Commit e34f8725 authored by Rusty Russell's avatar Rusty Russell

virtio: Add transport feature handling stub for virtio_ring.

To prepare for virtio_ring transport feature bits, hook in a call in
all the users to manipulate them.  This currently just clears all the
bits, since it doesn't understand any features.
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent c624896e
......@@ -105,6 +105,9 @@ static void lg_finalize_features(struct virtio_device *vdev)
/* Second half of bitmap is features we accept. */
u8 *out_features = lg_features(desc) + desc->feature_len;
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
memset(out_features, 0, desc->feature_len);
bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
......
......@@ -95,6 +95,9 @@ static void kvm_finalize_features(struct virtio_device *vdev)
/* Second half of bitmap is features we accept. */
u8 *out_features = kvm_vq_features(desc) + desc->feature_len;
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
memset(out_features, 0, desc->feature_len);
bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
......
......@@ -99,6 +99,9 @@ static void vp_finalize_features(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
/* We only support 32 feature bits. */
BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
......
......@@ -18,6 +18,7 @@
*/
#include <linux/virtio.h>
#include <linux/virtio_ring.h>
#include <linux/virtio_config.h>
#include <linux/device.h>
#ifdef DEBUG
......@@ -323,4 +324,19 @@ void vring_del_virtqueue(struct virtqueue *vq)
}
EXPORT_SYMBOL_GPL(vring_del_virtqueue);
/* Manipulates transport-specific feature bits. */
void vring_transport_features(struct virtio_device *vdev)
{
unsigned int i;
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
switch (i) {
default:
/* We don't understand this bit. */
clear_bit(i, vdev->features);
}
}
}
EXPORT_SYMBOL_GPL(vring_transport_features);
MODULE_LICENSE("GPL");
......@@ -120,6 +120,8 @@ struct virtqueue *vring_new_virtqueue(unsigned int num,
void (*notify)(struct virtqueue *vq),
void (*callback)(struct virtqueue *vq));
void vring_del_virtqueue(struct virtqueue *vq);
/* Filter out transport-specific feature bits. */
void vring_transport_features(struct virtio_device *vdev);
irqreturn_t vring_interrupt(int irq, void *_vq);
#endif /* __KERNEL__ */
......
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