Jason Wang
2023-Sep-18 08:41 UTC
[RFC v2 1/4] vduse: Add function to get/free the pages for reconnection
On Tue, Sep 12, 2023 at 11:00?AM Cindy Lu <lulu at 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.Please explain why this is needed instead of only describing how it is implemented. (Code can explain itself).> > Signed-off-by: Cindy Lu <lulu at redhat.com> > --- > drivers/vdpa/vdpa_user/vduse_dev.c | 86 ++++++++++++++++++++++++++++++ > 1 file changed, 86 insertions(+) > > diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c > index 26b7e29cb900..4c256fa31fc4 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 at bytedance.com>" > @@ -41,6 +45,23 @@ > #define VDUSE_IOVA_SIZE (128 * 1024 * 1024) > #define VDUSE_MSG_DEFAULT_TIMEOUT 30 > > +/* struct vdpa_reconnect_info save the page information for reconnection > + * kernel will init these information while alloc the pages > + * and use these information to free the pages > + */ > +struct vdpa_reconnect_info { > + /* Offset (within vm_file) in PAGE_SIZE, > + * this just for check, not using > + */ > + u32 index; > + /* physical address for this page*/ > + phys_addr_t addr; > + /* virtual address for this page*/ > + unsigned long vaddr;If it could be switched by virt_to_phys() why duplicate those fields?> + /* memory size, here always page_size*/ > + phys_addr_t size;If it's always PAGE_SIZE why would we have this?> +}; > + > struct vduse_virtqueue { > u16 index; > u16 num_max; > @@ -57,6 +78,7 @@ 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 +128,7 @@ 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 +1053,65 @@ static int vduse_dev_reg_umem(struct vduse_dev *dev, > return ret; > } > > +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;-ENOMEM? Thanks