Re: [PATCH v2 10/22] vfio/pci: Skip reset of preserved device after Live Update

[Vipin Sharma]

On Fri, Mar 13, 2026 at 08:39:18AM -0700, Jacob Pan wrote:
> Hi David,
> 
> > +config VFIO_PCI_LIVEUPDATE
> > +       bool "VFIO PCI support for Live Update (EXPERIMENTAL)"
> > +       depends on LIVEUPDATE && VFIO_PCI
> > +       help
> > +         Support for preserving devices bound to vfio-pci across a
> > Live
> > +         Update. The eventual goal is that preserved devices can run
> > +         uninterrupted during a Live Update, including DMA to
> > preserved
> > +         memory buffers and P2P. However there are many steps still
> > needed to
> > +         achieve this, including:
> > +
> > +          - Preservation of iommufd files
> > +          - Preservation of IOMMU driver state
> In the interim, what do you think about moving forward with noiommu
> mode without preserving IOMMU driver state? I’ve tested your
> vfio_pci_liveupdate_kexec_test with the noiommu cdev, and it works as
> expected.
> 

Just curious, are you using qemu VM without iommu device for noiommu
work or do you have actual system without iommu hardware for testing?