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| author | Joerg Roedel <jroedel@suse.de> | 2020-09-08 15:35:17 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-09 11:45:24 +0300 |
| commit | 74d8d9d531b4cc945a9f75aa2fc21d99ca5a9fe3 (patch) | |
| tree | ba719ed3c3be8531a375850a80df229a29c375e1 /arch/x86/kernel/head_64.S | |
| parent | f980f9c31a923e9040dee0bc679a5f5b09e61f40 (diff) | |
| download | linux-74d8d9d531b4cc945a9f75aa2fc21d99ca5a9fe3.tar.xz | |
x86/sev-es: Setup an early #VC handler
Setup an early handler for #VC exceptions. There is no GHCB mapped
yet, so just re-use the vc_no_ghcb_handler(). It can only handle
CPUID exit-codes, but that should be enough to get the kernel through
verify_cpu() and __startup_64() until it runs on virtual addresses.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
[ boot failure Error: kernel_ident_mapping_init() failed. ]
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20200908123517.GA3764@8bytes.org
Diffstat (limited to 'arch/x86/kernel/head_64.S')
| -rw-r--r-- | arch/x86/kernel/head_64.S | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 3b40ec44a67d..6e68bca64ae4 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -348,6 +348,36 @@ SYM_CODE_START_LOCAL(early_idt_handler_common) jmp restore_regs_and_return_to_kernel SYM_CODE_END(early_idt_handler_common) +#ifdef CONFIG_AMD_MEM_ENCRYPT +/* + * VC Exception handler used during very early boot. The + * early_idt_handler_array can't be used because it returns via the + * paravirtualized INTERRUPT_RETURN and pv-ops don't work that early. + * + * This handler will end up in the .init.text section and not be + * available to boot secondary CPUs. + */ +SYM_CODE_START_NOALIGN(vc_no_ghcb) + UNWIND_HINT_IRET_REGS offset=8 + + /* Build pt_regs */ + PUSH_AND_CLEAR_REGS + + /* Call C handler */ + movq %rsp, %rdi + movq ORIG_RAX(%rsp), %rsi + call do_vc_no_ghcb + + /* Unwind pt_regs */ + POP_REGS + + /* Remove Error Code */ + addq $8, %rsp + + /* Pure iret required here - don't use INTERRUPT_RETURN */ + iretq +SYM_CODE_END(vc_no_ghcb) +#endif #define SYM_DATA_START_PAGE_ALIGNED(name) \ SYM_START(name, SYM_L_GLOBAL, .balign PAGE_SIZE) |