[PATCH v1.1 1/2] x86emul: drop wrapper C file

[Jan Beulich <jbeulich@xxxxxxxx>]

Move the little bit that's still left in x86/x86_emulate.c into a __XEN__
conditional in x86/x86_emulate/x86_emulate.c. Move what are roughly the
test/fuzzing harness counterparts from there into the corresponding #else.

Interestingly more recent gcc takes issue with three static const arrays
which are unused when HVM=n (noticeable in particule in the shim build).
Apparently such are diagnosed only when present in the top-level file, but
not when living in an #include-d one.

Requested-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
v1.1: Address HVM=n build issues. See
      
https://gitlab.com/xen-project/hardware/xen-staging/-/pipelines/2674985992.

--- a/tools/tests/x86_emulator/x86-emulate.c
+++ b/tools/tests/x86_emulator/x86-emulate.c
@@ -3,27 +3,6 @@
 #include <errno.h>
 #include <sys/mman.h>
 
-/* See gcc bug 100680, but here don't bother making this version dependent. */
-#define gcc11_wrap(x) ({                  \
-    unsigned long x_;                     \
-    __asm__ ( "" : "=g" (x_) : "0" (x) ); \
-    (typeof(x))x_;                        \
-})
-
-#define cpu_has_amd_erratum(nr) 0
-#define cpu_has_mpx false
-#define read_bndcfgu() 0
-#define xstate_set_init(what)
-
-/* For generic assembly code: use macros to define operation/operand sizes. */
-#ifdef __i386__
-# define __OS          "l"  /* Operation Suffix */
-# define __OP          "e"  /* Operand Prefix */
-#else
-# define __OS          "q"  /* Operation Suffix */
-# define __OP          "r"  /* Operand Prefix */
-#endif
-
 uint32_t mxcsr_mask = 0x0000ffbf;
 struct cpu_policy cpu_policy;
 
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -69,7 +69,6 @@ obj-y += traps-setup.o
 obj-y += traps.o
 obj-$(CONFIG_INTEL) += tsx.o
 obj-$(CONFIG_VM_EVENT) += vm_event.o
-obj-y += x86_emulate.o
 obj-y += xstate.o
 
 ifneq ($(CONFIG_PV_SHIM_EXCLUSIVE),y)
@@ -86,13 +85,6 @@ hostprogs-y += efi/mkreloc
 
 $(obj)/efi/mkreloc: HOSTCFLAGS += -I$(srctree)/include
 
-ifneq ($(CONFIG_HVM),y)
-$(obj)/x86_emulate.o: CFLAGS-y += -Wno-unused-label
-endif
-ifeq ($(CONFIG_CONDITION_COVERAGE)$(CONFIG_CC_IS_GCC),yy)
-$(obj)/x86_emulate.o: CFLAGS-y += -Wno-error=coverage-too-many-conditions
-endif
-
 efi-y := $(shell if [ ! -r $(objtree)/include/xen/compile.h -o \
                       -O $(objtree)/include/xen/compile.h ]; then \
                          echo '$(TARGET).efi'; fi) \
--- a/xen/arch/x86/x86_emulate.c
+++ /dev/null
@@ -1,37 +0,0 @@
-/******************************************************************************
- * x86_emulate.c
- * 
- * Wrapper for generic x86 instruction decoder and emulator.
- * 
- * Copyright (c) 2008, Citrix Systems, Inc.
- * 
- * Authors:
- *    Keir Fraser <keir@xxxxxxx>
- */
-
-#include <xen/event.h>
-
-#include <asm/x86_emulate.h>
-#include <asm/processor.h> /* current_cpu_info */
-#include <asm/xstate.h>
-#include <asm/amd.h> /* cpu_has_amd_erratum() */
-
-/* Avoid namespace pollution. */
-#undef cmpxchg
-#undef cpuid
-#undef wbinvd
-
-#define cpu_has_amd_erratum(nr) \
-        cpu_has_amd_erratum(&current_cpu_data, AMD_ERRATUM_##nr)
-
-#include "x86_emulate/x86_emulate.c"
-
-/*
- * Local variables:
- * mode: C
- * c-file-style: "BSD"
- * c-basic-offset: 4
- * tab-width: 4
- * indent-tabs-mode: nil
- * End:
- */
--- a/xen/arch/x86/x86_emulate/Makefile
+++ b/xen/arch/x86/x86_emulate/Makefile
@@ -1,3 +1,14 @@
+# Put this ahead of the sorted list below, as it takes long to build and hence
+# we'd like parallel make to schedule its building early.
+obj-y += x86_emulate.o
+
+ifneq ($(CONFIG_HVM),y)
+$(obj)/x86_emulate.o: CFLAGS-y += -Wno-unused-label
+endif
+ifeq ($(CONFIG_CONDITION_COVERAGE)$(CONFIG_CC_IS_GCC),yy)
+$(obj)/x86_emulate.o: CFLAGS-y += -Wno-error=coverage-too-many-conditions
+endif
+
 obj-y += 0f01.o
 obj-y += 0fae.o
 obj-y += 0fc7.o
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -8,8 +8,52 @@
  * Copyright (c) 2005-2007 XenSource Inc.
  */
 
+#ifdef __XEN__
+
+# include <xen/event.h>
+
+# include <asm/amd.h> /* cpu_has_amd_erratum() */
+# include <asm/processor.h> /* current_cpu_info */
+# include <asm/x86_emulate.h>
+# include <asm/xstate.h>
+
+/* Avoid namespace pollution. */
+# undef cmpxchg
+# undef cpuid
+# undef wbinvd
+
+# define cpu_has_amd_erratum(nr) \
+         cpu_has_amd_erratum(&current_cpu_data, AMD_ERRATUM_##nr)
+
+#else /* !__XEN__ */
+
+/* See gcc bug 100680, but here don't bother making this version dependent. */
+# define gcc11_wrap(x) ({                  \
+     unsigned long x_;                     \
+     __asm__ ( "" : "=g" (x_) : "0" (x) ); \
+     (typeof(x))x_;                        \
+})
+
+# define cpu_has_amd_erratum(nr) 0
+# define cpu_has_mpx false
+# define read_bndcfgu() 0
+# define xstate_set_init(what)
+
+/* For generic assembly code: use macros to define operation/operand sizes. */
+# ifdef __i386__
+#  define __OS          "l"  /* Operation Suffix */
+#  define __OP          "e"  /* Operand Prefix */
+# else
+#  define __OS          "q"  /* Operation Suffix */
+#  define __OP          "r"  /* Operand Prefix */
+# endif
+
+#endif /* __XEN__ */
+
 #include "private.h"
 
+#ifndef X86EMUL_NO_MMX
+
 /*
  * The next two tables are indexed by high opcode extension byte (the one
  * that's encoded like an immediate) nibble, with each table element then
@@ -45,9 +89,15 @@ static const uint16_t _3dnow_ext_table[1
     [0xb] = (1 << 0xb) /* pswapd */,
 };
 
+#endif /* !X86EMUL_NO_MMX */
+
+#ifndef X86EMUL_NO_SIMD
+
 /* Shift values between src and dst sizes of pmov{s,z}x{b,w,d}{w,d,q}. */
 static const uint8_t pmov_convert_delta[] = { 1, 2, 3, 1, 2, 1 };
 
+#endif /* !X86EMUL_NO_SIMD */
+
 static const uint8_t sse_prefix[] = { 0x66, 0xf3, 0xf2 };
 
 #ifdef __x86_64__