Based on several threads from last year I found on this issue, and this issue:
https://github.com/QubesOS/qubes-issues/issues/2182
Is it correct that once this bug with the dvm savefile is triggered, then dvms will never work on your system again unless you manually patch xen and recompile?
Are there instructions anywhere for doing this?
I never heard of that. Have you tried to just delete the dvm from qubes manager, then from dom0 terminal type qvm-create-default-dvm fedora-24? That always works for me.
to me it happens where I get the bug that a dispvm won't start. You click it from start menu and nothing happens. I just delete the internal dvm template file and create a new one. I think some people might have the issue of trying to create them without deleting old one first.
But one time I even noticed I must of went to some bad webpage or that the firefox couldn't handle it and it crashed out. I mean closed and disappeared. after that dispvms wouldn't start. could of been a porn page, or a news site I can't remember. Not sure how to trace anything with that.
has only happened no more then a handful of times the few years I've used Qubes.
I forgot on one of my machines for over a week now, every time I start a dispvm it has a yellow triangle for not allrequested memory being returned. I shut down the vm and triangle goes away, start it and it comes back. Deleting the dvm and recreating it is not fixing this, nor is rebooting. Even if its the only vm I load. Only recent anomaly. no idea what log to look at, makes me uncomfortable using it on that machine.
also the vm on this machine is running terribly slow even with more cpu cores enabled. I thought it was slow internet just now and realized its osmething wrong with this dvm.