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[PATCH v5 0/3] Enable QEMU NVMe userspace driver on s390x

Farhan Ali posted 3 patches 7 months ago
Failed in applying to current master (apply log)
There is a newer version of this series
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
[PATCH v5 0/3] Enable QEMU NVMe userspace driver on s390x
Posted by Farhan Ali 7 months ago 
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/

ChangeLog
---------
v4 series https://lore.kernel.org/qemu-devel/20250414213616.2675-1-alifm@linux.ibm.com/
v4 -> v5
    - Fixup typo in PCI MMIO API (patch 2).

v3 series https://lore.kernel.org/qemu-devel/20250401172246.2688-1-alifm@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

-- 
2.43.0
Re: [PATCH v5 0/3] Enable QEMU NVMe userspace driver on s390x
Posted by Farhan Ali 6 months, 3 weeks ago 
Hi 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-c5c0f1d26efd@linux.ibm.com/
>
> ChangeLog
> ---------
> v4 series https://lore.kernel.org/qemu-devel/20250414213616.2675-1-alifm@linux.ibm.com/
> v4 -> v5
>      - Fixup typo in PCI MMIO API (patch 2).
>
> v3 series https://lore.kernel.org/qemu-devel/20250401172246.2688-1-alifm@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
>
Re: [PATCH v5 0/3] Enable QEMU NVMe userspace driver on s390x
Posted by Philippe Mathieu-Daudé 6 months, 3 weeks ago 
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- 
>> c5c0f1d26efd@linux.ibm.com/
>>
>> ChangeLog
>> ---------
>> v4 series https://lore.kernel.org/qemu-devel/20250414213616.2675-1- 
>> alifm@linux.ibm.com/
>> v4 -> v5
>>      - Fixup typo in PCI MMIO API (patch 2).
>>
>> v3 series https://lore.kernel.org/qemu-devel/20250401172246.2688-1- 
>> alifm@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
>>
Re: [PATCH v5 0/3] Enable QEMU NVMe userspace driver on s390x
Posted by Thomas Huth 6 months, 3 weeks ago 
On 24/04/2025 18.24, Farhan Ali wrote:
> Hi Alex,
> 
> Polite ping. Please let me know if there are any concerns with this version 
> of the patches.

I assumed that Stefan would pick the patches up for the nvme/block tree, but 
I can also take them through the s390x tree instead if that's preferred.
But please address/comment on the nits that I found first.

  Thanks,
   Thomas

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