diff options
Diffstat (limited to 'arch/x86/kernel/relocate_kernel_64.S')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index 26e945f85d19..11e20bb13aca 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -198,14 +198,21 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) movq %r9, %cr3 /* + * If the memory cache is in incoherent state, e.g., due to + * memory encryption, do WBINVD to flush cache. + * * If SME is active, there could be old encrypted cache line * entries that will conflict with the now unencrypted memory * used by kexec. Flush the caches before copying the kernel. + * + * Note SME sets this flag to true when the platform supports + * SME, so the WBINVD is performed even SME is not activated + * by the kernel. But this has no harm. */ - testb $RELOC_KERNEL_HOST_MEM_ENC_ACTIVE, %r11b - jz .Lsme_off + testb $RELOC_KERNEL_CACHE_INCOHERENT, %r11b + jz .Lnowbinvd wbinvd -.Lsme_off: +.Lnowbinvd: call swap_pages |