From: Greg KH <gregkh@linuxfoundation.org>
To: cat <cat@plan9.rocks>
Cc: regressions@lists.linux.dev, stable@vger.kernel.org
Subject: Re: [REGRESSION] vfio gpu passthrough stopped working
Date: Thu, 7 Aug 2025 16:52:41 +0100 [thread overview]
Message-ID: <2025080724-sage-subplot-3d0f@gregkh> (raw)
In-Reply-To: <718C209F-22BD-4AF3-9B6F-E87E98B5239E@plan9.rocks>
On Thu, Aug 07, 2025 at 03:31:17PM +0000, cat wrote:
> #regzbot introduced: v6.12.34..v6.12.35
>
> After upgrade to kernel 6.12.35, vfio passthrough for my GPU has stopped working within a windows VM, it sees device in device manager but reports that it did not start correctly. I compared lspci logs in the vm before and after upgrade to 6.12.35, and here are the changes I noticed:
>
> - the reported link speed for the passthrough GPU has changed from 2.5 to 16GT/s
> - the passthrough GPU has lost it's 'BusMaster' and MSI enable flags
> - latency measurement feature appeared
>
> These entries also began appearing within the vm in dmesg when host kernel is 6.12.35 or above:
>
> [ 1.963177] nouveau 0000:01:00.0: sec2(gsp): mbox 1c503000 00000001
> [ 1.963296] nouveau 0000:01:00.0: sec2(gsp):booter-load: boot failed: -5
> ...
> [ 1.964580] nouveau 0000:01:00.0: gsp: init failed, -5
> [ 1.964641] nouveau 0000:01:00.0: init failed with -5
> [ 1.964681] nouveau: drm:00000000:00000080: init failed with -5
> [ 1.964721] nouveau 0000:01:00.0: drm: Device allocation failed: -5
> [ 1.966318] nouveau 0000:01:00.0: probe with driver nouveau failed with error -5
>
>
> 6.12.34 worked fine, and latest 6.12 LTS does not work either. I am using intel CPU and nvidia GPU (for passthrough, and as my GPU on linux system).
Can you use git bisect to find the offending commit?
next prev parent reply other threads:[~2025-08-07 15:52 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-07 15:31 [REGRESSION] vfio gpu passthrough stopped working cat
2025-08-07 15:52 ` Greg KH [this message]
2025-08-07 18:31 ` Harshit Mogalapalli
2025-08-08 4:40 ` cat
2025-08-08 9:00 ` cat
2025-08-08 9:22 ` Harshit Mogalapalli
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