Re: [Qemu-devel] [PATCH v2 2/2] vga: don't pick cirrus by default

[Gerd Hoffmann]

On Thu, Jul 05, 2018 at 01:35:01PM -0300, Eduardo Habkost wrote:
> Do we have a list of all machine-types with default_display==NULL
> that would be affected by this?

There are not many which use the default vga thing in the first place.
Workflow is this:

 (1) vl.c calls select_vgahw(vga_model) after setting vga_model.
 (2) select_hw() sets vga_interface_type.
 (3) isa_vga_init() and pci_vga_init() look at vga_interface_type.

Checking where either vga_interface_type or *_vga_init() is used doesn't
yield many places:

# find -name "*.[ch]" | xargs egrep '((isa|pci)_vga_init|vga_interface_type)'
./hw/alpha/dp264.c:    pci_vga_init(pci_bus);
./hw/i386/pc.c:        PCIDevice *pcidev = pci_vga_init(pci_bus);
./hw/i386/pc.c:        ISADevice *isadev = isa_vga_init(isa_bus);
./hw/isa/isa-bus.c:ISADevice *isa_vga_init(ISABus *bus)
./hw/isa/isa-bus.c:    switch (vga_interface_type) {
./hw/mips/mips_malta.c:    pci_vga_init(pci_bus);
./hw/mips/mips_r4k.c:    isa_vga_init(isa_bus);
./hw/pci/pci.c:PCIDevice *pci_vga_init(PCIBus *bus)
./hw/pci/pci.c:    switch (vga_interface_type) {
./hw/ppc/mac_newworld.c:    pci_vga_init(pci_bus);
./hw/ppc/mac_oldworld.c:    pci_vga_init(pci_bus);
./hw/ppc/spapr.c:    switch (vga_interface_type) {
./hw/ppc/spapr.c:        return pci_vga_init(pci_bus) != NULL;
./hw/ppc/prep.c:    pci_vga_init(pci_bus);
./hw/ppc/prep.c:        pci_vga_init(pci_bus);
./hw/sparc/sun4m.c:        if (vga_interface_type == VGA_CG3) {
./include/hw/isa/isa.h:ISADevice *isa_vga_init(ISABus *bus);
./include/hw/pci/pci.h:PCIDevice *pci_vga_init(PCIBus *bus);
./include/sysemu/sysemu.h:extern int vga_interface_type;
./include/sysemu/sysemu.h:#define xenfb_enabled (vga_interface_type == 
VGA_XENFB)
./vl.c:int vga_interface_type = VGA_NONE;
./vl.c:    assert(vga_interface_type == VGA_NONE);
./vl.c:            vga_interface_type = t;
./vl.c:        vga_interface_type = VGA_DEVICE;

So it is alpha, mips, i386, ppc.

Also some hits vl.c, headers and isa/pci code.
Xen and sparc check for something which is never picked as default,
so no worries here.

cheers,
  Gerd