style
>   virtio_net: virtnet_tx_timeout() stop ref sq->vq
>   virtio_net: split free_unused_bufs()
>   virtio_net: support pair disable/enable
>
>  drivers/net/virtio_net.c               | 220 ++++++++++++++++++++++---
>  drivers/virtio/virtio_pci_common.c     |  62 ++++---
>  drivers/virtio/virtio_pci_common.h     |  11 +-
>  drivers/virtio/virtio_pci_legacy.c     |   5 +-
>  drivers/virtio/virtio_pci_modern.c     | 120 +++++++++++++-
>  drivers/virtio/virtio_pci_modern_dev.c |  28 ++++
>  drivers/virtio/virtio_ring.c           | 144 +++++++++++-----
>  include/linux/virtio.h                 |   1 +
>  include/linux/virtio_config.h          |  75 ++++++++-
>  include/linux/virtio_pci_modern.h      |   2 +
>  include/linux/virtio_ring.h            |  42 +++--
>  include/uapi/linux/virtio_config.h     |   7 +-
>  include/uapi/linux/virtio_pci.h        |   2 +
>  13 files changed, 618 insertions(+), 101 deletions(-)
>
> --
> 2.31.0
>

Jason Wang

2022-Feb-07 03:41 UTC

head link

[PATCH v3 01/17] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data

? 2022/1/26 ??3:35, Xuan Zhuo ??:> Add queue_notify_data in struct virtio_pci_common_cfg, which comes from
> here https://github.com/oasis-tcs/virtio-spec/issues/89
>
> Since I want to add queue_reset after it, I submitted this patch first.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> ---
>   include/uapi/linux/virtio_pci.h | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/include/uapi/linux/virtio_pci.h
b/include/uapi/linux/virtio_pci.h
> index 3a86f36d7e3d..492c89f56c6a 100644
> --- a/include/uapi/linux/virtio_pci.h
> +++ b/include/uapi/linux/virtio_pci.h
> @@ -164,6 +164,7 @@ struct virtio_pci_common_cfg {
>   	__le32 queue_avail_hi;		/* read-write */
>   	__le32 queue_used_lo;		/* read-write */
>   	__le32 queue_used_hi;		/* read-write */
> +	__le16 queue_notify_data;	/* read-write */
>   };

So I had the same concern as previous version.

This breaks uABI where program may try to use sizeof(struct 
virtio_pci_common_cfg).

We probably need a container structure here.

THanks

>   
>   /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */

Jason Wang

2022-Feb-07 06:45 UTC

head link

[PATCH v3 03/17] virtio: queue_reset: struct virtio_config_ops add callbacks for queue_reset

? 2022/1/26 ??3:35, Xuan Zhuo ??:> Performing reset on a queue is divided into two steps:
>
> 1. reset_vq: reset one vq
> 2. enable_reset_vq: re-enable the reset queue
>
> In the first step, these tasks will be completed:
>      1. notify the hardware queue to reset
>      2. recycle the buffer from vq
>      3. release the ring of the vq
>
> The second step is similar to find vqs,

Not sure, since find_vqs will usually try to allocate interrupts.

>   passing parameters callback and
> name, etc. Based on the original vq, the ring is re-allocated and
> configured to the backend.

I wonder whether we really have such requirement.

For example, do we really have a use case that may change:

vq callback, ctx, ring_num or even re-create the virtqueue?

Thanks

>
> So add two callbacks reset_vq, enable_reset_vq to struct
> virtio_config_ops.
>
> Add a structure for passing parameters. This will facilitate subsequent
> expansion of the parameters of enable reset vq.
> There is currently only one default extended parameter ring_num.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> ---
>   include/linux/virtio_config.h | 43 ++++++++++++++++++++++++++++++++++-
>   1 file changed, 42 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
> index 4d107ad31149..51dd8461d1b6 100644
> --- a/include/linux/virtio_config.h
> +++ b/include/linux/virtio_config.h
> @@ -16,6 +16,44 @@ struct virtio_shm_region {
>   	u64 len;
>   };
>   
> +typedef void vq_callback_t(struct virtqueue *);
> +
> +/* virtio_reset_vq: specify parameters for queue_reset
> + *
> + *	vdev: the device
> + *	queue_index: the queue index
> + *
> + *	free_unused_cb: callback to free unused bufs
> + *	data: used by free_unused_cb
> + *
> + *	callback: callback for the virtqueue, NULL for vq that do not need a
> + *	          callback
> + *	name: virtqueue names (mainly for debugging), NULL for vq unused by
> + *	      driver
> + *	ctx: ctx
> + *
> + *	ring_num: specify ring num for the vq to be re-enabled. 0 means use the
> + *	          default value. MUST be a power of 2.
> + */
> +struct virtio_reset_vq;
> +typedef void vq_reset_callback_t(struct virtio_reset_vq *param, void
*buf);
> +struct virtio_reset_vq {
> +	struct virtio_device *vdev;
> +	u16 queue_index;
> +
> +	/* reset vq param */
> +	vq_reset_callback_t *free_unused_cb;
> +	void *data;
> +
> +	/* enable reset vq param */
> +	vq_callback_t *callback;
> +	const char *name;
> +	const bool *ctx;
> +
> +	/* ext enable reset vq param */
> +	u16 ring_num;
> +};
> +
>   /**
>    * virtio_config_ops - operations for configuring a virtio device
>    * Note: Do not assume that a transport implements all of the operations
> @@ -74,8 +112,9 @@ struct virtio_shm_region {
>    * @set_vq_affinity: set the affinity for a virtqueue (optional).
>    * @get_vq_affinity: get the affinity for a virtqueue (optional).
>    * @get_shm_region: get a shared memory region based on the index.
> + * @reset_vq: reset a queue individually
> + * @enable_reset_vq: enable a reset queue
>    */
> -typedef void vq_callback_t(struct virtqueue *);
>   struct virtio_config_ops {
>   	void (*enable_cbs)(struct virtio_device *vdev);
>   	void (*get)(struct virtio_device *vdev, unsigned offset,
> @@ -100,6 +139,8 @@ struct virtio_config_ops {
>   			int index);
>   	bool (*get_shm_region)(struct virtio_device *vdev,
>   			       struct virtio_shm_region *region, u8 id);
> +	int (*reset_vq)(struct virtio_reset_vq *param);
> +	struct virtqueue *(*enable_reset_vq)(struct virtio_reset_vq *param);
>   };
>   
>   /* If driver didn't advertise the feature, it will never appear. */

Jason Wang

2022-Feb-07 06:57 UTC

head link

[PATCH v3 13/17] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET

? 2022/1/26 ??3:35, Xuan Zhuo ??:> This patch implements virtio pci support for QUEUE RESET.
>
> Performing reset on a queue is divided into two steps:
>
> 1. reset_vq: reset one vq
> 2. enable_reset_vq: re-enable the reset queue
>
> In the first step, these tasks will be completed:
>     1. notify the hardware queue to reset
>     2. recycle the buffer from vq
>     3. release the ring of the vq
>
> The process of enable reset vq:
>      vp_modern_enable_reset_vq()
>      vp_enable_reset_vq()
>      __vp_setup_vq()
>      setup_vq()
>      vring_setup_virtqueue()
>
> In this process, we added two parameters, vq and num, and finally passed
> them to vring_setup_virtqueue().  And reuse the original info and vq.
>
> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> ---
>   drivers/virtio/virtio_pci_common.c |  36 +++++++----
>   drivers/virtio/virtio_pci_common.h |   5 ++
>   drivers/virtio/virtio_pci_modern.c | 100 +++++++++++++++++++++++++++++
>   3 files changed, 128 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
> index c02936d29a31..ad21638fbf66 100644
> --- a/drivers/virtio/virtio_pci_common.c
> +++ b/drivers/virtio/virtio_pci_common.c
> @@ -205,23 +205,28 @@ static int vp_request_msix_vectors(struct
virtio_device *vdev, int nvectors,
>   	return err;
>   }
>   
> -static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned
index,
> -				     void (*callback)(struct virtqueue *vq),
> -				     const char *name,
> -				     bool ctx,
> -				     u16 msix_vec, u16 num)
> +struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
> +			      void (*callback)(struct virtqueue *vq),
> +			      const char *name,
> +			      bool ctx,
> +			      u16 msix_vec, u16 num)
>   {
>   	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
> -	struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL);
> +	struct virtio_pci_vq_info *info;
>   	struct virtqueue *vq;
>   	unsigned long flags;
>   
> -	/* fill out our structure that represents an active queue */
> -	if (!info)
> -		return ERR_PTR(-ENOMEM);
> +	info = vp_dev->vqs[index];
> +	if (!info) {
> +		info = kzalloc(sizeof *info, GFP_KERNEL);
> +
> +		/* fill out our structure that represents an active queue */
> +		if (!info)
> +			return ERR_PTR(-ENOMEM);
> +	}
>   
>   	vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, ctx,
> -			      msix_vec, NULL, num);
> +			      msix_vec, info->vq, num);
>   	if (IS_ERR(vq))
>   		goto out_info;
>   
> @@ -238,6 +243,9 @@ static struct virtqueue *vp_setup_vq(struct
virtio_device *vdev, unsigned index,
>   	return vq;
>   
>   out_info:
> +	if (info->vq && info->vq->reset)
> +		return vq;
> +
>   	kfree(info);
>   	return vq;
>   }
> @@ -248,9 +256,11 @@ static void vp_del_vq(struct virtqueue *vq)
>   	struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
>   	unsigned long flags;
>   
> -	spin_lock_irqsave(&vp_dev->lock, flags);
> -	list_del(&info->node);
> -	spin_unlock_irqrestore(&vp_dev->lock, flags);
> +	if (!vq->reset) {
> +		spin_lock_irqsave(&vp_dev->lock, flags);
> +		list_del(&info->node);
> +		spin_unlock_irqrestore(&vp_dev->lock, flags);
> +	}
>   
>   	vp_dev->del_vq(info);
>   	kfree(info);
> diff --git a/drivers/virtio/virtio_pci_common.h
b/drivers/virtio/virtio_pci_common.h
> index 65db92245e41..c1d15f7c0be4 100644
> --- a/drivers/virtio/virtio_pci_common.h
> +++ b/drivers/virtio/virtio_pci_common.h
> @@ -119,6 +119,11 @@ int vp_find_vqs(struct virtio_device *vdev, unsigned
nvqs,
>   		struct virtqueue *vqs[], vq_callback_t *callbacks[],
>   		const char * const names[], const bool *ctx,
>   		struct irq_affinity *desc);
> +struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
> +			      void (*callback)(struct virtqueue *vq),
> +			      const char *name,
> +			      bool ctx,
> +			      u16 msix_vec, u16 num);
>   const char *vp_bus_name(struct virtio_device *vdev);
>   
>   /* Setup the affinity for a virtqueue:
> diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
> index 2ce58de549de..6789411169e4 100644
> --- a/drivers/virtio/virtio_pci_modern.c
> +++ b/drivers/virtio/virtio_pci_modern.c
> @@ -34,6 +34,9 @@ static void vp_transport_features(struct virtio_device
*vdev, u64 features)
>   	if ((features & BIT_ULL(VIRTIO_F_SR_IOV)) &&
>   			pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV))
>   		__virtio_set_bit(vdev, VIRTIO_F_SR_IOV);
> +
> +	if (features & BIT_ULL(VIRTIO_F_RING_RESET))
> +		__virtio_set_bit(vdev, VIRTIO_F_RING_RESET);
>   }
>   
>   /* virtio config->finalize_features() implementation */
> @@ -176,6 +179,94 @@ static void vp_reset(struct virtio_device *vdev)
>   	vp_disable_cbs(vdev);
>   }
>   
> +static int vp_modern_reset_vq(struct virtio_reset_vq *param)
> +{
> +	struct virtio_pci_device *vp_dev = to_vp_device(param->vdev);
> +	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> +	struct virtio_pci_vq_info *info;
> +	u16 msix_vec, queue_index;
> +	unsigned long flags;
> +	void *buf;
> +
> +	if (!virtio_has_feature(param->vdev, VIRTIO_F_RING_RESET))
> +		return -ENOENT;
> +
> +	queue_index = param->queue_index;
> +
> +	vp_modern_set_queue_reset(mdev, queue_index);
> +
> +	/* After write 1 to queue reset, the driver MUST wait for a read of
> +	 * queue reset to return 1.
> +	 */
> +	while (vp_modern_get_queue_reset(mdev, queue_index) != 1)
> +		msleep(1);

Is this better to move this logic into vp_modern_set_queue_reset()?

> +
> +	info = vp_dev->vqs[queue_index];
> +	msix_vec = info->msix_vector;
> +
> +	/* Disable VQ callback. */
> +	if (vp_dev->per_vq_vectors && msix_vec !=
VIRTIO_MSI_NO_VECTOR)
> +		disable_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec));

How about the INTX case where irq is shared? I guess we need to disable 
and enable the irq as well.

> +
> +	while ((buf = virtqueue_detach_unused_buf(info->vq)) != NULL)
> +		param->free_unused_cb(param, buf);

Any reason that we can't leave this logic to driver? (Or is there any 
operations that must be done before the following operations?)

> +
> +	/* delete vq */
> +	spin_lock_irqsave(&vp_dev->lock, flags);
> +	list_del(&info->node);
> +	spin_unlock_irqrestore(&vp_dev->lock, flags);
> +
> +	INIT_LIST_HEAD(&info->node);
> +
> +	if (vp_dev->msix_enabled)
> +		vp_modern_queue_vector(mdev, info->vq->index,
> +				       VIRTIO_MSI_NO_VECTOR);

I wonder if this is a must.

> +
> +	if (!mdev->notify_base)
> +		pci_iounmap(mdev->pci_dev,
> +			    (void __force __iomem *)info->vq->priv);

Is this a must? what happens if we simply don't do this?

> +
> +	vring_reset_virtqueue(info->vq);
> +
> +	return 0;
> +}
> +
> +static struct virtqueue *vp_modern_enable_reset_vq(struct virtio_reset_vq
*param)
> +{
> +	struct virtio_pci_device *vp_dev = to_vp_device(param->vdev);
> +	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
> +	struct virtio_pci_vq_info *info;
> +	u16 msix_vec, queue_index;
> +	struct virtqueue *vq;
> +
> +	if (!virtio_has_feature(param->vdev, VIRTIO_F_RING_RESET))
> +		return ERR_PTR(-ENOENT);
> +
> +	queue_index = param->queue_index;
> +
> +	info = vp_dev->vqs[queue_index];
> +
> +	if (!info->vq->reset)
> +		return ERR_PTR(-EPERM);
> +
> +	/* check queue reset status */
> +	if (vp_modern_get_queue_reset(mdev, queue_index) != 1)
> +		return ERR_PTR(-EBUSY);
> +
> +	vq = vp_setup_vq(param->vdev, queue_index, param->callback,
param->name,
> +			 param->ctx, info->msix_vector, param->ring_num);
> +	if (IS_ERR(vq))
> +		return vq;
> +
> +	vp_modern_set_queue_enable(&vp_dev->mdev, vq->index, true);
> +
> +	msix_vec = vp_dev->vqs[queue_index]->msix_vector;
> +	if (vp_dev->per_vq_vectors && msix_vec !=
VIRTIO_MSI_NO_VECTOR)
> +		enable_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec));

How about the INT-X case?

Thanks

> +
> +	return vq;
> +}
> +
>   static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
>   {
>   	return vp_modern_config_vector(&vp_dev->mdev, vector);
> @@ -284,6 +375,11 @@ static void del_vq(struct virtio_pci_vq_info *info)
>   	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
>   	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
>   
> +	if (vq->reset) {
> +		vring_del_virtqueue(vq);
> +		return;
> +	}
> +
>   	if (vp_dev->msix_enabled)
>   		vp_modern_queue_vector(mdev, vq->index,
>   				       VIRTIO_MSI_NO_VECTOR);
> @@ -403,6 +499,8 @@ static const struct virtio_config_ops
virtio_pci_config_nodev_ops = {
>   	.set_vq_affinity = vp_set_vq_affinity,
>   	.get_vq_affinity = vp_get_vq_affinity,
>   	.get_shm_region  = vp_get_shm_region,
> +	.reset_vq	 = vp_modern_reset_vq,
> +	.enable_reset_vq = vp_modern_enable_reset_vq,
>   };
>   
>   static const struct virtio_config_ops virtio_pci_config_ops = {
> @@ -421,6 +519,8 @@ static const struct virtio_config_ops
virtio_pci_config_ops = {
>   	.set_vq_affinity = vp_set_vq_affinity,
>   	.get_vq_affinity = vp_get_vq_affinity,
>   	.get_shm_region  = vp_get_shm_region,
> +	.reset_vq	 = vp_modern_reset_vq,
> +	.enable_reset_vq = vp_modern_enable_reset_vq,
>   };
>   
>   /* the PCI probing function */

Virtualization - Feb 2022 - [PATCH v3 01/17] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data

[PATCH v3 00/17] virtio pci support VIRTIO_F_RING_RESET

[PATCH v3 01/17] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data

[PATCH v3 02/17] virtio: queue_reset: add VIRTIO_F_RING_RESET

[PATCH v3 03/17] virtio: queue_reset: struct virtio_config_ops add callbacks for queue_reset

[PATCH v3 04/17] virtio: queue_reset: add helper

[PATCH v3 05/17] vritio_ring: queue_reset: extract the release function of the vq ring

[PATCH v3 06/17] virtio_ring: queue_reset: split: add __vring_init_virtqueue()

[PATCH v3 07/17] virtio_ring: queue_reset: split: support enable reset queue

[PATCH v3 08/17] virtio_ring: queue_reset: packed: support enable reset queue

[PATCH v3 09/17] virtio_ring: queue_reset: add vring_reset_virtqueue()

[PATCH v3 10/17] virtio_pci: queue_reset: update struct virtio_pci_common_cfg and option functions

[PATCH v3 11/17] virtio_pci: queue_reset: release vq by vp_dev->vqs

[PATCH v3 12/17] virtio_pci: queue_reset: setup_vq use vring_setup_virtqueue()

[PATCH v3 13/17] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET

[PATCH v3 14/17] virtio_net: virtnet_tx_timeout() fix style

[PATCH v3 15/17] virtio_net: virtnet_tx_timeout() stop ref sq->vq

[PATCH v3 16/17] virtio_net: split free_unused_bufs()

[PATCH v3 17/17] virtio_net: support pair disable/enable

[PATCH v3 00/17] virtio pci support VIRTIO_F_RING_RESET

[PATCH v3 01/17] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data

[PATCH v3 03/17] virtio: queue_reset: struct virtio_config_ops add callbacks for queue_reset

[PATCH v3 13/17] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET