2023-10-11 06:43:30

by Cindy Lu

[permalink] [raw]
Subject: [PATCH v1 1/4] vduse: Add function to get/free the pages for reconnection

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 <[email protected]>
---
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
+
#include "iova_domain.h"

#define DRV_AUTHOR "Yongji Xie <[email protected]>"
@@ -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;
--
2.34.3


2023-10-18 02:58:12

by Jason Wang

[permalink] [raw]
Subject: Re: [PATCH v1 1/4] vduse: Add function to get/free the pages for reconnection

On Wed, Oct 11, 2023 at 2:42 PM Cindy Lu <[email protected]> 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 <[email protected]>
> ---
> 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 <[email protected]>"
> @@ -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
>

2023-11-07 07:28:06

by Cindy Lu

[permalink] [raw]
Subject: Re: [PATCH v1 1/4] vduse: Add function to get/free the pages for reconnection

On Wed, Oct 18, 2023 at 10:57 AM Jason Wang <[email protected]> wrote:
>
> On Wed, Oct 11, 2023 at 2:42 PM Cindy Lu <[email protected]> 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 <[email protected]>
> > ---
> > 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 <[email protected]>"
> > @@ -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
> >
>