Re: [Qemu-devel] [PATCH 2/2] vga: ppm_save(): Return error on failure

[Alon Levy]

On Wed, Mar 14, 2012 at 02:40:42PM -0300, Luiz Capitulino wrote:
> On Wed, 14 Mar 2012 17:55:33 +0200
> Alon Levy <address@hidden> wrote:
> 
> > From: Luiz Capitulino <address@hidden>
> > 
> > This makes all devices using ppm_save() return an error appropriately
> > when the screendump command fails.
> > 
> > Based on a code by Anthony Liguori.
> > 
> > Signed-off-by: Luiz Capitulino <address@hidden>
> > ---
> >  hw/blizzard.c   |    2 +-
> >  hw/qxl.c        |    2 +-
> >  hw/vga.c        |   10 ++++++----
> >  hw/vga_int.h    |    3 ++-
> >  hw/vmware_vga.c |    2 +-
> >  5 files changed, 11 insertions(+), 8 deletions(-)
> > 
> > diff --git a/hw/blizzard.c b/hw/blizzard.c
> > index 76df78c..29e5ae6 100644
> > --- a/hw/blizzard.c
> > +++ b/hw/blizzard.c
> > @@ -942,7 +942,7 @@ static void blizzard_screen_dump(void *opaque, const 
> > char *filename,
> >          blizzard_update_display(opaque);
> >      }
> >      if (s && ds_get_data(s->state))
> > -        ppm_save(filename, s->state->surface);
> > +        ppm_save(filename, s->state->surface, errp);
> >  }
> >  
> >  #define DEPTH 8
> > diff --git a/hw/qxl.c b/hw/qxl.c
> > index 27f27f5..aa68612 100644
> > --- a/hw/qxl.c
> > +++ b/hw/qxl.c
> > @@ -1503,7 +1503,7 @@ static void qxl_hw_screen_dump(void *opaque, const 
> > char *filename, bool cswitch,
> >      case QXL_MODE_COMPAT:
> >      case QXL_MODE_NATIVE:
> >          qxl_render_update(qxl);
> > -        ppm_save(filename, qxl->ssd.ds->surface);
> > +        ppm_save(filename, qxl->ssd.ds->surface, errp);
> >          break;
> >      case QXL_MODE_VGA:
> >          vga->screen_dump(vga, filename, cswitch, errp);
> > diff --git a/hw/vga.c b/hw/vga.c
> > index b80a079..7e90cf4 100644
> > --- a/hw/vga.c
> > +++ b/hw/vga.c
> > @@ -165,7 +165,7 @@ static uint16_t expand2[256];
> >  static uint8_t expand4to8[16];
> >  
> >  static void vga_screen_dump(void *opaque, const char *filename, bool 
> > cswitch,
> > -                            Error *errp);
> > +                            Error **errp);
> >  
> >  static void vga_update_memory_access(VGACommonState *s)
> >  {
> > @@ -2365,7 +2365,7 @@ void vga_init_vbe(VGACommonState *s, MemoryRegion 
> > *system_memory)
> >  /********************************************************/
> >  /* vga screen dump */
> >  
> > -int ppm_save(const char *filename, struct DisplaySurface *ds)
> > +int ppm_save(const char *filename, struct DisplaySurface *ds, Error **errp)
> >  {
> >      FILE *f;
> >      uint8_t *d, *d1;
> > @@ -2377,8 +2377,10 @@ int ppm_save(const char *filename, struct 
> > DisplaySurface *ds)
> >  
> >      trace_ppm_save(filename, ds);
> >      f = fopen(filename, "wb");
> > -    if (!f)
> > +    if (!f) {
> > +        error_set(errp, QERR_OPEN_FILE_FAILED, filename);
> 
> This is a generic error, and it's unfortunate that we're using it in several
> places now. The best thing to do here - and I'm including write() in this
> discussion - is to report the most possible errors, like EACCESS, ENOSPC,
> EPERM, EIO. Maybe not all of them exist as QErrors.

OK, I'll add new QErrors then.

> 
> Also, note that some device models have their own way of saving the screen
> dump (eg. g364fb_screen_dump()) and should be converted to error_set()
> separately.

Makes sense.

> 
> >          return -1;
> > +    }
> >      fprintf(f, "P6\n%d %d\n%d\n",
> >              ds->width, ds->height, 255);
> >      linebuf = g_malloc(ds->width * 3);
> > @@ -2420,5 +2422,5 @@ static void vga_screen_dump(void *opaque, const char 
> > *filename, bool cswitch,
> >          vga_invalidate_display(s);
> >          vga_hw_update();
> >      }
> > -    ppm_save(filename, s->ds->surface);
> > +    ppm_save(filename, s->ds->surface, errp);
> >  }
> > diff --git a/hw/vga_int.h b/hw/vga_int.h
> > index 7685b2b..63078ba 100644
> > --- a/hw/vga_int.h
> > +++ b/hw/vga_int.h
> > @@ -24,6 +24,7 @@
> >  
> >  #include <hw/hw.h>
> >  #include "memory.h"
> > +#include "error.h"
> >  
> >  #define ST01_V_RETRACE      0x08
> >  #define ST01_DISP_ENABLE    0x01
> > @@ -200,7 +201,7 @@ void vga_ioport_write(void *opaque, uint32_t addr, 
> > uint32_t val);
> >  uint32_t vga_mem_readb(VGACommonState *s, target_phys_addr_t addr);
> >  void vga_mem_writeb(VGACommonState *s, target_phys_addr_t addr, uint32_t 
> > val);
> >  void vga_invalidate_scanlines(VGACommonState *s, int y1, int y2);
> > -int ppm_save(const char *filename, struct DisplaySurface *ds);
> > +int ppm_save(const char *filename, struct DisplaySurface *ds, Error 
> > **errp);
> >  
> >  int vga_ioport_invalid(VGACommonState *s, uint32_t addr);
> >  void vga_init_vbe(VGACommonState *s, MemoryRegion *address_space);
> > diff --git a/hw/vmware_vga.c b/hw/vmware_vga.c
> > index 6868778..0769652 100644
> > --- a/hw/vmware_vga.c
> > +++ b/hw/vmware_vga.c
> > @@ -1016,7 +1016,7 @@ static void vmsvga_screen_dump(void *opaque, const 
> > char *filename, bool cswitch,
> >      if (s->depth == 32) {
> >          DisplaySurface *ds = qemu_create_displaysurface_from(s->width,
> >                  s->height, 32, ds_get_linesize(s->vga.ds), 
> > s->vga.vram_ptr);
> > -        ppm_save(filename, ds);
> > +        ppm_save(filename, ds, errp);
> >          g_free(ds);
> >      }
> >  }
>