[Qemu-devel] Re: [PATCH] Add -display option

["Sebastian Herbszt" <herbszt@gmx.de>]

From: "Daniel P. Berrange"
> On Sun, Apr 20, 2008 at 05:01:27PM -0500, Anthony Liguori wrote:
>> Sebastian Herbszt wrote:
>> >>I would better name it -display, as not all computers have 
>> >>VGA-compatible cards.
> 
>> >+                break;
>> >+            case QEMU_OPTION_display:
>> >+                if (!strcmp(optarg, "cirrus")) {
>> >+                    cirrus_vga_enabled = 1;
>> >+                    vmsvga_enabled = 0;
>> >+                } else if (!strcmp(optarg, "std")) {
>> >+                    cirrus_vga_enabled = 0;
>> >+                    vmsvga_enabled = 0;
>> >+                } else if (!strcmp(optarg, "vmware")) {
>> >+                    cirrus_vga_enabled = 0;
>> >+                    vmsvga_enabled = 1;
>> >+                } else if (!strcmp(optarg, "none")) {
>> >+                    serial_devices[0] = "stdio";
>> >+                    parallel_devices[0] = "null";
>> >+                    monitor_device = "stdio";
>> >+                    nographic = 1;
>> 
>> I don't think -display none should be a synonym for -nographic.  It 
>> should just suppress the creation of a VGA device.  If a platform 
>> doesn't support that, it should raise an error.
> 
> I agree - its rather unfortunate that -nographic changes the default
> settings for serial / parallel devices - it makes it troublesome to 
> launch QEMU with a predictable config. Having 'none' merely supress
> the VGA device would be preferrable behaviour.

Since i did not find that functionality yet, what would be the correct
implementation? Would adding an "int display_enabled = 1" in vl.c
suffice? With "-display none" display_enabled would be set to 0.
A platform not supporting it would then bail out with an error in its
init (e.g. pc_init1 from hw/pc.c).

- Sebastian