From 7f31fe05000af54e1af81f65a96cab90db8d7ed8 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 29 May 2008 11:08:01 +0200 Subject: virtio_config: fix len calculation of config elements Rusty, This patch is a prereq for the virtio_blk blocksize patch, please apply it first. Adding an u32 value to the virtio_blk_config unconvered a small bug the config space defintions: v is a pointer, to we have to use sizeof(*v) instead of sizeof(v). Signed-off-by: Christian Borntraeger Signed-off-by: Rusty Russell --- include/linux/virtio_config.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/virtio_config.h') diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 50db245c81a..71d6c102497 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -99,7 +99,7 @@ static inline bool virtio_has_feature(const struct virtio_device *vdev, * The return value is -ENOENT if the feature doesn't exist. Otherwise * the config value is copied into whatever is pointed to by v. */ #define virtio_config_val(vdev, fbit, offset, v) \ - virtio_config_buf((vdev), (fbit), (offset), (v), sizeof(v)) + virtio_config_buf((vdev), (fbit), (offset), (v), sizeof(*v)) static inline int virtio_config_buf(struct virtio_device *vdev, unsigned int fbit, -- cgit v1.2.3 From b4f68be6c5d507afdcd74f5be3df0b1209cda503 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 30 May 2008 15:09:45 -0500 Subject: virtio: force callback on empty. virtio allows drivers to suppress callbacks (ie. interrupts) for efficiency (no locking, it's just an optimization). There's a similar mechanism for the host to suppress notifications coming from the guest: in that case, we ignore the suppression if the ring is completely full. It turns out that life is simpler if the host similarly ignores callback suppression when the ring is completely empty: the network driver wants to free up old packets in a timely manner, and otherwise has to use a timer to poll. We have to remove the code which ignores interrupts when the driver has disabled them (again, it had no locking and hence was unreliable anyway). Signed-off-by: Rusty Russell --- include/linux/virtio_config.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/virtio_config.h') diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 71d6c102497..f364bbf63c3 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -15,6 +15,10 @@ /* We've given up on this device. */ #define VIRTIO_CONFIG_S_FAILED 0x80 +/* Do we get callbacks when the ring is completely used, even if we've + * suppressed them? */ +#define VIRTIO_F_NOTIFY_ON_EMPTY 24 + #ifdef __KERNEL__ #include -- cgit v1.2.3