Public bug reported: * 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. * 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 ** Affects: linux-bluefield (Ubuntu) Importance: Undecided Status: New -- 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 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. * 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
