Re: [PATCH v2 1/7] PCI/IOV: Return u16 from pci_sriov_get_totalvfs()

[Alexandre Courbot]

On Tue Jun 23, 2026 at 4:43 AM JST, Zhi Wang wrote:
> pci_sriov_get_totalvfs() reports a VF count, not an errno-style
> status. It returns 0 when SR-IOV is unavailable or the device is not a
> PF, and otherwise returns the PF's driver_max_VFs value.
>
> driver_max_VFs is stored as a u16 in struct pci_sriov. It is derived
> from the SR-IOV TotalVFs field or from a driver-provided limit, so the
> implementation cannot return a negative value.
>
> Change the declaration, CONFIG_PCI_IOV stub, and implementation to
> return u16. Update callers to store the result in u16 variables, remove
> obsolete negative-value checks, and use unsigned format specifiers where
> needed.
>
> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx
> Signed-off-by: Zhi Wang <zhiw@xxxxxxxxxx>

Suggested-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
Link: https://lore.kernel.org/all/DETDILPA1GFY.27WND0TEC5352@xxxxxxxxxx/

> ---
>  drivers/crypto/hisilicon/qm.c                   | 8 +++++---
>  drivers/crypto/intel/qat/qat_common/adf_sriov.c | 6 +++---
>  drivers/gpu/drm/xe/xe_sriov_pf.c                | 6 ++----
>  drivers/misc/genwqe/card_base.c                 | 6 ++----
>  drivers/net/ethernet/cavium/thunder/nic_main.c  | 2 +-
>  drivers/net/ethernet/emulex/benet/be_main.c     | 3 ++-
>  drivers/net/ethernet/mellanox/mlx5/core/sriov.c | 3 ++-
>  drivers/net/ethernet/sfc/ef10_sriov.c           | 2 +-

I believe that you can avoid converting all these drivers in this patch.
The implicit `u16 -> int` conversion done by C should result in the
expected behavior, and it will be fewer Acked-by to collect.

I.e. just updating drivers/pci/iov.c and include/linux/pci.h should be
sufficient as the first step. Specific drivers can then be updated using
separate patches that will be easier to merge individually, if you want
to do so.