diff mbox series

[v1,1/4] vduse: Add function to get/free the pages for reconnection

Message ID 20231011064208.2143245-2-lulu@redhat.com
State New
Headers
Series vduse: Reconnection support in vduse |

Commit Message

Cindy Lu Oct. 11, 2023, 6:42 a.m. UTC 
  Add the function vduse_alloc_reconnnect_info_mem
and vduse_alloc_reconnnect_info_mem
In this 2 function, vduse will get/free (vq_num + 1)*page  
Page 0 will be used to save the reconnection information, The
Userspace App will maintain this. Page 1 ~ vq_num + 1 will save
the reconnection information for vqs.

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 78 ++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

Comments

Jason Wang Oct. 18, 2023, 2:56 a.m. UTC | #1 
On Wed, Oct 11, 2023 at 2:42 PM Cindy Lu <lulu@redhat.com> wrote:
>
> Add the function vduse_alloc_reconnnect_info_mem
> and vduse_alloc_reconnnect_info_mem
> In this 2 function, vduse will get/free (vq_num + 1)*page
> Page 0 will be used to save the reconnection information, The
> Userspace App will maintain this. Page 1 ~ vq_num + 1 will save
> the reconnection information for vqs.

I'd align this with the spec. E.g spec starts virtqueue index from 0.

>
> Signed-off-by: Cindy Lu <lulu@redhat.com>
> ---
>  drivers/vdpa/vdpa_user/vduse_dev.c | 78 ++++++++++++++++++++++++++++++
>  1 file changed, 78 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> index 26b7e29cb900..565126a9ab01 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -30,6 +30,10 @@
>  #include <uapi/linux/virtio_blk.h>
>  #include <linux/mod_devicetable.h>
>
> +#ifdef CONFIG_X86
> +#include <asm/set_memory.h>
> +#endif

Why do we need special care for x86?

> +
>  #include "iova_domain.h"
>
>  #define DRV_AUTHOR   "Yongji Xie <xieyongji@bytedance.com>"
> @@ -41,6 +45,19 @@
>  #define VDUSE_IOVA_SIZE (128 * 1024 * 1024)
>  #define VDUSE_MSG_DEFAULT_TIMEOUT 30
>
> +/* struct vdpa_reconnect_info saved the alloc pages info
> + * these pages will mmaped to userspace for reconnection
> + */
> +struct vdpa_reconnect_info {
> +       /* Offset (within vm_file) in PAGE_SIZE
> +        */
> +       u32 index;
> +       /* virtual address for this page*/
> +       unsigned long vaddr;
> +       /* allocated memory size, */
> +       phys_addr_t size;

Anything wrong with using "unsigned long" here.

Btw, what is "allocated memory size" since I think we can use up to
PAGE_SIZE here?

> +};
> +
>  struct vduse_virtqueue {
>         u16 index;
>         u16 num_max;
> @@ -57,6 +74,7 @@ struct vduse_virtqueue {
>         struct vdpa_callback cb;
>         struct work_struct inject;
>         struct work_struct kick;
> +       struct vdpa_reconnect_info reconnect_info;
>  };
>
>  struct vduse_dev;
> @@ -106,6 +124,7 @@ struct vduse_dev {
>         u32 vq_align;
>         struct vduse_umem *umem;
>         struct mutex mem_lock;
> +       struct vdpa_reconnect_info reconnect_status;
>  };
>
>  struct vduse_dev_msg {
> @@ -1030,6 +1049,61 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
>         return ret;
>  }
>
> +static int vduse_alloc_reconnnect_info_mem(struct vduse_dev *dev)
> +{
> +       struct vdpa_reconnect_info *info;
> +       struct vduse_virtqueue *vq;
> +       void *addr;
> +
> +       /*page 0 is use to save status,dpdk will use this to save the information
> +        *needed in reconnection,kernel don't need to maintain this
> +        */

Let's avoid mentioning any specific userspace like DPDK in the kernel
source. A good uAPI should not be designed for a specific userspace.

> +       info = &dev->reconnect_status;
> +       addr = (void *)get_zeroed_page(GFP_KERNEL);
> +       if (!addr)
> +               return -1;

Let's don't use magic number here but something like -ENOMEM.

> +
> +       info->vaddr = (unsigned long)(addr);
> +       info->size = PAGE_SIZE;
> +       /* index is vm Offset in PAGE_SIZE */
> +       info->index = 0;
> +
> +       /*page 1~ vq_num + 1 save the reconnect info for vqs*/

There's no need to explain what the code does.

> +       for (int i = 0; i < dev->vq_num + 1; i++) {
> +               vq = &dev->vqs[i];
> +               info = &vq->reconnect_info;
> +               addr = (void *)get_zeroed_page(GFP_KERNEL);
> +               if (!addr)
> +                       return -1;
> +
> +               info->vaddr = (unsigned long)(addr);
> +               info->size = PAGE_SIZE;
> +               info->index = i + 1;

Btw, I don't see an obvious difference in the page for virtqueue and
device. Could we unify the logic there? So did the free.

> +       }
> +
> +       return 0;
> +}
> +
> +static int vduse_free_reconnnect_info_mem(struct vduse_dev *dev)
> +{
> +       struct vdpa_reconnect_info *info;
> +       struct vduse_virtqueue *vq;
> +
> +       info = &dev->reconnect_status;
> +       free_page(info->vaddr);
> +       info->size = 0;
> +       info->vaddr = 0;
> +       for (int i = 0; i < dev->vq_num + 1; i++) {
> +               vq = &dev->vqs[i];
> +               info = &vq->reconnect_info;
> +               free_page(info->vaddr);
> +               info->size = 0;
> +               info->vaddr = 0;
> +       }
> +
> +       return 0;
> +}
> +
>  static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
>                             unsigned long arg)
>  {
> @@ -1390,6 +1464,8 @@ 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);
>
> @@ -1542,6 +1618,8 @@ static int vduse_create_dev(struct vduse_dev_config *config,
>                 ret = PTR_ERR(dev->dev);
>                 goto err_dev;
>         }
> +
> +       vduse_alloc_reconnnect_info_mem(dev);

The errors were ignored here.

Thanks

>         __module_get(THIS_MODULE);
>
>         return 0;
> --
> 2.34.3
>
Cindy Lu Nov. 7, 2023, 7:26 a.m. UTC | #2 
On Wed, Oct 18, 2023 at 10:57 AM Jason Wang <jasowang@redhat.com> wrote:
>
> On Wed, Oct 11, 2023 at 2:42 PM Cindy Lu <lulu@redhat.com> wrote:
> >
> > Add the function vduse_alloc_reconnnect_info_mem
> > and vduse_alloc_reconnnect_info_mem
> > In this 2 function, vduse will get/free (vq_num + 1)*page
> > Page 0 will be used to save the reconnection information, The
> > Userspace App will maintain this. Page 1 ~ vq_num + 1 will save
> > the reconnection information for vqs.
>
> I'd align this with the spec. E.g spec starts virtqueue index from 0.
>
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
> >  drivers/vdpa/vdpa_user/vduse_dev.c | 78 ++++++++++++++++++++++++++++++
> >  1 file changed, 78 insertions(+)
> >
> > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
> > index 26b7e29cb900..565126a9ab01 100644
> > --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> > +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> > @@ -30,6 +30,10 @@
> >  #include <uapi/linux/virtio_blk.h>
> >  #include <linux/mod_devicetable.h>
> >
> > +#ifdef CONFIG_X86
> > +#include <asm/set_memory.h>
> > +#endif
>
> Why do we need special care for x86?
>
> > +
> >  #include "iova_domain.h"
> >
> >  #define DRV_AUTHOR   "Yongji Xie <xieyongji@bytedance.com>"
> > @@ -41,6 +45,19 @@
> >  #define VDUSE_IOVA_SIZE (128 * 1024 * 1024)
> >  #define VDUSE_MSG_DEFAULT_TIMEOUT 30
> >
> > +/* struct vdpa_reconnect_info saved the alloc pages info
> > + * these pages will mmaped to userspace for reconnection
> > + */
> > +struct vdpa_reconnect_info {
> > +       /* Offset (within vm_file) in PAGE_SIZE
> > +        */
> > +       u32 index;
> > +       /* virtual address for this page*/
> > +       unsigned long vaddr;
> > +       /* allocated memory size, */
> > +       phys_addr_t size;
>
> Anything wrong with using "unsigned long" here.
>
> Btw, what is "allocated memory size" since I think we can use up to
> PAGE_SIZE here?
>
sure， will remove this here
Thanks
Cindy
> > +};
> > +
> >  struct vduse_virtqueue {
> >         u16 index;
> >         u16 num_max;
> > @@ -57,6 +74,7 @@ struct vduse_virtqueue {
> >         struct vdpa_callback cb;
> >         struct work_struct inject;
> >         struct work_struct kick;
> > +       struct vdpa_reconnect_info reconnect_info;
> >  };
> >
> >  struct vduse_dev;
> > @@ -106,6 +124,7 @@ struct vduse_dev {
> >         u32 vq_align;
> >         struct vduse_umem *umem;
> >         struct mutex mem_lock;
> > +       struct vdpa_reconnect_info reconnect_status;
> >  };
> >
> >  struct vduse_dev_msg {
> > @@ -1030,6 +1049,61 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev,
> >         return ret;
> >  }
> >
> > +static int vduse_alloc_reconnnect_info_mem(struct vduse_dev *dev)
> > +{
> > +       struct vdpa_reconnect_info *info;
> > +       struct vduse_virtqueue *vq;
> > +       void *addr;
> > +
> > +       /*page 0 is use to save status,dpdk will use this to save the information
> > +        *needed in reconnection,kernel don't need to maintain this
> > +        */
>
> Let's avoid mentioning any specific userspace like DPDK in the kernel
> source. A good uAPI should not be designed for a specific userspace.
>
will change this
> > +       info = &dev->reconnect_status;
> > +       addr = (void *)get_zeroed_page(GFP_KERNEL);
> > +       if (!addr)
> > +               return -1;
>
> Let's don't use magic number here but something like -ENOMEM.
>
> > +
> > +       info->vaddr = (unsigned long)(addr);
> > +       info->size = PAGE_SIZE;
> > +       /* index is vm Offset in PAGE_SIZE */
> > +       info->index = 0;
> > +
> > +       /*page 1~ vq_num + 1 save the reconnect info for vqs*/
>
> There's no need to explain what the code does.
>
will change this

> > +       for (int i = 0; i < dev->vq_num + 1; i++) {
> > +               vq = &dev->vqs[i];
> > +               info = &vq->reconnect_info;
> > +               addr = (void *)get_zeroed_page(GFP_KERNEL);
> > +               if (!addr)
> > +                       return -1;
> > +
> > +               info->vaddr = (unsigned long)(addr);
> > +               info->size = PAGE_SIZE;
> > +               info->index = i + 1;
>
> Btw, I don't see an obvious difference in the page for virtqueue and
> device. Could we unify the logic there? So did the free.
>
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static int vduse_free_reconnnect_info_mem(struct vduse_dev *dev)
> > +{
> > +       struct vdpa_reconnect_info *info;
> > +       struct vduse_virtqueue *vq;
> > +
> > +       info = &dev->reconnect_status;
> > +       free_page(info->vaddr);
> > +       info->size = 0;
> > +       info->vaddr = 0;
> > +       for (int i = 0; i < dev->vq_num + 1; i++) {
> > +               vq = &dev->vqs[i];
> > +               info = &vq->reconnect_info;
> > +               free_page(info->vaddr);
> > +               info->size = 0;
> > +               info->vaddr = 0;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> >  static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
> >                             unsigned long arg)
> >  {
> > @@ -1390,6 +1464,8 @@ 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);
> >
> > @@ -1542,6 +1618,8 @@ static int vduse_create_dev(struct vduse_dev_config *config,
> >                 ret = PTR_ERR(dev->dev);
> >                 goto err_dev;
> >         }
> > +
> > +       vduse_alloc_reconnnect_info_mem(dev);
>
> The errors were ignored here.
>
> Thanks
>
sure will add the check here

Thanks
cindy

> >         __module_get(THIS_MODULE);
> >
> >         return 0;
> > --
> > 2.34.3
> >
>
diff mbox series

Patch

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 26b7e29cb900..565126a9ab01 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -30,6 +30,10 @@ 
 #include <uapi/linux/virtio_blk.h>
 #include <linux/mod_devicetable.h>
 
+#ifdef CONFIG_X86
+#include <asm/set_memory.h>
+#endif
+
 #include "iova_domain.h"
 
 #define DRV_AUTHOR   "Yongji Xie <xieyongji@bytedance.com>"
@@ -41,6 +45,19 @@ 
 #define VDUSE_IOVA_SIZE (128 * 1024 * 1024)
 #define VDUSE_MSG_DEFAULT_TIMEOUT 30
 
+/* struct vdpa_reconnect_info saved the alloc pages info
+ * these pages will mmaped to userspace for reconnection
+ */
+struct vdpa_reconnect_info {
+	/* Offset (within vm_file) in PAGE_SIZE
+	 */
+	u32 index;
+	/* virtual address for this page*/
+	unsigned long vaddr;
+	/* allocated memory size, */
+	phys_addr_t size;
+};
+
 struct vduse_virtqueue {
 	u16 index;
 	u16 num_max;
@@ -57,6 +74,7 @@  struct vduse_virtqueue {
 	struct vdpa_callback cb;
 	struct work_struct inject;
 	struct work_struct kick;
+	struct vdpa_reconnect_info reconnect_info;
 };
 
 struct vduse_dev;
@@ -106,6 +124,7 @@  struct vduse_dev {
 	u32 vq_align;
 	struct vduse_umem *umem;
 	struct mutex mem_lock;
+	struct vdpa_reconnect_info reconnect_status;
 };
 
 struct vduse_dev_msg {
@@ -1030,6 +1049,61 @@  static int vduse_dev_reg_umem(struct vduse_dev *dev,
 	return ret;
 }
 
+static int vduse_alloc_reconnnect_info_mem(struct vduse_dev *dev)
+{
+	struct vdpa_reconnect_info *info;
+	struct vduse_virtqueue *vq;
+	void *addr;
+
+	/*page 0 is use to save status,dpdk will use this to save the information
+	 *needed in reconnection,kernel don't need to maintain this
+	 */
+	info = &dev->reconnect_status;
+	addr = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!addr)
+		return -1;
+
+	info->vaddr = (unsigned long)(addr);
+	info->size = PAGE_SIZE;
+	/* index is vm Offset in PAGE_SIZE */
+	info->index = 0;
+
+	/*page 1~ vq_num + 1 save the reconnect info for vqs*/
+	for (int i = 0; i < dev->vq_num + 1; i++) {
+		vq = &dev->vqs[i];
+		info = &vq->reconnect_info;
+		addr = (void *)get_zeroed_page(GFP_KERNEL);
+		if (!addr)
+			return -1;
+
+		info->vaddr = (unsigned long)(addr);
+		info->size = PAGE_SIZE;
+		info->index = i + 1;
+	}
+
+	return 0;
+}
+
+static int vduse_free_reconnnect_info_mem(struct vduse_dev *dev)
+{
+	struct vdpa_reconnect_info *info;
+	struct vduse_virtqueue *vq;
+
+	info = &dev->reconnect_status;
+	free_page(info->vaddr);
+	info->size = 0;
+	info->vaddr = 0;
+	for (int i = 0; i < dev->vq_num + 1; i++) {
+		vq = &dev->vqs[i];
+		info = &vq->reconnect_info;
+		free_page(info->vaddr);
+		info->size = 0;
+		info->vaddr = 0;
+	}
+
+	return 0;
+}
+
 static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 			    unsigned long arg)
 {
@@ -1390,6 +1464,8 @@  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);
 
@@ -1542,6 +1618,8 @@  static int vduse_create_dev(struct vduse_dev_config *config,
 		ret = PTR_ERR(dev->dev);
 		goto err_dev;
 	}
+
+	vduse_alloc_reconnnect_info_mem(dev);
 	__module_get(THIS_MODULE);
 
 	return 0;