linux-zen-desktop/drivers/virt/coco/tdx-guest/tdx-guest.c

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2023-08-30 17:31:07 +02:00
// SPDX-License-Identifier: GPL-2.0
/*
* TDX guest user interface driver
*
* Copyright (C) 2022 Intel Corporation
*/
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/string.h>
#include <linux/uaccess.h>
#include <uapi/linux/tdx-guest.h>
#include <asm/cpu_device_id.h>
#include <asm/tdx.h>
static long tdx_get_report0(struct tdx_report_req __user *req)
{
u8 *reportdata, *tdreport;
long ret;
reportdata = kmalloc(TDX_REPORTDATA_LEN, GFP_KERNEL);
if (!reportdata)
return -ENOMEM;
tdreport = kzalloc(TDX_REPORT_LEN, GFP_KERNEL);
if (!tdreport) {
ret = -ENOMEM;
goto out;
}
if (copy_from_user(reportdata, req->reportdata, TDX_REPORTDATA_LEN)) {
ret = -EFAULT;
goto out;
}
/* Generate TDREPORT0 using "TDG.MR.REPORT" TDCALL */
ret = tdx_mcall_get_report0(reportdata, tdreport);
if (ret)
goto out;
if (copy_to_user(req->tdreport, tdreport, TDX_REPORT_LEN))
ret = -EFAULT;
out:
kfree(reportdata);
kfree(tdreport);
return ret;
}
static long tdx_guest_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
switch (cmd) {
case TDX_CMD_GET_REPORT0:
return tdx_get_report0((struct tdx_report_req __user *)arg);
default:
return -ENOTTY;
}
}
static const struct file_operations tdx_guest_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = tdx_guest_ioctl,
.llseek = no_llseek,
};
static struct miscdevice tdx_misc_dev = {
.name = KBUILD_MODNAME,
.minor = MISC_DYNAMIC_MINOR,
.fops = &tdx_guest_fops,
};
static const struct x86_cpu_id tdx_guest_ids[] = {
X86_MATCH_FEATURE(X86_FEATURE_TDX_GUEST, NULL),
{}
};
MODULE_DEVICE_TABLE(x86cpu, tdx_guest_ids);
static int __init tdx_guest_init(void)
{
if (!x86_match_cpu(tdx_guest_ids))
return -ENODEV;
return misc_register(&tdx_misc_dev);
}
module_init(tdx_guest_init);
static void __exit tdx_guest_exit(void)
{
misc_deregister(&tdx_misc_dev);
}
module_exit(tdx_guest_exit);
MODULE_AUTHOR("Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>");
MODULE_DESCRIPTION("TDX Guest Driver");
MODULE_LICENSE("GPL");