Re: [Qemu-devel] [PATCH] virtio-vga: only enable for specific boards

[Laszlo Ersek]

On 03/22/19 23:00, Paolo Bonzini wrote:
> 
> 
> ----- Original Message -----
>> From: "Laszlo Ersek" <address@hidden>
>> To: "Paolo Bonzini" <address@hidden>, address@hidden
>> Cc: address@hidden
>> Sent: Thursday, March 21, 2019 8:34:46 PM
>> Subject: Re: [PATCH] virtio-vga: only enable for specific boards
>>
>> On 03/21/19 15:29, Paolo Bonzini wrote:
>>> When virtio-vga was added, the intention was to only support it for
>>> those machines where the firmware does not know about virtio-gpu,
>>> and supported VGA legacy hardware before virtio-{gpu,vga} were
>>> introduced.
>>>
>>> The Kconfig switch however enabled virtio-vga for all machines with
>>> a PCI bus, and libvirt then prefers it even on hardware where
>>> virtio-gpu would be preferrable.  At least for now, only enable
>>> virtio-vga for PC, hppa and pSeries machines, as was the case
>>> before Kconfig dependencies were introduced.
>>>
>>> Reported-by: Laszlo Ersek <address@hidden>
>>> Signed-off-by: Paolo Bonzini <address@hidden>
>>> ---
>>>  hw/display/Kconfig | 2 +-
>>>  hw/hppa/Kconfig    | 1 +
>>>  hw/i386/Kconfig    | 1 +
>>>  hw/ppc/Kconfig     | 1 +
>>>  4 files changed, 4 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/hw/display/Kconfig b/hw/display/Kconfig
>>> index 86c1d544c5..72be57a403 100644
>>> --- a/hw/display/Kconfig
>>> +++ b/hw/display/Kconfig
>>> @@ -100,7 +100,7 @@ config VIRTIO_GPU
>>>  
>>>  config VIRTIO_VGA
>>>      bool
>>> -    default y if PCI_DEVICES
>>> +    # defaults to "N", enabled by specific boards
>>>      depends on VIRTIO_PCI
>>>      select VGA
>>>  
>>> diff --git a/hw/hppa/Kconfig b/hw/hppa/Kconfig
>>> index 7334f57081..6e5d74a825 100644
>>> --- a/hw/hppa/Kconfig
>>> +++ b/hw/hppa/Kconfig
>>> @@ -2,6 +2,7 @@ config DINO
>>>      bool
>>>      imply PCI_DEVICES
>>>      imply E1000_PCI
>>> +    imply VIRTIO_VGA
>>>      select PCI
>>>      select SERIAL
>>>      select ISA_BUS
>>> diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
>>> index 8e8444dbf9..a6aed7c131 100644
>>> --- a/hw/i386/Kconfig
>>> +++ b/hw/i386/Kconfig
>>> @@ -19,6 +19,7 @@ config PC
>>>      imply TPM_CRB
>>>      imply TPM_TIS
>>>      imply VGA_PCI
>>> +    imply VIRTIO_VGA
>>>      select FDC
>>>      select I8259
>>>      select I8254
>>> diff --git a/hw/ppc/Kconfig b/hw/ppc/Kconfig
>>> index ae07b4da63..a3465155f0 100644
>>> --- a/hw/ppc/Kconfig
>>> +++ b/hw/ppc/Kconfig
>>> @@ -2,6 +2,7 @@ config PSERIES
>>>      bool
>>>      imply PCI_DEVICES
>>>      imply TEST_DEVICES
>>> +    imply VIRTIO_VGA
>>>      select DIMM
>>>      select PCI
>>>      select SPAPR_VSCSI
>>>
>>
>> I tried to apply this for testing, on top of
>> c692931cda9dc6cbc16b89d5094a725a10dbb641, but git-am failed. The
>> conflicts are in "hw/hppa/Kconfig" and "hw/i386/Kconfig". In the former,
>> the conflict is due to E1000_PCI, in the latter, the conflict occurs due
>> to VGA_PCI -- upstream doesn't seem to have either of those.
> 
> Yeah, it is on top of my tree.  You can find it as tag for-upstream at
> https://github.com/bonzini/qemu, but it is not tested yet.

I've now tested this at your commit 938912a86611 ("virtio-vga: only
enable for specific boards", 2019-03-21).

Tested-by: Laszlo Ersek <address@hidden>
Reviewed-by: Laszlo Ersek <address@hidden>

Thank you!
Laszlo