[PATCH v8 04/21] x86/cea: Prefix event stack names with ESTACK_

Xin Li (Intel)
2025-10-14T01:11:12Z

Add the ESTACK_ prefix to event stack names to improve clarity and
readability. Without the prefix, names like DF, NMI, and DB are too
brief and potentially ambiguous.

This renaming also prepares for converting __this_cpu_ist_top_va from
a macro into a function that accepts an enum exception_stack_ordering
argument, without requiring changes to existing callsites.

Signed-off-by: Xin Li (Intel) <xin@zytor.com>
---

Changes in v7:
* Move rename code to this patch (Dave Hansen).
* Fix a vertical alignment (Dave Hansen).
---
arch/x86/coco/sev/noinstr.c | 4 ++--
arch/x86/coco/sev/vc-handle.c | 2 +-
arch/x86/include/asm/cpu_entry_area.h | 26 +++++++++++++-------------
arch/x86/kernel/cpu/common.c | 10 +++++-----
arch/x86/kernel/dumpstack_64.c | 14 +++++++-------
arch/x86/kernel/fred.c | 6 +++---
arch/x86/kernel/traps.c | 2 +-
arch/x86/mm/cpu_entry_area.c | 12 ++++++------
arch/x86/mm/fault.c | 2 +-
9 files changed, 39 insertions(+), 39 deletions(-)

diff --git a/arch/x86/coco/sev/noinstr.c b/arch/x86/coco/sev/noinstr.c
index b527eafb6312..c3985c9b232c 100644
--- a/arch/x86/coco/sev/noinstr.c
+++ b/arch/x86/coco/sev/noinstr.c
@@ -30,7 +30,7 @@ static __always_inline bool on_vc_stack(struct pt_regs *regs)
if (ip_within_syscall_gap(regs))
return false;

- return ((sp >= __this_cpu_ist_bottom_va(VC)) && (sp < __this_cpu_ist_top_va(VC)));
+ return ((sp >= __this_cpu_ist_bottom_va(ESTACK_VC)) && (sp < __this_cpu_ist_top_va(ESTACK_VC)));
}

/*
@@ -82,7 +82,7 @@ void noinstr __sev_es_ist_exit(void)
/* Read IST entry */
ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);

- if (WARN_ON(ist == __this_cpu_ist_top_va(VC)))
+ if (WARN_ON(ist == __this_cpu_ist_top_va(ESTACK_VC)))
return;

/* Read back old IST entry and write it to the TSS */
diff --git a/arch/x86/coco/sev/vc-handle.c b/arch/x86/coco/sev/vc-handle.c
index 7fc136a35334..1d3f086ae4c3 100644
--- a/arch/x86/coco/sev/vc-handle.c
+++ b/arch/x86/coco/sev/vc-handle.c
@@ -871,7 +871,7 @@ static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,

static __always_inline bool is_vc2_stack(unsigned long sp)
{
- return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
+ return (sp >= __this_cpu_ist_bottom_va(ESTACK_VC2) && sp < __this_cpu_ist_top_va(ESTACK_VC2));
}

static __always_inline bool vc_from_invalid_context(struct pt_regs *regs)
diff --git a/arch/x86/include/asm/cpu_entry_area.h b/arch/x86/include/asm/cpu_entry_area.h
index 462fc34f1317..d0f884c28178 100644
--- a/arch/x86/include/asm/cpu_entry_area.h
+++ b/arch/x86/include/asm/cpu_entry_area.h
@@ -18,19 +18,19 @@

/* Macro to enforce the same ordering and stack sizes */
#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]; \
+ char ESTACK_DF_stack_guard[guardsize]; \
+ char ESTACK_DF_stack[EXCEPTION_STKSZ]; \
+ char ESTACK_NMI_stack_guard[guardsize]; \
+ char ESTACK_NMI_stack[EXCEPTION_STKSZ]; \
+ char ESTACK_DB_stack_guard[guardsize]; \
+ char ESTACK_DB_stack[EXCEPTION_STKSZ]; \
+ char ESTACK_MCE_stack_guard[guardsize]; \
+ char ESTACK_MCE_stack[EXCEPTION_STKSZ]; \
+ char ESTACK_VC_stack_guard[guardsize]; \
+ char ESTACK_VC_stack[optional_stack_size]; \
+ char ESTACK_VC2_stack_guard[guardsize]; \
+ char ESTACK_VC2_stack[optional_stack_size]; \
+ char ESTACK_IST_top_guard[guardsize]; \

/* The exception stacks' physical storage. No guard pages required */
struct exception_stacks {
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index c7d3512914ca..5f78b8f63d8d 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -2332,12 +2332,12 @@ static inline void setup_getcpu(int cpu)
static inline void tss_setup_ist(struct tss_struct *tss)
{
/* Set up the per-CPU TSS IST stacks */
- tss->x86_tss.ist[IST_INDEX_DF] = __this_cpu_ist_top_va(DF);
- tss->x86_tss.ist[IST_INDEX_NMI] = __this_cpu_ist_top_va(NMI);
- tss->x86_tss.ist[IST_INDEX_DB] = __this_cpu_ist_top_va(DB);
- tss->x86_tss.ist[IST_INDEX_MCE] = __this_cpu_ist_top_va(MCE);
+ tss->x86_tss.ist[IST_INDEX_DF] = __this_cpu_ist_top_va(ESTACK_DF);
+ tss->x86_tss.ist[IST_INDEX_NMI] = __this_cpu_ist_top_va(ESTACK_NMI);
+ tss->x86_tss.ist[IST_INDEX_DB] = __this_cpu_ist_top_va(ESTACK_DB);
+ tss->x86_tss.ist[IST_INDEX_MCE] = __this_cpu_ist_top_va(ESTACK_MCE);
/* Only mapped when SEV-ES is active */
- tss->x86_tss.ist[IST_INDEX_VC] = __this_cpu_ist_top_va(VC);
+ tss->x86_tss.ist[IST_INDEX_VC] = __this_cpu_ist_top_va(ESTACK_VC);
}
#else /* CONFIG_X86_64 */
static inline void tss_setup_ist(struct tss_struct *tss) { }
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 6c5defd6569a..40f51e278171 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -73,7 +73,7 @@ struct estack_pages {
PFN_DOWN(CEA_ESTACK_OFFS(st) + CEA_ESTACK_SIZE(st) - 1)] = { \
.offs = CEA_ESTACK_OFFS(st), \
.size = CEA_ESTACK_SIZE(st), \
- .type = STACK_TYPE_EXCEPTION + ESTACK_ ##st, }
+ .type = STACK_TYPE_EXCEPTION + st, }

/*
* Array of exception stack page descriptors. If the stack is larger than
@@ -83,12 +83,12 @@ struct estack_pages {
*/
static const
struct estack_pages estack_pages[CEA_ESTACK_PAGES] ____cacheline_aligned = {
- EPAGERANGE(DF),
- EPAGERANGE(NMI),
- EPAGERANGE(DB),
- EPAGERANGE(MCE),
- EPAGERANGE(VC),
- EPAGERANGE(VC2),
+ EPAGERANGE(ESTACK_DF),
+ EPAGERANGE(ESTACK_NMI),
+ EPAGERANGE(ESTACK_DB),
+ EPAGERANGE(ESTACK_MCE),
+ EPAGERANGE(ESTACK_VC),
+ EPAGERANGE(ESTACK_VC2),
};

static __always_inline bool in_exception_stack(unsigned long *stack, struct stack_info *info)
diff --git a/arch/x86/kernel/fred.c b/arch/x86/kernel/fred.c
index 816187da3a47..06d944a3d051 100644
--- a/arch/x86/kernel/fred.c
+++ b/arch/x86/kernel/fred.c
@@ -87,7 +87,7 @@ void cpu_init_fred_rsps(void)
FRED_STKLVL(X86_TRAP_DF, FRED_DF_STACK_LEVEL));

/* The FRED equivalents to IST stacks... */
- wrmsrq(MSR_IA32_FRED_RSP1, __this_cpu_ist_top_va(DB));
- wrmsrq(MSR_IA32_FRED_RSP2, __this_cpu_ist_top_va(NMI));
- wrmsrq(MSR_IA32_FRED_RSP3, __this_cpu_ist_top_va(DF));
+ wrmsrq(MSR_IA32_FRED_RSP1, __this_cpu_ist_top_va(ESTACK_DB));
+ wrmsrq(MSR_IA32_FRED_RSP2, __this_cpu_ist_top_va(ESTACK_NMI));
+ wrmsrq(MSR_IA32_FRED_RSP3, __this_cpu_ist_top_va(ESTACK_DF));
}
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 6b22611e69cc..47b7b7495114 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -954,7 +954,7 @@ asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *r

if (!get_stack_info_noinstr(stack, current, &info) || info.type == STACK_TYPE_ENTRY ||
info.type > STACK_TYPE_EXCEPTION_LAST)
- sp = __this_cpu_ist_top_va(VC2);
+ sp = __this_cpu_ist_top_va(ESTACK_VC2);

sync:
/*
diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
index 575f863f3c75..9fa371af8abc 100644
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -151,15 +151,15 @@ static void __init percpu_setup_exception_stacks(unsigned int cpu)
* by guard pages so each stack must be mapped separately. DB2 is
* not mapped; it just exists to catch triple nesting of #DB.
*/
- cea_map_stack(DF);
- cea_map_stack(NMI);
- cea_map_stack(DB);
- cea_map_stack(MCE);
+ cea_map_stack(ESTACK_DF);
+ cea_map_stack(ESTACK_NMI);
+ cea_map_stack(ESTACK_DB);
+ cea_map_stack(ESTACK_MCE);

if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) {
- cea_map_stack(VC);
- cea_map_stack(VC2);
+ cea_map_stack(ESTACK_VC);
+ cea_map_stack(ESTACK_VC2);
}
}
}
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 998bd807fc7b..1804eb86cc14 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -671,7 +671,7 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code,
* and then double-fault, though, because we're likely to
* break the console driver and lose most of the stack dump.
*/
- call_on_stack(__this_cpu_ist_top_va(DF) - sizeof(void*),
+ call_on_stack(__this_cpu_ist_top_va(ESTACK_DF) - sizeof(void*),
handle_stack_overflow,
ASM_CALL_ARG3,
, [arg1] "r" (regs), [arg2] "r" (address), [arg3] "r" (&info));
--
2.51.0