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author | Tom Lendacky <thomas.lendacky@amd.com> | 2018-03-28 01:07:11 +0300 |
---|---|---|
committer | Thomas Gleixner <tglx@linutronix.de> | 2018-03-28 11:42:57 +0300 |
commit | 07344b15a994acadbe439aa4e75127ed1ccca099 (patch) | |
tree | 2fe67e65764d6975111d44881fb5b513440710ff /arch | |
parent | 547edaca247abf910e32f0cd883ba83b8fc6d0ed (diff) | |
download | linux-07344b15a994acadbe439aa4e75127ed1ccca099.tar.xz |
x86/boot: Fix SEV boot failure from change to __PHYSICAL_MASK_SHIFT
In arch/x86/boot/compressed/kaslr_64.c, CONFIG_AMD_MEM_ENCRYPT support was
initially #undef'd to support SME with minimal effort. When support for
SEV was added, the #undef remained and some minimal support for setting the
encryption bit was added for building identity mapped pagetable entries.
Commit b83ce5ee9147 ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52")
changed __PHYSICAL_MASK_SHIFT from 46 to 52 in support of 5-level paging.
This change resulted in SEV guests failing to boot because the encryption
bit was no longer being automatically masked out. The compressed boot
path now requires sme_me_mask to be defined in order for the pagetable
functions, such as pud_present(), to properly mask out the encryption bit
(currently bit 47) when evaluating pagetable entries.
Add an sme_me_mask variable in arch/x86/boot/compressed/mem_encrypt.S,
which is set when SEV is active, delete the #undef CONFIG_AMD_MEM_ENCRYPT
from arch/x86/boot/compressed/kaslr_64.c and use sme_me_mask when building
the identify mapped pagetable entries.
Fixes: b83ce5ee9147 ("x86/mm/64: Make __PHYSICAL_MASK_SHIFT always 52")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180327220711.8702.55842.stgit@tlendack-t1.amdoffice.net
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/boot/compressed/kaslr_64.c | 14 | ||||
-rw-r--r-- | arch/x86/boot/compressed/mem_encrypt.S | 17 | ||||
-rw-r--r-- | arch/x86/boot/compressed/misc.h | 2 |
3 files changed, 15 insertions, 18 deletions
diff --git a/arch/x86/boot/compressed/kaslr_64.c b/arch/x86/boot/compressed/kaslr_64.c index b5e5e02f8cde..522d11431433 100644 --- a/arch/x86/boot/compressed/kaslr_64.c +++ b/arch/x86/boot/compressed/kaslr_64.c @@ -16,13 +16,6 @@ #define __pa(x) ((unsigned long)(x)) #define __va(x) ((void *)((unsigned long)(x))) -/* - * The pgtable.h and mm/ident_map.c includes make use of the SME related - * information which is not used in the compressed image support. Un-define - * the SME support to avoid any compile and link errors. - */ -#undef CONFIG_AMD_MEM_ENCRYPT - /* No PAGE_TABLE_ISOLATION support needed either: */ #undef CONFIG_PAGE_TABLE_ISOLATION @@ -85,13 +78,14 @@ static struct x86_mapping_info mapping_info; /* Locates and clears a region for a new top level page table. */ void initialize_identity_maps(void) { - unsigned long sev_me_mask = get_sev_encryption_mask(); + /* If running as an SEV guest, the encryption mask is required. */ + set_sev_encryption_mask(); /* Init mapping_info with run-time function/buffer pointers. */ mapping_info.alloc_pgt_page = alloc_pgt_page; mapping_info.context = &pgt_data; - mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sev_me_mask; - mapping_info.kernpg_flag = _KERNPG_TABLE | sev_me_mask; + mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sme_me_mask; + mapping_info.kernpg_flag = _KERNPG_TABLE; /* * It should be impossible for this not to already be true, diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S index 54f5f6625a73..eaa843a52907 100644 --- a/arch/x86/boot/compressed/mem_encrypt.S +++ b/arch/x86/boot/compressed/mem_encrypt.S @@ -88,9 +88,7 @@ ENTRY(get_sev_encryption_bit) ENDPROC(get_sev_encryption_bit) .code64 -ENTRY(get_sev_encryption_mask) - xor %rax, %rax - +ENTRY(set_sev_encryption_mask) #ifdef CONFIG_AMD_MEM_ENCRYPT push %rbp push %rdx @@ -101,9 +99,7 @@ ENTRY(get_sev_encryption_mask) testl %eax, %eax jz .Lno_sev_mask - xor %rdx, %rdx - bts %rax, %rdx /* Create the encryption mask */ - mov %rdx, %rax /* ... and return it */ + bts %rax, sme_me_mask(%rip) /* Create the encryption mask */ .Lno_sev_mask: movq %rbp, %rsp /* Restore original stack pointer */ @@ -112,9 +108,16 @@ ENTRY(get_sev_encryption_mask) pop %rbp #endif + xor %rax, %rax ret -ENDPROC(get_sev_encryption_mask) +ENDPROC(set_sev_encryption_mask) .data enc_bit: .int 0xffffffff + +#ifdef CONFIG_AMD_MEM_ENCRYPT + .balign 8 +GLOBAL(sme_me_mask) + .quad 0 +#endif diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 4d369c308ed7..9e11be4cae19 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -114,6 +114,6 @@ static inline void console_init(void) { } #endif -unsigned long get_sev_encryption_mask(void); +void set_sev_encryption_mask(void); #endif |