[PATCH v6 06/26] virtio_ring: packed: extrace the logic of creating vring
Xuan Zhuo
xuanzhuo at linux.alibaba.com
Tue Mar 8 00:01:01 PST 2022
On Tue, 8 Mar 2022 15:28:22 +0800, Jason Wang <jasowang at redhat.com> wrote:
>
> 在 2022/3/8 下午3:01, Xuan Zhuo 写道:
> > On Mon, 7 Mar 2022 17:17:51 -0500, "Michael S. Tsirkin" <mst at redhat.com> wrote:
> >> On Thu, Feb 24, 2022 at 04:10:42PM +0800, Xuan Zhuo wrote:
> >>> Separate the logic of packed to create vring queue.
> >>>
> >>> For the convenience of passing parameters, add a structure
> >>> vring_packed.
> >>>
> >>> This feature is required for subsequent virtuqueue reset vring.
> >>>
> >>> Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com>
> >> Subject has a typo.
> > I will fix it.
> >
> >> Besides:
> >>
> >>> ---
> >>> drivers/virtio/virtio_ring.c | 121 ++++++++++++++++++++++++++---------
> >>> 1 file changed, 92 insertions(+), 29 deletions(-)
> >>>
> >>> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> >>> index dc6313b79305..41864c5e665f 100644
> >>> --- a/drivers/virtio/virtio_ring.c
> >>> +++ b/drivers/virtio/virtio_ring.c
> >>> @@ -92,6 +92,18 @@ struct vring_split {
> >>> struct vring vring;
> >>> };
> >>>
> >>> +struct vring_packed {
> >>> + u32 num;
> >>> + struct vring_packed_desc *ring;
> >>> + struct vring_packed_desc_event *driver;
> >>> + struct vring_packed_desc_event *device;
> >>> + dma_addr_t ring_dma_addr;
> >>> + dma_addr_t driver_event_dma_addr;
> >>> + dma_addr_t device_event_dma_addr;
> >>> + size_t ring_size_in_bytes;
> >>> + size_t event_size_in_bytes;
> >>> +};
> >>> +
> >>> struct vring_virtqueue {
> >>> struct virtqueue vq;
> >>>
> >>> @@ -1683,45 +1695,101 @@ static struct vring_desc_extra *vring_alloc_desc_extra(struct vring_virtqueue *v
> >>> return desc_extra;
> >>> }
> >>>
> >>> -static struct virtqueue *vring_create_virtqueue_packed(
> >>> - unsigned int index,
> >>> - unsigned int num,
> >>> - unsigned int vring_align,
> >>> - struct virtio_device *vdev,
> >>> - bool weak_barriers,
> >>> - bool may_reduce_num,
> >>> - bool context,
> >>> - bool (*notify)(struct virtqueue *),
> >>> - void (*callback)(struct virtqueue *),
> >>> - const char *name)
> >>> +static void vring_free_vring_packed(struct vring_packed *vring,
> >>> + struct virtio_device *vdev)
> >>> +{
> >>> + dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
> >>> + struct vring_packed_desc_event *driver, *device;
> >>> + size_t ring_size_in_bytes, event_size_in_bytes;
> >>> + struct vring_packed_desc *ring;
> >>> +
> >>> + ring = vring->ring;
> >>> + driver = vring->driver;
> >>> + device = vring->device;
> >>> + ring_dma_addr = vring->ring_size_in_bytes;
> >>> + event_size_in_bytes = vring->event_size_in_bytes;
> >>> + ring_dma_addr = vring->ring_dma_addr;
> >>> + driver_event_dma_addr = vring->driver_event_dma_addr;
> >>> + device_event_dma_addr = vring->device_event_dma_addr;
> >>> +
> >>> + if (device)
> >>> + vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr);
> >>> +
> >>> + if (driver)
> >>> + vring_free_queue(vdev, event_size_in_bytes, driver, driver_event_dma_addr);
> >>> +
> >>> + if (ring)
> >>> + vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr);
> >> ring_size_in_bytes is uninitialized here.
> >>
> >> Which begs the question how was this tested patchset generally and
> >> this patch in particular.
> >> Please add note on tested configurations and tests run to the patchset.
> > Sorry, my environment is running in split mode. I did not retest the packed mode
> > before sending patches. Because my dpdk vhost-user is not easy to use, I
> > need to change the kernel of the host.
> >
> > I would like to ask if there are other lightweight environments that can be used
> > to test packed mode.
>
>
> You can use Qemu's dataplane. It has support for packed virtqueue.
I thought about it, I feel that the current Qemu's virtio-net seems to have no
problem if it adds a PACKED feature, so I tried it. I manually added the PACKED
feature to Qemu's virtio-net. After I start the vm, run OK. PACKED also
negotiated successfully. After the test, it is also OK.
I think virtio-net in Qemu just does not open PACKED, but the implementation of
PACKED is in virtio core, so as long as virtio-net opens PACKED, it will be
fine. If there is any problem, I hope someone will approve it.
If my idea is correct, then virtio-net can add a parameter to open PACKED, which
will be very convenient when testing the packed mode of virtio.
Thanks.
>
> Thanks
>
>
> >
> >
> > Thanks.
> >
> >
> >>> +}
> >>> +
> >>> +static int vring_create_vring_packed(struct vring_packed *vring,
> >>> + struct virtio_device *vdev,
> >>> + u32 num)
> >>> {
> >>> - struct vring_virtqueue *vq;
> >>> struct vring_packed_desc *ring;
> >>> struct vring_packed_desc_event *driver, *device;
> >>> dma_addr_t ring_dma_addr, driver_event_dma_addr, device_event_dma_addr;
> >>> size_t ring_size_in_bytes, event_size_in_bytes;
> >>>
> >>> + memset(vring, 0, sizeof(*vring));
> >>> +
> >>> ring_size_in_bytes = num * sizeof(struct vring_packed_desc);
> >>>
> >>> ring = vring_alloc_queue(vdev, ring_size_in_bytes,
> >>> &ring_dma_addr,
> >>> GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> >>> if (!ring)
> >>> - goto err_ring;
> >>> + goto err;
> >>> +
> >>> + vring->num = num;
> >>> + vring->ring = ring;
> >>> + vring->ring_size_in_bytes = ring_size_in_bytes;
> >>> + vring->ring_dma_addr = ring_dma_addr;
> >>>
> >>> event_size_in_bytes = sizeof(struct vring_packed_desc_event);
> >>> + vring->event_size_in_bytes = event_size_in_bytes;
> >>>
> >>> driver = vring_alloc_queue(vdev, event_size_in_bytes,
> >>> &driver_event_dma_addr,
> >>> GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> >>> if (!driver)
> >>> - goto err_driver;
> >>> + goto err;
> >>> +
> >>> + vring->driver = driver;
> >>> + vring->driver_event_dma_addr = driver_event_dma_addr;
> >>>
> >>> device = vring_alloc_queue(vdev, event_size_in_bytes,
> >>> &device_event_dma_addr,
> >>> GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
> >>> if (!device)
> >>> - goto err_device;
> >>> + goto err;
> >>> +
> >>> + vring->device = device;
> >>> + vring->device_event_dma_addr = device_event_dma_addr;
> >>> + return 0;
> >>> +
> >>> +err:
> >>> + vring_free_vring_packed(vring, vdev);
> >>> + return -ENOMEM;
> >>> +}
> >>> +
> >>> +static struct virtqueue *vring_create_virtqueue_packed(
> >>> + unsigned int index,
> >>> + unsigned int num,
> >>> + unsigned int vring_align,
> >>> + struct virtio_device *vdev,
> >>> + bool weak_barriers,
> >>> + bool may_reduce_num,
> >>> + bool context,
> >>> + bool (*notify)(struct virtqueue *),
> >>> + void (*callback)(struct virtqueue *),
> >>> + const char *name)
> >>> +{
> >>> + struct vring_virtqueue *vq;
> >>> + struct vring_packed vring;
> >>> +
> >>> + if (vring_create_vring_packed(&vring, vdev, num))
> >>> + goto err_vq;
> >>>
> >>> vq = kmalloc(sizeof(*vq), GFP_KERNEL);
> >>> if (!vq)
> >>> @@ -1753,17 +1821,17 @@ static struct virtqueue *vring_create_virtqueue_packed(
> >>> if (virtio_has_feature(vdev, VIRTIO_F_ORDER_PLATFORM))
> >>> vq->weak_barriers = false;
> >>>
> >>> - vq->packed.ring_dma_addr = ring_dma_addr;
> >>> - vq->packed.driver_event_dma_addr = driver_event_dma_addr;
> >>> - vq->packed.device_event_dma_addr = device_event_dma_addr;
> >>> + vq->packed.ring_dma_addr = vring.ring_dma_addr;
> >>> + vq->packed.driver_event_dma_addr = vring.driver_event_dma_addr;
> >>> + vq->packed.device_event_dma_addr = vring.device_event_dma_addr;
> >>>
> >>> - vq->packed.ring_size_in_bytes = ring_size_in_bytes;
> >>> - vq->packed.event_size_in_bytes = event_size_in_bytes;
> >>> + vq->packed.ring_size_in_bytes = vring.ring_size_in_bytes;
> >>> + vq->packed.event_size_in_bytes = vring.event_size_in_bytes;
> >>>
> >>> vq->packed.vring.num = num;
> >>> - vq->packed.vring.desc = ring;
> >>> - vq->packed.vring.driver = driver;
> >>> - vq->packed.vring.device = device;
> >>> + vq->packed.vring.desc = vring.ring;
> >>> + vq->packed.vring.driver = vring.driver;
> >>> + vq->packed.vring.device = vring.device;
> >>>
> >>> vq->packed.next_avail_idx = 0;
> >>> vq->packed.avail_wrap_counter = 1;
> >>> @@ -1804,12 +1872,7 @@ static struct virtqueue *vring_create_virtqueue_packed(
> >>> err_desc_state:
> >>> kfree(vq);
> >>> err_vq:
> >>> - vring_free_queue(vdev, event_size_in_bytes, device, device_event_dma_addr);
> >>> -err_device:
> >>> - vring_free_queue(vdev, event_size_in_bytes, driver, driver_event_dma_addr);
> >>> -err_driver:
> >>> - vring_free_queue(vdev, ring_size_in_bytes, ring, ring_dma_addr);
> >>> -err_ring:
> >>> + vring_free_vring_packed(&vring, vdev);
> >>> return NULL;
> >>> }
> >>>
> >>> --
> >>> 2.31.0
>
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