[PATCH v4 11/18] vdpa_sim: make 'config' generic and usable for any device type

[Stefano Garzarella]

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

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

diff --git a/drivers/vdpa/vdpa_sim/vdpa_sim.c b/drivers/vdpa/vdpa_sim/vdpa_sim.c
index ccb40501cbd7..4a0a6cadb9ff 100644
--- a/drivers/vdpa/vdpa_sim/vdpa_sim.c
+++ b/drivers/vdpa/vdpa_sim/vdpa_sim.c
@@ -70,6 +70,7 @@ struct vdpasim_virtqueue {
 
 struct vdpasim_dev_attr {
        u64 supported_features;
+       size_t config_size;
        int nvqs;
        u32 id;
 
@@ -84,7 +85,8 @@ 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;
@@ -384,6 +386,10 @@ 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)
@@ -524,7 +530,8 @@ 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)))
@@ -596,8 +603,8 @@ 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,
@@ -684,6 +691,7 @@ 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 = {
@@ -746,6 +754,7 @@ 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);
-- 
2.26.2