# Commit 7125429aafb9e3c9c88fc93001fc2300e0ac2cc8
# Date 2023-09-18 16:43:01 +0100
# Author Andrew Cooper <andrew.cooper3@citrix.com>
# Committer Andrew Cooper <andrew.cooper3@citrix.com>
x86/spec-ctrl: Turn the remaining SPEC_CTRL_{ENTRY,EXIT}_* into asm macros

These have grown more complex over time, with some already having been
converted.

Provide full Requires/Clobbers comments, otherwise missing at this level of
indirection.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/include/asm-x86/spec_ctrl_asm.h
+++ b/xen/include/asm-x86/spec_ctrl_asm.h
@@ -290,30 +290,50 @@ LBLn(insert_rsb_entry):;
 .endm
 
 /* Use after an entry from PV context (syscall/sysenter/int80/int82/etc). */
-#define SPEC_CTRL_ENTRY_FROM_PV                                         \
+.macro SPEC_CTRL_ENTRY_FROM_PV
+/*
+ * Requires %rsp=regs/cpuinfo, %rdx=0
+ * Clobbers %rax, %rcx, %rdx
+ */
     ALTERNATIVE __stringify(ASM_NOP27),                                 \
         __stringify(DO_SPEC_CTRL_COND_IBPB maybexen=0),                 \
-        X86_FEATURE_IBPB_ENTRY_PV;                                      \
+        X86_FEATURE_IBPB_ENTRY_PV
+
     ALTERNATIVE __stringify(ASM_NOP40),                                 \
-        DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_PV;                        \
+        DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_PV
+
     ALTERNATIVE __stringify(ASM_NOP25),                                 \
         __stringify(DO_SPEC_CTRL_ENTRY maybexen=0), X86_FEATURE_SC_MSR_PV
+.endm
 
 /* Use in interrupt/exception context.  May interrupt Xen or PV context. */
-#define SPEC_CTRL_ENTRY_FROM_INTR                                       \
+.macro SPEC_CTRL_ENTRY_FROM_INTR
+/*
+ * Requires %rsp=regs, %r14=stack_end, %rdx=0
+ * Clobbers %rax, %rcx, %rdx
+ */
     ALTERNATIVE __stringify(ASM_NOP34),                                 \
         __stringify(DO_SPEC_CTRL_COND_IBPB maybexen=1),                 \
-        X86_FEATURE_IBPB_ENTRY_PV;                                      \
+        X86_FEATURE_IBPB_ENTRY_PV
+
     ALTERNATIVE __stringify(ASM_NOP40),                                 \
-        DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_PV;                        \
+        DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_PV
+
     ALTERNATIVE __stringify(ASM_NOP33),                                 \
         __stringify(DO_SPEC_CTRL_ENTRY maybexen=1), X86_FEATURE_SC_MSR_PV
+.endm
 
 /* Use when exiting to PV guest context. */
-#define SPEC_CTRL_EXIT_TO_PV                                            \
+.macro SPEC_CTRL_EXIT_TO_PV
+/*
+ * Requires %rax=spec_ctrl, %rsp=regs/info
+ * Clobbers %rcx, %rdx
+ */
     ALTERNATIVE __stringify(ASM_NOP24),                                 \
-        DO_SPEC_CTRL_EXIT_TO_GUEST, X86_FEATURE_SC_MSR_PV;              \
+        DO_SPEC_CTRL_EXIT_TO_GUEST, X86_FEATURE_SC_MSR_PV
+
     DO_SPEC_CTRL_COND_VERW
+.endm
 
 /*
  * Use in IST interrupt/exception context.  May interrupt Xen or PV context.