diff options
Diffstat (limited to 'arch/x86/kernel/relocate_kernel_64.S')
| -rw-r--r-- | arch/x86/kernel/relocate_kernel_64.S | 36 |
1 files changed, 24 insertions, 12 deletions
diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocate_kernel_64.S index ea604f4d0b52..11e20bb13aca 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -66,8 +66,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel) * %rdi indirection_page * %rsi pa_control_page * %rdx start address - * %rcx preserve_context - * %r8 host_mem_enc_active + * %rcx flags: RELOC_KERNEL_* */ /* Save the CPU context, used for jumping back */ @@ -111,7 +110,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel) /* save indirection list for jumping back */ movq %rdi, pa_backup_pages_map(%rip) - /* Save the preserve_context to %r11 as swap_pages clobbers %rcx. */ + /* Save the flags to %r11 as swap_pages clobbers %rcx. */ movq %rcx, %r11 /* setup a new stack at the end of the physical control page */ @@ -129,9 +128,8 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) /* * %rdi indirection page * %rdx start address - * %r8 host_mem_enc_active * %r9 page table page - * %r11 preserve_context + * %r11 flags: RELOC_KERNEL_* * %r13 original CR4 when relocate_kernel() was invoked */ @@ -200,14 +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. */ - testq %r8, %r8 - jz .Lsme_off + testb $RELOC_KERNEL_CACHE_INCOHERENT, %r11b + jz .Lnowbinvd wbinvd -.Lsme_off: +.Lnowbinvd: call swap_pages @@ -220,7 +225,7 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) movq %cr3, %rax movq %rax, %cr3 - testq %r11, %r11 /* preserve_context */ + testb $RELOC_KERNEL_PRESERVE_CONTEXT, %r11b jnz .Lrelocate /* @@ -273,7 +278,13 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) ANNOTATE_NOENDBR andq $PAGE_MASK, %r8 lea PAGE_SIZE(%r8), %rsp - movl $1, %r11d /* Ensure preserve_context flag is set */ + /* + * Ensure RELOC_KERNEL_PRESERVE_CONTEXT flag is set so that + * swap_pages() can swap pages correctly. Note all other + * RELOC_KERNEL_* flags passed to relocate_kernel() are not + * restored. + */ + movl $RELOC_KERNEL_PRESERVE_CONTEXT, %r11d call swap_pages movq kexec_va_control_page(%rip), %rax 0: addq $virtual_mapped - 0b, %rax @@ -321,7 +332,7 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages) UNWIND_HINT_END_OF_STACK /* * %rdi indirection page - * %r11 preserve_context + * %r11 flags: RELOC_KERNEL_* */ movq %rdi, %rcx /* Put the indirection_page in %rcx */ xorl %edi, %edi @@ -357,7 +368,8 @@ SYM_CODE_START_LOCAL_NOALIGN(swap_pages) movq %rdi, %rdx /* Save destination page to %rdx */ movq %rsi, %rax /* Save source page to %rax */ - testq %r11, %r11 /* Only actually swap for ::preserve_context */ + /* Only actually swap for ::preserve_context */ + testb $RELOC_KERNEL_PRESERVE_CONTEXT, %r11b jz .Lnoswap /* copy source page to swap page */ |