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virtio_pci: free up vq->priv

RFC PATCH New Michael S. Tsirkin 1 participant 2 messages Dec 3, 2014 virtio core

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Michael S. Tsirkin

author maintainer
#0 lore raw

RFC PATCH 1/2 virtio_pci: free up vq->priv

We don't need to go from vq to vq info on data path, so using direct vq->priv pointer for that seems like a waste.

Let's build an array of vq infos, then we can use vq->index for that lookup.

Signed-off-by Michael S. Tsirkin <[email protected]>
---
 drivers/virtio/virtio_pci.c | 38 +++++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 15 deletions(-)
drivers/virtio/virtio_pci.c +12 -4
index 40b4d47..91b479b 100644
@@ -47,6 +58,9 @@ struct virtio_pci_device {
 	spinlock_t lock;
 	struct list_head virtqueues;
 
+	/* array of all queues for house-keeping */
+	struct virtio_pci_vq_info **vqs;
+
 	/* MSI-X support */
 	int msix_enabled;
 	int intx_enabled;

@@ -429,7 +432,6 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
 		goto out_activate_queue;
 	}
 
-	vq->priv = info;
 	info->vq = vq;
 
 	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {

@@ -449,6 +451,7 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
 		INIT_LIST_HEAD(&info->node);
 	}
 
+	vp_dev->vqs[index] = info;
 	return vq;
 
 out_assign:

@@ -464,7 +467,7 @@ out_info:
 static void vp_del_vq(struct virtqueue *vq)
 {
 	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
-	struct virtio_pci_vq_info *info = vq->priv;
+	struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
 	unsigned int num = vring_get_num(vq);
 	void *queue = vring_get_pages(vq);
 	unsigned long flags, size;

@@ -501,7 +504,7 @@ static void vp_del_vqs(struct virtio_device *vdev)
 	struct virtio_pci_vq_info *info;
 
 	list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
-		info = vq->priv;
+		info = vp_dev->vqs[vq->index];
 		if (vp_dev->per_vq_vectors &&
 			info->msix_vector != VIRTIO_MSI_NO_VECTOR)
 			free_irq(vp_dev->msix_entries[info->msix_vector].vector,

@@ -511,6 +514,7 @@ static void vp_del_vqs(struct virtio_device *vdev)
 	vp_dev->per_vq_vectors = false;
 
 	vp_free_vectors(vdev);
+	kfree(vp_dev->vqs);
 }
 
 static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,

@@ -524,6 +528,10 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 	u16 msix_vec;
 	int i, err, nvectors, allocated_vectors;
 
+	vp_dev->vqs = kmalloc(nvqs * sizeof *vp_dev->vqs, GFP_KERNEL);
+	if (!vdev->vqs)
+		return -ENOMEM;
+
 	if (!use_msix) {
 		/* Old style: one normal interrupt for change and all vqs. */
 		err = vp_request_intx(vdev);

@@ -628,7 +636,7 @@ static int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
 {
 	struct virtio_device *vdev = vq->vdev;
 	struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-	struct virtio_pci_vq_info *info = vq->priv;
+	struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
 	struct cpumask *mask;
 	unsigned int irq;
Signature · 1 line
MST
author maintainer
#1 lore raw

RFC PATCH 2/2 virtio_pci: use priv for vq notification

slightly reduce the amount of pointer chasing this needs to do. More importantly, this will easily generalize to virtio 1.0.

Signed-off-by Michael S. Tsirkin <[email protected]>
---
 drivers/virtio/virtio_pci.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
drivers/virtio/virtio_pci.c +3 -3
index 91b479b..5791a93 100644
@@ -198,11 +198,9 @@ static void vp_reset(struct virtio_device *vdev)
 /* the notify function used when creating a virt queue */
 static bool vp_notify(struct virtqueue *vq)
 {
-	struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
-
 	/* we write the queue's selector into the notification register to
 	 * signal the other end */
-	iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY);
+	iowrite16(vq->index, (void __iomem *)vq->priv);
 	return true;
 }
 

@@ -432,6 +430,8 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
 		goto out_activate_queue;
 	}
 
+	vq->priv = (void __force *)vp_dev->ioaddr +
+		VIRTIO_PCI_QUEUE_NOTIFY;
 	info->vq = vq;
 
 	if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
Signature · 1 line
MST