[PATCH v5 3/5] vduse: Add function to get/free the pages for reconnection

[Cindy Lu]

Add the function vduse_alloc_reconnnect_info_mem
and vduse_alloc_reconnnect_info_mem
These functions allow vduse to allocate and free memory for reconnection
information. The amount of memory allocated is vq_num pages.
Each VQS will map its own page where the reconnection information will be saved

Signed-off-by: Cindy Lu <l...@redhat.com>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 40 ++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c 
b/drivers/vdpa/vdpa_user/vduse_dev.c
index ef3c9681941e..2da659d5f4a8 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -65,6 +65,7 @@ struct vduse_virtqueue {
        int irq_effective_cpu;
        struct cpumask irq_affinity;
        struct kobject kobj;
+       unsigned long vdpa_reconnect_vaddr;
 };
 
 struct vduse_dev;
@@ -1105,6 +1106,38 @@ static void vduse_vq_update_effective_cpu(struct 
vduse_virtqueue *vq)
 
        vq->irq_effective_cpu = curr_cpu;
 }
+static int vduse_alloc_reconnnect_info_mem(struct vduse_dev *dev)
+{
+       unsigned long vaddr = 0;
+       struct vduse_virtqueue *vq;
+
+       for (int i = 0; i < dev->vq_num; i++) {
+               /*page 0~ vq_num save the reconnect info for vq*/
+               vq = dev->vqs[i];
+               vaddr = get_zeroed_page(GFP_KERNEL);
+               if (vaddr == 0)
+                       return -ENOMEM;
+
+               vq->vdpa_reconnect_vaddr = vaddr;
+       }
+
+       return 0;
+}
+
+static int vduse_free_reconnnect_info_mem(struct vduse_dev *dev)
+{
+       struct vduse_virtqueue *vq;
+
+       for (int i = 0; i < dev->vq_num; i++) {
+               vq = dev->vqs[i];
+
+               if (vq->vdpa_reconnect_vaddr)
+                       free_page(vq->vdpa_reconnect_vaddr);
+               vq->vdpa_reconnect_vaddr = 0;
+       }
+
+       return 0;
+}
 
 static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
                            unsigned long arg)
@@ -1672,6 +1705,8 @@ static int vduse_destroy_dev(char *name)
                mutex_unlock(&dev->lock);
                return -EBUSY;
        }
+       vduse_free_reconnnect_info_mem(dev);
+
        dev->connected = true;
        mutex_unlock(&dev->lock);
 
@@ -1855,12 +1890,17 @@ static int vduse_create_dev(struct vduse_dev_config 
*config,
        ret = vduse_dev_init_vqs(dev, config->vq_align, config->vq_num);
        if (ret)
                goto err_vqs;
+       ret = vduse_alloc_reconnnect_info_mem(dev);
+       if (ret < 0)
+               goto err_mem;
 
        __module_get(THIS_MODULE);
 
        return 0;
 err_vqs:
        device_destroy(&vduse_class, MKDEV(MAJOR(vduse_major), dev->minor));
+err_mem:
+       vduse_free_reconnnect_info_mem(dev);
 err_dev:
        idr_remove(&vduse_idr, dev->minor);
 err_idr:
-- 
2.43.0