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-rw-r--r--arch/x86/boot/compressed/misc.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index b50c42455e25..98761a1576ce 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -169,6 +169,16 @@ void __puthex(unsigned long value)
}
}
+static bool l5_supported(void)
+{
+ /* Check if leaf 7 is supported. */
+ if (native_cpuid_eax(0) < 7)
+ return 0;
+
+ /* Check if la57 is supported. */
+ return native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31));
+}
+
#if CONFIG_X86_NEED_RELOCS
static void handle_relocations(void *output, unsigned long output_len,
unsigned long virt_addr)
@@ -362,6 +372,12 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
console_init();
debug_putstr("early console in extract_kernel\n");
+ if (IS_ENABLED(CONFIG_X86_5LEVEL) && !l5_supported()) {
+ error("This linux kernel as configured requires 5-level paging\n"
+ "This CPU does not support the required 'cr4.la57' feature\n"
+ "Unable to boot - please use a kernel appropriate for your CPU\n");
+ }
+
free_mem_ptr = heap; /* Heap */
free_mem_end_ptr = heap + BOOT_HEAP_SIZE;