Re: [PATCH v5 1/3] x86/tdx: Add TDX Guest attestation interface driver

[Wander Lairson Costa <wander@redhat.com>]

On Sun, May 01, 2022 at 11:34:58AM -0700, Kuppuswamy Sathyanarayanan wrote:

[snip]

> +
> +static struct miscdevice miscdev;
> +
> +static long tdx_get_report(void __user *argp)
> +{
> +	void *reportdata = NULL, *tdreport = NULL;
> +	long ret = 0;
> +
> +	/* Allocate buffer space for REPORTDATA */
> +	reportdata = kmalloc(TDX_REPORTDATA_LEN, GFP_KERNEL);
> +	if (!reportdata)
> +		return -ENOMEM;
> +
> +	/* Allocate buffer space for TDREPORT */
> +	tdreport = kmalloc(TDX_REPORT_LEN, GFP_KERNEL);
> +	if (!tdreport) {
> +		ret = -ENOMEM;
> +		goto failed;
> +	}
> +
> +	/* Copy REPORTDATA from the user buffer */
> +	if (copy_from_user(reportdata, argp, TDX_REPORTDATA_LEN)) {
> +		ret = -EFAULT;
> +		goto failed;
> +	}
> +
> +	/*
> +	 * Generate TDREPORT using "TDG.MR.REPORT" TDCALL.
> +	 *
> +	 * Pass the physical address of user generated REPORTDATA
> +	 * and the physical address of the output buffer to the TDX
> +	 * module to generate the TDREPORT. Generated data contains
> +	 * measurements/configuration data of the TD guest. More info
> +	 * about ABI can be found in TDX 1.0 Module specification, sec
> +	 * titled "TDG.MR.REPORT".
> +	 */
> +	ret = __tdx_module_call(TDX_GET_REPORT, virt_to_phys(tdreport),
> +				virt_to_phys(reportdata), 0, 0, NULL);
> +	if (ret) {
> +		pr_debug("TDREPORT TDCALL failed, status:%lx\n",
> +				TDCALL_STATUS_CODE(ret));

Should we use pr_err instead?

[snip]