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[35.247.89.60]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-35bada5c760sm115860a91.5.2026.03.16.09.28.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Mar 2026 09:28:36 -0700 (PDT) Date: Mon, 16 Mar 2026 09:28:32 -0700 From: Vipin Sharma To: Jacob Pan Cc: David Matlack , Alex Williamson , Adithya Jayachandran , Alexander Graf , Alex Mastro , Alistair Popple , Andrew Morton , Ankit Agrawal , Bjorn Helgaas , Chris Li , David Rientjes , Jason Gunthorpe , Jason Gunthorpe , Jonathan Corbet , Josh Hilke , Kevin Tian , kexec@lists.infradead.org, kvm@vger.kernel.org, Leon Romanovsky , Leon Romanovsky , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, Lukas Wunner , =?utf-8?Q?Micha=C5=82?= Winiarski , Mike Rapoport , Parav Pandit , Pasha Tatashin , Pranjal Shrivastava , Pratyush Yadav , Raghavendra Rao Ananta , Rodrigo Vivi , Saeed Mahameed , Samiullah Khawaja , Shuah Khan , Thomas =?utf-8?Q?Hellstr=C3=B6m?= , Tomita Moeko , Vivek Kasireddy , William Tu , Yi Liu , Zhu Yanjun Subject: Re: [PATCH v2 10/22] vfio/pci: Skip reset of preserved device after Live Update Message-ID: <20260316162518.GB1767448.vipinsh@google.com> References: <20260129212510.967611-1-dmatlack@google.com> <20260129212510.967611-11-dmatlack@google.com> <20260226170030.5a938c74@shazbot.org> <20260227084658.3767d801@shazbot.org> <20260227105720.522ca97f@shazbot.org> <20260313083918.00005731@linux.microsoft.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=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260313083918.00005731@linux.microsoft.com> 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?