Re: [PATCH v3 12/19] vdpa_sim: make 'config' generic and usable for any device type

[Jason Wang]

On 2020/12/4 上午1:05, Stefano Garzarella wrote:

Add new 'config_size' attribute in 'vdpasim_dev_attr' and allocates
'config' dynamically to support any device types.

Signed-off-by: Stefano Garzarella <sgarz...@redhat.com>
---
  drivers/vdpa/vdpa_sim/vdpa_sim.c | 17 +++++++++++++----
  1 file changed, 13 insertions(+), 4 deletions(-)

Acked-by: Jason Wang <jasow...@redhat.com>

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index 949f4231d08a..fe71ed7890e1 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -62,6 +62,7 @@ struct vdpasim_virtqueue {

struct vdpasim_dev_attr {

        u64 supported_features;
+       size_t config_size;
        int nvqs;
        u32 id;

@@ -76,7 +77,8 @@ struct vdpasim {

        struct vdpasim_dev_attr dev_attr;
        /* spinlock to synchronize virtqueue state */
        spinlock_t lock;
-       struct virtio_net_config config;
+       /* virtio config according to device type */
+       void *config;
        struct vhost_iotlb *iommu;
        void *buffer;
        u32 status;
@@ -376,6 +378,10 @@ static struct vdpasim *vdpasim_create(struct 
vdpasim_dev_attr *dev_attr)
                goto err_iommu;
        set_dma_ops(dev, &vdpasim_dma_ops);

+ vdpasim->config = kzalloc(dev_attr->config_size, GFP_KERNEL);

+       if (!vdpasim->config)
+               goto err_iommu;
+
        vdpasim->vqs = kcalloc(dev_attr->nvqs, sizeof(struct vdpasim_virtqueue),
                               GFP_KERNEL);
        if (!vdpasim->vqs)
@@ -516,7 +522,8 @@ static u64 vdpasim_get_features(struct vdpa_device *vdpa)
  static int vdpasim_set_features(struct vdpa_device *vdpa, u64 features)
  {
        struct vdpasim *vdpasim = vdpa_to_sim(vdpa);
-       struct virtio_net_config *config = &vdpasim->config;
+       struct virtio_net_config *config =
+               (struct virtio_net_config *)vdpasim->config;

/* DMA mapping must be done by driver */

        if (!(features & (1ULL << VIRTIO_F_ACCESS_PLATFORM)))
@@ -588,8 +595,8 @@ static void vdpasim_get_config(struct vdpa_device *vdpa, 
unsigned int offset,
  {
        struct vdpasim *vdpasim = vdpa_to_sim(vdpa);

- if (offset + len < sizeof(struct virtio_net_config))

-               memcpy(buf, (u8 *)&vdpasim->config + offset, len);
+       if (offset + len < vdpasim->dev_attr.config_size)
+               memcpy(buf, vdpasim->config + offset, len);
  }

static void vdpasim_set_config(struct vdpa_device *vdpa, unsigned int offset,

@@ -676,6 +683,7 @@ static void vdpasim_free(struct vdpa_device *vdpa)
        if (vdpasim->iommu)
                vhost_iotlb_free(vdpasim->iommu);
        kfree(vdpasim->vqs);
+       kfree(vdpasim->config);
  }

static const struct vdpa_config_ops vdpasim_config_ops = {

@@ -738,6 +746,7 @@ static int __init vdpasim_dev_init(void)
        dev_attr.id = VIRTIO_ID_NET;
        dev_attr.supported_features = VDPASIM_NET_FEATURES;
        dev_attr.nvqs = VDPASIM_VQ_NUM;
+       dev_attr.config_size = sizeof(struct virtio_net_config);
        dev_attr.work_fn = vdpasim_net_work;

vdpasim_dev = vdpasim_create(&dev_attr);

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