[PATCH v7 06/26] virtio_ring: packed: extract the logic of creating vring

Xuan Zhuo
2022-03-08T12:35:44Z

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@linux.alibaba.com>
---
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..1af98b112996 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_size_in_bytes = 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);
+}
+
+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