Messages in this thread | | | Subject | Re: [PATCH] virt: vbox: Implement passing requestor info to the host for VirtualBox 6.0.x | From | Hans de Goede <> | Date | Wed, 20 Mar 2019 20:52:57 +0100 |
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Hi,
On 20-03-19 19:19, Greg Kroah-Hartman wrote: > On Wed, Mar 20, 2019 at 10:52:05AM +0100, Hans de Goede wrote: >> Hi, >> >> On 20-03-19 10:46, Greg Kroah-Hartman wrote: >>> On Wed, Mar 20, 2019 at 10:35:19AM +0100, Hans de Goede wrote: >>>> VirtualBox 6.0.x has a new feature where the guest kernel driver passes >>>> info about the origin of the request (e.g. userspace or kernelspace) to >>>> the hypervisor. >>>> >>>> If we do not pass this information then when running the 6.0.x userspace >>>> guest-additions tools on a 6.0.x host, some requests will get denied >>>> with a VERR_VERSION_MISMATCH error, breaking vboxservice.service and >>>> the mounting of shared folders marked to be auto-mounted. >>>> >>>> This commit implements passing the requestor info to the host, fixing this. >>>> >>>> Cc: stable@vger.kernel.org >>> >>> This feels like support for a "new feature", so why would this need to >>> go to older kernels? >>> >>> It's not our fault that vb implemented a non-backwards-compatible change >>> for their new release, right? So why should we be forced to add new >>> features to stable kernels? >> >> From a technical point of view I completely agree with you and I'm unhappy >> with this breakage after vb agreed with me to keep ABI compatibility so >> that we could add a version of the vboxguest driver to the mainline kernel. > > So they broke that agreement, ugh. That implies they will do it again?
Well they did not really broke the ABI, they started using a reserved field and a 6.0.x host will happily work with 5.2.x guest-extensions (with the mainline vboxguest driver) the same way around, 5.2.x host als works with 6.0.x guest-extensions user-space bits + mainline kernel module.
Things break when using a 6.0.x host + 6.0.x guest-extensions userspace parts combined with the mainline kernel module. The 6.0.x + 6.0.x combi seems to assume that there is a 6.0.x vboxguest driver which fills in the reserved field. I believe this is an oversight and not a deliberate breakage. Perhaps this is even something which the VirtualBox devs can fix in a future 6.0.x update... Michael ?
>> OTOH this is going to bite users out there, which is why I added the Cc: >> stable. But this is entirely your call. > > Let me think about it... > >>> I have no problem to add this for 5.2, but not for older stuff. >> >> Can we at least at it as a fix to 5.1 ? It is not very adventurous. > > Sure, let me go review it now.
Thank you for the review, I will reply to it tomorrow (and prep a v2).
Regards,
Hans
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