(MST, is this what you were thinking?)
This uses the previously-unused field for "queue_notify". This contains
the offset from the notification area given by the VIRTIO_PCI_CAP_NOTIFY_CFG
header.
(A device can still make them all overlap if it wants, since the queue
index is written: it can still distinguish different notifications).
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_pci.c | 61 +++++++++++++++++++++++++++------------
include/uapi/linux/virtio_pci.h | 2 +-
2 files changed, 44 insertions(+), 19 deletions(-)
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index f252afe..d492361 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -37,11 +37,15 @@ struct virtio_pci_device {
struct virtio_pci_common_cfg __iomem *common;
/* Where to read and clear interrupt */
u8 __iomem *isr;
- /* Write the virtqueue index here to notify device of activity. */
- __le16 __iomem *notify;
+ /* Write the vq index here to notify device of activity. */
+ void __iomem *notify_base;
/* Device-specific data. */
void __iomem *device;
+ /* So we can sanity-check accesses. */
+ size_t notify_len;
+ size_t device_len;
+
/* a list of queues so we can dispatch IRQs */
spinlock_t lock;
struct list_head virtqueues;
@@ -84,6 +88,9 @@ struct virtio_pci_vq_info {
/* the list node for the virtqueues list */
struct list_head node;
+ /* Notify area for this vq. */
+ u16 __iomem *notify;
+
/* MSI-X vector (or none) */
unsigned msix_vector;
};
@@ -240,11 +247,11 @@ static void vp_reset(struct virtio_device *vdev)
/* the notify function used when creating a virt queue */
static void vp_notify(struct virtqueue *vq)
{
- struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+ struct virtio_pci_vq_info *info = vq->priv;
- /* we write the queue's selector into the notification register to
- * signal the other end */
- iowrite16(vq->index, vp_dev->notify);
+ /* we write the queue selector into the notification register
+ * to signal the other end */
+ iowrite16(vq->index, info->notify);
}
/* Handle a configuration change: Tell driver if it wants to know. */
@@ -460,7 +467,7 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
struct virtio_pci_vq_info *info;
struct virtqueue *vq;
u16 num;
- int err;
+ int err, off;
if (index >= ioread16(&vp_dev->common->num_queues))
return ERR_PTR(-ENOENT);
@@ -492,6 +499,17 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
info->msix_vector = msix_vec;
+ /* get offset of notification byte for this virtqueue */
+ off = ioread16(&vp_dev->common->queue_notify);
+ if (off > vp_dev->notify_len) {
+ dev_warn(&vp_dev->pci_dev->dev,
+ "bad notification offset %u for queue %u (> %u)",
+ off, index, vp_dev->notify_len);
+ err = -EINVAL;
+ goto out_info;
+ }
+ info->notify = vp_dev->notify_base + off;
+
info->queue = alloc_virtqueue_pages(&num);
if (info->queue == NULL) {
err = -ENOMEM;
@@ -787,7 +805,8 @@ static void virtio_pci_release_dev(struct device *_d)
*/
}
-static void __iomem *map_capability(struct pci_dev *dev, int off, size_t expect)
+static void __iomem *map_capability(struct pci_dev *dev, int off, size_t minlen,
+ size_t *len)
{
u8 bar;
u32 offset, length;
@@ -800,13 +819,16 @@ static void __iomem *map_capability(struct pci_dev *dev, int off, size_t expect)
pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap, length),
&length);
- if (length < expect) {
+ if (length < minlen) {
dev_err(&dev->dev,
- "virtio_pci: small capability len %u (%u expected)\n",
- length, expect);
+ "virtio_pci: small capability len %u (%zu expected)\n",
+ length, minlen);
return NULL;
}
+ if (len)
+ *len = length;
+
/* We want uncachable mapping, even if bar is cachable. */
p = pci_iomap_range(dev, bar, offset, length, PAGE_SIZE, true);
if (!p)
@@ -883,16 +905,19 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
err = -EINVAL;
vp_dev->common = map_capability(pci_dev, common,
- sizeof(struct virtio_pci_common_cfg));
+ sizeof(struct virtio_pci_common_cfg),
+ NULL);
if (!vp_dev->common)
goto out_req_regions;
- vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8));
+ vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8), NULL);
if (!vp_dev->isr)
goto out_map_common;
- vp_dev->notify = map_capability(pci_dev, notify, sizeof(u16));
- if (!vp_dev->notify)
+ vp_dev->notify_base = map_capability(pci_dev, notify, sizeof(u8),
+ &vp_dev->notify_len);
+ if (!vp_dev->notify_len)
goto out_map_isr;
- vp_dev->device = map_capability(pci_dev, device, 0);
+ vp_dev->device = map_capability(pci_dev, device, 0,
+ &vp_dev->device_len);
if (!vp_dev->device)
goto out_map_notify;
@@ -917,7 +942,7 @@ out_set_drvdata:
pci_set_drvdata(pci_dev, NULL);
pci_iounmap(pci_dev, vp_dev->device);
out_map_notify:
- pci_iounmap(pci_dev, vp_dev->notify);
+ pci_iounmap(pci_dev, vp_dev->notify_base);
out_map_isr:
pci_iounmap(pci_dev, vp_dev->isr);
out_map_common:
@@ -940,7 +965,7 @@ static void virtio_pci_remove(struct pci_dev *pci_dev)
vp_del_vqs(&vp_dev->vdev);
pci_set_drvdata(pci_dev, NULL);
pci_iounmap(pci_dev, vp_dev->device);
- pci_iounmap(pci_dev, vp_dev->notify);
+ pci_iounmap(pci_dev, vp_dev->notify_base);
pci_iounmap(pci_dev, vp_dev->isr);
pci_iounmap(pci_dev, vp_dev->common);
pci_release_regions(pci_dev);
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index b334cd9..23b90cb 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -144,13 +144,13 @@ struct virtio_pci_common_cfg {
__le16 num_queues; /* read-only */
__u8 device_status; /* read-write */
__u8 unused1;
- __le16 unused2;
/* About a specific virtqueue. */
__le16 queue_select; /* read-write */
__le16 queue_size; /* read-write, power of 2. */
__le16 queue_msix_vector;/* read-write */
__le16 queue_enable; /* read-write */
+ __le16 queue_notify; /* read-only */
__le64 queue_desc; /* read-write */
__le64 queue_avail; /* read-write */
__le64 queue_used; /* read-write */
--
1.7.10.4
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