diff options
Diffstat (limited to 'arch/x86/kernel/relocate_kernel_64.S')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 56cab1bb25f5..042c9a0334e9 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -5,6 +5,8 @@ */ #include <linux/linkage.h> +#include <linux/stringify.h> +#include <asm/alternative.h> #include <asm/page_types.h> #include <asm/kexec.h> #include <asm/processor-flags.h> @@ -145,16 +147,15 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) * Set cr4 to a known state: * - physical address extension enabled * - 5-level paging, if it was enabled before + * - Machine check exception on TDX guest, if it was enabled before. + * Clearing MCE might not be allowed in TDX guests, depending on setup. + * + * Use R13 that contains the original CR4 value, read in relocate_kernel(). + * PAE is always set in the original CR4. */ - movl $X86_CR4_PAE, %eax - testq $X86_CR4_LA57, %r13 - jz 1f - orl $X86_CR4_LA57, %eax -1: - movq %rax, %cr4 - - jmp 1f -1: + andl $(X86_CR4_PAE | X86_CR4_LA57), %r13d + ALTERNATIVE "", __stringify(orl $X86_CR4_MCE, %r13d), X86_FEATURE_TDX_GUEST + movq %r13, %cr4 /* Flush the TLB (needed?) */ movq %r9, %cr3 @@ -165,9 +166,9 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) * used by kexec. Flush the caches before copying the kernel. */ testq %r12, %r12 - jz 1f + jz .Lsme_off wbinvd -1: +.Lsme_off: movq %rcx, %r11 call swap_pages @@ -187,7 +188,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) */ testq %r11, %r11 - jnz 1f + jnz .Lrelocate xorl %eax, %eax xorl %ebx, %ebx xorl %ecx, %ecx @@ -208,7 +209,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) ret int3 -1: +.Lrelocate: popq %rdx leaq PAGE_SIZE(%r10), %rsp ANNOTATE_RETPOLINE_SAFE |