arch/x86/virt/svm/cmdline.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AMD SVM-SEV command line parsing support
   4  *
   5  * Copyright (C) 2023 - 2024 Advanced Micro Devices, Inc.
   6  *
   7  * Author: Michael Roth <michael.roth@amd.com>
   8  */
   9
  10 #include <linux/string.h>
  11 #include <linux/printk.h>
  12 #include <linux/cache.h>
  13 #include <linux/cpufeature.h>
  14
  15 #include <asm/sev-common.h>
  16
  17 struct sev_config sev_cfg __read_mostly;
  18
  19 static int __init init_sev_config(char *str)
  20 {
  21         char *s;
  22
  23         while ((s = strsep(&str, ","))) {
  24                 if (!strcmp(s, "debug")) {
  25                         sev_cfg.debug = true;
  26                         continue;
  27                 }
  28
  29                 if (!strcmp(s, "nosnp")) {
  30                         if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR)) {
  31                                 setup_clear_cpu_cap(X86_FEATURE_SEV_SNP);
  32                                 cc_platform_clear(CC_ATTR_HOST_SEV_SNP);
  33                                 continue;
  34                         } else {
  35                                 goto warn;
  36                         }
  37                 }
  38
  39 warn:
  40                 pr_info("SEV command-line option '%s' was not recognized\n", s);
  41         }
  42
  43         return 1;
  44 }
  45 __setup("sev=", init_sev_config);