Warn user if the vga flag is passed but no vga device is created

A global boolean variable "vga_interface_created"(declared in softmmu/globals.c)
has been used to track the creation of vga interface. If the vga flag is passed
in the command line "default_vga"(declared in softmmu/vl.c) variable is set to 0.
To warn user, the condition checks if vga_interface_created is false
and default_vga is equal to 0. If "-vga none" is passed, this patch will not warn the
user regarding the creation of VGA device.

The warning "A -vga option was passed but this
machine type does not use that option; no VGA device has been created"
is logged if vga flag is passed but no vga device is created.

This patch has been tested for x86_64, i386, sparc, sparc64 and arm boards.

Signed-off-by: Gautam Agrawal <gautamnagrawal@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/581
Message-Id: <20220501122505.29202-1-gautamnagrawal@gmail.com>
[thuth: Fix wrong warning with "-device" in some cases as reported by Paolo]
Signed-off-by: Thomas Huth <thuth@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/hw/mips/fuloong2e.c b/hw/mips/fuloong2e.c
index 7b13098f9b..5ee546f5f6 100644
--- a/hw/mips/fuloong2e.c
+++ b/hw/mips/fuloong2e.c
@@ -320,6 +320,7 @@ static void mips_fuloong2e_init(MachineState *machine)
 
     /* GPU */
     if (vga_interface_type != VGA_NONE) {
+        vga_interface_created = true;
         pci_dev = pci_new(-1, "ati-vga");
         dev = DEVICE(pci_dev);
         qdev_prop_set_uint32(dev, "vgamem_mb", 16);