similar to: [PATCH] virtio_rng: dont use vmalloced addresses for virtio

This helper returns 1 if a call to add_buf will not fail with -ENOSPC. This will help callers that do while(1) { alloc() if (add_buf()) { free(); break; } } This will result in one less alloc/free exercise. Signed-off-by: Amit Shah <amit.shah at redhat.com> --- drivers/virtio/virtio_ring.c | 8 ++++++++ include/linux/virtio.h | 5 +++++ 2 files changed, 13

This helper returns 1 if a call to add_buf will not fail with -ENOSPC. This will help callers that do while(1) { alloc() if (add_buf()) { free(); break; } } This will result in one less alloc/free exercise. Signed-off-by: Amit Shah <amit.shah at redhat.com> --- drivers/virtio/virtio_ring.c | 8 ++++++++ include/linux/virtio.h | 5 +++++ 2 files changed, 13

From 2334d90a3b9f8b9207163e9e0fad714e88a28771 Mon Sep 17 00:00:00 2001 From: Rusty Russell <rusty@rustcorp.com.au> Date: Wed, 7 Nov 2007 21:02:22 +1100 Subject: [PATCH] virtio: An entropy device, as suggested by hpa. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- Documentation/lguest/lguest.c | 53 +++++++++++++++ drivers/char/hw_random/Kconfig | 10 +++

From 2334d90a3b9f8b9207163e9e0fad714e88a28771 Mon Sep 17 00:00:00 2001 From: Rusty Russell <rusty@rustcorp.com.au> Date: Wed, 7 Nov 2007 21:02:22 +1100 Subject: [PATCH] virtio: An entropy device, as suggested by hpa. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- Documentation/lguest/lguest.c | 53 +++++++++++++++ drivers/char/hw_random/Kconfig | 10 +++

This API change means that virtio_net can tell how much capacity remains for buffers. It's necessarily fuzzy, since VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors in one, *if* we can kmalloc. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Cc: Dinesh Subhraveti <dineshs at us.ibm.com> --- drivers/block/virtio_blk.c | 2 +-

This API change means that virtio_net can tell how much capacity remains for buffers. It's necessarily fuzzy, since VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors in one, *if* we can kmalloc. Signed-off-by: Rusty Russell <rusty at rustcorp.com.au> Cc: Dinesh Subhraveti <dineshs at us.ibm.com> --- drivers/block/virtio_blk.c | 2 +-

Rusty, This patch changes the virtio_rng to a callback without a return value. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> --- drivers/char/hw_random/virtio-rng.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) Index: kvm/drivers/char/hw_random/virtio-rng.c =================================================================== ---

Rusty, This patch changes the virtio_rng to a callback without a return value. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> --- drivers/char/hw_random/virtio-rng.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) Index: kvm/drivers/char/hw_random/virtio-rng.c =================================================================== ---

Rusty, I have seen an oops triggered by the following bug statement in virtio-rng: if (vq->vq_ops->add_buf(vq, &sg, 0, 1, &random_data) != 0) BUG(); The problem is that we never called get_buf for complete buffers. The fix is simple: We have to free the buffer on interrupt to avoid a virtqueue "overflow". Christian Signed-off-by: Christian Borntraeger

Rusty, I have seen an oops triggered by the following bug statement in virtio-rng: if (vq->vq_ops->add_buf(vq, &sg, 0, 1, &random_data) != 0) BUG(); The problem is that we never called get_buf for complete buffers. The fix is simple: We have to free the buffer on interrupt to avoid a virtqueue "overflow". Christian Signed-off-by: Christian Borntraeger

Current hwrng core supports to register multiple hwrng devices, and there is only one device really works in the same time. QEMU alsu supports to have multiple virtio-rng backends. This patch changes virtio-rng driver to support multiple virtio-rng devices. ]# cat /sys/class/misc/hw_random/rng_available virtio_rng.0 virtio_rng.1 ]# cat /sys/class/misc/hw_random/rng_current virtio_rng.0 ]# echo

Current hwrng core supports to register multiple hwrng devices, and there is only one device really works in the same time. QEMU alsu supports to have multiple virtio-rng backends. This patch changes virtio-rng driver to support multiple virtio-rng devices. ]# cat /sys/class/misc/hw_random/rng_available virtio_rng.0 virtio_rng.1 ]# cat /sys/class/misc/hw_random/rng_current virtio_rng.0 ]# echo

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

From: Christian Borntraeger <borntraeger at de.ibm.com> The virtio-rng drivers checks for spurious callbacks. Since callbacks can be implemented via shared interrupts (e.g. PCI) this could lead to guest kernel oopses with lots of virtio devices. Signed-off-by: Christian Borntraeger <borntraeger at de.ibm.com> --- drivers/char/hw_random/virtio-rng.c | 4 ++-- 1 file changed, 2

From: Christian Borntraeger <borntraeger at de.ibm.com> The virtio-rng drivers checks for spurious callbacks. Since callbacks can be implemented via shared interrupts (e.g. PCI) this could lead to guest kernel oopses with lots of virtio devices. Signed-off-by: Christian Borntraeger <borntraeger at de.ibm.com> --- drivers/char/hw_random/virtio-rng.c | 4 ++-- 1 file changed, 2

A bit late to a party, but: On Mon, Dec 8, 2014 at 12:50 AM, Amos Kong <akong at redhat.com> wrote: > From: Rusty Russell <rusty at rustcorp.com.au> > > There's currently a big lock around everything, and it means that we > can't query sysfs (eg /sys/devices/virtual/misc/hw_random/rng_current) > while the rng is reading. This is a real problem when the rng is

A bit late to a party, but: On Mon, Dec 8, 2014 at 12:50 AM, Amos Kong <akong at redhat.com> wrote: > From: Rusty Russell <rusty at rustcorp.com.au> > > There's currently a big lock around everything, and it means that we > can't query sysfs (eg /sys/devices/virtual/misc/hw_random/rng_current) > while the rng is reading. This is a real problem when the rng is

The following changes since commit 0a2ce2ffc358da96792d514c1024b72c52be9cc1: David Howells (1): Fix FRV minimum slab/kmalloc alignment are available in the git repository at: ssh://master.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus.git master Chris Lalancette (1): Fix crash in virtio_blk during modprobe ; rmmod ; modprobe Christian Borntraeger (4):

The following changes since commit 0a2ce2ffc358da96792d514c1024b72c52be9cc1: David Howells (1): Fix FRV minimum slab/kmalloc alignment are available in the git repository at: ssh://master.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus.git master Chris Lalancette (1): Fix crash in virtio_blk during modprobe ; rmmod ; modprobe Christian Borntraeger (4):