Re: [PATCH edk2-stable202002] OvmfPkg/QemuVideoDxe: unbreak "secondary-vga" and "bochs-display" support

[Gerd Hoffmann <kraxel@redhat.com>]

On Mon, Feb 24, 2020 at 06:17:41PM +0100, Laszlo Ersek wrote:
> In edk2 commit 333f32ec23dd, QemuVideoDxe gained support for QEMU's
> "secondary-vga" device model (originally introduced in QEMU commit
> 63e3e24db2e9).
> 
> In QEMU commit 765c94290863, the "bochs-display" device was introduced,
> which would work with QemuVideoDxe out of the box, reusing the
> "secondary-vga" logic.
> 
> Support for both models has been broken since edk2 commit 662bd0da7fd7.
> Said patch ended up requiring VGA IO Ports -- i.e., at least one of
> EFI_PCI_IO_ATTRIBUTE_VGA_IO and EFI_PCI_IO_ATTRIBUTE_VGA_IO_16 -- even if
> the device wasn't actually VGA compatible.
> 
> Restrict the IO Ports requirement to VGA compatible devices.
> 
> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Marc W Chen <marc.w.chen@intel.com>
> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
> Fixes: 662bd0da7fd77e4d2cf9ef4a78015af5cad7d9db
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2555
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
> 
> Notes:
>     Repo:   https://github.com/lersek/edk2.git
>     Branch: vga_io_bz_2555
> 
>  OvmfPkg/QemuVideoDxe/Driver.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/OvmfPkg/QemuVideoDxe/Driver.c b/OvmfPkg/QemuVideoDxe/Driver.c
> index 6a4a860b3c25..37bbbbe843c9 100644
> --- a/OvmfPkg/QemuVideoDxe/Driver.c
> +++ b/OvmfPkg/QemuVideoDxe/Driver.c
> @@ -292,7 +292,7 @@ QemuVideoControllerDriverStart (
>    }
>  
>    SupportedVgaIo &= (UINT64)(EFI_PCI_IO_ATTRIBUTE_VGA_IO | EFI_PCI_IO_ATTRIBUTE_VGA_IO_16);
> -  if (SupportedVgaIo == 0) {
> +  if (SupportedVgaIo == 0 && IS_PCI_VGA (&Pci)) {
>      Status = EFI_UNSUPPORTED;
>      goto ClosePciIo;
>    }

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>