[PATCH 0/4] char: Minor fixes, and a tighter QAPI schema

[PATCH 0/4] char: Minor fixes, and a tighter QAPI schema

[Markus Armbruster]

Markus Armbruster (4):
  chardev/parallel: Don't close stdin on inappropriate device
  tests/unit/test-char: Fix qemu_socket(), make_udp_socket() check
  qapi/char: Make backend types properly conditional
  qapi/char: Deprecate backend type "memory"

 docs/about/deprecated.rst |  8 ++++++++
 qapi/char.json            | 28 +++++++++++++++++-----------
 include/qemu/osdep.h      |  9 ++++++++-
 chardev/char-parallel.c   |  7 +++++--
 tests/unit/test-char.c    | 25 +++++++++++++++++++++++--
 chardev/meson.build       |  4 +---
 6 files changed, 62 insertions(+), 19 deletions(-)

-- 
2.43.0

[PATCH 1/4] chardev/parallel: Don't close stdin on inappropriate device

[Markus Armbruster]

The __linux__ version of qemu_chr_open_pp_fd() tries to claim the
parport device with a PPCLAIM ioctl().  On success, it stores the file
descriptor in the chardev object, and returns success.  On failure, it
closes the file descriptor, and returns failure.

chardev_new() then passes the Chardev to object_unref().  This duly
calls char_parallel_finalize(), which closes the file descriptor
stored in the chardev object.  Since qemu_chr_open_pp_fd() didn't
store it, it's still zero, so this closes standard input.  Ooopsie.

To demonstate, add a unit test.  With the bug above unfixed, running
this test closes standard input.  char_hotswap_test() happens to run
next.  It opens a socket, duly gets file descriptor 0, and since it
tests for success with > 0 instead of >= 0, it fails.

The test needs to be conditional exactly like the chardev it tests.
Since the condition is rather complicated, steal the solution from the
serial chardev: define HAVE_CHARDEV_PARALLEL in qemu/osdep.h.  This
also permits simplifying chardev/meson.build a bit.

The bug fix is easy enough: store the file descriptor, and leave
closing it to char_parallel_finalize().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 include/qemu/osdep.h    |  9 ++++++++-
 chardev/char-parallel.c |  7 +++++--
 tests/unit/test-char.c  | 21 +++++++++++++++++++++
 chardev/meson.build     |  4 +---
 4 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
index c9692cc314..3b0f3389d3 100644
--- a/include/qemu/osdep.h
+++ b/include/qemu/osdep.h
@@ -508,11 +508,18 @@ void qemu_anon_ram_free(void *ptr, size_t size);
 
 #ifdef _WIN32
 #define HAVE_CHARDEV_SERIAL 1
-#elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)    \
+#define HAVE_CHARDEV_PARALLEL 1
+#else
+#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)   \
     || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
     || defined(__GLIBC__) || defined(__APPLE__)
 #define HAVE_CHARDEV_SERIAL 1
 #endif
+#if defined(__linux__) || defined(__FreeBSD__) \
+    || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
+#define HAVE_CHARDEV_PARALLEL 1
+#endif
+#endif
 
 #if defined(__HAIKU__)
 #define SIGIO SIGPOLL
diff --git a/chardev/char-parallel.c b/chardev/char-parallel.c
index a5164f975a..78697d7522 100644
--- a/chardev/char-parallel.c
+++ b/chardev/char-parallel.c
@@ -164,13 +164,13 @@ static void qemu_chr_open_pp_fd(Chardev *chr,
 {
     ParallelChardev *drv = PARALLEL_CHARDEV(chr);
 
+    drv->fd = fd;
+
     if (ioctl(fd, PPCLAIM) < 0) {
         error_setg_errno(errp, errno, "not a parallel port");
-        close(fd);
         return;
     }
 
-    drv->fd = fd;
     drv->mode = IEEE1284_MODE_COMPAT;
 }
 #endif /* __linux__ */
@@ -238,6 +238,7 @@ static void qemu_chr_open_pp_fd(Chardev *chr,
 }
 #endif
 
+#ifdef HAVE_CHARDEV_PARALLEL
 static void qmp_chardev_open_parallel(Chardev *chr,
                                       ChardevBackend *backend,
                                       bool *be_opened,
@@ -306,3 +307,5 @@ static void register_types(void)
 }
 
 type_init(register_types);
+
+#endif  /* HAVE_CHARDEV_PARALLEL */
diff --git a/tests/unit/test-char.c b/tests/unit/test-char.c
index 649fdf64e1..76946e6f90 100644
--- a/tests/unit/test-char.c
+++ b/tests/unit/test-char.c
@@ -1203,6 +1203,24 @@ static void char_serial_test(void)
 }
 #endif
 
+#if defined(HAVE_CHARDEV_PARALLEL) && !defined(WIN32)
+static void char_parallel_test(void)
+{
+    QemuOpts *opts;
+    Chardev *chr;
+
+    opts = qemu_opts_create(qemu_find_opts("chardev"), "parallel-id",
+                            1, &error_abort);
+    qemu_opt_set(opts, "backend", "parallel", &error_abort);
+    qemu_opt_set(opts, "path", "/dev/null", &error_abort);
+
+    chr = qemu_chr_new_from_opts(opts, NULL, NULL);
+    g_assert_null(chr);
+
+    qemu_opts_del(opts);
+}
+#endif
+
 #ifndef _WIN32
 static void char_file_fifo_test(void)
 {
@@ -1544,6 +1562,9 @@ int main(int argc, char **argv)
     g_test_add_func("/char/udp", char_udp_test);
 #if defined(HAVE_CHARDEV_SERIAL) && !defined(WIN32)
     g_test_add_func("/char/serial", char_serial_test);
+#endif
+#if defined(HAVE_CHARDEV_PARALLEL) && !defined(WIN32)
+    g_test_add_func("/char/parallel", char_parallel_test);
 #endif
     g_test_add_func("/char/hotswap", char_hotswap_test);
     g_test_add_func("/char/websocket", char_websock_test);
diff --git a/chardev/meson.build b/chardev/meson.build
index c80337d15f..b39028b7b0 100644
--- a/chardev/meson.build
+++ b/chardev/meson.build
@@ -21,11 +21,9 @@ if host_os == 'windows'
 else
   chardev_ss.add(files(
       'char-fd.c',
+        'char-parallel.c',
       'char-pty.c',
     ), util)
-  if host_os in ['linux', 'gnu/kfreebsd', 'freebsd', 'dragonfly']
-    chardev_ss.add(files('char-parallel.c'))
-  endif
 endif
 
 chardev_ss = chardev_ss.apply({})
-- 
2.43.0

Re: [PATCH 1/4] chardev/parallel: Don't close stdin on inappropriate device

[Eric Blake]

On Sat, Feb 03, 2024 at 09:02:25AM +0100, Markus Armbruster wrote:
> The __linux__ version of qemu_chr_open_pp_fd() tries to claim the
> parport device with a PPCLAIM ioctl().  On success, it stores the file
> descriptor in the chardev object, and returns success.  On failure, it
> closes the file descriptor, and returns failure.
> 
> chardev_new() then passes the Chardev to object_unref().  This duly
> calls char_parallel_finalize(), which closes the file descriptor
> stored in the chardev object.  Since qemu_chr_open_pp_fd() didn't
> store it, it's still zero, so this closes standard input.  Ooopsie.
> 
> To demonstate, add a unit test.  With the bug above unfixed, running
> this test closes standard input.  char_hotswap_test() happens to run
> next.  It opens a socket, duly gets file descriptor 0, and since it
> tests for success with > 0 instead of >= 0, it fails.

Two bugs for the price of one!

> 
> The test needs to be conditional exactly like the chardev it tests.
> Since the condition is rather complicated, steal the solution from the
> serial chardev: define HAVE_CHARDEV_PARALLEL in qemu/osdep.h.  This
> also permits simplifying chardev/meson.build a bit.
> 
> The bug fix is easy enough: store the file descriptor, and leave
> closing it to char_parallel_finalize().
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---

> +++ b/include/qemu/osdep.h
> @@ -508,11 +508,18 @@ void qemu_anon_ram_free(void *ptr, size_t size);
>  
>  #ifdef _WIN32
>  #define HAVE_CHARDEV_SERIAL 1
> -#elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)    \
> +#define HAVE_CHARDEV_PARALLEL 1
> +#else
> +#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)   \
>      || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
>      || defined(__GLIBC__) || defined(__APPLE__)
>  #define HAVE_CHARDEV_SERIAL 1
>  #endif
> +#if defined(__linux__) || defined(__FreeBSD__) \
> +    || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
> +#define HAVE_CHARDEV_PARALLEL 1
> +#endif
> +#endif

Not for this patch, but I've grown to like a preprocessor style I've
seen in other projects to make it easier to read nested #if:

#ifdef _WIN32
# define HAVE_CHARDEV_SERIAL 1
# define HAVE_CHARDEV_PARALLEL 1
#else
# if defined(__linux__) ... defined(__APPLE__)
#  define HAVE_CHARDEV_SERIAL 1
# endif
# if defined(__linux__) ... defined(__DragonFly__)
#  define HAVE_CHARDEV_PARALLEL 1
# endif
#endif

> +++ b/chardev/meson.build
> @@ -21,11 +21,9 @@ if host_os == 'windows'
>  else
>    chardev_ss.add(files(
>        'char-fd.c',
> +        'char-parallel.c',
>        'char-pty.c',

Indentation looks off.  Otherwise,

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization:  qemu.org | libguestfs.org

Re: [PATCH 1/4] chardev/parallel: Don't close stdin on inappropriate device

[Markus Armbruster]

Eric Blake <eblake@redhat.com> writes:

> On Sat, Feb 03, 2024 at 09:02:25AM +0100, Markus Armbruster wrote:
>> The __linux__ version of qemu_chr_open_pp_fd() tries to claim the
>> parport device with a PPCLAIM ioctl().  On success, it stores the file
>> descriptor in the chardev object, and returns success.  On failure, it
>> closes the file descriptor, and returns failure.
>> 
>> chardev_new() then passes the Chardev to object_unref().  This duly
>> calls char_parallel_finalize(), which closes the file descriptor
>> stored in the chardev object.  Since qemu_chr_open_pp_fd() didn't
>> store it, it's still zero, so this closes standard input.  Ooopsie.
>> 
>> To demonstate, add a unit test.  With the bug above unfixed, running
>> this test closes standard input.  char_hotswap_test() happens to run
>> next.  It opens a socket, duly gets file descriptor 0, and since it
>> tests for success with > 0 instead of >= 0, it fails.
>
> Two bugs for the price of one!
>
>> 
>> The test needs to be conditional exactly like the chardev it tests.
>> Since the condition is rather complicated, steal the solution from the
>> serial chardev: define HAVE_CHARDEV_PARALLEL in qemu/osdep.h.  This
>> also permits simplifying chardev/meson.build a bit.
>> 
>> The bug fix is easy enough: store the file descriptor, and leave
>> closing it to char_parallel_finalize().
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>
>> +++ b/include/qemu/osdep.h
>> @@ -508,11 +508,18 @@ void qemu_anon_ram_free(void *ptr, size_t size);
>>  
>>  #ifdef _WIN32
>>  #define HAVE_CHARDEV_SERIAL 1
>> -#elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)    \
>> +#define HAVE_CHARDEV_PARALLEL 1
>> +#else
>> +#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__)   \
>>      || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
>>      || defined(__GLIBC__) || defined(__APPLE__)
>>  #define HAVE_CHARDEV_SERIAL 1
>>  #endif
>> +#if defined(__linux__) || defined(__FreeBSD__) \
>> +    || defined(__FreeBSD_kernel__) || defined(__DragonFly__)
>> +#define HAVE_CHARDEV_PARALLEL 1
>> +#endif
>> +#endif
>
> Not for this patch, but I've grown to like a preprocessor style I've
> seen in other projects to make it easier to read nested #if:
>
> #ifdef _WIN32
> # define HAVE_CHARDEV_SERIAL 1
> # define HAVE_CHARDEV_PARALLEL 1
> #else
> # if defined(__linux__) ... defined(__APPLE__)
> #  define HAVE_CHARDEV_SERIAL 1
> # endif
> # if defined(__linux__) ... defined(__DragonFly__)
> #  define HAVE_CHARDEV_PARALLEL 1
> # endif
> #endif

I like this style, too.

>> +++ b/chardev/meson.build
>> @@ -21,11 +21,9 @@ if host_os == 'windows'
>>  else
>>    chardev_ss.add(files(
>>        'char-fd.c',
>> +        'char-parallel.c',
>>        'char-pty.c',
>
> Indentation looks off.  Otherwise,

Will fix.

> Reviewed-by: Eric Blake <eblake@redhat.com>

Thanks!

Re: [PATCH 1/4] chardev/parallel: Don't close stdin on inappropriate device

[Markus Armbruster]

Markus Armbruster <armbru@redhat.com> writes:

> The __linux__ version of qemu_chr_open_pp_fd() tries to claim the
> parport device with a PPCLAIM ioctl().  On success, it stores the file
> descriptor in the chardev object, and returns success.  On failure, it
> closes the file descriptor, and returns failure.
>
> chardev_new() then passes the Chardev to object_unref().  This duly
> calls char_parallel_finalize(), which closes the file descriptor
> stored in the chardev object.  Since qemu_chr_open_pp_fd() didn't
> store it, it's still zero, so this closes standard input.  Ooopsie.
>
> To demonstate, add a unit test.  With the bug above unfixed, running
> this test closes standard input.  char_hotswap_test() happens to run
> next.  It opens a socket, duly gets file descriptor 0, and since it
> tests for success with > 0 instead of >= 0, it fails.
>
> The test needs to be conditional exactly like the chardev it tests.
> Since the condition is rather complicated, steal the solution from the
> serial chardev: define HAVE_CHARDEV_PARALLEL in qemu/osdep.h.  This
> also permits simplifying chardev/meson.build a bit.
>
> The bug fix is easy enough: store the file descriptor, and leave
> closing it to char_parallel_finalize().
>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

[...]

> diff --git a/chardev/char-parallel.c b/chardev/char-parallel.c
> index a5164f975a..78697d7522 100644
> --- a/chardev/char-parallel.c
> +++ b/chardev/char-parallel.c
> @@ -164,13 +164,13 @@ static void qemu_chr_open_pp_fd(Chardev *chr,
>  {
>      ParallelChardev *drv = PARALLEL_CHARDEV(chr);
>  
> +    drv->fd = fd;
> +
>      if (ioctl(fd, PPCLAIM) < 0) {
>          error_setg_errno(errp, errno, "not a parallel port");
> -        close(fd);
>          return;
>      }
>  
> -    drv->fd = fd;
>      drv->mode = IEEE1284_MODE_COMPAT;
>  }
>  #endif /* __linux__ */
> @@ -238,6 +238,7 @@ static void qemu_chr_open_pp_fd(Chardev *chr,
>  }
>  #endif
>  
> +#ifdef HAVE_CHARDEV_PARALLEL
>  static void qmp_chardev_open_parallel(Chardev *chr,
>                                        ChardevBackend *backend,
>                                        bool *be_opened,
> @@ -306,3 +307,5 @@ static void register_types(void)
>  }
>  
>  type_init(register_types);
> +
> +#endif  /* HAVE_CHARDEV_PARALLEL */
> diff --git a/tests/unit/test-char.c b/tests/unit/test-char.c
> index 649fdf64e1..76946e6f90 100644
> --- a/tests/unit/test-char.c
> +++ b/tests/unit/test-char.c
> @@ -1203,6 +1203,24 @@ static void char_serial_test(void)
>  }
>  #endif
>  
> +#if defined(HAVE_CHARDEV_PARALLEL) && !defined(WIN32)
> +static void char_parallel_test(void)
> +{
> +    QemuOpts *opts;
> +    Chardev *chr;
> +
> +    opts = qemu_opts_create(qemu_find_opts("chardev"), "parallel-id",
> +                            1, &error_abort);
> +    qemu_opt_set(opts, "backend", "parallel", &error_abort);
> +    qemu_opt_set(opts, "path", "/dev/null", &error_abort);
> +
> +    chr = qemu_chr_new_from_opts(opts, NULL, NULL);
> +    g_assert_null(chr);

This is wrong.

On a Linux host, qemu_chr_new_from_opts() fails, because
qemu_chr_open_pp_fd()'s attempt to PPCLAIM fails.

On a BSD host, it succeeds.

Proposed fixup appended.  Marc-André, is respinning the PR with the
fixup okay, or would you prefer a v2?

> +
> +    qemu_opts_del(opts);
> +}
> +#endif
> +
>  #ifndef _WIN32
>  static void char_file_fifo_test(void)
>  {
> @@ -1544,6 +1562,9 @@ int main(int argc, char **argv)
>      g_test_add_func("/char/udp", char_udp_test);
>  #if defined(HAVE_CHARDEV_SERIAL) && !defined(WIN32)
>      g_test_add_func("/char/serial", char_serial_test);
> +#endif
> +#if defined(HAVE_CHARDEV_PARALLEL) && !defined(WIN32)
> +    g_test_add_func("/char/parallel", char_parallel_test);
>  #endif
>      g_test_add_func("/char/hotswap", char_hotswap_test);
>      g_test_add_func("/char/websocket", char_websock_test);

[...]

diff --git a/tests/unit/test-char.c b/tests/unit/test-char.c
index e3b783c06b..f273ce5226 100644
--- a/tests/unit/test-char.c
+++ b/tests/unit/test-char.c
@@ -1215,7 +1215,13 @@ static void char_parallel_test(void)
     qemu_opt_set(opts, "path", "/dev/null", &error_abort);
 
     chr = qemu_chr_new_from_opts(opts, NULL, NULL);
+#ifdef __linux__
+    /* fails to PPCLAIM, see qemu_chr_open_pp_fd() */
     g_assert_null(chr);
+#else
+    g_assert_nonnull(chr);
+    object_unparent(OBJECT(chr));
+#endif
 
     qemu_opts_del(opts);
 }

Re: [PATCH 1/4] chardev/parallel: Don't close stdin on inappropriate device

[Marc-André Lureau]

Hi

On Tue, Feb 13, 2024 at 5:58 PM Markus Armbruster <armbru@redhat.com> wrote:
>
> Markus Armbruster <armbru@redhat.com> writes:
>
> > The __linux__ version of qemu_chr_open_pp_fd() tries to claim the
> > parport device with a PPCLAIM ioctl().  On success, it stores the file
> > descriptor in the chardev object, and returns success.  On failure, it
> > closes the file descriptor, and returns failure.
> >
> > chardev_new() then passes the Chardev to object_unref().  This duly
> > calls char_parallel_finalize(), which closes the file descriptor
> > stored in the chardev object.  Since qemu_chr_open_pp_fd() didn't
> > store it, it's still zero, so this closes standard input.  Ooopsie.
> >
> > To demonstate, add a unit test.  With the bug above unfixed, running
> > this test closes standard input.  char_hotswap_test() happens to run
> > next.  It opens a socket, duly gets file descriptor 0, and since it
> > tests for success with > 0 instead of >= 0, it fails.
> >
> > The test needs to be conditional exactly like the chardev it tests.
> > Since the condition is rather complicated, steal the solution from the
> > serial chardev: define HAVE_CHARDEV_PARALLEL in qemu/osdep.h.  This
> > also permits simplifying chardev/meson.build a bit.
> >
> > The bug fix is easy enough: store the file descriptor, and leave
> > closing it to char_parallel_finalize().
> >
> > Signed-off-by: Markus Armbruster <armbru@redhat.com>
>
> [...]
>
> > diff --git a/chardev/char-parallel.c b/chardev/char-parallel.c
> > index a5164f975a..78697d7522 100644
> > --- a/chardev/char-parallel.c
> > +++ b/chardev/char-parallel.c
> > @@ -164,13 +164,13 @@ static void qemu_chr_open_pp_fd(Chardev *chr,
> >  {
> >      ParallelChardev *drv = PARALLEL_CHARDEV(chr);
> >
> > +    drv->fd = fd;
> > +
> >      if (ioctl(fd, PPCLAIM) < 0) {
> >          error_setg_errno(errp, errno, "not a parallel port");
> > -        close(fd);
> >          return;
> >      }
> >
> > -    drv->fd = fd;
> >      drv->mode = IEEE1284_MODE_COMPAT;
> >  }
> >  #endif /* __linux__ */
> > @@ -238,6 +238,7 @@ static void qemu_chr_open_pp_fd(Chardev *chr,
> >  }
> >  #endif
> >
> > +#ifdef HAVE_CHARDEV_PARALLEL
> >  static void qmp_chardev_open_parallel(Chardev *chr,
> >                                        ChardevBackend *backend,
> >                                        bool *be_opened,
> > @@ -306,3 +307,5 @@ static void register_types(void)
> >  }
> >
> >  type_init(register_types);
> > +
> > +#endif  /* HAVE_CHARDEV_PARALLEL */
> > diff --git a/tests/unit/test-char.c b/tests/unit/test-char.c
> > index 649fdf64e1..76946e6f90 100644
> > --- a/tests/unit/test-char.c
> > +++ b/tests/unit/test-char.c
> > @@ -1203,6 +1203,24 @@ static void char_serial_test(void)
> >  }
> >  #endif
> >
> > +#if defined(HAVE_CHARDEV_PARALLEL) && !defined(WIN32)
> > +static void char_parallel_test(void)
> > +{
> > +    QemuOpts *opts;
> > +    Chardev *chr;
> > +
> > +    opts = qemu_opts_create(qemu_find_opts("chardev"), "parallel-id",
> > +                            1, &error_abort);
> > +    qemu_opt_set(opts, "backend", "parallel", &error_abort);
> > +    qemu_opt_set(opts, "path", "/dev/null", &error_abort);
> > +
> > +    chr = qemu_chr_new_from_opts(opts, NULL, NULL);
> > +    g_assert_null(chr);
>
> This is wrong.
>
> On a Linux host, qemu_chr_new_from_opts() fails, because
> qemu_chr_open_pp_fd()'s attempt to PPCLAIM fails.
>
> On a BSD host, it succeeds.
>
> Proposed fixup appended.  Marc-André, is respinning the PR with the
> fixup okay, or would you prefer a v2?

I am okay with a new PR.

thanks

>
> > +
> > +    qemu_opts_del(opts);
> > +}
> > +#endif
> > +
> >  #ifndef _WIN32
> >  static void char_file_fifo_test(void)
> >  {
> > @@ -1544,6 +1562,9 @@ int main(int argc, char **argv)
> >      g_test_add_func("/char/udp", char_udp_test);
> >  #if defined(HAVE_CHARDEV_SERIAL) && !defined(WIN32)
> >      g_test_add_func("/char/serial", char_serial_test);
> > +#endif
> > +#if defined(HAVE_CHARDEV_PARALLEL) && !defined(WIN32)
> > +    g_test_add_func("/char/parallel", char_parallel_test);
> >  #endif
> >      g_test_add_func("/char/hotswap", char_hotswap_test);
> >      g_test_add_func("/char/websocket", char_websock_test);
>
> [...]
>
> diff --git a/tests/unit/test-char.c b/tests/unit/test-char.c
> index e3b783c06b..f273ce5226 100644
> --- a/tests/unit/test-char.c
> +++ b/tests/unit/test-char.c
> @@ -1215,7 +1215,13 @@ static void char_parallel_test(void)
>      qemu_opt_set(opts, "path", "/dev/null", &error_abort);
>
>      chr = qemu_chr_new_from_opts(opts, NULL, NULL);
> +#ifdef __linux__
> +    /* fails to PPCLAIM, see qemu_chr_open_pp_fd() */
>      g_assert_null(chr);
> +#else
> +    g_assert_nonnull(chr);
> +    object_unparent(OBJECT(chr));
> +#endif
>
>      qemu_opts_del(opts);
>  }
>

[PATCH 2/4] tests/unit/test-char: Fix qemu_socket(), make_udp_socket() check

[Markus Armbruster]

qemu_socket() and make_udp_socket() return a file descriptor on
success, -1 on failure.  The check misinterprets 0 as failure.  Fix
that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 tests/unit/test-char.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/unit/test-char.c b/tests/unit/test-char.c
index 76946e6f90..e3b783c06b 100644
--- a/tests/unit/test-char.c
+++ b/tests/unit/test-char.c
@@ -556,7 +556,7 @@ static int make_udp_socket(int *port)
     socklen_t alen = sizeof(addr);
     int ret, sock = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 
-    g_assert_cmpint(sock, >, 0);
+    g_assert_cmpint(sock, >=, 0);
     addr.sin_family = AF_INET ;
     addr.sin_addr.s_addr = htonl(INADDR_ANY);
     addr.sin_port = 0;
@@ -1401,7 +1401,7 @@ static void char_hotswap_test(void)
 
     int port;
     int sock = make_udp_socket(&port);
-    g_assert_cmpint(sock, >, 0);
+    g_assert_cmpint(sock, >=, 0);
 
     chr_args = g_strdup_printf("udp:127.0.0.1:%d", port);
 
-- 
2.43.0

Re: [PATCH 2/4] tests/unit/test-char: Fix qemu_socket(), make_udp_socket() check

[Eric Blake]

On Sat, Feb 03, 2024 at 09:02:26AM +0100, Markus Armbruster wrote:
> qemu_socket() and make_udp_socket() return a file descriptor on
> success, -1 on failure.  The check misinterprets 0 as failure.  Fix
> that.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  tests/unit/test-char.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

Might be worth amending the commit message of 1/4 where you called out
this bug to mention it will be fixed in the next patch.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization:  qemu.org | libguestfs.org

Re: [PATCH 2/4] tests/unit/test-char: Fix qemu_socket(), make_udp_socket() check

[Markus Armbruster]

Eric Blake <eblake@redhat.com> writes:

> On Sat, Feb 03, 2024 at 09:02:26AM +0100, Markus Armbruster wrote:
>> qemu_socket() and make_udp_socket() return a file descriptor on
>> success, -1 on failure.  The check misinterprets 0 as failure.  Fix
>> that.
>> 
>> Signed-off-by: Markus Armbruster <armbru@redhat.com>
>> ---
>>  tests/unit/test-char.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> Reviewed-by: Eric Blake <eblake@redhat.com>
>
> Might be worth amending the commit message of 1/4 where you called out
> this bug to mention it will be fixed in the next patch.

Yes.  Thanks!

[PATCH 3/4] qapi/char: Make backend types properly conditional

[Markus Armbruster]

Character backends are actually QOM types.  When a backend's
compile-time conditional QOM type is not compiled in, creation fails
with "'FOO' is not a valid char driver name".  Okay, except
introspecting chardev-add with query-qmp-schema doesn't work then: the
backend type is there even though the QOM type isn't.

A management application can work around this issue by using
qom-list-types instead.

Fix the issue anyway: add the conditionals to the QAPI schema.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 qapi/char.json | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/qapi/char.json b/qapi/char.json
index 6c6ad3b10c..2d74e66746 100644
--- a/qapi/char.json
+++ b/qapi/char.json
@@ -472,8 +472,8 @@
 ##
 { 'enum': 'ChardevBackendKind',
   'data': [ 'file',
-            'serial',
-            'parallel',
+            { 'name': 'serial', 'if': 'HAVE_CHARDEV_SERIAL' },
+            { 'name': 'parallel', 'if': 'HAVE_CHARDEV_PARALLEL' },
             'pipe',
             'socket',
             'udp',
@@ -482,10 +482,10 @@
             'mux',
             'msmouse',
             'wctablet',
-            'braille',
+            { 'name': 'braille', 'if': 'CONFIG_BRLAPI' },
             'testdev',
             'stdio',
-            'console',
+            { 'name': 'console', 'if': 'CONFIG_WIN32' },
             { 'name': 'spicevmc', 'if': 'CONFIG_SPICE' },
             { 'name': 'spiceport', 'if': 'CONFIG_SPICE' },
             { 'name': 'qemu-vdagent', 'if': 'CONFIG_SPICE_PROTOCOL' },
@@ -614,8 +614,10 @@
   'base': { 'type': 'ChardevBackendKind' },
   'discriminator': 'type',
   'data': { 'file': 'ChardevFileWrapper',
-            'serial': 'ChardevHostdevWrapper',
-            'parallel': 'ChardevHostdevWrapper',
+            'serial': { 'type': 'ChardevHostdevWrapper',
+                        'if': 'HAVE_CHARDEV_SERIAL' },
+            'parallel': { 'type': 'ChardevHostdevWrapper',
+                          'if': 'HAVE_CHARDEV_PARALLEL' },
             'pipe': 'ChardevHostdevWrapper',
             'socket': 'ChardevSocketWrapper',
             'udp': 'ChardevUdpWrapper',
@@ -624,10 +626,12 @@
             'mux': 'ChardevMuxWrapper',
             'msmouse': 'ChardevCommonWrapper',
             'wctablet': 'ChardevCommonWrapper',
-            'braille': 'ChardevCommonWrapper',
+            'braille': { 'type': 'ChardevCommonWrapper',
+                         'if': 'CONFIG_BRLAPI' },
             'testdev': 'ChardevCommonWrapper',
             'stdio': 'ChardevStdioWrapper',
-            'console': 'ChardevCommonWrapper',
+            'console': { 'type': 'ChardevCommonWrapper',
+                         'if': 'CONFIG_WIN32' },
             'spicevmc': { 'type': 'ChardevSpiceChannelWrapper',
                           'if': 'CONFIG_SPICE' },
             'spiceport': { 'type': 'ChardevSpicePortWrapper',
-- 
2.43.0

Re: [PATCH 3/4] qapi/char: Make backend types properly conditional

[Eric Blake]

On Sat, Feb 03, 2024 at 09:02:27AM +0100, Markus Armbruster wrote:
> Character backends are actually QOM types.  When a backend's
> compile-time conditional QOM type is not compiled in, creation fails
> with "'FOO' is not a valid char driver name".  Okay, except
> introspecting chardev-add with query-qmp-schema doesn't work then: the
> backend type is there even though the QOM type isn't.
> 
> A management application can work around this issue by using
> qom-list-types instead.
> 
> Fix the issue anyway: add the conditionals to the QAPI schema.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  qapi/char.json | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization:  qemu.org | libguestfs.org

[PATCH 4/4] qapi/char: Deprecate backend type "memory"

[Markus Armbruster]

It's an alias for "ringbuf" we kept for backward compatibility; see
commit 3a1da42eb35 (qapi: Rename ChardevBackend member "memory" to
"ringbuf").  Deprecation is long overdue.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
---
 docs/about/deprecated.rst | 8 ++++++++
 qapi/char.json            | 8 +++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index d4492b9460..ae1a520c26 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -371,6 +371,14 @@ Specifying the iSCSI password in plain text on the command line using the
 used instead, to refer to a ``--object secret...`` instance that provides
 a password via a file, or encrypted.
 
+Character device options
+''''''''''''''''''''''''
+
+Backend ``memory`` (since 9.0)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+``memory`` is a deprecated synonym for ``ringbuf``.
+
 CPU device properties
 '''''''''''''''''''''
 
diff --git a/qapi/char.json b/qapi/char.json
index 2d74e66746..75a7e057f0 100644
--- a/qapi/char.json
+++ b/qapi/char.json
@@ -468,6 +468,10 @@
 #
 # @memory: Since 1.5
 #
+# Features:
+#
+# @deprecated: Member @memory is deprecated.  Use @ringbuf instead.
+#
 # Since: 1.4
 ##
 { 'enum': 'ChardevBackendKind',
@@ -492,8 +496,7 @@
             { 'name': 'dbus', 'if': 'CONFIG_DBUS_DISPLAY' },
             'vc',
             'ringbuf',
-            # next one is just for compatibility
-            'memory' ] }
+            { 'name': 'memory', 'features': [ 'deprecated' ] } ] }
 
 ##
 # @ChardevFileWrapper:
@@ -642,7 +645,6 @@
                       'if': 'CONFIG_DBUS_DISPLAY' },
             'vc': 'ChardevVCWrapper',
             'ringbuf': 'ChardevRingbufWrapper',
-            # next one is just for compatibility
             'memory': 'ChardevRingbufWrapper' } }
 
 ##
-- 
2.43.0

Re: [PATCH 4/4] qapi/char: Deprecate backend type "memory"

[Ján Tomko]

[-- Attachment #1: Type: text/plain, Size: 1125 bytes --]

On a Saturday in 2024, Markus Armbruster wrote:
>It's an alias for "ringbuf" we kept for backward compatibility; see
>commit 3a1da42eb35 (qapi: Rename ChardevBackend member "memory" to
>"ringbuf").  Deprecation is long overdue.
>
>Signed-off-by: Markus Armbruster <armbru@redhat.com>
>---
> docs/about/deprecated.rst | 8 ++++++++
> qapi/char.json            | 8 +++++---
> 2 files changed, 13 insertions(+), 3 deletions(-)
>
>diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
>index d4492b9460..ae1a520c26 100644
>--- a/docs/about/deprecated.rst
>+++ b/docs/about/deprecated.rst
>@@ -371,6 +371,14 @@ Specifying the iSCSI password in plain text on the command line using the
> used instead, to refer to a ``--object secret...`` instance that provides
> a password via a file, or encrypted.
>
>+Character device options
>+''''''''''''''''''''''''
>+
>+Backend ``memory`` (since 9.0)
>+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>+
>+``memory`` is a deprecated synonym for ``ringbuf``.
>+

For libvirt:
Reviewed-by: Ján Tomko <jtomko@redhat.com>

(We don't support either of those)

Jano

[-- Attachment #2: signature.asc --]
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Re: [PATCH 4/4] qapi/char: Deprecate backend type "memory"

[Eric Blake]

On Sat, Feb 03, 2024 at 09:02:28AM +0100, Markus Armbruster wrote:
> It's an alias for "ringbuf" we kept for backward compatibility; see
> commit 3a1da42eb35 (qapi: Rename ChardevBackend member "memory" to
> "ringbuf").  Deprecation is long overdue.
> 
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>  docs/about/deprecated.rst | 8 ++++++++
>  qapi/char.json            | 8 +++++---
>  2 files changed, 13 insertions(+), 3 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization:  qemu.org | libguestfs.org

Re: [PATCH 0/4] char: Minor fixes, and a tighter QAPI schema

[Marc-André Lureau]

Hi

On Sat, Feb 3, 2024 at 12:02 PM Markus Armbruster <armbru@redhat.com> wrote:
>
> Markus Armbruster (4):
>   chardev/parallel: Don't close stdin on inappropriate device
>   tests/unit/test-char: Fix qemu_socket(), make_udp_socket() check
>   qapi/char: Make backend types properly conditional
>   qapi/char: Deprecate backend type "memory"

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>

>
>  docs/about/deprecated.rst |  8 ++++++++
>  qapi/char.json            | 28 +++++++++++++++++-----------
>  include/qemu/osdep.h      |  9 ++++++++-
>  chardev/char-parallel.c   |  7 +++++--
>  tests/unit/test-char.c    | 25 +++++++++++++++++++++++--
>  chardev/meson.build       |  4 +---
>  6 files changed, 62 insertions(+), 19 deletions(-)
>
> --
> 2.43.0
>