Hi, Recently on s390x we have enabled mmap support for vfio-pci devices [1]. This allows us to take advantage and use userspace drivers on s390x. However, on s390x we have special instructions for MMIO access. Starting with z15 (and newer platforms) we have new PCI Memory I/O (MIO) instructions which operate on virtually mapped PCI memory spaces, and can be used from userspace. On older platforms we would fallback to using existing system calls for MMIO access.
This patch series introduces support the PCI MIO instructions, and enables s390x support for the userspace NVMe driver on s390x. I would appreciate any review/feedback on the patches. Thanks Farhan [1] https://lore.kernel.org/linux-s390/20250226-vfio_pci_mmap-v7-0-c5c0f1d26...@linux.ibm.com/ Farhan Ali (2): util: Add functions for s390x mmio read/write block/nvme: Enable NVMe userspace driver for s390x block/nvme.c | 95 ++++++++++++++++++++++++------ include/qemu/s390x_pci_mmio.h | 17 ++++++ util/meson.build | 2 + util/s390x_pci_mmio.c | 105 ++++++++++++++++++++++++++++++++++ 4 files changed, 201 insertions(+), 18 deletions(-) create mode 100644 include/qemu/s390x_pci_mmio.h create mode 100644 util/s390x_pci_mmio.c -- 2.43.0