Hi, this is your Linux kernel regression tracker.
On 10.05.22 02:12, Zack Rusin wrote:
On May 9, 2022, at 6:57 AM, Hans de Goede hdegoede@redhat.com wrote: On 4/11/22 16:24, Zack Rusin wrote:
On Mon, 2022-04-11 at 10:52 +0200, Hans de Goede wrote:
Fedora has received a bug report here:
https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.r...
That Fedora rawhide VMs no longer boot under the VirtualBox
hypervisor after the VM has been updated to a 5.18-rc# kernel.
Switching the emulated GPU from vmwaregfx to VirtualBoxSVGA fixes this, so this seems to be a vmwgfx driver regression.
Note I've not investigated/reproduced this myself due to -ENOTIME.
Thanks for letting us know. Unfortunately we do not support vmwgfx on VirtualBox. I'd be happy to review patches related to this, but it's very unlikely we'd have to time to look at this ourselves.
I somewhat understand where you are coming from, but this is not how the kernels "no regressions" policy works.
Hans, many thx for writing your mail, I once intended to write something similar, but then forgot about it. :-/
For the end user a regression is a regression and as maintainers we are supposed to make sure any regressions noticed are fixed before a new kernel hits end user's systems.
I think there’s a misunderstanding here - the vmwgfx driver never supported VirtualBox. VirtualBox implementation of the svga device lacks a bunch of features,
Which from the kernel's point of view is irrelevant. If the Linux kernel's vmwgfx driver ever supported the VirtualBox implementation then things shouldn't regress with later versions.
vmwgfx has been put on denylists
/me wonders what exactly is meant by "denylists" here in the upstream context(¹), but whatever, doesn't matter much now afaics.
(¹) Did the users that reported the issue do anything unusual (like writing telling the driver to load with a pciid that is normally doesn't support) to be enable vmwgfx for this hardware?
before due to bugs in VirtualBox implementation of it, we just didn’t feel like playing games like having the driver query the hypervisor “are you really from VMware?” and refuse to load.
In this case it’s their lack of mksStats interfaces that’s the issue. We can’t stop development of vmwgfx because our competitor was trying to reuse our work and didn’t implement the features we have. vmwgfx patches are now months ahead on drm-misc-next which should give anyone working on that device in VirtualBox plenty of time to fix it.
As Hans said: 'this is not how the kernels "no regressions" policy works.' For details see these documents, esp. the quotes from Linus.
https://www.kernel.org/doc/html/latest/admin-guide/reporting-regressions.htm... https://www.kernel.org/doc/html/latest/process/handling-regressions.html
I’m happy to spend my spare time reviewing patches that would make it work but it’s just not reasonable to expect anyone to spend their time in the office working on a directly competing product.
No, but maintaining the driver in the kernel also means that you can't break a directly competing product, otherwise Linus might revert the commits that cause this, unless someone fixes the breakage.
At a minimum it would have been good if you had tried to at least reproduce this bug by installing Fedora rawhide inside an actual vmware VM. I've just spend a couple of hours debugging this and the bug definitely impacts vmware VMs too; and thus very likely also reproduces there.
We’re always running Fedora, it should always just work on vmwgfx.
I've a patch fixing this, which I will send out right after this email.
Many thx for taking care of this, Hans!
That looks like a back porting issue. drm-misc/drm-misc-next is continuously tested on Fedora with vmwgfx so any breaks should never last more than a day. I’ll back port some patches tomorrow when drm-misc-next-fixes opens (because it’s after rc6). I’m sorry you had to deal with this, just send me an email next time, I should always have a pretty good handle on any issues with Fedora with latest vmwgfx.
Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
P.S.: As the Linux kernel's regression tracker I deal with a lot of reports and sometimes miss something important when writing mails like this. If that's the case here, don't hesitate to tell me in a public reply, it's in everyone's interest to set the public record straight.