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-c5c0f1d26efd@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

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2.43.0