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

Vipin Sharma
2026-03-16T16:28:37Z

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?