On 24/4/25 18:24, Farhan Ali wrote:
Hi Alex,
Cc'ing Cédric as co-maintainer with Alex.
Polite ping. Please let me know if there are any concerns with this
version of the patches.
Thanks
Farhan
On 4/17/2025 10:37 AM, Farhan Ali wrote:
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/
ChangeLog
---------
v4 series https://lore.kernel.org/qemu-devel/20250414213616.2675-1-
al...@linux.ibm.com/
v4 -> v5
- Fixup typo in PCI MMIO API (patch 2).
v3 series https://lore.kernel.org/qemu-devel/20250401172246.2688-1-
al...@linux.ibm.com/
v3 -> v4
- Use generic ld/st functions for non s390x PCI access suggested
by Alex (patch 2).
- Removed R-b for patch 2 as the host PCI MMIO access API changed
for non-s390x.
Would appreciate review on this again.
v2 series https://mail.gnu.org/archive/html/qemu-devel/2025-03/
msg06847.html
v2 -> v3
- Update the PCI MMIO APIs to reflect that its PCI MMIO access on
host
as suggested by Stefan(patch 2)
- Move s390x ifdef check to s390x_pci_mmio.h as suggested by
Philippe (patch 1)
- Add R-bs for the respective patches.
v1 series https://mail.gnu.org/archive/html/qemu-devel/2025-03/
msg06596.html
v1 -> v2
- Add 8 and 16 bit reads/writes for completeness (patch 1)
- Introduce new QEMU PCI MMIO read/write API as suggested by
Stefan (patch 2)
- Update NVMe userspace driver to use QEMU PCI MMIO functions
(patch 3)
Farhan Ali (3):
util: Add functions for s390x mmio read/write
include: Add a header to define host PCI MMIO functions
block/nvme: Use host PCI MMIO API
block/nvme.c | 41 +++++-----
include/qemu/host-pci-mmio.h | 141 ++++++++++++++++++++++++++++++++
include/qemu/s390x_pci_mmio.h | 24 ++++++
util/meson.build | 2 +
util/s390x_pci_mmio.c | 148 ++++++++++++++++++++++++++++++++++
5 files changed, 338 insertions(+), 18 deletions(-)
create mode 100644 include/qemu/host-pci-mmio.h
create mode 100644 include/qemu/s390x_pci_mmio.h
create mode 100644 util/s390x_pci_mmio.c
