similar to: using cache for virtio allocations?

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

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

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

This fixes virtio on Xen guests as well as on any other platform on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches, everything works. There

This fixes virtio on Xen guests as well as on any other platform on which physical addresses don't match bus addresses. This can be tested with: virtme-run --xen xen --kimg arch/x86/boot/bzImage --console using virtme from here: https://git.kernel.org/cgit/utils/kernel/virtme/virtme.git Without these patches, the guest hangs forever. With these patches, everything works. There

Some virtio device drivers (9p) need to translate high virtual addresses to physical addresses, which are inserted into the virtqueue for processing by userspace. This patch exports the kmap_to_page symbol, so that the affected drivers can be compiled as modules. Signed-off-by: Will Deacon <will.deacon at arm.com> --- mm/highmem.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)

Some virtio device drivers (9p) need to translate high virtual addresses to physical addresses, which are inserted into the virtqueue for processing by userspace. This patch exports the kmap_to_page symbol, so that the affected drivers can be compiled as modules. Signed-off-by: Will Deacon <will.deacon at arm.com> --- mm/highmem.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)

On Fri, Apr 13, 2018 at 12:30:24PM +0800, Jason Wang wrote: > On 2018?04?01? 22:12, Tiwei Bie wrote: > > Hello everyone, > > > > This RFC implements packed ring support for virtio driver. > > > > The code was tested with DPDK vhost (testpmd/vhost-PMD) implemented > > by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html > > Minor changes

On Fri, Apr 13, 2018 at 12:30:24PM +0800, Jason Wang wrote: > On 2018?04?01? 22:12, Tiwei Bie wrote: > > Hello everyone, > > > > This RFC implements packed ring support for virtio driver. > > > > The code was tested with DPDK vhost (testpmd/vhost-PMD) implemented > > by Jens at http://dpdk.org/ml/archives/dev/2018-January/089417.html > > Minor changes

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks, instead of one by one; and 2) cmdq: a new virtqueue to send commands between the device and driver. Currently, it supports commands to report memory stats (replace the old statq mechanism) and report guest unused pages. Liang Li

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks, instead of one by one; and 2) cmdq: a new virtqueue to send commands between the device and driver. Currently, it supports commands to report memory stats (replace the old statq mechanism) and report guest unused pages. Liang Li

I resurrected these patches after prompting from Andy Lutomirski's recent patches. I put them on the back-burner because vring_bench had a 15% slowdown on my laptop: pktgen testing revealed a speedup, if anything, so I've cleaned them up. Rusty Russell (3): virtio_net: pass well-formed sgs to virtqueue_add_*() virtio_ring: assume sgs are always well-formed. virtio_ring: unify

I resurrected these patches after prompting from Andy Lutomirski's recent patches. I put them on the back-burner because vring_bench had a 15% slowdown on my laptop: pktgen testing revealed a speedup, if anything, so I've cleaned them up. Rusty Russell (3): virtio_net: pass well-formed sgs to virtqueue_add_*() virtio_ring: assume sgs are always well-formed. virtio_ring: unify

Don't print warning if memory allocation fails. The virtio driver can handle allocation failure (it falls back to direct sglist), so there is no functionality degradation. This warning was observed when swapping to virtio scsi device because there may be not enough free memory during swapping. Signed-off-by: Mikulas Patocka <mpatocka at redhat.com> --- drivers/virtio/virtio_ring.c |

Don't print warning if memory allocation fails. The virtio driver can handle allocation failure (it falls back to direct sglist), so there is no functionality degradation. This warning was observed when swapping to virtio scsi device because there may be not enough free memory during swapping. Signed-off-by: Mikulas Patocka <mpatocka at redhat.com> --- drivers/virtio/virtio_ring.c |

This oops manifests itself on the following hardware: 01:00.0 VGA compatible controller: NVIDIA Corporation G98M [GeForce G 103M] (rev a1) Oct 09 14:17:46 lp-sasha kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000 Oct 09 14:17:46 lp-sasha kernel: #PF: supervisor read access in kernel mode Oct 09 14:17:46 lp-sasha kernel: #PF: error_code(0x0000) - not-present page Oct 09

This oops manifests itself on the following hardware: 01:00.0 VGA compatible controller: NVIDIA Corporation G98M [GeForce G 103M] (rev a1) Oct 09 14:17:46 lp-sasha kernel: BUG: kernel NULL pointer dereference, address: 0000000000000000 Oct 09 14:17:46 lp-sasha kernel: #PF: supervisor read access in kernel mode Oct 09 14:17:46 lp-sasha kernel: #PF: error_code(0x0000) - not-present page Oct 09