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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/x86/boot/compressed/mem_encrypt.S | |
| 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/x86/boot/compressed/mem_encrypt.S')
| -rw-r--r-- | arch/x86/boot/compressed/mem_encrypt.S | 17 |
1 files changed, 10 insertions, 7 deletions
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 |