[1/2] qapi: Convert screendump

From: Luiz Capitulino <lcapitulino@redhat.com>

Also, makes it possible for devices to report errors in the
hw_screen_dump() callback.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
---
 console.c        |    5 +++--
 console.h        |    6 ++++--
 hmp-commands.hx  |    3 +--
 hmp.c            |    8 ++++++++
 hmp.h            |    1 +
 hw/blizzard.c    |    3 ++-
 hw/g364fb.c      |    4 +++-
 hw/omap_lcdc.c   |    4 +++-
 hw/qxl.c         |    6 ++++--
 hw/tcx.c         |   13 +++++++++----
 hw/vga.c         |    7 +++++--
 hw/vmware_vga.c  |    6 ++++--
 monitor.c        |    6 ------
 qapi-schema.json |   13 +++++++++++++
 qmp-commands.hx  |    5 +----
 qmp.c            |    5 +++++
 16 files changed, 66 insertions(+), 29 deletions(-)

On Wed, 14 Mar 2012 17:55:32 +0200
Alon Levy <alevy@redhat.com> wrote:

> From: Luiz Capitulino <lcapitulino@redhat.com>
> 
> Also, makes it possible for devices to report errors in the
> hw_screen_dump() callback.
> 
> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

Please, split this into two patches. The first one just adds the Error parameter
to the hw_screen_dump() callback, the second does the actual conversion.

And please, add your signed-off-by so that I don't feel I'm talking to myself :)
and an intro email is also a good thing (you'll need a changelog).

> ---
>  console.c        |    5 +++--
>  console.h        |    6 ++++--
>  hmp-commands.hx  |    3 +--
>  hmp.c            |    8 ++++++++
>  hmp.h            |    1 +
>  hw/blizzard.c    |    3 ++-
>  hw/g364fb.c      |    4 +++-
>  hw/omap_lcdc.c   |    4 +++-
>  hw/qxl.c         |    6 ++++--
>  hw/tcx.c         |   13 +++++++++----
>  hw/vga.c         |    7 +++++--
>  hw/vmware_vga.c  |    6 ++++--
>  monitor.c        |    6 ------
>  qapi-schema.json |   13 +++++++++++++
>  qmp-commands.hx  |    5 +----
>  qmp.c            |    5 +++++
>  16 files changed, 66 insertions(+), 29 deletions(-)
> 
> diff --git a/console.c b/console.c
> index 6a463f5..d3fccf3 100644
> --- a/console.c
> +++ b/console.c
> @@ -24,6 +24,7 @@
>  #include "qemu-common.h"
>  #include "console.h"
>  #include "qemu-timer.h"
> +#include "error.h"
>  
>  //#define DEBUG_CONSOLE
>  #define DEFAULT_BACKSCROLL 512
> @@ -173,7 +174,7 @@ void vga_hw_invalidate(void)
>          active_console->hw_invalidate(active_console->hw);
>  }
>  
> -void vga_hw_screen_dump(const char *filename)
> +void vga_hw_screen_dump(const char *filename, Error **errp)
>  {
>      TextConsole *previous_active_console;
>      bool cswitch;
> @@ -187,7 +188,7 @@ void vga_hw_screen_dump(const char *filename)
>          console_select(0);
>      }
>      if (consoles[0] && consoles[0]->hw_screen_dump) {
> -        consoles[0]->hw_screen_dump(consoles[0]->hw, filename, cswitch);
> +        consoles[0]->hw_screen_dump(consoles[0]->hw, filename, cswitch, errp);
>      } else {
>          error_report("screen dump not implemented");
>      }
> diff --git a/console.h b/console.h
> index 4334db5..caf13f5 100644
> --- a/console.h
> +++ b/console.h
> @@ -6,6 +6,7 @@
>  #include "notify.h"
>  #include "monitor.h"
>  #include "trace.h"
> +#include "error.h"
>  
>  /* keyboard/mouse support */
>  
> @@ -343,7 +344,8 @@ static inline void console_write_ch(console_ch_t *dest, uint32_t ch)
>  
>  typedef void (*vga_hw_update_ptr)(void *);
>  typedef void (*vga_hw_invalidate_ptr)(void *);
> -typedef void (*vga_hw_screen_dump_ptr)(void *, const char *, bool cswitch);
> +typedef void (*vga_hw_screen_dump_ptr)(void *, const char *, bool cswitch,
> +                                       Error **errp);
>  typedef void (*vga_hw_text_update_ptr)(void *, console_ch_t *);
>  
>  DisplayState *graphic_console_init(vga_hw_update_ptr update,
> @@ -354,7 +356,7 @@ DisplayState *graphic_console_init(vga_hw_update_ptr update,
>  
>  void vga_hw_update(void);
>  void vga_hw_invalidate(void);
> -void vga_hw_screen_dump(const char *filename);
> +void vga_hw_screen_dump(const char *filename, Error **errp);
>  void vga_hw_text_update(console_ch_t *chardata);
>  
>  int is_graphic_console(void);
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 6980214..d26421a 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -194,8 +194,7 @@ ETEXI
>          .args_type  = "filename:F",
>          .params     = "filename",
>          .help       = "save screen into PPM image 'filename'",
> -        .user_print = monitor_user_noop,
> -        .mhandler.cmd_new = do_screen_dump,
> +        .mhandler.cmd = hmp_screendump,
>      },
>  
>  STEXI
> diff --git a/hmp.c b/hmp.c
> index 290c43d..42dc79a 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -860,3 +860,11 @@ void hmp_block_job_cancel(Monitor *mon, const QDict *qdict)
>  
>      hmp_handle_error(mon, &error);
>  }
> +
> +void hmp_screendump(Monitor *mon, const QDict *qdict)
> +{
> +    Error *err = NULL;
> +
> +    qmp_screendump(qdict_get_str(qdict, "filename"), &err);
> +    hmp_handle_error(mon, &err);
> +}
> diff --git a/hmp.h b/hmp.h
> index 5409464..25d123f 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -59,5 +59,6 @@ void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict);
>  void hmp_block_stream(Monitor *mon, const QDict *qdict);
>  void hmp_block_job_set_speed(Monitor *mon, const QDict *qdict);
>  void hmp_block_job_cancel(Monitor *mon, const QDict *qdict);
> +void hmp_screendump(Monitor *mon, const QDict *qdict);
>  
>  #endif
> diff --git a/hw/blizzard.c b/hw/blizzard.c
> index c7d844d..76df78c 100644
> --- a/hw/blizzard.c
> +++ b/hw/blizzard.c
> @@ -23,6 +23,7 @@
>  #include "devices.h"
>  #include "vga_int.h"
>  #include "pixel_ops.h"
> +#include "error.h"
>  
>  typedef void (*blizzard_fn_t)(uint8_t *, const uint8_t *, unsigned int);
>  
> @@ -933,7 +934,7 @@ static void blizzard_update_display(void *opaque)
>  }
>  
>  static void blizzard_screen_dump(void *opaque, const char *filename,
> -                                 bool cswitch)
> +                                 bool cswitch, Error **errp)
>  {
>      BlizzardState *s = (BlizzardState *) opaque;
>  
> diff --git a/hw/g364fb.c b/hw/g364fb.c
> index 3a0b68f..7774d05 100644
> --- a/hw/g364fb.c
> +++ b/hw/g364fb.c
> @@ -22,6 +22,7 @@
>  #include "pixel_ops.h"
>  #include "trace.h"
>  #include "sysbus.h"
> +#include "error.h"
>  
>  typedef struct G364State {
>      /* hardware */
> @@ -289,7 +290,8 @@ static void g364fb_reset(G364State *s)
>      g364fb_invalidate_display(s);
>  }
>  
> -static void g364fb_screen_dump(void *opaque, const char *filename, bool cswitch)
> +static void g364fb_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                               Error **errp)
>  {
>      G364State *s = opaque;
>      int y, x;
> diff --git a/hw/omap_lcdc.c b/hw/omap_lcdc.c
> index f172093..aec7210 100644
> --- a/hw/omap_lcdc.c
> +++ b/hw/omap_lcdc.c
> @@ -20,6 +20,7 @@
>  #include "console.h"
>  #include "omap.h"
>  #include "framebuffer.h"
> +#include "error.h"
>  
>  struct omap_lcd_panel_s {
>      MemoryRegion *sysmem;
> @@ -264,7 +265,8 @@ static int ppm_save(const char *filename, uint8_t *data,
>      return 0;
>  }
>  
> -static void omap_screen_dump(void *opaque, const char *filename, bool cswitch)
> +static void omap_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                             Error **errp)
>  {
>      struct omap_lcd_panel_s *omap_lcd = opaque;
>      if (cswitch) {
> diff --git a/hw/qxl.c b/hw/qxl.c
> index e17b0e3..27f27f5 100644
> --- a/hw/qxl.c
> +++ b/hw/qxl.c
> @@ -23,6 +23,7 @@
>  #include "qemu-queue.h"
>  #include "monitor.h"
>  #include "sysemu.h"
> +#include "error.h"
>  
>  #include "qxl.h"
>  
> @@ -1492,7 +1493,8 @@ static void qxl_hw_invalidate(void *opaque)
>      vga->invalidate(vga);
>  }
>  
> -static void qxl_hw_screen_dump(void *opaque, const char *filename, bool cswitch)
> +static void qxl_hw_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                               Error **errp)
>  {
>      PCIQXLDevice *qxl = opaque;
>      VGACommonState *vga = &qxl->vga;
> @@ -1504,7 +1506,7 @@ static void qxl_hw_screen_dump(void *opaque, const char *filename, bool cswitch)
>          ppm_save(filename, qxl->ssd.ds->surface);
>          break;
>      case QXL_MODE_VGA:
> -        vga->screen_dump(vga, filename, cswitch);
> +        vga->screen_dump(vga, filename, cswitch, errp);
>          break;
>      default:
>          break;
> diff --git a/hw/tcx.c b/hw/tcx.c
> index ac7dcb4..f342a5d 100644
> --- a/hw/tcx.c
> +++ b/hw/tcx.c
> @@ -26,6 +26,7 @@
>  #include "pixel_ops.h"
>  #include "sysbus.h"
>  #include "qdev-addr.h"
> +#include "error.h"
>  
>  #define MAXX 1024
>  #define MAXY 768
> @@ -56,8 +57,10 @@ typedef struct TCXState {
>      uint8_t dac_index, dac_state;
>  } TCXState;
>  
> -static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch);
> -static void tcx24_screen_dump(void *opaque, const char *filename, bool cswitch);
> +static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                            Error *errp);
> +static void tcx24_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                              Error *errp);
>  
>  static void tcx_set_dirty(TCXState *s)
>  {
> @@ -574,7 +577,8 @@ static int tcx_init1(SysBusDevice *dev)
>      return 0;
>  }
>  
> -static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch)
> +static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                            Error *errp)
>  {
>      TCXState *s = opaque;
>      FILE *f;
> @@ -601,7 +605,8 @@ static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch)
>      return;
>  }
>  
> -static void tcx24_screen_dump(void *opaque, const char *filename, bool cswitch)
> +static void tcx24_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                              Error *errp)
>  {
>      TCXState *s = opaque;
>      FILE *f;
> diff --git a/hw/vga.c b/hw/vga.c
> index 6dc98f6..b80a079 100644
> --- a/hw/vga.c
> +++ b/hw/vga.c
> @@ -31,6 +31,7 @@
>  #include "qemu-timer.h"
>  #include "xen.h"
>  #include "trace.h"
> +#include "error.h"
>  
>  //#define DEBUG_VGA
>  //#define DEBUG_VGA_MEM
> @@ -163,7 +164,8 @@ static uint32_t expand4[256];
>  static uint16_t expand2[256];
>  static uint8_t expand4to8[16];
>  
> -static void vga_screen_dump(void *opaque, const char *filename, bool cswitch);
> +static void vga_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                            Error *errp);
>  
>  static void vga_update_memory_access(VGACommonState *s)
>  {
> @@ -2409,7 +2411,8 @@ int ppm_save(const char *filename, struct DisplaySurface *ds)
>  
>  /* save the vga display in a PPM image even if no display is
>     available */
> -static void vga_screen_dump(void *opaque, const char *filename, bool cswitch)
> +static void vga_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                            Error **errp)
>  {
>      VGACommonState *s = opaque;
>  
> diff --git a/hw/vmware_vga.c b/hw/vmware_vga.c
> index 142d9f4..6868778 100644
> --- a/hw/vmware_vga.c
> +++ b/hw/vmware_vga.c
> @@ -26,6 +26,7 @@
>  #include "console.h"
>  #include "pci.h"
>  #include "vmware_vga.h"
> +#include "error.h"
>  
>  #undef VERBOSE
>  #define HW_RECT_ACCEL
> @@ -1003,11 +1004,12 @@ static void vmsvga_invalidate_display(void *opaque)
>  
>  /* save the vga display in a PPM image even if no display is
>     available */
> -static void vmsvga_screen_dump(void *opaque, const char *filename, bool cswitch)
> +static void vmsvga_screen_dump(void *opaque, const char *filename, bool cswitch,
> +                               Error **errp)
>  {
>      struct vmsvga_state_s *s = opaque;
>      if (!s->enable) {
> -        s->vga.screen_dump(&s->vga, filename, cswitch);
> +        s->vga.screen_dump(&s->vga, filename, cswitch, errp);
>          return;
>      }
>  
> diff --git a/monitor.c b/monitor.c
> index cbdfbad..f79ce9a 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -893,12 +893,6 @@ static int client_migrate_info(Monitor *mon, const QDict *qdict,
>      return -1;
>  }
>  
> -static int do_screen_dump(Monitor *mon, const QDict *qdict, QObject **ret_data)
> -{
> -    vga_hw_screen_dump(qdict_get_str(qdict, "filename"));
> -    return 0;
> -}
> -
>  static void do_logfile(Monitor *mon, const QDict *qdict)
>  {
>      cpu_set_log_filename(qdict_get_str(qdict, "filename"));
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 04fa84f..4f251ca 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1663,3 +1663,16 @@
>  { 'command': 'qom-list-types',
>    'data': { '*implements': 'str', '*abstract': 'bool' },
>    'returns': [ 'ObjectTypeInfo' ] }
> +
> +##
> +# @screendump:
> +#
> +# Write a PPM of the VGA screen to a file.
> +#
> +# @filename: the name of a new PPM file to create to store the image
> +#
> +# Returns: Nothing on success
> +#
> +# Since: 1.1
> +##
> +{ 'command': 'screendump', 'data': {'filename': 'str'} }
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index dfe8a5b..5fe57fd 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -146,10 +146,7 @@ EQMP
>      {
>          .name       = "screendump",
>          .args_type  = "filename:F",
> -        .params     = "filename",
> -        .help       = "save screen into PPM image 'filename'",
> -        .user_print = monitor_user_noop,
> -        .mhandler.cmd_new = do_screen_dump,
> +        .mhandler.cmd_new = qmp_marshal_input_screendump,
>      },
>  
>  SQMP
> diff --git a/qmp.c b/qmp.c
> index a182b51..086cec8 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -415,3 +415,8 @@ ObjectTypeInfoList *qmp_qom_list_types(bool has_implements,
>  
>      return ret;
>  }
> +
> +void qmp_screendump(const char *filename, Error **errp)
> +{
> +    vga_hw_screen_dump(filename, errp);
> +}

On Wed, Mar 14, 2012 at 02:33:53PM -0300, Luiz Capitulino wrote:
> On Wed, 14 Mar 2012 17:55:32 +0200
> Alon Levy <alevy@redhat.com> wrote:
> 
> > From: Luiz Capitulino <lcapitulino@redhat.com>
> > 
> > Also, makes it possible for devices to report errors in the
> > hw_screen_dump() callback.
> > 
> > Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
> 
> Please, split this into two patches. The first one just adds the Error parameter
> to the hw_screen_dump() callback, the second does the actual conversion.

OK.

> 
> And please, add your signed-off-by so that I don't feel I'm talking to myself :)
> and an intro email is also a good thing (you'll need a changelog).

I assumed I could save myself one cover letter from v1 :)

> 
> > ---
> >  console.c        |    5 +++--
> >  console.h        |    6 ++++--
> >  hmp-commands.hx  |    3 +--
> >  hmp.c            |    8 ++++++++
> >  hmp.h            |    1 +
> >  hw/blizzard.c    |    3 ++-
> >  hw/g364fb.c      |    4 +++-
> >  hw/omap_lcdc.c   |    4 +++-
> >  hw/qxl.c         |    6 ++++--
> >  hw/tcx.c         |   13 +++++++++----
> >  hw/vga.c         |    7 +++++--
> >  hw/vmware_vga.c  |    6 ++++--
> >  monitor.c        |    6 ------
> >  qapi-schema.json |   13 +++++++++++++
> >  qmp-commands.hx  |    5 +----
> >  qmp.c            |    5 +++++
> >  16 files changed, 66 insertions(+), 29 deletions(-)
> > 
> > diff --git a/console.c b/console.c
> > index 6a463f5..d3fccf3 100644
> > --- a/console.c
> > +++ b/console.c
> > @@ -24,6 +24,7 @@
> >  #include "qemu-common.h"
> >  #include "console.h"
> >  #include "qemu-timer.h"
> > +#include "error.h"
> >  
> >  //#define DEBUG_CONSOLE
> >  #define DEFAULT_BACKSCROLL 512
> > @@ -173,7 +174,7 @@ void vga_hw_invalidate(void)
> >          active_console->hw_invalidate(active_console->hw);
> >  }
> >  
> > -void vga_hw_screen_dump(const char *filename)
> > +void vga_hw_screen_dump(const char *filename, Error **errp)
> >  {
> >      TextConsole *previous_active_console;
> >      bool cswitch;
> > @@ -187,7 +188,7 @@ void vga_hw_screen_dump(const char *filename)
> >          console_select(0);
> >      }
> >      if (consoles[0] && consoles[0]->hw_screen_dump) {
> > -        consoles[0]->hw_screen_dump(consoles[0]->hw, filename, cswitch);
> > +        consoles[0]->hw_screen_dump(consoles[0]->hw, filename, cswitch, errp);
> >      } else {
> >          error_report("screen dump not implemented");
> >      }
> > diff --git a/console.h b/console.h
> > index 4334db5..caf13f5 100644
> > --- a/console.h
> > +++ b/console.h
> > @@ -6,6 +6,7 @@
> >  #include "notify.h"
> >  #include "monitor.h"
> >  #include "trace.h"
> > +#include "error.h"
> >  
> >  /* keyboard/mouse support */
> >  
> > @@ -343,7 +344,8 @@ static inline void console_write_ch(console_ch_t *dest, uint32_t ch)
> >  
> >  typedef void (*vga_hw_update_ptr)(void *);
> >  typedef void (*vga_hw_invalidate_ptr)(void *);
> > -typedef void (*vga_hw_screen_dump_ptr)(void *, const char *, bool cswitch);
> > +typedef void (*vga_hw_screen_dump_ptr)(void *, const char *, bool cswitch,
> > +                                       Error **errp);
> >  typedef void (*vga_hw_text_update_ptr)(void *, console_ch_t *);
> >  
> >  DisplayState *graphic_console_init(vga_hw_update_ptr update,
> > @@ -354,7 +356,7 @@ DisplayState *graphic_console_init(vga_hw_update_ptr update,
> >  
> >  void vga_hw_update(void);
> >  void vga_hw_invalidate(void);
> > -void vga_hw_screen_dump(const char *filename);
> > +void vga_hw_screen_dump(const char *filename, Error **errp);
> >  void vga_hw_text_update(console_ch_t *chardata);
> >  
> >  int is_graphic_console(void);
> > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > index 6980214..d26421a 100644
> > --- a/hmp-commands.hx
> > +++ b/hmp-commands.hx
> > @@ -194,8 +194,7 @@ ETEXI
> >          .args_type  = "filename:F",
> >          .params     = "filename",
> >          .help       = "save screen into PPM image 'filename'",
> > -        .user_print = monitor_user_noop,
> > -        .mhandler.cmd_new = do_screen_dump,
> > +        .mhandler.cmd = hmp_screendump,
> >      },
> >  
> >  STEXI
> > diff --git a/hmp.c b/hmp.c
> > index 290c43d..42dc79a 100644
> > --- a/hmp.c
> > +++ b/hmp.c
> > @@ -860,3 +860,11 @@ void hmp_block_job_cancel(Monitor *mon, const QDict *qdict)
> >  
> >      hmp_handle_error(mon, &error);
> >  }
> > +
> > +void hmp_screendump(Monitor *mon, const QDict *qdict)
> > +{
> > +    Error *err = NULL;
> > +
> > +    qmp_screendump(qdict_get_str(qdict, "filename"), &err);
> > +    hmp_handle_error(mon, &err);
> > +}
> > diff --git a/hmp.h b/hmp.h
> > index 5409464..25d123f 100644
> > --- a/hmp.h
> > +++ b/hmp.h
> > @@ -59,5 +59,6 @@ void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict);
> >  void hmp_block_stream(Monitor *mon, const QDict *qdict);
> >  void hmp_block_job_set_speed(Monitor *mon, const QDict *qdict);
> >  void hmp_block_job_cancel(Monitor *mon, const QDict *qdict);
> > +void hmp_screendump(Monitor *mon, const QDict *qdict);
> >  
> >  #endif
> > diff --git a/hw/blizzard.c b/hw/blizzard.c
> > index c7d844d..76df78c 100644
> > --- a/hw/blizzard.c
> > +++ b/hw/blizzard.c
> > @@ -23,6 +23,7 @@
> >  #include "devices.h"
> >  #include "vga_int.h"
> >  #include "pixel_ops.h"
> > +#include "error.h"
> >  
> >  typedef void (*blizzard_fn_t)(uint8_t *, const uint8_t *, unsigned int);
> >  
> > @@ -933,7 +934,7 @@ static void blizzard_update_display(void *opaque)
> >  }
> >  
> >  static void blizzard_screen_dump(void *opaque, const char *filename,
> > -                                 bool cswitch)
> > +                                 bool cswitch, Error **errp)
> >  {
> >      BlizzardState *s = (BlizzardState *) opaque;
> >  
> > diff --git a/hw/g364fb.c b/hw/g364fb.c
> > index 3a0b68f..7774d05 100644
> > --- a/hw/g364fb.c
> > +++ b/hw/g364fb.c
> > @@ -22,6 +22,7 @@
> >  #include "pixel_ops.h"
> >  #include "trace.h"
> >  #include "sysbus.h"
> > +#include "error.h"
> >  
> >  typedef struct G364State {
> >      /* hardware */
> > @@ -289,7 +290,8 @@ static void g364fb_reset(G364State *s)
> >      g364fb_invalidate_display(s);
> >  }
> >  
> > -static void g364fb_screen_dump(void *opaque, const char *filename, bool cswitch)
> > +static void g364fb_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                               Error **errp)
> >  {
> >      G364State *s = opaque;
> >      int y, x;
> > diff --git a/hw/omap_lcdc.c b/hw/omap_lcdc.c
> > index f172093..aec7210 100644
> > --- a/hw/omap_lcdc.c
> > +++ b/hw/omap_lcdc.c
> > @@ -20,6 +20,7 @@
> >  #include "console.h"
> >  #include "omap.h"
> >  #include "framebuffer.h"
> > +#include "error.h"
> >  
> >  struct omap_lcd_panel_s {
> >      MemoryRegion *sysmem;
> > @@ -264,7 +265,8 @@ static int ppm_save(const char *filename, uint8_t *data,
> >      return 0;
> >  }
> >  
> > -static void omap_screen_dump(void *opaque, const char *filename, bool cswitch)
> > +static void omap_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                             Error **errp)
> >  {
> >      struct omap_lcd_panel_s *omap_lcd = opaque;
> >      if (cswitch) {
> > diff --git a/hw/qxl.c b/hw/qxl.c
> > index e17b0e3..27f27f5 100644
> > --- a/hw/qxl.c
> > +++ b/hw/qxl.c
> > @@ -23,6 +23,7 @@
> >  #include "qemu-queue.h"
> >  #include "monitor.h"
> >  #include "sysemu.h"
> > +#include "error.h"
> >  
> >  #include "qxl.h"
> >  
> > @@ -1492,7 +1493,8 @@ static void qxl_hw_invalidate(void *opaque)
> >      vga->invalidate(vga);
> >  }
> >  
> > -static void qxl_hw_screen_dump(void *opaque, const char *filename, bool cswitch)
> > +static void qxl_hw_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                               Error **errp)
> >  {
> >      PCIQXLDevice *qxl = opaque;
> >      VGACommonState *vga = &qxl->vga;
> > @@ -1504,7 +1506,7 @@ static void qxl_hw_screen_dump(void *opaque, const char *filename, bool cswitch)
> >          ppm_save(filename, qxl->ssd.ds->surface);
> >          break;
> >      case QXL_MODE_VGA:
> > -        vga->screen_dump(vga, filename, cswitch);
> > +        vga->screen_dump(vga, filename, cswitch, errp);
> >          break;
> >      default:
> >          break;
> > diff --git a/hw/tcx.c b/hw/tcx.c
> > index ac7dcb4..f342a5d 100644
> > --- a/hw/tcx.c
> > +++ b/hw/tcx.c
> > @@ -26,6 +26,7 @@
> >  #include "pixel_ops.h"
> >  #include "sysbus.h"
> >  #include "qdev-addr.h"
> > +#include "error.h"
> >  
> >  #define MAXX 1024
> >  #define MAXY 768
> > @@ -56,8 +57,10 @@ typedef struct TCXState {
> >      uint8_t dac_index, dac_state;
> >  } TCXState;
> >  
> > -static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch);
> > -static void tcx24_screen_dump(void *opaque, const char *filename, bool cswitch);
> > +static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                            Error *errp);
> > +static void tcx24_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                              Error *errp);
> >  
> >  static void tcx_set_dirty(TCXState *s)
> >  {
> > @@ -574,7 +577,8 @@ static int tcx_init1(SysBusDevice *dev)
> >      return 0;
> >  }
> >  
> > -static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch)
> > +static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                            Error *errp)
> >  {
> >      TCXState *s = opaque;
> >      FILE *f;
> > @@ -601,7 +605,8 @@ static void tcx_screen_dump(void *opaque, const char *filename, bool cswitch)
> >      return;
> >  }
> >  
> > -static void tcx24_screen_dump(void *opaque, const char *filename, bool cswitch)
> > +static void tcx24_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                              Error *errp)
> >  {
> >      TCXState *s = opaque;
> >      FILE *f;
> > diff --git a/hw/vga.c b/hw/vga.c
> > index 6dc98f6..b80a079 100644
> > --- a/hw/vga.c
> > +++ b/hw/vga.c
> > @@ -31,6 +31,7 @@
> >  #include "qemu-timer.h"
> >  #include "xen.h"
> >  #include "trace.h"
> > +#include "error.h"
> >  
> >  //#define DEBUG_VGA
> >  //#define DEBUG_VGA_MEM
> > @@ -163,7 +164,8 @@ static uint32_t expand4[256];
> >  static uint16_t expand2[256];
> >  static uint8_t expand4to8[16];
> >  
> > -static void vga_screen_dump(void *opaque, const char *filename, bool cswitch);
> > +static void vga_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                            Error *errp);
> >  
> >  static void vga_update_memory_access(VGACommonState *s)
> >  {
> > @@ -2409,7 +2411,8 @@ int ppm_save(const char *filename, struct DisplaySurface *ds)
> >  
> >  /* save the vga display in a PPM image even if no display is
> >     available */
> > -static void vga_screen_dump(void *opaque, const char *filename, bool cswitch)
> > +static void vga_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                            Error **errp)
> >  {
> >      VGACommonState *s = opaque;
> >  
> > diff --git a/hw/vmware_vga.c b/hw/vmware_vga.c
> > index 142d9f4..6868778 100644
> > --- a/hw/vmware_vga.c
> > +++ b/hw/vmware_vga.c
> > @@ -26,6 +26,7 @@
> >  #include "console.h"
> >  #include "pci.h"
> >  #include "vmware_vga.h"
> > +#include "error.h"
> >  
> >  #undef VERBOSE
> >  #define HW_RECT_ACCEL
> > @@ -1003,11 +1004,12 @@ static void vmsvga_invalidate_display(void *opaque)
> >  
> >  /* save the vga display in a PPM image even if no display is
> >     available */
> > -static void vmsvga_screen_dump(void *opaque, const char *filename, bool cswitch)
> > +static void vmsvga_screen_dump(void *opaque, const char *filename, bool cswitch,
> > +                               Error **errp)
> >  {
> >      struct vmsvga_state_s *s = opaque;
> >      if (!s->enable) {
> > -        s->vga.screen_dump(&s->vga, filename, cswitch);
> > +        s->vga.screen_dump(&s->vga, filename, cswitch, errp);
> >          return;
> >      }
> >  
> > diff --git a/monitor.c b/monitor.c
> > index cbdfbad..f79ce9a 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -893,12 +893,6 @@ static int client_migrate_info(Monitor *mon, const QDict *qdict,
> >      return -1;
> >  }
> >  
> > -static int do_screen_dump(Monitor *mon, const QDict *qdict, QObject **ret_data)
> > -{
> > -    vga_hw_screen_dump(qdict_get_str(qdict, "filename"));
> > -    return 0;
> > -}
> > -
> >  static void do_logfile(Monitor *mon, const QDict *qdict)
> >  {
> >      cpu_set_log_filename(qdict_get_str(qdict, "filename"));
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index 04fa84f..4f251ca 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -1663,3 +1663,16 @@
> >  { 'command': 'qom-list-types',
> >    'data': { '*implements': 'str', '*abstract': 'bool' },
> >    'returns': [ 'ObjectTypeInfo' ] }
> > +
> > +##
> > +# @screendump:
> > +#
> > +# Write a PPM of the VGA screen to a file.
> > +#
> > +# @filename: the name of a new PPM file to create to store the image
> > +#
> > +# Returns: Nothing on success
> > +#
> > +# Since: 1.1
> > +##
> > +{ 'command': 'screendump', 'data': {'filename': 'str'} }
> > diff --git a/qmp-commands.hx b/qmp-commands.hx
> > index dfe8a5b..5fe57fd 100644
> > --- a/qmp-commands.hx
> > +++ b/qmp-commands.hx
> > @@ -146,10 +146,7 @@ EQMP
> >      {
> >          .name       = "screendump",
> >          .args_type  = "filename:F",
> > -        .params     = "filename",
> > -        .help       = "save screen into PPM image 'filename'",
> > -        .user_print = monitor_user_noop,
> > -        .mhandler.cmd_new = do_screen_dump,
> > +        .mhandler.cmd_new = qmp_marshal_input_screendump,
> >      },
> >  
> >  SQMP
> > diff --git a/qmp.c b/qmp.c
> > index a182b51..086cec8 100644
> > --- a/qmp.c
> > +++ b/qmp.c
> > @@ -415,3 +415,8 @@ ObjectTypeInfoList *qmp_qom_list_types(bool has_implements,
> >  
> >      return ret;
> >  }
> > +
> > +void qmp_screendump(const char *filename, Error **errp)
> > +{
> > +    vga_hw_screen_dump(filename, errp);
> > +}
>