similar to: [PATCH] virtio_rng: adopt driver to newest virtio code

If virtio_rng is build as a module, random_data is an address in vmalloc space. As virtio expects guest real addresses, this can cause any kind of funny behaviour, so lets allocate random_data dynamically with kmalloc. Signed-off-by: Christian Borntraeger <borntraeger at de.ibm.com> --- drivers/char/hw_random/virtio-rng.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)

If virtio_rng is build as a module, random_data is an address in vmalloc space. As virtio expects guest real addresses, this can cause any kind of funny behaviour, so lets allocate random_data dynamically with kmalloc. Signed-off-by: Christian Borntraeger <borntraeger at de.ibm.com> --- drivers/char/hw_random/virtio-rng.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)

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

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 +++

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

On Thu, Jan 19, 2023 at 07:43:47PM +0100, Babis Chalios wrote: > Implement the virtio-rng feature that allows a guest driver to request > from the device to perform certain operations in the event of an > "entropy leak", such as when taking a VM snapshot or restoring a VM from > a snapshot. The guest can request one of two operations: (i) fill a > buffer with random bytes,

> > 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

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

Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will use indirect descriptors even if we have plenty of space in the ring. This means that we take a performance hit at all times due to the overhead of creating indirect descriptors. Instead, use it only after we're below a configurable offset. Signed-off-by: Sasha Levin <levinsasha928 at gmail.com> --- drivers/block/virtio_blk.c

Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will use indirect descriptors even if we have plenty of space in the ring. This means that we take a performance hit at all times due to the overhead of creating indirect descriptors. Instead, use it only after we're below a configurable offset. Signed-off-by: Sasha Levin <levinsasha928 at gmail.com> --- drivers/block/virtio_blk.c

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):

Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will use indirect descriptors even if we have plenty of space in the ring. This means that we take a performance hit at all times due to the overhead of creating indirect descriptors. Instead, use it only after we're below a configurable offset. Signed-off-by: Sasha Levin <levinsasha928 at gmail.com> --- drivers/block/virtio_blk.c

Currently if VIRTIO_RING_F_INDIRECT_DESC is enabled we will use indirect descriptors even if we have plenty of space in the ring. This means that we take a performance hit at all times due to the overhead of creating indirect descriptors. Instead, use it only after we're below a configurable offset. Signed-off-by: Sasha Levin <levinsasha928 at gmail.com> --- drivers/block/virtio_blk.c