search for: virtqueue_get_buf

..._ring: change host notification API virtio_ring: let virtqueue_{kick()/notify()} return a bool virtio_net: verify if virtqueue_kick() succeeded virtio_test: verify if virtqueue_kick() succeeded virtio_ring: add new function virtqueue_is_broken() virtio_blk: verify if queue is broken after virtqueue_get_buf() virtio_console: verify if queue is broken after virtqueue_get_buf() virtio_net: verify if queue is broken after virtqueue_get_buf() virtio_scsi: verify if queue is broken after virtqueue_get_buf() drivers/block/virtio_blk.c | 2 ++ drivers/char/virtio_console.c | 6...

..._ring: change host notification API virtio_ring: let virtqueue_{kick()/notify()} return a bool virtio_net: verify if virtqueue_kick() succeeded virtio_test: verify if virtqueue_kick() succeeded virtio_ring: add new function virtqueue_is_broken() virtio_blk: verify if queue is broken after virtqueue_get_buf() virtio_console: verify if queue is broken after virtqueue_get_buf() virtio_net: verify if queue is broken after virtqueue_get_buf() virtio_scsi: verify if queue is broken after virtqueue_get_buf() drivers/block/virtio_blk.c | 2 ++ drivers/char/virtio_console.c | 6...

On Wed, Nov 20, 2013 at 07:08:50AM -0500, Jason Wang wrote: > > > ----- ???? ----- > > On Wed, Nov 20, 2013 at 05:07:26PM +0800, Jason Wang wrote: > > > We need decrease the rq->num after we can get a buf through > > > virtqueue_get_buf() even if we could not allocate frag skb. Otherwise, the > > > refill routine won't be triggered under heavy memory stress since the > > > driver may > > > still think there's enough room. > > > > > > This bug was introduced by commit 2613af0ed1...

We need to drop the refcnt of page when we fail to allocate an skb for frag list, otherwise it will be leaked. The bug was introduced by commit 2613af0ed18a11d5c566a81f9a6510b73180660a ("virtio_net: migrate mergeable rx buffers to page frag allocators"). Cc: Michael Dalton <mwdalton at google.com> Cc: Eric Dumazet <edumazet at google.com> Cc: Rusty Russell <rusty at

On Wed, Nov 20, 2013 at 07:08:50AM -0500, Jason Wang wrote: > > > ----- ???? ----- > > On Wed, Nov 20, 2013 at 05:07:26PM +0800, Jason Wang wrote: > > > We need decrease the rq->num after we can get a buf through > > > virtqueue_get_buf() even if we could not allocate frag skb. Otherwise, the > > > refill routine won't be triggered under heavy memory stress since the > > > driver may > > > still think there's enough room. > > > > > > This bug was introduced by commit 2613af0ed1...

We need to drop the refcnt of page when we fail to allocate an skb for frag list, otherwise it will be leaked. The bug was introduced by commit 2613af0ed18a11d5c566a81f9a6510b73180660a ("virtio_net: migrate mergeable rx buffers to page frag allocators"). Cc: Michael Dalton <mwdalton at google.com> Cc: Eric Dumazet <edumazet at google.com> Cc: Rusty Russell <rusty at

On Fri, Jun 09, 2017 at 06:41:41PM +0800, Wei Wang wrote: > - if (!virtqueue_indirect_desc_table_add(vq, desc, num)) { > + if (!virtqueue_indirect_desc_table_add(vq, desc, *num)) { > virtqueue_kick(vq); > - wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > - vb->balloon_page_chunk.chunk_num = 0; > + if (busy_wait) > + while (!virtqueue_get_buf(vq, &len) && > + !virtqueue_is_broken(vq)) > + cpu_relax(); > + else > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); Thi...

On Fri, Jun 09, 2017 at 06:41:41PM +0800, Wei Wang wrote: > - if (!virtqueue_indirect_desc_table_add(vq, desc, num)) { > + if (!virtqueue_indirect_desc_table_add(vq, desc, *num)) { > virtqueue_kick(vq); > - wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > - vb->balloon_page_chunk.chunk_num = 0; > + if (busy_wait) > + while (!virtqueue_get_buf(vq, &len) && > + !virtqueue_is_broken(vq)) > + cpu_relax(); > + else > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); Thi...

On Wed, Nov 20, 2013 at 05:07:26PM +0800, Jason Wang wrote: > We need decrease the rq->num after we can get a buf through > virtqueue_get_buf() even if we could not allocate frag skb. Otherwise, the > refill routine won't be triggered under heavy memory stress since the driver may > still think there's enough room. > > This bug was introduced by commit 2613af0ed18a11d5c566a81f9a6510b73180660a > (virtio_net: migrat...

On Wed, Nov 20, 2013 at 05:07:26PM +0800, Jason Wang wrote: > We need decrease the rq->num after we can get a buf through > virtqueue_get_buf() even if we could not allocate frag skb. Otherwise, the > refill routine won't be triggered under heavy memory stress since the driver may > still think there's enough room. > > This bug was introduced by commit 2613af0ed18a11d5c566a81f9a6510b73180660a > (virtio_net: migrat...

If virtqueue_get_buf() returned with a NULL pointer avoid a possibly endless loop by checking for a broken virtqueue. Signed-off-by: Heinz Graalfs <graalfs at linux.vnet.ibm.com> --- drivers/scsi/virtio_scsi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/virtio_scsi.c b/dri...

If virtqueue_get_buf() returned with a NULL pointer avoid a possibly endless loop by checking for a broken virtqueue. Signed-off-by: Heinz Graalfs <graalfs at linux.vnet.ibm.com> --- drivers/scsi/virtio_scsi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virti...

...e is now flagged as 'broken'. Patches [3,4] add code to verify host kicks by testing the return value of virtqueue_kick() in order to avoid potential loops. Patch [5] adds a new function virtqueue_is_broken(). This function should be used to verify the state of a virtqueue when a previous virtqueue_get_buf() returned a NULL pointer. Patch [6,7,8,9] add virtqueue_is_broken() calls to handle potential errors when a virtqueue_bet_buf() doesn't deliver any more buffers. Heinz Graalfs (9): virtio_ring: change host notification API virtio_ring: let virtqueue_{kick()/notify()} return a bool vir...

...e is now flagged as 'broken'. Patches [3,4] add code to verify host kicks by testing the return value of virtqueue_kick() in order to avoid potential loops. Patch [5] adds a new function virtqueue_is_broken(). This function should be used to verify the state of a virtqueue when a previous virtqueue_get_buf() returned a NULL pointer. Patch [6,7,8,9] add virtqueue_is_broken() calls to handle potential errors when a virtqueue_bet_buf() doesn't deliver any more buffers. Heinz Graalfs (9): virtio_ring: change host notification API virtio_ring: let virtqueue_{kick()/notify()} return a bool vir...

...en. Just an idea, up to you > > whether to do it. > > > > > + > > > + /* If batching is in use, we batch the sgs till the vq is full. */ > > > + if (!batch || !vq->num_free) { > > > + virtqueue_kick(vq); > > > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > > > + /* Release all the entries if there are */ > > Meaning > > Account for all used entries if any > > ? > > > > > + while (virtqueue_get_buf(vq, &len)) > > > + ; > > > > Above code is reused below. Add a...

...en. Just an idea, up to you > > whether to do it. > > > > > + > > > + /* If batching is in use, we batch the sgs till the vq is full. */ > > > + if (!batch || !vq->num_free) { > > > + virtqueue_kick(vq); > > > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > > > + /* Release all the entries if there are */ > > Meaning > > Account for all used entries if any > > ? > > > > > + while (virtqueue_get_buf(vq, &len)) > > > + ; > > > > Above code is reused below. Add a...

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

...> > > > > > > > + > > > > > + /* If batching is in use, we batch the sgs till the vq is full. */ > > > > > + if (!batch || !vq->num_free) { > > > > > + virtqueue_kick(vq); > > > > > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > > > > > + /* Release all the entries if there are */ > > > > Meaning > > > > Account for all used entries if any > > > > ? > > > > > > > > > + while (virtqueue_get_buf(vq, &len)) > > > &...

...> > > > > > > > + > > > > > + /* If batching is in use, we batch the sgs till the vq is full. */ > > > > > + if (!batch || !vq->num_free) { > > > > > + virtqueue_kick(vq); > > > > > + wait_event(vb->acked, virtqueue_get_buf(vq, &len)); > > > > > + /* Release all the entries if there are */ > > > > Meaning > > > > Account for all used entries if any > > > > ? > > > > > > > > > + while (virtqueue_get_buf(vq, &len)) > > > &...