similar to: [PATCH 1/5] virtio: document functions better.

The old documentation is left over from when we used a structure with strategy pointers. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> --- include/linux/virtio.h | 130 ++++++++++++++++++++++++++++++++----------------- 1 file changed, 87 insertions(+), 43 deletions(-) diff --git a/include/linux/virtio.h b/include/linux/virtio.h --- a/include/linux/virtio.h +++

The old documentation is left over from when we used a structure with strategy pointers. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> --- include/linux/virtio.h | 130 ++++++++++++++++++++++++++++++++----------------- 1 file changed, 87 insertions(+), 43 deletions(-) diff --git a/include/linux/virtio.h b/include/linux/virtio.h --- a/include/linux/virtio.h +++

There are lots of mismatches between comments and codes, this patch do these comment fixes. Signed-off-by: Jiang Biao <benbjiang at tencent.com> --- drivers/virtio/virtio_ring.c | 27 ++++++++++++++------------- 1 file changed, 14 insertions(+), 13 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 5df92c308286..3794c7666a99 100644 ---

Remove wrapper functions. This makes the allocation type explicit in all callers; I used GPF_KERNEL where it seemed obvious, left it at GFP_ATOMIC otherwise. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -171,7 +171,7 @@ static bool

Remove wrapper functions. This makes the allocation type explicit in all callers; I used GPF_KERNEL where it seemed obvious, left it at GFP_ATOMIC otherwise. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -171,7 +171,7 @@ static bool

This adds a way to check ring empty state after enable_cb outside any locks. Will be used by virtio_net. Note: there's room for more optimization: caller is likely to have a memory barrier already, which means we might be able to get rid of a barrier here. Deferring this optimization until we do some benchmarking. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

This adds a way to check ring empty state after enable_cb outside any locks. Will be used by virtio_net. Note: there's room for more optimization: caller is likely to have a memory barrier already, which means we might be able to get rid of a barrier here. Deferring this optimization until we do some benchmarking. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

On Sat, Oct 11, 2014 at 03:16:44PM +0800, Jason Wang wrote: > Below should be useful for some experiments Jason is doing. > I thought I'd send it out for early review/feedback. > > event idx feature allows us to defer interrupts until > a specific # of descriptors were used. > Sometimes it might be useful to get an interrupt after > a specific descriptor, regardless. >

This adds a way to check ring empty state after enable_cb outside any locks. Will be used by virtio_net. Note: there's room for more optimization: caller is likely to have a memory barrier already, which means we might be able to get rid of a barrier here. Deferring this optimization until we do some benchmarking. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

This adds a way to check ring empty state after enable_cb outside any locks. Will be used by virtio_net. Note: there's room for more optimization: caller is likely to have a memory barrier already, which means we might be able to get rid of a barrier here. Deferring this optimization until we do some benchmarking. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> ---

Below should be useful for some experiments Jason is doing. I thought I'd send it out for early review/feedback. event idx feature allows us to defer interrupts until a specific # of descriptors were used. Sometimes it might be useful to get an interrupt after a specific descriptor, regardless. This adds a descriptor flag for this, and an API to create an urgent output descriptor. This is

Below should be useful for some experiments Jason is doing. I thought I'd send it out for early review/feedback. event idx feature allows us to defer interrupts until a specific # of descriptors were used. Sometimes it might be useful to get an interrupt after a specific descriptor, regardless. This adds a descriptor flag for this, and an API to create an urgent output descriptor. This is

This implements a virtio simulator: - adds stubs for enough support functions to compile virtio ring in userspace. - Adds a stub vhost based module this can talk to. This should help us decide things like which ring layout works best. Communication is currently done using an eventfd descriptor. This means there's a shared spinlock there: what I would like to do in the future, is run this

This implements a virtio simulator: - adds stubs for enough support functions to compile virtio ring in userspace. - Adds a stub vhost based module this can talk to. This should help us decide things like which ring layout works best. Communication is currently done using an eventfd descriptor. This means there's a shared spinlock there: what I would like to do in the future, is run this

virtio net will never try to overflow the TX ring, so the only reason add_buf may fail is out of memory. Thus, we can not stop the device until some request completes - there's no guarantee anything at all is outstanding. Make the error message clearer as well: error here does not indicate queue full. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c |

virtio net will never try to overflow the TX ring, so the only reason add_buf may fail is out of memory. Thus, we can not stop the device until some request completes - there's no guarantee anything at all is outstanding. Make the error message clearer as well: error here does not indicate queue full. Signed-off-by: Michael S. Tsirkin <mst at redhat.com> --- drivers/net/virtio_net.c |

The virtio block device holds a lock during I/O request processing. Kicking the virtqueue while the lock is held results in long lock hold times and increases contention for the lock. This patch modifies virtqueue_kick() to optionally release a lock while notifying the host. Virtio block is modified to pass in its lock. This allows other vcpus to queue I/O requests during the time spent

The virtio block device holds a lock during I/O request processing. Kicking the virtqueue while the lock is held results in long lock hold times and increases contention for the lock. This patch modifies virtqueue_kick() to optionally release a lock while notifying the host. Virtio block is modified to pass in its lock. This allows other vcpus to queue I/O requests during the time spent

virtqueue ops were introduced in the hope that we'll have multiple implementations besides virtio_ring, but none have surfaced so far, and given that existing virtio ring is deployed in production we are likely stuck with it now, so this layer just adds complexity and overhead. Further, the need to pass vq twice to each call (as in dev->vq->vq_ops->kick(dev->vq) ) adds potential

virtqueue ops were introduced in the hope that we'll have multiple implementations besides virtio_ring, but none have surfaced so far, and given that existing virtio ring is deployed in production we are likely stuck with it now, so this layer just adds complexity and overhead. Further, the need to pass vq twice to each call (as in dev->vq->vq_ops->kick(dev->vq) ) adds potential