Hi David, On Mon, 16 Mar 2026 11:11:20 -0700 David Matlack <[email protected]> wrote:
> On Fri, Mar 13, 2026 at 8:39 AM Jacob Pan > <[email protected]> wrote: > > On Thu, 12 Mar 2026 23:39:45 +0000 > > David Matlack <[email protected]> wrote: > > > > +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 haven't gotten a chance to look at your noiommu patches yet, but I > do think noiommu will probably be a good way to develop the VFIO and > PCI support for Live Update without blocking on IOMMU driver support. > > > I’ve tested your > > vfio_pci_liveupdate_kexec_test with the noiommu cdev, and it works > > as expected. > > Would you be able to send patches to add noiommu support to VFIO > selftests? That would be very helpful toward allowing us to develop > and test Live Update support with noiommu. It is included in the noiommu patchset; the only difference is that the VFIO cdev name is prefixed with noiommu, which is not strictly required and is done out of caution. /dev/vfio/ |-- devices | `-- noiommu-vfio0 https://lore.kernel.org/linux-iommu/[email protected]/
