Re: [PATCH v4 3/4] iommufd: Add IOMMU_GET_HW_INFO

On Mon, Jul 24, 2023 at 03:59:35AM -0700, Yi Liu wrote:

diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 94c498b8fdf6..bd3efc1d8509 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -17,6 +17,7 @@ #include <linux/bug.h> #include <uapi/linux/iommufd.h> #include <linux/iommufd.h> +#include "../iommu-priv.h" #include "io_pagetable.h" #include "iommufd_private.h" @@ -177,6 +178,78 @@ static int iommufd_destroy(struct iommufd_ucmd *ucmd) return 0; } +static int iommufd_zero_fill_user(u64 ptr, int bytes)

(void __user * ptr, size_t bytes)

+{

• int index = 0;
• for (; index < bytes; index++) {

• if (put_user(0, (uint8_t __user *)u64_to_user_ptr(ptr + index)))
  

• 	return -EFAULT;
  

• }
• return 0;

+}

+static int iommufd_get_hw_info(struct iommufd_ucmd *ucmd) +{

• struct iommu_hw_info *cmd = ucmd->cmd;
• unsigned int length = 0, data_len;
• struct iommufd_device *idev;
• const struct iommu_ops *ops;
• void *data = NULL;
• int rc = 0;
• if (cmd->flags || cmd->__reserved || !cmd->data_len)

• return -EOPNOTSUPP;
  

• idev = iommufd_get_device(ucmd, cmd->dev_id);
• if (IS_ERR(idev))

• return PTR_ERR(idev);
  

• ops = dev_iommu_ops(idev->dev);
• if (!ops->hw_info)

• goto done;
  

• /* driver has hw_info callback should have a unique hw_info_type */
• if (WARN_ON_ONCE(ops->hw_info_type == IOMMU_HW_INFO_TYPE_NONE)) {

• pr_warn_ratelimited("iommu driver set an invalid type\n");
  

Don't really need both a WARN and pr_warn(), just keep the WARN_ON

Jason