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| author | Joerg Roedel <jroedel@suse.de> | 2020-09-07 16:15:43 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-09-09 12:33:19 +0300 |
| commit | 02772fb9b68e6a72a5e17f994048df832fe2b15e (patch) | |
| tree | ac6c3c2e41d924a7ddd9bbce6d605b0790dbc978 /arch/x86/include/asm | |
| parent | 885689e47dfa1499b756a07237eb645234d93cf9 (diff) | |
| download | linux-02772fb9b68e6a72a5e17f994048df832fe2b15e.tar.xz | |
x86/sev-es: Allocate and map an IST stack for #VC handler
Allocate and map an IST stack and an additional fall-back stack for
the #VC handler. The memory for the stacks is allocated only when
SEV-ES is active.
The #VC handler needs to use an IST stack because a #VC exception can be
raised from kernel space with unsafe stack, e.g. in the SYSCALL entry
path.
Since the #VC exception can be nested, the #VC handler switches back to
the interrupted stack when entered from kernel space. If switching back
is not possible, the fall-back stack is used.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-43-joro@8bytes.org
Diffstat (limited to 'arch/x86/include/asm')
| -rw-r--r-- | arch/x86/include/asm/cpu_entry_area.h | 33 | ||||
| -rw-r--r-- | arch/x86/include/asm/page_64_types.h | 1 |
2 files changed, 22 insertions, 12 deletions
diff --git a/arch/x86/include/asm/cpu_entry_area.h b/arch/x86/include/asm/cpu_entry_area.h index 8902fdb7de13..3d52b094850a 100644 --- a/arch/x86/include/asm/cpu_entry_area.h +++ b/arch/x86/include/asm/cpu_entry_area.h @@ -11,25 +11,29 @@ #ifdef CONFIG_X86_64 /* Macro to enforce the same ordering and stack sizes */ -#define ESTACKS_MEMBERS(guardsize) \ - char DF_stack_guard[guardsize]; \ - char DF_stack[EXCEPTION_STKSZ]; \ - char NMI_stack_guard[guardsize]; \ - char NMI_stack[EXCEPTION_STKSZ]; \ - char DB_stack_guard[guardsize]; \ - char DB_stack[EXCEPTION_STKSZ]; \ - char MCE_stack_guard[guardsize]; \ - char MCE_stack[EXCEPTION_STKSZ]; \ - char IST_top_guard[guardsize]; \ +#define ESTACKS_MEMBERS(guardsize, optional_stack_size) \ + char DF_stack_guard[guardsize]; \ + char DF_stack[EXCEPTION_STKSZ]; \ + char NMI_stack_guard[guardsize]; \ + char NMI_stack[EXCEPTION_STKSZ]; \ + char DB_stack_guard[guardsize]; \ + char DB_stack[EXCEPTION_STKSZ]; \ + char MCE_stack_guard[guardsize]; \ + char MCE_stack[EXCEPTION_STKSZ]; \ + char VC_stack_guard[guardsize]; \ + char VC_stack[optional_stack_size]; \ + char VC2_stack_guard[guardsize]; \ + char VC2_stack[optional_stack_size]; \ + char IST_top_guard[guardsize]; \ /* The exception stacks' physical storage. No guard pages required */ struct exception_stacks { - ESTACKS_MEMBERS(0) + ESTACKS_MEMBERS(0, 0) }; /* The effective cpu entry area mapping with guard pages. */ struct cea_exception_stacks { - ESTACKS_MEMBERS(PAGE_SIZE) + ESTACKS_MEMBERS(PAGE_SIZE, EXCEPTION_STKSZ) }; /* @@ -40,6 +44,8 @@ enum exception_stack_ordering { ESTACK_NMI, ESTACK_DB, ESTACK_MCE, + ESTACK_VC, + ESTACK_VC2, N_EXCEPTION_STACKS }; @@ -139,4 +145,7 @@ static inline struct entry_stack *cpu_entry_stack(int cpu) #define __this_cpu_ist_top_va(name) \ CEA_ESTACK_TOP(__this_cpu_read(cea_exception_stacks), name) +#define __this_cpu_ist_bottom_va(name) \ + CEA_ESTACK_BOT(__this_cpu_read(cea_exception_stacks), name) + #endif diff --git a/arch/x86/include/asm/page_64_types.h b/arch/x86/include/asm/page_64_types.h index 288b065955b7..d0c6c10c18a0 100644 --- a/arch/x86/include/asm/page_64_types.h +++ b/arch/x86/include/asm/page_64_types.h @@ -28,6 +28,7 @@ #define IST_INDEX_NMI 1 #define IST_INDEX_DB 2 #define IST_INDEX_MCE 3 +#define IST_INDEX_VC 4 /* * Set __PAGE_OFFSET to the most negative possible address + |