Re: [PATCH 07/11] bochs-display: Fix vgamem=SIZE error handling

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 4/20/20 10:32 AM, Markus Armbruster wrote:
> bochs_display_realize() rejects out-of-range vgamem.  The error
> handling is broken:
> 
>      $ qemu-system-x86_64 -S -display none -monitor stdio
>      QEMU 4.2.93 monitor - type 'help' for more information
>      (qemu) device_add bochs-display,vgamem=1
>      Error: bochs-display: video memory too small
>      (qemu) device_add bochs-display,vgamem=1
>      RAMBlock "0000:00:04.0/bochs-display-vram" already registered, abort!
>      Aborted (core dumped)
> 
> Cause: bochs_display_realize() neglects to bail out after setting the
> error.  Fix that.
> 
> Fixes: 765c94290863eef1fc4a67819d452cc13b7854a1
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>
> ---
>   hw/display/bochs-display.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/display/bochs-display.c b/hw/display/bochs-display.c
> index 70eb619ef4..e763a0a72d 100644
> --- a/hw/display/bochs-display.c
> +++ b/hw/display/bochs-display.c
> @@ -267,16 +267,18 @@ static void bochs_display_realize(PCIDevice *dev, Error **errp)
>       Object *obj = OBJECT(dev);
>       int ret;
>   
> -    s->con = graphic_console_init(DEVICE(dev), 0, &bochs_display_gfx_ops, s);
> -
>       if (s->vgamem < 4 * MiB) {
>           error_setg(errp, "bochs-display: video memory too small");
> +        return;
>       }
>       if (s->vgamem > 256 * MiB) {
>           error_setg(errp, "bochs-display: video memory too big");
> +        return;
>       }
>       s->vgamem = pow2ceil(s->vgamem);
>   
> +    s->con = graphic_console_init(DEVICE(dev), 0, &bochs_display_gfx_ops, s);
> +
>       memory_region_init_ram(&s->vram, obj, "bochs-display-vram", s->vgamem,
>                              &error_fatal);
>       memory_region_init_io(&s->vbe, obj, &bochs_display_vbe_ops, s,
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>