Re: [PATCH] PCI: Avoid FLR for NVIDIA 5090 GPU

From: Jason Gunthorpe

Date: Thu Apr 16 2026 - 18:38:08 EST


On Thu, Apr 16, 2026 at 12:31:00PM -0500, Bjorn Helgaas wrote:
> On Thu, Apr 16, 2026 at 03:07:06PM +0800, yuan.gao wrote:
> > When passing through the NVIDIA 5090 GPU to a vm, there is a certain
> > probability of encountering an flr timeout during vm shutdown, which
> > subsequently leads to a soft lock of the host cpu.
>
> If possible, would like confirmation of device erratum from Nvidia.
> If there's no known erratum, there might be something wrong in the
> Linux FLR and wait.

I asked and was told there is a known device firmware defect that
causes this.

So blanket disabling FLR without detecting good and bad FW is not a
good idea.

I suggest Yuan try to use an NVIDIA support channel to try to resolve
the issue with their card..

Jason