[pve-devel] [PATCH qemu-server v1 1/2] virtio-vga-gl: add Vulkan (venus) support

[Thomas Lamprecht]

Am 10.11.25 um 12:40 schrieb Markus Frank:
> The venus protocol facilitates the translation of Vulkan API calls via
> the virglrenderer. To use it, the virgl-server package must be installed
> on the host.
> 
> The Vulkan option is represented by an enum with values such as
> 'venus-512' and 'venus-1024'. This is to allow for the potential
> addition of another Vulkan implementation in the future. The number
> indicates the memory window in MiB for Venus.

Meh, if it provides no obvious benefit I'm not sure if this makes sense
to add now already.

I'd also mention more prominently that this only works for the virtio-gl
type, at least in the commit message and probably also in the description
of the vulkan "flag".
Is this strongly limited to that display type? And are there errors
generated with others combination that block the start?
Asking mostly to see if it would be an option to just generate a log_warn
about a useless combination of display and venus that then shows up in the
start task in such a case.

And is it likely that there might be another protocol that relays vulkan?

Mostly asking this key questions to better judge the design/approach you
chose.

> 
> Signed-off-by: Markus Frank <m.frank at proxmox.com>
> ---
>  src/PVE/QemuServer.pm | 20 +++++++++++++++++++-
>  1 file changed, 19 insertions(+), 1 deletion(-)
> 
> diff --git a/src/PVE/QemuServer.pm b/src/PVE/QemuServer.pm
> index cf195ccc..2b358e9f 100644
> --- a/src/PVE/QemuServer.pm
> +++ b/src/PVE/QemuServer.pm
> @@ -160,6 +160,12 @@ my $vga_fmt = {
>              qw(cirrus qxl qxl2 qxl3 qxl4 none serial0 serial1 serial2 serial3 std virtio virtio-gl vmware)
>          ],
>      },
> +    vulkan => {
> +        description => 'Enable vulkan by using the venus protocol.',
> +        type => 'string',
> +        enum => ['venus-512', 'venus-1024', 'venus-2048', 'venus-4096', 'venus-8192'],
> +        optional => 1,
> +    },
>      memory => {
>          description => "Sets the VGA memory (in MiB). Has no effect with serial display.",
>          type => 'integer',
> @@ -1499,6 +1505,15 @@ sub print_vga_device {
>          $pciaddr = print_pci_addr($vgaid, $bridges, $arch);
>      }
>  
> +    my $venus = "";
> +    if ($vga->{vulkan} && $vga->{vulkan} =~ /^venus-(\d+)/) {
> +        my $virgl_memory_window = $1;
> +        $venus = ",hostmem=${virgl_memory_window}M,venus=on,blob=on";
> +
> +        die "You need to use virtio-gl to enable vulkan (venus) support!\n"
> +            if $vga->{type} !~ /^virtio-gl/;
> +    }
> +
>      if ($vga->{type} eq 'virtio-gl') {
>          my $base = '/usr/lib/x86_64-linux-gnu/lib';
>          die "missing libraries for '$vga->{type}' detected! Please install 'libgl1' and 'libegl1'\n"
> @@ -1507,9 +1522,12 @@ sub print_vga_device {
>          die
>              "no DRM render node detected (/dev/dri/renderD*), no GPU? - needed for '$vga->{type}' display\n"
>              if !PVE::Tools::dir_glob_regex('/dev/dri/', "renderD.*");
> +
> +        die "missing virgl render server for vulkan (venus)! Please install 'virgl-server'.\n"
> +            if $vga->{vulkan} && !-e "/usr/libexec/virgl_render_server";
>      }
>  
> -    return "$type,id=${vgaid}${memory}${max_outputs}${pciaddr}${edidoff}";
> +    return "$type,id=${vgaid}${memory}${max_outputs}${pciaddr}${edidoff}${venus}";
>  }
>  
>  sub vm_is_volid_owner {