在nvme_dev_ioctl里,存在switch语句,列举ioctl的几种cmd,其中我们主要关注的是:NVME_IOCTL_ADMIN_CMD和NVME_IO_CMD。 staticlongnvme_dev_ioctl(structfile *file, unsignedintcmd, unsignedlongarg) {structnvme_ctrl *ctrl = file->private_data;void__user *argp = (void__user *)arg;switch(cmd) {case...
unlocked_ioctl = nvme_dev_ioctl nvme_user_cmd copy_from_user nvme_validate_passthru_nsid c.common.opcode = cmd.opcode; ... nvme_cmd_allowed status = nvme_submit_user_cmd nvme_alloc_user_request blk_mq_alloc_request nvme_init_request nvme_req(req)->flags |= NVME_REQ_USERCMD nvme_map...
ioctl(s->container, VFIO_IOMMU_MAP_DMA, &dma_map); IOVA 操作小结:用户态操作IO的内存需要分配好,然后分配IO地址空间,这个地址空间需要用户态自己管理, 然后,将host的buf内存地址,IO地址一起发给VFIO来做DMA映射。 总结 到此为止,已经揭开了 NVMe 用户驱动的面纱,同时也了解了部分 NVMe 协议的内容。回顾一...
nvme_discovery_log -> int nvme_get_log -> nvme_get_log13 -> .opcode = nvme_admin_get_log_page -> return ioctl(fd, ioctl_cmd, cmd) -> 管理命令: nvme_admin_get_log_page = 0x02 enum nvme_admin_opcode nvme管理命令 -> linux/nvme.h nvme_submit_admin_passthru ioctl(fd, NVME_IOCT...
ioctl(s->container, VFIO_GET_API_VERSION) != VFIO_API_VERSION) // 检查版本 ioctl(s->container, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU) // 检查IOMMU group_file = sysfs_find_group_file(device, errp); //查找device对应的group,这里就是/dev/vfio/4 ...
DAX: 磁盘(disk)的访问模式有三种 BUFFERED、DIRECT、DAX。前面提到的由于page cache存在可以避免耗时的磁盘通信就是BUFFERED访问模式的集中体现;但是如果我要求用户的write请求要实时存储到磁盘里,不能只在内存中更新,那么此时我便需要DIRECT模式;大家可能听说过flash
https://docs.kernel.org/process/submitting-patches.html# That means the changes should be a clean series (no merges should be present in a github PR for example) and every commit should build. See alsohttps://opensource.com/article/19/7/create-pull-request-github ...
Then some user mode process sends an IOCTL_STORAGE_DEVICE_POWER_CAP request to the disk with a value of 5W. StorNVMe will choose PS2 now because it is the highest operational power state whose Max Power value (4W) is less than the max operational power requirement of 5W....
有了这个字符设备之后,我们就可以通过open、ioctl之类的接口去操作它了。 AI检测代码解析 static const struct file_operations nvme_dev_fops = { .owner = THIS_MODULE, .open = nvme_dev_open, .release = nvme_dev_release, .unlocked_ioctl = nvme_dev_ioctl, .compat_ioctl = nvme_dev_ioctl, }; ...
在初始化阶段,管理工具使用ioctl()给队列管理模块发通知,告知访问权限和可用的队列数。当应用请求创建一个队列的时候,队列管理模块检查权限,然后创建一个包含提交队列(SQ)和完成队列(CQ)的队列对(QP)。队列管理模块使用dma_common_mmap()将创建的队列的内核空间的内存地址和门铃寄存器映射到用户态地址空间,这样用户...