can we skip the verification? this needs a very special setup to verify. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-bluefield in Ubuntu. https://bugs.launchpad.net/bugs/2077887
Title: Backport VFIO P2P patch for BlueField 5.15 Status in linux-bluefield package in Ubuntu: New Status in linux-bluefield source package in Jammy: Fix Committed Bug description: * Summary Current BF kernel doesn't support VFIO P2P, the following patches need to backport, based on 6.0 kernel. 1. https://patchwork.kernel.org/project/kvm/cover/0-v2-1bd95d72f298+e0e-vfio_pci_priv_...@nvidia.com/ 2. https://patchwork.kernel.org/project/kvm/cover/0-v2-0f9e632d54fb+d6-vfio_ioctl_split_...@nvidia.com/ 3. https://patchwork.kernel.org/project/linux-rdma/cover/0-v2-472615b3877e+28f7-vfio_dma_buf_...@nvidia.com/ Due to it's huge dependency, we didn't backport from 1, but instead, we directly take patch series 3 and fix the code to make it work. * Kernel Config Need to enable CONFIG_PCI_P2PDMA (enable p2p dma transaction) CONFIG_DMABUF_MOVE_NOTIFY (no need to pin down the memory) The feature doesn't work with IOMMU, so either we disable it for the system, "iommu.passthrough=1 iommu=off" in kernel boot parameter, or conditionally disable it for VFIO. CONFIG_VFIO_NOIOMMU (optional) - You should enable CONFIG_VFIO_NOIOMMU in the kernel config if your vfio module does not have vfio enable_unsafe_noiommu_mode in the parameter list. * /etc/modprobe.d/vfio.conf $ cat /etc/modprobe.d/vfio.conf # The kernel hungs when 0000:06:00.0 (Non-Volatile memory controller: KIOXIA # Corporation Device 0001) is bound to the vfio-pci module, and the following # error is printed: # # vfio-pci 0000:06:00.0: Unable to change power state from D3hot to D0, device inaccessible # # The configuration below is a workarround for the issue. options vfio-pci disable_idle_d3=1 # Allow using VFIO without IOMMU. This is only required when SMMU is disabled. options vfio enable_unsafe_noiommu_mode=1 * Setup and Test 1. For ease of testing, we take a BF3 and boot the OS into mmc instead of NVMe drive. So leaving NVMe drive free to use. 2. use a test program to verify its correctness. The program create ibv rdma program, open nvme drive, create dma vfio buf from nvme, and let the rdma program read (DMA P2P) the version number of the nvme drive. https://gitlab.com/Mellanox/spdk_team/vfio-dmabuf-test * UAPI changes The backport patches are not upstreamed and we have to maintain it if conflict in the future.Specifically, the patch "vfio/pci: Allow MMIO regions to be exported through dma-buf" adds the following struct and define. /** * Upon VFIO_DEVICE_FEATURE_GET create a dma_buf fd for the * region selected. * * open_flags are the typical flags passed to open(2), eg O_RDWR, O_CLOEXEC, * etc. offset/length specify a slice of the region to create the dmabuf from. * If both are 0 then the whole region is used. * * Return: The fd number on success, -1 and errno is set on failure. */ struct vfio_device_feature_dma_buf { __u32 region_index; __u32 open_flags; __u32 offset; __u64 length; }; #define VFIO_DEVICE_FEATURE_DMA_BUF 3 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-bluefield/+bug/2077887/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
