From e34f87256794b87e7f4a8f1812538be7b7b5214c Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 25 Jul 2008 12:06:13 -0500 Subject: [PATCH] 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: Rusty Russell --- drivers/lguest/lguest_device.c | 3 +++ drivers/s390/kvm/kvm_virtio.c | 3 +++ drivers/virtio/virtio_pci.c | 3 +++ drivers/virtio/virtio_ring.c | 16 ++++++++++++++++ include/linux/virtio_ring.h | 2 ++ 5 files changed, 27 insertions(+) diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index 54fdc2aa480..37344aaee22 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -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++) { diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c index 5953510e7d5..79954bd6bfa 100644 --- a/drivers/s390/kvm/kvm_virtio.c +++ b/drivers/s390/kvm/kvm_virtio.c @@ -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++) { diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 9855975a72a..c7dc37c7cce 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -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); diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 21d9a62767a..6eb5303fed1 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -18,6 +18,7 @@ */ #include #include +#include #include #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"); diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h index abe481ed990..c4a598fb382 100644 --- a/include/linux/virtio_ring.h +++ b/include/linux/virtio_ring.h @@ -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__ */ -- 2.41.1