Arch Linux

Name Taken

Banned

Registered: 2014-04-09

Posts: 113

QXL Driver

This is not a problem but I'm just curious from running Arch in KVM with Red Hat, Inc. QXL paravirtual graphic card (rev 04) driver. Installing xf86-video-qxl from the AUR as mentioned here works fine but alternatively installing xorg-drivers pack from the official repo works just as well so I'm wondering what's going on.

Last edited by Name Taken (2014-08-17 10:58:04)

Rexilion

Member

Registered: 2013-12-23

Posts: 784

Re: QXL Driver

If you look at the list here:

https://www.archlinux.org/groups/i686/xorg-drivers/

You will see that there is no dedicated qxl. So, big chance another driver is being used. Something like vesa, fbdev or modesetting. But determining that would require Xorg.0.log.

It's better to install the dedicated qxl as that will allow host 3D rendering, dynamic resize and reduce virtualization overhead.

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Name Taken

Banned

Registered: 2014-04-09

Posts: 113

Re: QXL Driver

If you look at the list here:

https://www.archlinux.org/groups/i686/xorg-drivers/

You will see that there is no dedicated qxl. So, big chance another driver is being used. Something like vesa, fbdev or modesetting. But determining that would require Xorg.0.log.

It's better to install the dedicated qxl as that will allow host 3D rendering, dynamic resize and reduce virtualization overhead.

I know there is no QXL which is why I asked. It still shows QXL driver is being used with xorg-drivers

[root@kvm ~]# lshw -c video
  *-display               
       description: VGA compatible controller
       product: QXL paravirtual graphic card
       vendor: Red Hat, Inc.
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 04
       width: 32 bits
       clock: 33MHz
       capabilities: vga_controller rom
       configuration: driver=qxl latency=0
       resources: irq:11 memory:f4000000-f7ffffff memory:f8000000-fbffffff memory:fc054000-fc055fff ioport:c040(size=32) memory:fc040000-fc04ffff

[root@kvm ~]# lsmod | grep qxl
qxl                    63309  2 
ttm                    67279  1 qxl
drm_kms_helper         42670  1 qxl
drm                   247997  5 qxl,ttm,drm_kms_helper

Dynamic resizing does not work with either so using xrandr or the desktop's resolution changer works fine. I do not using 3D rendering but if I did, I would use a dedicated GPU for PCI passthrough.

Last edited by Name Taken (2014-08-17 13:16:58)

tomk

Forum Fellow

From: Ireland

Registered: 2004-07-21

Posts: 9,839

Re: QXL Driver

That shows the qxl kernel driver being used, not the qxl xorg driver.

Name Taken

Banned

Registered: 2014-04-09

Posts: 113

Re: QXL Driver

That shows the qxl kernel driver being used, not the qxl xorg driver.

Something I found out just now with xf86-video-qxl is when scrolling through a large text file or using the browser the display would lag and afterwards the desktop would look like this. With xorg-drivers the scrolling is smooth without a big CPU spike.

Last edited by Name Taken (2014-08-17 13:33:16)