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[34.145.255.212]) by smtp.gmail.com with ESMTPSA id 956f58d0204a3-6664083f9f6sm1511013d50.16.2026.07.03.17.52.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Jul 2026 17:52:06 -0700 (PDT) Date: Fri, 3 Jul 2026 20:52:05 -0400 From: Pasha Tatashin To: Pasha Tatashin , Alexander Graf , "Andersen, Tycho" , Anthony Yznaga , Baolu Lu , David Hildenbrand , David Matlack , "Heyne, Maximillian" , James Gowans , Jason Gunthorpe , Mike Rapoport , Pankaj Gupta , Pratyush Yadav , Praveen Kumar , Vipin Sharma , Vishal Annapurve , "Woodhouse, David" , Luca Boccassi , Samiullah Khawaja , Jork Loeser , Chenghao Duan , Zhu Yanjun Cc: linux-mm@kvack.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [Hypervisor Live Update] Notes from June 15 and June 29, 2026 Message-ID: References: <20260704004316.1109918-1-pasha.tatashin@soleen.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260704004316.1109918-1-pasha.tatashin@soleen.com> Adding missing CCs to the mailing lists. On 07-03 20:43, Pasha Tatashin wrote: > Hi everybody, > > Here are the combined notes from our last two Hypervisor Live Update > calls, held on June 15 and June 29. These notes are intended to bring > those who could not attend up to speed and to keep the momentum going > between meetings. > > ----->o----- > LPC 2026 Call for Proposals > > The Call for Proposals for the Live Update Microconference at LPC 2026 > in Prague is open. Please make sure to submit your topics and abstracts > before the upcoming deadline on July 24th. > > https://lore.kernel.org/all/ahcc3Qyuy7Oy03Iq@plex > > ----->o----- > VFIO & PCIe Persistence Roadmap > > * Roadmap Recap (June 15): Vipin Sharma outlined the five-milestone > roadmap for preserving PCIe endpoint functions (and upstream bridges) > across live updates without disrupting registers or ongoing DMA. > > * Status Update (June 29): Vipin has addressed feedback on the v4 > submission. Revision v5 is currently undergoing internal validation > and is on track for the mailing list before our next sync. > > PCIe Core Updates > > * v6/v7 Evolution: David Matlack is preparing the v7 PCI series. The > group aligned on deploying an FLB reference-counting model to maintain > symmetry for incoming/outgoing sessions across kexec. > > * Pratyush Yadav suggested that drivers should explicitly isolate > structural "probe" routines from "retrieve" logic and separate > "shutdown" from "finish" callbacks. David is evaluating the > feasibility of deferring probes until the retrieve phase to improve > driver cleanliness. > > * David is refactoring the PCI series to utilize KHO blocks. > > IOMMU & Dependency Management > > * v3 Status: Samiullah has posted v3 of the IOMMU persistence series, > addressing hot-plug handling and context entry preservation. > > * Dependency Policy: The group agreed that the Live Update framework > will not enforce a hardcoded preservation sequence. Instead, > individual subsystem file handlers will verify dependency states > locally during their freeze/finish callbacks. > > LUO, KHO > > * Terminology Updates: "Scratch" memory is now designated as > "unpreserved memory" (memblock perspective). KHO "Scratch" is renamed > to "KHO boot memory". > > * LUO Limits: Limits on the number of sessions and preserved files have > been removed and landed in upstream Linux. > > Guest Memory (guest_memfd) > > * Naming Conventions: Regarding the KVM file binding debate, the team is > moving away from the debugfs-based incremented value approach (due to > production compilation concerns). We are exploring using unique names > derived from user-space file-handler compatibility strings. Tarun will > escalate this to the KVM maintainers. > > ----->o----- > Action Items & Next Steps > > Pasha: Consult with Mike regarding KHO component splitting without > versioning support. > > David M: Send next version of the FLB ref-count patch; refactor PCI > series to use KHO blocks; share recording link from June 29. > > Pratyush: Implement rename of KHO scratch/boot mem. > > Vipin: Submit VFIO v5. > > Group: Review Guest Memory Preservation V3 series (Pasha/David). > > ----->o----- > > Next meeting will be on Monday, July 13 at 8am PDT (UTC-7), everybody is > welcome! > > Join Here: https://meet.google.com/rjn-dmzu-hgq > > Please let me know if you'd like to propose additional topics for > discussion, thank you! > > Best regards, > Pasha