1) Drop the FIXME reference to BIR, just use BAR.
2) Make queue addresses explicit: desc/avail/used.
3) Add an explicit number of queues.
4) Have explicit queue_enable, which can double as a method to disable
all activity on a queue (write 0, read until 0).
I also noticed that the 64-bit queue_address was at offset 28 (0x1C),
which is unusual, so add more padding to take the first 64-bit value
to offset 32 (0x20).
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
---
drivers/virtio/virtio_pci.c | 48 +++++++++++++++++++++++++++++++--------
include/uapi/linux/virtio_pci.h | 11 +++++----
2 files changed, 46 insertions(+), 13 deletions(-)
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index b86b99c..0169531 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -457,13 +457,14 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
u16 num;
int err;
+ if (index >= ioread16(&vp_dev->common->num_queues))
+ return ERR_PTR(-ENOENT);
+
/* Select the queue we're interested in */
iowrite16(index, &vp_dev->common->queue_select);
- switch (ioread64(&vp_dev->common->queue_address)) {
- case 0xFFFFFFFFFFFFFFFFULL:
- return ERR_PTR(-ENOENT);
- case 0:
+ /* Sanity check */
+ switch (ioread64(&vp_dev->common->queue_desc)) {
/* Uninitialized. Excellent. */
break;
default:
@@ -522,9 +523,11 @@ static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
}
/* Activate the queue. */
- iowrite64(virt_to_phys(info->queue), &vp_dev->common->queue_address);
- iowrite16(SMP_CACHE_BYTES, &vp_dev->common->queue_align);
iowrite16(num, &vp_dev->common->queue_size);
+ iowrite64(virt_to_phys(vq->vring.desc), &vp_dev->common->queue_desc);
+ iowrite64(virt_to_phys(vq->vring.avail), &vp_dev->common->queue_avail);
+ iowrite64(virt_to_phys(vq->vring.used), &vp_dev->common->queue_used);
+ iowrite8(1, &vp_dev->common->queue_enable);
return vq;
@@ -537,6 +540,29 @@ out_info:
return ERR_PTR(err);
}
+static void vp_vq_disable(struct virtio_pci_device *vp_dev,
+ struct virtqueue *vq)
+{
+ unsigned long end;
+
+ /* Select the queue */
+ iowrite16(vq->index, &vp_dev->common->queue_select);
+
+ /* Disable it */
+ iowrite16(0, &vp_dev->common->queue_enable);
+
+ /* It's almost certainly synchronous, but just in case. */
+ end = jiffies + HZ/2;
+ while (ioread16(&vp_dev->common->queue_enable) != 0) {
+ if (time_after(jiffies, end)) {
+ dev_warn(&vp_dev->pci_dev->dev,
+ "virtio_pci: disable ignored\n");
+ break;
+ }
+ cpu_relax();
+ }
+}
+
static void vp_del_vq(struct virtqueue *vq)
{
struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
@@ -547,7 +573,10 @@ static void vp_del_vq(struct virtqueue *vq)
list_del(&info->node);
spin_unlock_irqrestore(&vp_dev->lock, flags);
- /* Select and deactivate the queue */
+ /* It should be quiescent, but disable first just in case. */
+ vp_vq_disable(vp_dev, vq);
+
+ /* Select the queue */
iowrite16(vq->index, &vp_dev->common->queue_select);
if (vp_dev->msix_enabled) {
@@ -560,9 +589,10 @@ static void vp_del_vq(struct virtqueue *vq)
vring_del_virtqueue(vq);
/* This is for our own benefit, not the device's! */
- iowrite64(0, &vp_dev->common->queue_address);
iowrite16(0, &vp_dev->common->queue_size);
- iowrite16(0, &vp_dev->common->queue_align);
+ iowrite64(0, &vp_dev->common->queue_desc);
+ iowrite64(0, &vp_dev->common->queue_avail);
+ iowrite64(0, &vp_dev->common->queue_used);
free_pages_exact(info->queue, size);
kfree(info);
diff --git a/include/uapi/linux/virtio_pci.h b/include/uapi/linux/virtio_pci.h
index 0d12828..b334cd9 100644
--- a/include/uapi/linux/virtio_pci.h
+++ b/include/uapi/linux/virtio_pci.h
@@ -128,7 +128,6 @@ struct virtio_pci_cap {
u8 cap_vndr; /* Generic PCI field: PCI_CAP_ID_VNDR */
u8 cap_next; /* Generic PCI field: next ptr. */
u8 cfg_type; /* One of the VIRTIO_PCI_CAP_*_CFG. */
-/* FIXME: Should we use a bir, instead of raw bar number? */
u8 bar; /* Where to find it. */
__le32 offset; /* Offset within bar. */
__le32 length; /* Length. */
@@ -142,14 +141,18 @@ struct virtio_pci_common_cfg {
__le32 guest_feature_select; /* read-write */
__le32 guest_feature; /* read-only */
__le16 msix_config; /* read-write */
+ __le16 num_queues; /* read-only */
__u8 device_status; /* read-write */
- __u8 unused;
+ __u8 unused1;
+ __le16 unused2;
/* About a specific virtqueue. */
__le16 queue_select; /* read-write */
- __le16 queue_align; /* read-write, power of 2. */
__le16 queue_size; /* read-write, power of 2. */
__le16 queue_msix_vector;/* read-write */
- __le64 queue_address; /* read-write: 0xFFFFFFFFFFFFFFFF == DNE. */
+ __le16 queue_enable; /* read-write */
+ __le64 queue_desc; /* read-write */
+ __le64 queue_avail; /* read-write */
+ __le64 queue_used; /* read-write */
};
#endif /* _UAPI_LINUX_VIRTIO_PCI_H */
--
1.7.10.4
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