diff --git a/grub-core/commands/i386/rdmsr.c b/grub-core/commands/i386/rdmsr.c
index 89ece7657..2e42f6197 100644
--- a/grub-core/commands/i386/rdmsr.c
+++ b/grub-core/commands/i386/rdmsr.c
@@ -42,27 +42,16 @@ static const struct grub_arg_option options[] =
 static grub_err_t
 grub_cmd_msr_read (grub_extcmd_context_t ctxt, int argc, char **argv)
 {
-  grub_uint32_t manufacturer[3], max_cpuid, a, b, c, features, addr;
+  grub_err_t err;
+  grub_uint32_t addr;
   grub_uint64_t value;
   const char *ptr;
   char buf[sizeof("1122334455667788")];
 
-  /*
-   * The CPUID instruction should be used to determine whether MSRs
-   * are supported. (CPUID.01H:EDX[5] = 1)
-   */
-  if (! grub_cpu_is_cpuid_supported ())
-    return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
+  err = grub_cpu_is_msr_supported ();
 
-  grub_cpuid (0, max_cpuid, manufacturer[0], manufacturer[2], manufacturer[1]);
-
-  if (max_cpuid < 1)
-    return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
-
-  grub_cpuid (1, a, b, c, features);
-
-  if (!(features & (1 << 5)))
-    return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
+  if (err != GRUB_ERR_NONE)
+    return grub_error (err, N_("RDMSR is unsupported"));
 
   if (argc != 1)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("one argument expected"));
diff --git a/grub-core/commands/i386/wrmsr.c b/grub-core/commands/i386/wrmsr.c
index cf6bf6c8f..7fbedaed9 100644
--- a/grub-core/commands/i386/wrmsr.c
+++ b/grub-core/commands/i386/wrmsr.c
@@ -36,26 +36,15 @@ static grub_command_t cmd_write;
 static grub_err_t
 grub_cmd_msr_write (grub_command_t cmd __attribute__ ((unused)), int argc, char **argv)
 {
-  grub_uint32_t manufacturer[3], max_cpuid, a, b, c, features, addr;
+  grub_err_t err;
+  grub_uint32_t addr;
   grub_uint64_t value;
   const char *ptr;
 
-  /*
-   * The CPUID instruction should be used to determine whether MSRs
-   * are supported. (CPUID.01H:EDX[5] = 1)
-   */
-  if (!grub_cpu_is_cpuid_supported ())
-    return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
+  err = grub_cpu_is_msr_supported ();
 
-  grub_cpuid (0, max_cpuid, manufacturer[0], manufacturer[2], manufacturer[1]);
-
-  if (max_cpuid < 1)
-    return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
-
-  grub_cpuid (1, a, b, c, features);
-
-  if (!(features & (1 << 5)))
-    return grub_error (GRUB_ERR_BUG, N_("unsupported instruction"));
+  if (err != GRUB_ERR_NONE)
+    return grub_error (err, N_("WRMSR is unsupported"));
 
   if (argc != 2)
     return grub_error (GRUB_ERR_BAD_ARGUMENT, N_("two arguments expected"));
diff --git a/include/grub/i386/msr.h b/include/grub/i386/msr.h
index 4fba1b8e0..1e838c022 100644
--- a/include/grub/i386/msr.h
+++ b/include/grub/i386/msr.h
@@ -19,6 +19,35 @@
 #ifndef GRUB_I386_MSR_H
 #define GRUB_I386_MSR_H 1
 
+#include <grub/err.h>
+#include <grub/i386/cpuid.h>
+#include <grub/types.h>
+
+static inline grub_err_t
+grub_cpu_is_msr_supported (void)
+{
+  grub_uint32_t eax, ebx, ecx, edx;
+
+  /*
+   * The CPUID instruction should be used to determine whether MSRs
+   * are supported, CPUID.01H:EDX[5] = 1.
+   */
+  if (!grub_cpu_is_cpuid_supported ())
+    return GRUB_ERR_BAD_DEVICE;
+
+  grub_cpuid (0, eax, ebx, ecx, edx);
+
+  if (eax < 1)
+    return GRUB_ERR_BAD_DEVICE;
+
+  grub_cpuid (1, eax, ebx, ecx, edx);
+
+  if (!(edx & (1 << 5)))
+    return GRUB_ERR_BAD_DEVICE;
+
+  return GRUB_ERR_NONE;
+}
+
 /*
  * TODO: Add a general protection exception handler.
  *       Accessing a reserved or unimplemented MSR address results in a GP#.