Re: [Qemu-devel] [PULL v3 00/54] Kconfig conversion, excluding ARM and MIPS

[Peter Maydell]

On Thu, 21 Mar 2019 at 12:40, Laszlo Ersek <address@hidden> wrote:
> In brief, the regression is that the aarch64 system emulator now lists
> the "virtio-vga" device for the "virt" machine type:
>
> $ qemu-system-aarch64 -M virt -device \? | grep virtio-vga
> name "virtio-vga", bus PCI
>
> Here's where I think the issue was introduced:
>
> (1) In commit 82f5181777eb ("kconfig: introduce kconfig files",
> 2019-03-07), VIRTIO_VGA was introduced simply as a bool (with no other
> clauses) in "hw/display/Kconfig".
>
> (2) In commit 7c28b925b7e1 ("build: convert pci.mak to Kconfig",
> 2019-03-07), VIRTIO_VGA received the following clauses:
>
>     default y if PCI_DEVICES
>     depends on VIRTIO_PCI
>     select VGA
>
> This is too lax, because it permits virtio-vga for aarch64, while that
> shouldn't happen (and it doesn't matches the previous state of the tree).
>
> (3) In commit b42075bb7767 ("virtio: express virtio dependencies with
> Kconfig", 2019-03-07), the determination of virtio-vga was switched to
> the Kconfig system. Importantly, in this patch, the line
>
>   CONFIG_VIRTIO_VGA=y
>
> was removed *only* from the following file:
>
>   default-configs/i386-softmmu.mak
>
> (4) Both of the remaining instances of
>
>   CONFIG_VIRTIO_VGA=y
>
> were then removed in commit 9483cf27dd36 ("hppa-softmmu.mak: express
> dependencies with Kconfig", 2019-03-07) and commit 87f9108bad0c ("ppc64:
> Express dependencies of 'pseries' and 'powernv' machines with kconfig",
> 2019-03-07), from files
>
>   default-configs/hppa-softmmu.mak
>   default-configs/ppc64-softmmu.mak
>
> respectively.
>
>
> Therefore I think commit 7c28b925b7e1 has the bug. The VIRTIO_VGA
> restriction
>
>   depends on VIRTIO_PCI
>
> should now be replaced with
>
>   depends on VIRTIO_PCI && (PC || DINO || PSERIES)

Should it? What makes the virtio-vga device only
suitable for those three machines?

thanks
-- PMM