Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
---
 qga/vss-win32/meson.build   |  2 +-
 qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
 qga/vss-win32/vss-debug.h   | 24 ++++++++++++++++++++++++
 3 files changed, 56 insertions(+), 1 deletion(-)
 create mode 100644 qga/vss-win32/vss-debug.cpp
 create mode 100644 qga/vss-win32/vss-debug.h

diff --git a/qga/vss-win32/meson.build b/qga/vss-win32/meson.build
index 9483ccd3b8..0ac918910b 100644
--- a/qga/vss-win32/meson.build
+++ b/qga/vss-win32/meson.build
@@ -7,7 +7,7 @@ link_args = cc.get_supported_link_arguments([
 
 qga_vss = shared_module(
   'qga-vss',
-  ['requester.cpp', 'provider.cpp', 'install.cpp', genh],
+  ['requester.cpp', 'provider.cpp', 'install.cpp', 'vss-debug.cpp', genh],
   name_prefix: '',
   cpp_args: ['-Wno-unknown-pragmas', '-Wno-delete-non-virtual-dtor', '-Wno-non-virtual-dtor'],
   link_args: link_args,
diff --git a/qga/vss-win32/vss-debug.cpp b/qga/vss-win32/vss-debug.cpp
new file mode 100644
index 0000000000..de190a53f4
--- /dev/null
+++ b/qga/vss-win32/vss-debug.cpp
@@ -0,0 +1,31 @@
+/*
+ * QEMU Guest Agent VSS debug declarations
+ *
+ * Copyright (C) 2023 Red Hat Inc
+ *
+ * Authors:
+ *  Konstantin Kostiuk <kkostiuk@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "vss-common.h"
+
+void G_GNUC_PRINTF(2, 3)
+qga_debug_internal(const char *funcname, const char *fmt, ...)  {
+    char user_sting[512] = {0};
+    char full_string[640] = {0};
+
+    va_list args;
+    va_start(args, fmt);
+    vsnprintf(user_sting, 512, fmt, args);
+    va_end(args);
+
+    snprintf(full_string, 640, QGA_PROVIDER_NAME "[%lu]: %s %s\n",
+             GetCurrentThreadId(), funcname, user_sting);
+
+    OutputDebugString(full_string);
+    fprintf(stderr, "%s", full_string);
+}
diff --git a/qga/vss-win32/vss-debug.h b/qga/vss-win32/vss-debug.h
new file mode 100644
index 0000000000..4a15049a62
--- /dev/null
+++ b/qga/vss-win32/vss-debug.h
@@ -0,0 +1,24 @@
+/*
+ * QEMU Guest Agent VSS debug declarations
+ *
+ * Copyright (C) 2023 Red Hat Inc
+ *
+ * Authors:
+ *  Konstantin Kostiuk <kkostiuk@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include <vss-handles.h>
+
+#ifndef VSS_DEBUG_H
+#define VSS_DEBUG_H
+
+void qga_debug_internal(const char *funcname, const char *fmt, ...);
+
+#define qga_debug(fmt, ...) qga_debug_internal(__func__, fmt, ## __VA_ARGS__)
+#define qga_debug_begin qga_debug("begin")
+#define qga_debug_end qga_debug("end")
+
+#endif
-- 
2.34.1

On 7/7/23 10:31, Konstantin Kostiuk wrote:
> Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
> ---
>   qga/vss-win32/meson.build   |  2 +-
>   qga/vss-win32/vss-debug.cpp | 31 +++++++++++++++++++++++++++++++
>   qga/vss-win32/vss-debug.h   | 24 ++++++++++++++++++++++++
>   3 files changed, 56 insertions(+), 1 deletion(-)
>   create mode 100644 qga/vss-win32/vss-debug.cpp
>   create mode 100644 qga/vss-win32/vss-debug.h
> 
> diff --git a/qga/vss-win32/meson.build b/qga/vss-win32/meson.build
> index 9483ccd3b8..0ac918910b 100644
> --- a/qga/vss-win32/meson.build
> +++ b/qga/vss-win32/meson.build
> @@ -7,7 +7,7 @@ link_args = cc.get_supported_link_arguments([
>   
>   qga_vss = shared_module(
>     'qga-vss',
> -  ['requester.cpp', 'provider.cpp', 'install.cpp', genh],
> +  ['requester.cpp', 'provider.cpp', 'install.cpp', 'vss-debug.cpp', genh],
>     name_prefix: '',
>     cpp_args: ['-Wno-unknown-pragmas', '-Wno-delete-non-virtual-dtor', '-Wno-non-virtual-dtor'],
>     link_args: link_args,
> diff --git a/qga/vss-win32/vss-debug.cpp b/qga/vss-win32/vss-debug.cpp
> new file mode 100644
> index 0000000000..de190a53f4
> --- /dev/null
> +++ b/qga/vss-win32/vss-debug.cpp
> @@ -0,0 +1,31 @@
> +/*
> + * QEMU Guest Agent VSS debug declarations
> + *
> + * Copyright (C) 2023 Red Hat Inc
> + *
> + * Authors:
> + *  Konstantin Kostiuk <kkostiuk@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "vss-common.h"
> +
> +void G_GNUC_PRINTF(2, 3)

"G_GNUC_PRINTF(2, 3)" attribute goes with the declaration,
not the definition ...

> +qga_debug_internal(const char *funcname, const char *fmt, ...)  {
> +    char user_sting[512] = {0};
> +    char full_string[640] = {0};
> +
> +    va_list args;
> +    va_start(args, fmt);
> +    vsnprintf(user_sting, 512, fmt, args);
> +    va_end(args);
> +
> +    snprintf(full_string, 640, QGA_PROVIDER_NAME "[%lu]: %s %s\n",
> +             GetCurrentThreadId(), funcname, user_sting);
> +
> +    OutputDebugString(full_string);
> +    fprintf(stderr, "%s", full_string);
> +}
> diff --git a/qga/vss-win32/vss-debug.h b/qga/vss-win32/vss-debug.h
> new file mode 100644
> index 0000000000..4a15049a62
> --- /dev/null
> +++ b/qga/vss-win32/vss-debug.h
> @@ -0,0 +1,24 @@
> +/*
> + * QEMU Guest Agent VSS debug declarations
> + *
> + * Copyright (C) 2023 Red Hat Inc
> + *
> + * Authors:
> + *  Konstantin Kostiuk <kkostiuk@redhat.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include <vss-handles.h>
> +
> +#ifndef VSS_DEBUG_H
> +#define VSS_DEBUG_H
> +

... here: "G_GNUC_PRINTF(2, 3)".

> +void qga_debug_internal(const char *funcname, const char *fmt, ...);
> +
> +#define qga_debug(fmt, ...) qga_debug_internal(__func__, fmt, ## __VA_ARGS__)
> +#define qga_debug_begin qga_debug("begin")
> +#define qga_debug_end qga_debug("end")
> +
> +#endif

Otherwise LGTM, thanks for the rework.