[virt-tools-list] virt-manager -- unwatchable choppy performance using fullscreen flash in windows VM

Cole Robinson crobinso at redhat.com
Wed Oct 15 08:03:58 UTC 2014


On 10/12/2014 10:05 PM, Greg Sheremeta wrote:
> Hey all,
> 
> Using a high-end Fedora 20 host, I get very poor choppy performance running flash full-screen
> in a Windows VM. I need to use Windows due to DRM stuff (nflsundayticket.tv). I've tried
> different virtual graphics adapters, but nothing helps. Attempting 1920x1080. Flash 15.
> Using remote-viewer or virt-manager, spice, QXL is set to 64 MB RAM.
> 
> Some googling suggests that QXL just can't handle 1920x1080 flash fullscreen.
> 
> Using VirtualBox gives pretty flawless performance at 1920x1080. But I want to use
> virt-manager, of course :)
> 
> I've also had success using VLC to stream the non-maximized flash player from the windows
> guest to the host, and then VLC scales up on the host (using host hardware acceleration,
> I'm sure). But this is a bit of a pain to manage.
> 
> One option I've read about is passing through a graphics adapter. My host machine has
> my primary nvidia card, but it also has the onboard Intel adapter that I don't use. Maybe
> if I can pass this Intel card through, I'd get the performance I'm looking for. From what
> I can tell, this isn't quite ready for primetime. 
> 
> 1. Can someone update me on the status of graphics passthrough in virt-manager?

Graphics passthrough only works with a small selection of graphics cards, and
requires latest upstream code. So if you're motivated you can get it to work
but it isn't trivial. There's some info here: http://vfio.blogspot.com/

> 2. Does anyone have any ideas other than passing through a card?

Try virt-viewer to eliminate virt-manager from the equation. Aside from that,
ask on a spice specific list for more info.

- Cole




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