Re: [PATCH v3 0/2] Extend 8-byte PCI load/store support to x86 arch

Alex Williamson
2025-01-06T16:28:51Z

On Tue, 10 Dec 2024 05:19:36 -0800
Ramesh Thomas <ramesh.thomas@intel.com> wrote:

> This patch series extends the recently added 8-byte PCI load/store
> support to the x86 architecture.
>
> Refer patch series adding above support:
> https://lore.kernel.org/all/20240522150651.1999584-1-gbayer@linux.ibm.com/
>
> The 8-byte implementations are enclosed inside #ifdef checks of the
> macros "ioread64" and "iowrite64". These macros don't get defined if
> CONFIG_GENERIC_IOMAP is defined. CONFIG_GENERIC_IOMAP gets defined for
> x86 and hence the macros are undefined. Due to this the 8-byte support
> was not enabled for x86 architecture.
>
> To resolve this, include the header file io-64-nonatomic-lo-hi.h that
> maps the ioread64 and iowrite64 macros to a generic implementation in
> lib/iomap.c. This was the intention of defining CONFIG_GENERIC_IOMAP.
>
> Tested using a pass-through PCI device bound to vfio-pci driver and
> doing BAR reads and writes that trigger calls to
> vfio_pci_core_do_io_rw() that does the 8-byte reads and writes.
>
> Patch history:
> v3: Do not add the check for CONFIG_64BIT and only remove the checks for
> ioread64 and iowrite64.
>
> v2: Based on Jason's feedback moved #include io-64-nonatomic-lo-hi.h
> to vfio_pci_rdwr.c and replaced #ifdef checks of iowrite64 and ioread64
> macros with checks for CONFIG_64BIT.
>
> https://lore.kernel.org/all/20240522232125.548643-1-ramesh.thomas@intel.com/
> https://lore.kernel.org/all/20240524140013.GM69273@ziepe.ca/
> https://lore.kernel.org/all/bfb273b2-fc5e-4a8b-a40d-56996fc9e0af@intel.com/
>
> Ramesh Thomas (2):
> vfio/pci: Enable iowrite64 and ioread64 for vfio pci
> vfio/pci: Remove #ifdef iowrite64 and #ifdef ioread64
>
> drivers/vfio/pci/vfio_pci_rdwr.c | 13 +------------
> 1 file changed, 1 insertion(+), 12 deletions(-)
>

Applied to vfio next branch for v6.14. Thanks,

Alex