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Xuan Zhuo

2022-Feb-14 08:13 UTC

[PATCH v5 00/22] 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.

Performing reset on a queue is divided into four steps:
    1. reset_vq: reset one vq
    2. recycle the buffer from vq by virtqueue_detach_unused_buf()
    3. release the ring of the vq by vring_release_virtqueue()
    4. enable_reset_vq: re-enable the reset queue

#2-#8  : virtio ring support re-enable reset queue and release vring
#9-#14 : virtio PCI support reset queue and re-enable
#15    : add queue reset helper
#16-#17: virtio-net support rx, tx reset
#18-#22: virtio-net support set ringparam

Please review. Thanks.

v5:
  1. add virtio-net support set_ringparam

v4:
  1. just the code of virtio, without virtio-net
  2. Performing reset on a queue is divided into these steps:
    1. reset_vq: reset one vq
    2. recycle the buffer from vq by virtqueue_detach_unused_buf()
    3. release the ring of the vq by vring_release_virtqueue()
    4. enable_reset_vq: re-enable the reset queue
  3. Simplify the parameters of enable_reset_vq()
  4. add container structures for virtio_pci_common_cfg

v3:
  1. keep vq, irq unreleased

Xuan Zhuo (22):
  virtio_pci: struct virtio_pci_common_cfg add queue_notify_data
  virtio: queue_reset: add VIRTIO_F_RING_RESET
  virtio_ring: queue_reset: add function vring_setup_virtqueue()
  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: extract the release function of the vq ring
  virtio_ring: queue_reset: add vring_release_virtqueue()
  virtio: queue_reset: struct virtio_config_ops add callbacks for
    queue_reset
  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() support vring_setup_virtqueue()
  virtio_pci: queue_reset: reserve vq->priv for re-enable queue
  virtio_pci: queue_reset: support VIRTIO_F_RING_RESET
  virtio: queue_reset: add helper
  virtio_net: split free_unused_bufs()
  virtio_net: support rx/tx queue reset
  virtio: add helper virtqueue_get_vring_max_size()
  virtio: add helper virtio_set_max_ring_num()
  virtio_net: set the default max ring num
  virtio_net: get max ring size by virtqueue_get_vring_max_size()
  virtio_net: support set_ringparam

 drivers/net/virtio_net.c               | 238 ++++++++++++++++++++++---
 drivers/virtio/virtio_mmio.c           |   2 +
 drivers/virtio/virtio_pci_common.c     |  61 +++++--
 drivers/virtio/virtio_pci_common.h     |  10 +-
 drivers/virtio/virtio_pci_legacy.c     |   6 +-
 drivers/virtio/virtio_pci_modern.c     |  82 ++++++++-
 drivers/virtio/virtio_pci_modern_dev.c |  36 ++++
 drivers/virtio/virtio_ring.c           | 193 +++++++++++++++-----
 include/linux/virtio.h                 |  15 ++
 include/linux/virtio_config.h          |  82 +++++++++
 include/linux/virtio_pci_modern.h      |   2 +
 include/linux/virtio_ring.h            |  37 ++--
 include/uapi/linux/virtio_config.h     |   7 +-
 include/uapi/linux/virtio_pci.h        |  14 ++
 14 files changed, 668 insertions(+), 117 deletions(-)

--
2.31.0

Xuan Zhuo

2022-Feb-14 08:13 UTC

head link

[PATCH v5 01/22] 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

For not breaks uABI, add a new struct virtio_pci_common_cfg_notify.

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

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

diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 3a86f36d7e3d..22bec9bd0dfc 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -166,6 +166,13 @@ struct virtio_pci_common_cfg {
 	__le32 queue_used_hi;		/* read-write */
 };
 
+struct virtio_pci_common_cfg_notify {
+	struct virtio_pci_common_cfg cfg;
+
+	__le16 queue_notify_data;	/* read-write */
+	__le16 padding;
+};
+
 /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
 struct virtio_pci_cfg_cap {
 	struct virtio_pci_cap cap;
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:13 UTC

head link

[PATCH v5 02/22] 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-Feb-14 08:13 UTC

head link

[PATCH v5 03/22] virtio_ring: queue_reset: add function vring_setup_virtqueue()

Added function vring_setup_virtqueue() to allow passing existing vq
without reallocating vq.

The purpose of adding this function is to not break the form of
vring_create_virtqueue().

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c |  7 ++++---
 include/linux/virtio_ring.h  | 37 ++++++++++++++++++++++++++----------
 2 files changed, 31 insertions(+), 13 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 962f1477b1fa..4f95d650b066 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2255,7 +2255,7 @@ 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,
@@ -2265,7 +2265,8 @@ 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))
@@ -2277,7 +2278,7 @@ struct virtqueue *vring_create_virtqueue(
 			vdev, weak_barriers, may_reduce_num,
 			context, notify, callback, name);
 }
-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_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-Feb-14 08:13 UTC

head link

[PATCH v5 04/22] 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 4f95d650b066..9cfbe45ab286 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2169,23 +2169,17 @@ 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;
@@ -2245,13 +2239,42 @@ 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-Feb-14 08:13 UTC

head link

[PATCH v5 05/22] virtio_ring: queue_reset: split: support enable reset queue

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

Based on whether the incoming vq passed by vring_setup_virtqueue() is
NULL or not, distinguish whether it is a normal create virtqueue or
re-enable a reset queue.

When re-enable a reset queue, reuse the original callback, name,
indirect.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 52 +++++++++++++++++++++++++-----------
 1 file changed, 37 insertions(+), 15 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 9cfbe45ab286..4639e1643c78 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -198,6 +198,16 @@ 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,
+				  bool reset);
 
 /*
  * Helpers.
@@ -925,9 +935,9 @@ 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 +974,17 @@ 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, true))
+			goto err;
 	}
 
 	to_vvq(vq)->split.queue_dma_addr = dma_addr;
@@ -977,6 +992,9 @@ 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;
 }
 
 
@@ -2177,14 +2195,20 @@ static int __vring_init_virtqueue(struct virtqueue *_vq,
 				  bool context,
 				  bool (*notify)(struct virtqueue *),
 				  void (*callback)(struct virtqueue *),
-				  const char *name)
+				  const char *name,
+				  bool reset)
 {
 	struct vring_virtqueue *vq = to_vvq(_vq);
 
+	if (!reset) {
+		vq->vq.callback = callback;
+		vq->vq.name = name;
+		vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)
&&
+			!context;
+	}
+
 	vq->packed_ring = false;
-	vq->vq.callback = callback;
 	vq->vq.vdev = vdev;
-	vq->vq.name = name;
 	vq->vq.num_free = vring.num;
 	vq->vq.index = index;
 	vq->we_own_ring = false;
@@ -2200,8 +2224,6 @@ static int __vring_init_virtqueue(struct virtqueue *_vq,
 	vq->last_add_time_valid = false;
 #endif
 
-	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)
&&
-		!context;
 	vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
 
 	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
@@ -2215,7 +2237,7 @@ static int __vring_init_virtqueue(struct virtqueue *_vq,
 	vq->split.avail_idx_shadow = 0;
 
 	/* No callback?  Tell other side not to bother us. */
-	if (!callback) {
+	if (!vq->vq.callback) {
 		vq->split.avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
 		if (!vq->event)
 			vq->split.vring.avail->flags = cpu_to_virtio16(vdev,
@@ -2267,7 +2289,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int
index,
 		return NULL;
 
 	err = __vring_init_virtqueue(&vq->vq, index, vring, vdev,
weak_barriers,
-				     context, notify, callback, name);
+				     context, notify, callback, name, false);
 
 	if (err) {
 		kfree(vq);
@@ -2299,7 +2321,7 @@ struct virtqueue *vring_setup_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_setup_virtqueue);
 
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 06/22] virtio_ring: queue_reset: packed: support enable reset queue

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

Based on whether the incoming vq passed by vring_setup_virtqueue() is
NULL or not, distinguish whether it is a normal create virtqueue or
re-enable a reset queue.

When re-enable a reset queue, reuse the original callback, name, indirect.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 4639e1643c78..20659f7ca582 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1683,7 +1683,8 @@ 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;
@@ -1713,13 +1714,20 @@ 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.name = name;
+		vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)
&&
+			!context;
+	}
 
-	vq->vq.callback = callback;
 	vq->vq.vdev = vdev;
-	vq->vq.name = name;
 	vq->vq.num_free = num;
 	vq->vq.index = index;
 	vq->we_own_ring = true;
@@ -1736,8 +1744,6 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	vq->last_add_time_valid = false;
 #endif
 
-	vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)
&&
-		!context;
 	vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
 
 	if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
@@ -1778,7 +1784,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
 		goto err_desc_extra;
 
 	/* No callback?  Tell other side not to bother us. */
-	if (!callback) {
+	if (!vq->vq.callback) {
 		vq->packed.event_flags_shadow = VRING_PACKED_EVENT_FLAG_DISABLE;
 		vq->packed.vring.driver->flags  		
cpu_to_le16(vq->packed.event_flags_shadow);
@@ -1792,7 +1798,8 @@ 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:
@@ -2317,7 +2324,7 @@ 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-Feb-14 08:14 UTC

head link

[PATCH v5 07/22] virtio_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 20659f7ca582..c5dd17c7dd4a 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2355,12 +2355,10 @@ 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) {
@@ -2393,6 +2391,13 @@ 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-Feb-14 08:14 UTC

head link

[PATCH v5 08/22] virtio_ring: queue_reset: add vring_release_virtqueue()

Added vring_release_virtqueue() to release the ring of the vq.

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 | 18 +++++++++++++++++-
 include/linux/virtio.h       | 12 ++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index c5dd17c7dd4a..b37753bdbbc4 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1730,6 +1730,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	vq->vq.vdev = vdev;
 	vq->vq.num_free = num;
 	vq->vq.index = index;
+	vq->vq.reset = VIRTQUEUE_RESET_STAGE_NONE;
 	vq->we_own_ring = true;
 	vq->notify = notify;
 	vq->weak_barriers = weak_barriers;
@@ -2218,6 +2219,7 @@ static int __vring_init_virtqueue(struct virtqueue *_vq,
 	vq->vq.vdev = vdev;
 	vq->vq.num_free = vring.num;
 	vq->vq.index = index;
+	vq->vq.reset = VIRTQUEUE_RESET_STAGE_NONE;
 	vq->we_own_ring = false;
 	vq->notify = notify;
 	vq->weak_barriers = weak_barriers;
@@ -2397,11 +2399,25 @@ void vring_del_virtqueue(struct virtqueue *_vq)
 {
 	struct vring_virtqueue *vq = to_vvq(_vq);
 
-	__vring_del_virtqueue(vq);
+	if (_vq->reset != VIRTQUEUE_RESET_STAGE_RELEASE)
+		__vring_del_virtqueue(vq);
 	kfree(vq);
 }
 EXPORT_SYMBOL_GPL(vring_del_virtqueue);
 
+void vring_release_virtqueue(struct virtqueue *_vq)
+{
+	struct vring_virtqueue *vq = to_vvq(_vq);
+
+	if (_vq->reset != VIRTQUEUE_RESET_STAGE_DEVICE)
+		return;
+
+	__vring_del_virtqueue(vq);
+
+	_vq->reset = VIRTQUEUE_RESET_STAGE_RELEASE;
+}
+EXPORT_SYMBOL_GPL(vring_release_virtqueue);
+
 /* Manipulates transport-specific feature bits. */
 void vring_transport_features(struct virtio_device *vdev)
 {
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 72292a62cd90..cdb2a551257c 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -10,6 +10,12 @@
 #include <linux/mod_devicetable.h>
 #include <linux/gfp.h>
 
+enum virtqueue_reset_stage {
+	VIRTQUEUE_RESET_STAGE_NONE,
+	VIRTQUEUE_RESET_STAGE_DEVICE,
+	VIRTQUEUE_RESET_STAGE_RELEASE,
+};
+
 /**
  * virtqueue - a queue to register buffers for sending or receiving.
  * @list: the chain of virtqueues for this device
@@ -32,6 +38,7 @@ struct virtqueue {
 	unsigned int index;
 	unsigned int num_free;
 	void *priv;
+	enum virtqueue_reset_stage reset;
 };
 
 int virtqueue_add_outbuf(struct virtqueue *vq,
@@ -196,4 +203,9 @@ void unregister_virtio_driver(struct virtio_driver *drv);
 #define module_virtio_driver(__virtio_driver) \
 	module_driver(__virtio_driver, register_virtio_driver, \
 			unregister_virtio_driver)
+/*
+ * Resets a virtqueue. Just frees the ring, not free vq.
+ * This function must be called after reset_vq().
+ */
+void vring_release_virtqueue(struct virtqueue *vq);
 #endif /* _LINUX_VIRTIO_H */
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 09/22] virtio: queue_reset: struct virtio_config_ops add callbacks for queue_reset

Performing reset on a queue is divided into four steps:

1. reset_vq: reset one vq
2. recycle the buffer from vq by virtqueue_detach_unused_buf()
3. release the ring of the vq by vring_release_virtqueue()
4. enable_reset_vq: re-enable the reset queue

So add two callbacks reset_vq, enable_reset_vq to struct
virtio_config_ops.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 include/linux/virtio_config.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 4d107ad31149..8cde339d40b4 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -74,6 +74,18 @@ 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 (optional).
+ *	vq: the virtqueue
+ *	Returns 0 on success or error status
+ *	After successfully calling this, be sure to call
+ *	virtqueue_detach_unused_buf() to recycle the buffer in the ring, and
+ *	then call vring_release_virtqueue() to release the vq ring.
+ *	Caller should guarantee that the vring is not accessed by any functions
+ *	of virtqueue.
+ * @enable_reset_vq: enable a reset queue
+ *	vq: the virtqueue
+ *	Returns 0 on success or error status
+ *	If reset_vq is set, then enable_reset_vq must also be set.
  */
 typedef void vq_callback_t(struct virtqueue *);
 struct virtio_config_ops {
@@ -100,6 +112,8 @@ 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 virtqueue *vq);
+	int (*enable_reset_vq)(struct virtqueue *vq);
 };
 
 /* If driver didn't advertise the feature, it will never appear. */
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 10/22] 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.

For not breaks uABI, add a new struct virtio_pci_common_cfg_reset.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_pci_modern_dev.c | 36 ++++++++++++++++++++++++++
 include/linux/virtio_pci_modern.h      |  2 ++
 include/uapi/linux/virtio_pci.h        |  7 +++++
 3 files changed, 45 insertions(+)

diff --git a/drivers/virtio/virtio_pci_modern_dev.c
b/drivers/virtio/virtio_pci_modern_dev.c
index e8b3ff2b9fbc..f67e88982918 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -3,6 +3,7 @@
 #include <linux/virtio_pci_modern.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/delay.h>
 
 /*
  * vp_modern_map_capability - map a part of virtio pci capability
@@ -463,6 +464,41 @@ 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_reset __iomem *cfg;
+
+	cfg = (struct virtio_pci_common_cfg_reset *)mdev->common;
+
+	vp_iowrite16(index, &cfg->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_reset __iomem *cfg;
+
+	cfg = (struct virtio_pci_common_cfg_reset *)mdev->common;
+
+	vp_iowrite16(index, &cfg->cfg.queue_select);
+	vp_iowrite16(1, &cfg->queue_reset);
+
+	while (vp_ioread16(&cfg->queue_reset) != 1)
+		msleep(1);
+}
+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 22bec9bd0dfc..d9462efd6ce8 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -173,6 +173,13 @@ struct virtio_pci_common_cfg_notify {
 	__le16 padding;
 };
 
+struct virtio_pci_common_cfg_reset {
+	struct virtio_pci_common_cfg cfg;
+
+	__le16 queue_notify_data;	/* read-write */
+	__le16 queue_reset;		/* read-write */
+};
+
 /* Fields in VIRTIO_PCI_CAP_PCI_CFG: */
 struct virtio_pci_cfg_cap {
 	struct virtio_pci_cap cap;
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 11/22] 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-Feb-14 08:14 UTC

head link

[PATCH v5 12/22] virtio_pci: queue_reset: setup_vq() support vring_setup_virtqueue()

modern setup_vq() replaces vring_create_virtqueue() with
vring_setup_virtqueue()

vp_setup_vq() can pass the original vq(from info->vq) to re-enable vq.

Allow direct calls to vp_setup_vq() in virtio_pci_modern.c

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_pci_common.c | 31 ++++++++++++++++++------------
 drivers/virtio/virtio_pci_common.h |  8 +++++++-
 drivers/virtio/virtio_pci_legacy.c |  4 ++--
 drivers/virtio/virtio_pci_modern.c | 12 ++++++------
 4 files changed, 34 insertions(+), 21 deletions(-)

diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index 6b2573ec1ae8..5a4f750a0b97 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -205,28 +205,33 @@ 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)
+struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned int index,
+			      void (*callback)(struct virtqueue *vq),
+			      const char *name,
+			      bool ctx,
+			      u16 msix_vec)
 {
 	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);
+			      msix_vec, info->vq);
 	if (IS_ERR(vq))
 		goto out_info;
 
 	info->vq = vq;
-	if (callback) {
+	if (vq->callback) {
 		spin_lock_irqsave(&vp_dev->lock, flags);
 		list_add(&info->node, &vp_dev->virtqueues);
 		spin_unlock_irqrestore(&vp_dev->lock, flags);
@@ -238,7 +243,9 @@ static struct virtqueue *vp_setup_vq(struct virtio_device
*vdev, unsigned index,
 	return vq;
 
 out_info:
-	kfree(info);
+	if (!info->vq)
+		kfree(info);
+
 	return vq;
 }
 
diff --git a/drivers/virtio/virtio_pci_common.h
b/drivers/virtio/virtio_pci_common.h
index 392d990b7c73..696e3f6a493b 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -84,7 +84,8 @@ struct virtio_pci_device {
 				      void (*callback)(struct virtqueue *vq),
 				      const char *name,
 				      bool ctx,
-				      u16 msix_vec);
+				      u16 msix_vec,
+				      struct virtqueue *vq);
 	void (*del_vq)(struct virtio_pci_vq_info *info);
 
 	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
@@ -117,6 +118,11 @@ 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 int index,
+			      void (*callback)(struct virtqueue *vq),
+			      const char *name,
+			      bool ctx,
+			      u16 msix_vec);
 const char *vp_bus_name(struct virtio_device *vdev);
 
 /* Setup the affinity for a virtqueue:
diff --git a/drivers/virtio/virtio_pci_legacy.c
b/drivers/virtio/virtio_pci_legacy.c
index 34141b9abe27..96ec2b04e97d 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -113,9 +113,9 @@ 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)
 {
-	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..5af82948f0ae 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -187,11 +187,11 @@ 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)
 {
 
 	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
-	struct virtqueue *vq;
 	u16 num;
 	int err;
 
@@ -211,10 +211,10 @@ 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-Feb-14 08:14 UTC

head link

[PATCH v5 13/22] virtio_pci: queue_reset: reserve vq->priv for re-enable queue

Reserve vq->priv during reset. Prevent vp_modern_map_vq_notify() from
being called repeatedly.

Only set vq->priv = NULL in normal setup virtqueue, and keep
vq->priv in the process of re-enable queue.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_pci_modern.c | 8 +++++---
 drivers/virtio/virtio_ring.c       | 2 ++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index 5af82948f0ae..bed3e9b84272 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -224,10 +224,12 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 				virtqueue_get_avail_addr(vq),
 				virtqueue_get_used_addr(vq));
 
-	vq->priv = (void __force *)vp_modern_map_vq_notify(mdev, index, NULL);
 	if (!vq->priv) {
-		err = -ENOMEM;
-		goto err_map_notify;
+		vq->priv = (void __force *)vp_modern_map_vq_notify(mdev, index, NULL);
+		if (!vq->priv) {
+			err = -ENOMEM;
+			goto err_map_notify;
+		}
 	}
 
 	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index b37753bdbbc4..6a892c8ea16e 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1723,6 +1723,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
 
 		vq->vq.callback = callback;
 		vq->vq.name = name;
+		vq->vq.priv = NULL;
 		vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)
&&
 			!context;
 	}
@@ -2211,6 +2212,7 @@ static int __vring_init_virtqueue(struct virtqueue *_vq,
 	if (!reset) {
 		vq->vq.callback = callback;
 		vq->vq.name = name;
+		vq->vq.priv = NULL;
 		vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)
&&
 			!context;
 	}
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 14/22] 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 these steps:

1. reset_vq: reset one vq
2. recycle the buffer from vq by virtqueue_detach_unused_buf()
3. release the ring of the vq by vring_release_virtqueue()
4. enable_reset_vq: re-enable the reset queue

This patch implements reset_vq, enable_reset_vq in the pci scenario.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_pci_common.c |  8 ++--
 drivers/virtio/virtio_pci_modern.c | 60 ++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/drivers/virtio/virtio_pci_common.c
b/drivers/virtio/virtio_pci_common.c
index 5a4f750a0b97..9ea319b1d404 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -255,9 +255,11 @@ 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_modern.c
b/drivers/virtio/virtio_pci_modern.c
index bed3e9b84272..7d28f4c36fc2 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 +179,59 @@ static void vp_reset(struct virtio_device *vdev)
 	vp_disable_cbs(vdev);
 }
 
+static int vp_modern_reset_vq(struct virtqueue *vq)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+	struct virtio_pci_vq_info *info;
+	unsigned long flags;
+
+	if (!virtio_has_feature(vq->vdev, VIRTIO_F_RING_RESET))
+		return -ENOENT;
+
+	vp_modern_set_queue_reset(mdev, vq->index);
+
+	info = vp_dev->vqs[vq->index];
+
+	/* delete vq from irq handler */
+	spin_lock_irqsave(&vp_dev->lock, flags);
+	list_del(&info->node);
+	spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+	INIT_LIST_HEAD(&info->node);
+
+	vq->reset = VIRTQUEUE_RESET_STAGE_DEVICE;
+
+	return 0;
+}
+
+static int vp_modern_enable_reset_vq(struct virtqueue *vq)
+{
+	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+	struct virtio_pci_modern_device *mdev = &vp_dev->mdev;
+	struct virtio_pci_vq_info *info;
+	struct virtqueue *_vq;
+
+	if (vq->reset != VIRTQUEUE_RESET_STAGE_RELEASE)
+		return -EBUSY;
+
+	/* check queue reset status */
+	if (vp_modern_get_queue_reset(mdev, vq->index) != 1)
+		return -EBUSY;
+
+	info = vp_dev->vqs[vq->index];
+	_vq = vp_setup_vq(vq->vdev, vq->index, NULL, NULL, NULL,
+			 info->msix_vector);
+	if (IS_ERR(_vq)) {
+		vq->reset = VIRTQUEUE_RESET_STAGE_RELEASE;
+		return PTR_ERR(_vq);
+	}
+
+	vp_modern_set_queue_enable(&vp_dev->mdev, vq->index, true);
+
+	return 0;
+}
+
 static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
 {
 	return vp_modern_config_vector(&vp_dev->mdev, vector);
@@ -397,6 +453,8 @@ 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 = {
@@ -415,6 +473,8 @@ 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-Feb-14 08:14 UTC

head link

[PATCH v5 15/22] 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 | 38 +++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 8cde339d40b4..cd7f7f44ce38 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -233,6 +233,44 @@ int virtio_find_vqs_ctx(struct virtio_device *vdev,
unsigned nvqs,
 				      desc);
 }
 
+/**
+ * virtio_reset_vq - reset a queue individually
+ * @vq: the virtqueue
+ *
+ * returns 0 on success or error status
+ *
+ * After successfully calling this, be sure to call
+ * virtqueue_detach_unused_buf() to recycle the buffer in the ring, and
+ * then call vring_release_virtqueue() to release the vq ring.
+ *
+ * Caller should guarantee that the vring is not accessed by any functions
+ * of virtqueue.
+ */
+static inline
+int virtio_reset_vq(struct virtqueue *vq)
+{
+	if (!vq->vdev->config->reset_vq)
+		return -ENOENT;
+
+	return vq->vdev->config->reset_vq(vq);
+}
+
+/**
+ * virtio_enable_resetq - enable a reset queue
+ * @vq: the virtqueue
+ *
+ * returns 0 on success or error status
+ *
+ */
+static inline
+int virtio_enable_resetq(struct virtqueue *vq)
+{
+	if (!vq->vdev->config->enable_reset_vq)
+		return -ENOENT;
+
+	return vq->vdev->config->enable_reset_vq(vq);
+}
+
 /**
  * virtio_device_ready - enable vq use in probe function
  * @vdev: the device
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 16/22] 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 | 53 +++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 22 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index a801ea40908f..9a1445236e23 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2804,36 +2804,45 @@ static void free_receive_page_frags(struct virtnet_info
*vi)
 			put_page(vi->rq[i].alloc_frag.page);
 }
 
-static void free_unused_bufs(struct virtnet_info *vi)
+static void virtnet_sq_free_unused_bufs(struct virtnet_info *vi,
+					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));
-		}
+	while ((buf = virtqueue_detach_unused_buf(sq->vq)) != NULL) {
+		if (!is_xdp_frame(buf))
+			dev_kfree_skb(buf);
+		else
+			xdp_return_frame(ptr_to_xdp(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));
-			}
-		}
+static void virtnet_rq_free_unused_bufs(struct virtnet_info *vi,
+					struct receive_queue *rq)
+{
+	void *buf;
+
+	while ((buf = virtqueue_detach_unused_buf(rq->vq)) != NULL) {
+		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)
+{
+	int i;
+
+	for (i = 0; i < vi->max_queue_pairs; i++)
+		virtnet_sq_free_unused_bufs(vi, vi->sq + i);
+
+	for (i = 0; i < vi->max_queue_pairs; i++)
+		virtnet_rq_free_unused_bufs(vi, vi->rq + i);
+}
+
 static void virtnet_del_vqs(struct virtnet_info *vi)
 {
 	struct virtio_device *vdev = vi->vdev;
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 17/22] virtio_net: support rx/tx queue reset

This patch implements the reset function of the rx, tx queues.

Based on this function, it is possible to modify the ring num of the
queue. And quickly recycle the buffer in the queue.

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

However, in the process of the queue enable, there may be exceptions due to
memory allocation.  In this case, vq is not available, but we still have
to execute napi_enable(). Because napi_disable is similar to a lock,
napi_enable must be called after calling napi_disable.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c | 123 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 123 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 9a1445236e23..a4ffd7cdf623 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -251,6 +251,11 @@ struct padded_vnet_hdr {
 	char padding[4];
 };
 
+static void virtnet_sq_free_unused_bufs(struct virtnet_info *vi,
+					struct send_queue *sq);
+static void virtnet_rq_free_unused_bufs(struct virtnet_info *vi,
+					struct receive_queue *rq);
+
 static bool is_xdp_frame(void *ptr)
 {
 	return (unsigned long)ptr & VIRTIO_XDP_FLAG;
@@ -1369,6 +1374,9 @@ static void virtnet_napi_enable(struct virtqueue *vq,
struct napi_struct *napi)
 {
 	napi_enable(napi);
 
+	if (vq->reset)
+		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 +1421,10 @@ static void refill_work(struct work_struct *work)
 		struct receive_queue *rq = &vi->rq[i];
 
 		napi_disable(&rq->napi);
+		if (rq->vq->reset) {
+			virtnet_napi_enable(rq->vq, &rq->napi);
+			continue;
+		}
 		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
 		virtnet_napi_enable(rq->vq, &rq->napi);
 
@@ -1523,6 +1535,9 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
 	if (!sq->napi.weight || is_xdp_raw_buffer_queue(vi, index))
 		return;
 
+	if (sq->vq->reset)
+		return;
+
 	if (__netif_tx_trylock(txq)) {
 		do {
 			virtqueue_disable_cb(sq->vq);
@@ -1769,6 +1784,114 @@ static netdev_tx_t start_xmit(struct sk_buff *skb,
struct net_device *dev)
 	return NETDEV_TX_OK;
 }
 
+static int virtnet_rx_vq_disable(struct virtnet_info *vi,
+				 struct receive_queue *rq)
+{
+	int err;
+
+	napi_disable(&rq->napi);
+
+	err = virtio_reset_vq(rq->vq);
+	if (err)
+		goto err;
+
+	virtnet_rq_free_unused_bufs(vi, rq);
+
+	vring_release_virtqueue(rq->vq);
+
+	return 0;
+
+err:
+	virtnet_napi_enable(rq->vq, &rq->napi);
+	return err;
+}
+
+static int virtnet_tx_vq_disable(struct virtnet_info *vi,
+				 struct send_queue *sq)
+{
+	struct netdev_queue *txq;
+	int err, qindex;
+
+	qindex = sq - vi->sq;
+
+	txq = netdev_get_tx_queue(vi->dev, qindex);
+	__netif_tx_lock_bh(txq);
+
+	netif_stop_subqueue(vi->dev, qindex);
+	virtnet_napi_tx_disable(&sq->napi);
+
+	err = virtio_reset_vq(sq->vq);
+	if (err) {
+		virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
+		netif_start_subqueue(vi->dev, qindex);
+
+		__netif_tx_unlock_bh(txq);
+		return err;
+	}
+	__netif_tx_unlock_bh(txq);
+
+	virtnet_sq_free_unused_bufs(vi, sq);
+
+	vring_release_virtqueue(sq->vq);
+
+	return 0;
+}
+
+static int virtnet_tx_vq_enable(struct virtnet_info *vi, struct send_queue *sq)
+{
+	int err;
+
+	err = virtio_enable_resetq(sq->vq);
+	if (!err)
+		netif_start_subqueue(vi->dev, sq - vi->sq);
+
+	virtnet_napi_tx_enable(vi, sq->vq, &sq->napi);
+
+	return err;
+}
+
+static int virtnet_rx_vq_enable(struct virtnet_info *vi,
+				struct receive_queue *rq)
+{
+	int err;
+
+	err = virtio_enable_resetq(rq->vq);
+
+	virtnet_napi_enable(rq->vq, &rq->napi);
+
+	return err;
+}
+
+static int virtnet_rx_vq_reset(struct virtnet_info *vi, int i)
+{
+	int err;
+
+	err = virtnet_rx_vq_disable(vi, vi->rq + i);
+	if (err)
+		return err;
+
+	err = virtnet_rx_vq_enable(vi, vi->rq + i);
+	if (err)
+		netdev_err(vi->dev,
+			   "enable rx reset vq fail: rx queue index: %d err: %d\n", i,
err);
+	return err;
+}
+
+static int virtnet_tx_vq_reset(struct virtnet_info *vi, int i)
+{
+	int err;
+
+	err = virtnet_tx_vq_disable(vi, vi->sq + i);
+	if (err)
+		return err;
+
+	err = virtnet_tx_vq_enable(vi, vi->sq + i);
+	if (err)
+		netdev_err(vi->dev,
+			   "enable tx reset vq fail: tx queue index: %d err: %d\n", i,
err);
+	return err;
+}
+
 /*
  * Send command via the control virtqueue and check status.  Commands
  * supported by the hypervisor, as indicated by feature bits, should
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 18/22] virtio: add helper virtqueue_get_vring_max_size()

Record the maximum queue num supported by the device.

virtio-net can display the maximum (supported by hardware) ring size in
ethtool -g eth0.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_mmio.c       |  2 ++
 drivers/virtio/virtio_pci_legacy.c |  2 ++
 drivers/virtio/virtio_pci_modern.c |  2 ++
 drivers/virtio/virtio_ring.c       | 13 +++++++++++++
 include/linux/virtio.h             |  2 ++
 5 files changed, 21 insertions(+)

diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 56128b9c46eb..a41abc8051b9 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -390,6 +390,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device
*vdev, unsigned index,
 		goto error_new_virtqueue;
 	}
 
+	vq->num_max = num;
+
 	/* Activate the queue */
 	writel(virtqueue_get_vring_size(vq), vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
 	if (vm_dev->version == 1) {
diff --git a/drivers/virtio/virtio_pci_legacy.c
b/drivers/virtio/virtio_pci_legacy.c
index 96ec2b04e97d..340149f6196d 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -135,6 +135,8 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 	if (!vq)
 		return ERR_PTR(-ENOMEM);
 
+	vq->num_max = num;
+
 	q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
 	if (q_pfn >> 32) {
 		dev_err(&vp_dev->pci_dev->dev,
diff --git a/drivers/virtio/virtio_pci_modern.c
b/drivers/virtio/virtio_pci_modern.c
index 7d28f4c36fc2..5811691a90ec 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -274,6 +274,8 @@ static struct virtqueue *setup_vq(struct virtio_pci_device
*vp_dev,
 	if (!vq)
 		return ERR_PTR(-ENOMEM);
 
+	vq->num_max = num;
+
 	/* activate the queue */
 	vp_modern_set_queue_size(mdev, index, virtqueue_get_vring_size(vq));
 	vp_modern_queue_address(mdev, index, virtqueue_get_desc_addr(vq),
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 6a892c8ea16e..1a123b5e5371 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -2447,6 +2447,19 @@ void vring_transport_features(struct virtio_device *vdev)
 }
 EXPORT_SYMBOL_GPL(vring_transport_features);
 
+/**
+ * virtqueue_get_vring_max_size - return the max size of the virtqueue's
vring
+ * @_vq: the struct virtqueue containing the vring of interest.
+ *
+ * Returns the max 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_max_size(struct virtqueue *_vq)
+{
+	return _vq->num_max;
+}
+EXPORT_SYMBOL_GPL(virtqueue_get_vring_max_size);
+
 /**
  * virtqueue_get_vring_size - return the size of the virtqueue's vring
  * @_vq: the struct virtqueue containing the vring of interest.
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index cdb2a551257c..1153b093c53d 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -37,6 +37,7 @@ struct virtqueue {
 	struct virtio_device *vdev;
 	unsigned int index;
 	unsigned int num_free;
+	unsigned int num_max;
 	void *priv;
 	enum virtqueue_reset_stage reset;
 };
@@ -87,6 +88,7 @@ bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
 
 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
 
+unsigned int virtqueue_get_vring_max_size(struct virtqueue *vq);
 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
 
 bool virtqueue_is_broken(struct virtqueue *vq);
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 19/22] virtio: add helper virtio_set_max_ring_num()

Added helper virtio_set_max_ring_num() to set the upper limit of ring
num when creating a virtqueue.

Can be used to limit ring num before find_vqs() call. Or change ring num
when re-enable reset queue.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/virtio/virtio_ring.c  |  6 ++++++
 include/linux/virtio.h        |  1 +
 include/linux/virtio_config.h | 30 ++++++++++++++++++++++++++++++
 3 files changed, 37 insertions(+)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 1a123b5e5371..a77a82883e44 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -943,6 +943,9 @@ static struct virtqueue *vring_create_virtqueue_split(
 	size_t queue_size_in_bytes;
 	struct vring vring;
 
+	if (vdev->max_ring_num && num > vdev->max_ring_num)
+		num = vdev->max_ring_num;
+
 	/* We assume num is a power of 2. */
 	if (num & (num - 1)) {
 		dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
@@ -1692,6 +1695,9 @@ static struct virtqueue *vring_create_virtqueue_packed(
 	dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
 	size_t ring_size_in_bytes, event_size_in_bytes;
 
+	if (vdev->max_ring_num && num > vdev->max_ring_num)
+		num = vdev->max_ring_num;
+
 	ring_size_in_bytes = num * sizeof(struct vring_packed_desc);
 
 	ring = vring_alloc_queue(vdev, ring_size_in_bytes,
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
index 1153b093c53d..45525beb2ec4 100644
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -127,6 +127,7 @@ struct virtio_device {
 	struct list_head vqs;
 	u64 features;
 	void *priv;
+	u16 max_ring_num;
 };
 
 static inline struct virtio_device *dev_to_virtio(struct device *_dev)
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index cd7f7f44ce38..d7cb2d0341ee 100644
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -200,6 +200,36 @@ static inline bool virtio_has_dma_quirk(const struct
virtio_device *vdev)
 	return !virtio_has_feature(vdev, VIRTIO_F_ACCESS_PLATFORM);
 }
 
+/**
+ * virtio_set_max_ring_num - set max ring num
+ * @vdev: the device
+ * @num: max ring num. Zero clear the limit.
+ *
+ * When creating a virtqueue, use this value as the upper limit of ring num.
+ *
+ * Returns 0 on success or error status
+ */
+static inline
+int virtio_set_max_ring_num(struct virtio_device *vdev, u16 num)
+{
+	if (!num) {
+		vdev->max_ring_num = num;
+		return 0;
+	}
+
+	if (!virtio_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
+		if (!is_power_of_2(num)) {
+			num = __rounddown_pow_of_two(num);
+
+			if (!num)
+				return -EINVAL;
+		}
+	}
+
+	vdev->max_ring_num = num;
+	return 0;
+}
+
 static inline
 struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
 					vq_callback_t *c, const char *n)
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 20/22] virtio_net: set the default max ring num

Sets the default maximum ring num based on virtio_set_max_ring_num().

The default maximum ring num is 1024.

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

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index a4ffd7cdf623..77e61fe0b2ce 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -35,6 +35,8 @@ module_param(napi_tx, bool, 0644);
 #define GOOD_PACKET_LEN (ETH_HLEN + VLAN_HLEN + ETH_DATA_LEN)
 #define GOOD_COPY_LEN	128
 
+#define VIRTNET_DEFAULT_MAX_RING_NUM 1024
+
 #define VIRTNET_RX_PAD (NET_IP_ALIGN + NET_SKB_PAD)
 
 /* Amount of XDP headroom to prepend to packets for use by xdp_adjust_head */
@@ -3045,6 +3047,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi)
 			ctx[rxq2vq(i)] = true;
 	}
 
+	virtio_set_max_ring_num(vi->vdev, VIRTNET_DEFAULT_MAX_RING_NUM);
+
 	ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks,
 				  names, ctx, NULL);
 	if (ret)
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 21/22] virtio_net: get max ring size by virtqueue_get_vring_max_size()

Use virtqueue_get_vring_max_size() in virtnet_get_ringparam() to set
tx,rx_max_pending.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 77e61fe0b2ce..f9bb760c6dbd 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2302,10 +2302,10 @@ static void virtnet_get_ringparam(struct net_device
*dev,
 {
 	struct virtnet_info *vi = netdev_priv(dev);
 
-	ring->rx_max_pending = virtqueue_get_vring_size(vi->rq[0].vq);
-	ring->tx_max_pending = virtqueue_get_vring_size(vi->sq[0].vq);
-	ring->rx_pending = ring->rx_max_pending;
-	ring->tx_pending = ring->tx_max_pending;
+	ring->rx_max_pending = virtqueue_get_vring_max_size(vi->rq[0].vq);
+	ring->tx_max_pending = virtqueue_get_vring_max_size(vi->sq[0].vq);
+	ring->rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
+	ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
 }
 
 
-- 
2.31.0

Xuan Zhuo

2022-Feb-14 08:14 UTC

head link

[PATCH v5 22/22] virtio_net: support set_ringparam

Support set_ringparam based on virtio queue reset.

The rx,tx_pending required to be passed must be power of 2.

Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
---
 drivers/net/virtio_net.c | 50 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index f9bb760c6dbd..bf460ea87354 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2308,6 +2308,55 @@ static void virtnet_get_ringparam(struct net_device *dev,
 	ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
 }
 
+static int virtnet_set_ringparam(struct net_device *dev,
+				 struct ethtool_ringparam *ring,
+				 struct kernel_ethtool_ringparam *kernel_ring,
+				 struct netlink_ext_ack *extack)
+{
+	struct virtnet_info *vi = netdev_priv(dev);
+	u32 rx_pending, tx_pending;
+	int i, err;
+
+	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
+		return -EINVAL;
+
+	rx_pending = virtqueue_get_vring_size(vi->rq[0].vq);
+	tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
+
+	if (ring->rx_pending == rx_pending &&
+	    ring->tx_pending == tx_pending)
+		return 0;
+
+	if (ring->rx_pending > virtqueue_get_vring_max_size(vi->rq[0].vq))
+		return -EINVAL;
+
+	if (ring->tx_pending > virtqueue_get_vring_max_size(vi->sq[0].vq))
+		return -EINVAL;
+
+	if (!is_power_of_2(ring->rx_pending))
+		return -EINVAL;
+
+	if (!is_power_of_2(ring->tx_pending))
+		return -EINVAL;
+
+	for (i = 0; i < vi->max_queue_pairs; i++) {
+		if (ring->tx_pending != tx_pending) {
+			virtio_set_max_ring_num(vi->vdev, ring->tx_pending);
+			err = virtnet_tx_vq_reset(vi, i);
+			if (err)
+				return err;
+		}
+
+		if (ring->rx_pending != rx_pending) {
+			virtio_set_max_ring_num(vi->vdev, ring->rx_pending);
+			err = virtnet_rx_vq_reset(vi, i);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
 
 static void virtnet_get_drvinfo(struct net_device *dev,
 				struct ethtool_drvinfo *info)
@@ -2541,6 +2590,7 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
 	.get_drvinfo = virtnet_get_drvinfo,
 	.get_link = ethtool_op_get_link,
 	.get_ringparam = virtnet_get_ringparam,
+	.set_ringparam = virtnet_set_ringparam,
 	.get_strings = virtnet_get_strings,
 	.get_sset_count = virtnet_get_sset_count,
 	.get_ethtool_stats = virtnet_get_ethtool_stats,
-- 
2.31.0

Virtualization - Feb 2022 - [PATCH v5 04/22] virtio_ring: queue_reset: split: add __vring_init_virtqueue()

[PATCH v5 00/22] virtio pci support VIRTIO_F_RING_RESET

[PATCH v5 01/22] virtio_pci: struct virtio_pci_common_cfg add queue_notify_data

[PATCH v5 02/22] virtio: queue_reset: add VIRTIO_F_RING_RESET

[PATCH v5 03/22] virtio_ring: queue_reset: add function vring_setup_virtqueue()

[PATCH v5 04/22] virtio_ring: queue_reset: split: add __vring_init_virtqueue()

[PATCH v5 05/22] virtio_ring: queue_reset: split: support enable reset queue

[PATCH v5 06/22] virtio_ring: queue_reset: packed: support enable reset queue

[PATCH v5 07/22] virtio_ring: queue_reset: extract the release function of the vq ring

[PATCH v5 08/22] virtio_ring: queue_reset: add vring_release_virtqueue()

[PATCH v5 09/22] virtio: queue_reset: struct virtio_config_ops add callbacks for queue_reset

[PATCH v5 10/22] virtio_pci: queue_reset: update struct virtio_pci_common_cfg and option functions

[PATCH v5 11/22] virtio_pci: queue_reset: release vq by vp_dev->vqs

[PATCH v5 12/22] virtio_pci: queue_reset: setup_vq() support vring_setup_virtqueue()

[PATCH v5 13/22] virtio_pci: queue_reset: reserve vq->priv for re-enable queue

[PATCH v5 14/22] virtio_pci: queue_reset: support VIRTIO_F_RING_RESET

[PATCH v5 15/22] virtio: queue_reset: add helper

[PATCH v5 16/22] virtio_net: split free_unused_bufs()

[PATCH v5 17/22] virtio_net: support rx/tx queue reset

[PATCH v5 18/22] virtio: add helper virtqueue_get_vring_max_size()

[PATCH v5 19/22] virtio: add helper virtio_set_max_ring_num()

[PATCH v5 20/22] virtio_net: set the default max ring num

[PATCH v5 21/22] virtio_net: get max ring size by virtqueue_get_vring_max_size()

[PATCH v5 22/22] virtio_net: support set_ringparam