search for: vring_create_virtqueue_packed

We used to have use a single parent for all DMA operations. This tends to complicate the mdev based hardware virtio datapath offloading which may not implement the control path over datapath like ctrl vq in the case of virtio-net. So this series tries to intorduce per DMA domain by allowing trasnport to specify the parent device for each virtqueue. Then for the case of virtio-mdev device, it can

These patches are not ready to be merged because I was unable to measure a performance improvement. I'm publishing them so they are archived in case someone picks up this work again in the future. The goal of these patches is to allocate virtqueues and driver state from the device's NUMA node for optimal memory access latency. Only guests with a vNUMA topology and virtio devices spread

These patches are not ready to be merged because I was unable to measure a performance improvement. I'm publishing them so they are archived in case someone picks up this work again in the future. The goal of these patches is to allocate virtqueues and driver state from the device's NUMA node for optimal memory access latency. Only guests with a vNUMA topology and virtio devices spread

...vent) + /* TODO: this is a hack. Figure out a cleaner value to write. */ + vring_used_event(&vq->split.vring) = 0x0; + else vq->split.vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->split.avail_flags_shadow); @@ -1605,6 +1611,7 @@ static struct virtqueue *vring_create_virtqueue_packed( vq->weak_barriers = weak_barriers; vq->broken = false; vq->last_used_idx = 0; + vq->event_triggered = false; vq->num_added = 0; vq->packed_ring = true; vq->use_dma_api = vring_use_dma_api(vdev); @@ -1919,6 +1926,12 @@ void virtqueue_disable_cb(struct virtqueue *_vq...

...= off_wrap >> VRING_PACKED_EVENT_F_WRAP_CTR; - used_idx = off_wrap & ~(1 << VRING_PACKED_EVENT_F_WRAP_CTR); + used_idx = off_wrap & ~BIT(VRING_PACKED_EVENT_F_WRAP_CTR); return is_used_desc_packed(vq, used_idx, wrap_counter); } @@ -1625,7 +1642,7 @@ static struct virtqueue *vring_create_virtqueue_packed( vq->packed.avail_wrap_counter = 1; vq->packed.used_wrap_counter = 1; vq->packed.event_flags_shadow = 0; - vq->packed.avail_used_flags = 1 << VRING_PACKED_DESC_F_AVAIL; + vq->packed.avail_used_flags = BIT(VRING_PACKED_DESC_F_AVAIL); vq->packed.desc_state = kmalloc_...

Hi all: The code used to busy poll for cvq command which turns out to have several side effects: 1) infinite poll for buggy devices 2) bad interaction with scheduler So this series tries to use sleep + timeout instead of busy polling. Please review. Thanks Changes since RFC: - switch to use BAD_RING in virtio_break_device() - check virtqueue_is_broken() after being woken up - use

## About DMA APIs Now, virtio may can not work with DMA APIs when virtio features do not have VIRTIO_F_ACCESS_PLATFORM. 1. I tried to let DMA APIs return phy address by virtio-device. But DMA APIs just work with the "real" devices. 2. I tried to let xsk support callballs to get phy address from virtio-net driver as the dma address. But the maintainers of xsk may want to use

With the implementation of napi-tx in virtio driver, we clean tx descriptors from rx napi handler, for the purpose of reducing tx complete interrupts. But this introduces a race where tx complete interrupt has been raised, but the handler finds there is no work to do because we have done the work in the previous rx interrupt handler. A similar issue exists with polling from start_xmit, it is

With the implementation of napi-tx in virtio driver, we clean tx descriptors from rx napi handler, for the purpose of reducing tx complete interrupts. But this introduces a race where tx complete interrupt has been raised, but the handler finds there is no work to do because we have done the work in the previous rx interrupt handler. A similar issue exists with polling from start_xmit, it is

## About DMA APIs Now, virtio may can not work with DMA APIs when virtio features do not have VIRTIO_F_ACCESS_PLATFORM. 1. I tried to let DMA APIs return phy address by virtio-device. But DMA APIs just work with the "real" devices. 2. I tried to let xsk support callballs to get phy address from virtio-net driver as the dma address. But the maintainers of xsk may want to use

## About DMA APIs Now, virtio may can not work with DMA APIs when virtio features do not have VIRTIO_F_ACCESS_PLATFORM. 1. I tried to let DMA APIs return phy address by virtio-device. But DMA APIs just work with the "real" devices. 2. I tried to let xsk support callballs to get phy address from virtio-net driver as the dma address. But the maintainers of xsk may want to use

This is a follow up of the discussion in this thread: https://patchwork.ozlabs.org/patch/1001015/#2042353 Tiwei Bie (3): virtio_ring: define flags as shifts consistently virtio_ring: add VIRTIO_RING_NO_LEGACY virtio_ring: use new vring flags drivers/virtio/virtio_ring.c | 100 ++++++++++++++++++------------- include/uapi/linux/virtio_ring.h | 61 +++++++++++++------ 2 files changed,

This is a follow up of the discussion in this thread: https://patchwork.ozlabs.org/patch/1001015/#2042353 Tiwei Bie (3): virtio_ring: define flags as shifts consistently virtio_ring: add VIRTIO_RING_NO_LEGACY virtio_ring: use new vring flags drivers/virtio/virtio_ring.c | 100 ++++++++++++++++++------------- include/uapi/linux/virtio_ring.h | 61 +++++++++++++------ 2 files changed,

## About DMA APIs Now, virtio may can not work with DMA APIs when virtio features do not have VIRTIO_F_ACCESS_PLATFORM. 1. I tried to let DMA APIs return phy address by virtio-device. But DMA APIs just work with the "real" devices. 2. I tried to let xsk support callballs to get phy address from virtio-net driver as the dma address. But the maintainers of xsk may want to use

## About DMA APIs Now, virtio may can not work with DMA APIs when virtio features do not have VIRTIO_F_ACCESS_PLATFORM. 1. I tried to let DMA APIs return phy address by virtio-device. But DMA APIs just work with the "real" devices. 2. I tried to let xsk support callballs to get phy address from virtio-net driver as the dma address. But the maintainers of xsk may want to use

Hi, This patch set implements packed ring support in virtio driver. A performance test between pktgen (pktgen_sample03_burst_single_flow.sh) and DPDK vhost (testpmd/rxonly/vhost-PMD) has been done, I saw ~30% performance gain in packed ring in this case. To make this patch set work with below patch set for vhost, some hacks are needed to set the _F_NEXT flag in indirect descriptors (this should

Hi, This patch set implements packed ring support in virtio driver. A performance test between pktgen (pktgen_sample03_burst_single_flow.sh) and DPDK vhost (testpmd/rxonly/vhost-PMD) has been done, I saw ~30% performance gain in packed ring in this case. To make this patch set work with below patch set for vhost, some hacks are needed to set the _F_NEXT flag in indirect descriptors (this should