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

From: Cindy Lu
Date: Fri Apr 12 2024 - 09:31:37 EST


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 <lulu@xxxxxxxxxx>
---
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