I have a lenovo P50, with a nVidia Quadro M1000M. After discovering the environment variable to stop the flickering, I stumbled on what appears to be yet another nVidia related video bug. I normally suspend and resume my W10/64bit VM with the laptop. Using the Intel video, this has never giving me any trouble. But on a P50, using Intel basically blocks you from using the display ports to present. At least, I was able to get it to work. So after a resume, my W10 start menu looks like:
after resume.jpg (20.85 KiB) Viewed 1243 times
As a work-around, I restart the explorer that is doing the desktop, it all returns to normal:
after resume reset.jpg (35.96 KiB) Viewed 1243 times
But that approach also closes any open explorers I might have, besides the desktop.
I have also noticed that the control panel needs a little nudge to redisplay the options.
All of this never happened under the Intel video driver, so it is either a setting in the nVidia driver (I run the nVidia driver, not noveau, driver is 390.48), or something in VB that is not playing nVidia's game. Iḿ hoping some with a lot more insight into the video situation has some suggestions.
Before we let this "NVidia woes" meme get propagated too far, in fact I'm not aware of any other NVidia bug discussions around here. I am aware that they don't always sign their DLLs, but that is a management issue, I would not class it as a software bug: and that discussion only concerns Windows hosts anyway.
Your problem doesn't look like a certification issue, perhaps a configuration problem on your host, or a mismatch in video modes between guest and host?
I am not aware I stated it was a certification error. I have been running VB for a long time now, but normally use Intel graphics on the host. That's how I started on this particular machine as well. Due to circumstances I had to switch off the Intel card and energize he nVidia one. Naturally I first fixed the driver situation on the host.
Then I noticed heavy flickering on windows clients, which is well discussed and related to code inside VB and probably something nVidia is not doing. There's an environment variable you can set, to which VB reacts and this stops the flickering. I have also noticed what is shown in the screens, upon resume, something is not as it should be. This has never happened on an Intel graphic.
O yes, there's no DLL's, my host is Linux, Debian 10, 64 bits. Which is why I posted in the Linux Hosts. The client simply is running what it ran before, so the client sees only the virtualised graphic adapter. Windows 10 requires you switch on 3D acceleration.
And how would I mismatch the video modes? Wouldn't that then surface always?
AFAIK the Linux nVidia driver is somewhat lacking in proper implementation and this means it sometimes requires compensation from VB. In the flickering test, some posters actually found the workaround and posted a fix. I was hoping they might understand what is going here, as my knowledge interacting with graphic cards on this level is next to zero. The images shown are from the W10 client. My host has no issues, it runs well. If you virtualise an environment, which works well, change something host side and the client behaviour is affected, it points at the interaction between virtualiser and host not quite gelling. The whole point of virtualisation is that to an extent you isolate the client from the host by presenting a fixed hardware picture. That's why when I move to a new host, I only have to copy the clients over and it works. So in that light I simply don't understand the response, other than even the idea something might not be right being immediately rejected.
So, if Intel does not show this, nVidia does, and nVidia's lack of energy in providing either specs or a robust driver are well known, I think woes is an accurate description. It is not a meme, it's semantic description of a factual situation. If VB could be told to use the intel card always, great. But my attempts with Bumblebee were good in host situation, but what I never managed to get going was the use of nVidia whenever I plugged in an external display. I am awaiting delivery of one piece of kit, that might allow me to go back to Intel, and all will be fixed. So woes seems a good word to describe this misery.
In the meantime, I've moved back to a hybrid setup, meaning Intel rules the roost and all is well again. Will have another go with getting the external monitor to work with bumblebee, but right now, I would tend to agree with Linus Torvald's assessment of NVidia. The nouveau driver wouldn't allow the W10 to run the virtualised video card, reverting to their standard driver. the NVidia driver started arguing with kernel 4.16-2, so only 4.16-1 would actually boot. But seeing this was after upgrading VB, I am not totally convinced it was NVidia that was the root cause. But it is a factor, as switching to intel video, everything worked like a charm. The proper driver kicked-in, no flcikeing, no weird windows start screen in the client after a resume. Machine feels much snappier, but perhaps that is just my relief it all works, well all, external monitor is still something I need to solve. Or get a tiny laptop to display stuff With just an intel card.
With just an intel card.