dump: Simplify compiling win_dump.o by introducing win_dump_available()

To make dump.c less target dependent, move the TARGET_X86_64 #ifdef'ry
from dump.c to win_dump.c (introducing a win_dump_available() method
there). By doing so we can build win_dump.c on any target, and
simplify the meson rule.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20230225094903.53167-5-philmd@linaro.org>

dump/dump.c

@@ -28,10 +28,7 @@
 #include "hw/misc/vmcoreinfo.h"
 #include "migration/blocker.h"
 #include "hw/core/cpu.h"
-
-#ifdef TARGET_X86_64
 #include "win_dump.h"
-#endif
 
 #include <zlib.h>
 #ifdef CONFIG_LZO
@@ -2126,12 +2123,10 @@ void qmp_dump_guest_memory(bool paging, const char *file,
     }
 #endif
 
-#ifndef TARGET_X86_64
-    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
-        error_setg(errp, "Windows dump is only available for x86-64");
+    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP
+        && !win_dump_available(errp)) {
         return;
     }
-#endif
 
 #if !defined(WIN32)
     if (strstart(file, "fd:", &p)) {
@@ -2213,10 +2208,9 @@ DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY);
 #endif
 
-    /* Windows dump is available only if target is x86_64 */
-#ifdef TARGET_X86_64
-    QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
-#endif
+    if (win_dump_available(NULL)) {
+        QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
+    }
 
     return cap;
 }

dump/meson.build

@@ -1,4 +1,4 @@
 softmmu_ss.add(files('dump-hmp-cmds.c'))
 
 specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: [files('dump.c'), snappy, lzo])
-specific_ss.add(when: ['CONFIG_SOFTMMU', 'TARGET_X86_64'], if_true: files('win_dump.c'))
+specific_ss.add(when: 'CONFIG_SOFTMMU', if_true: files('win_dump.c'))

dump/win_dump.c

@@ -18,6 +18,13 @@
 #include "win_dump.h"
 #include "cpu.h"
 
+#if defined(TARGET_X86_64)
+
+bool win_dump_available(Error **errp)
+{
+    return true;
+}
+
 static size_t win_dump_ptr_size(bool x64)
 {
     return x64 ? sizeof(uint64_t) : sizeof(uint32_t);
@@ -470,3 +477,14 @@ out_cr3:
 
     return;
 }
+
+#else /* !TARGET_X86_64 */
+
+bool win_dump_available(Error **errp)
+{
+    error_setg(errp, "Windows dump is only available for x86-64");
+
+    return false;
+}
+
+#endif

dump/win_dump.h

@@ -13,6 +13,9 @@
 
 #include "sysemu/dump.h"
 
+/* Check Windows dump availability for the current target */
+bool win_dump_available(Error **errp);
+
 void create_win_dump(DumpState *s, Error **errp);
 
 #endif /* WIN_DUMP_H */