Re: [PATCH V4 vfio 8/9] vfio/pci: Expose vfio_pci_iowrite/read##size()

Alex Williamson
2023-12-04T22:57:24Z

On Sun, 3 Dec 2023 16:14:15 +0200
Yishai Hadas <yishaih@nvidia.com> wrote:

> On 30/11/2023 21:20, Alex Williamson wrote:
> > On Wed, 29 Nov 2023 16:37:45 +0200
> > Yishai Hadas <yishaih@nvidia.com> wrote:
> >
> >> Expose vfio_pci_iowrite/read##size() to let it be used by drivers.
> >>
> >> This functionality is needed to enable direct access to some physical
> >> BAR of the device with the proper locks/checks in place.
> >>
> >> The next patches from this series will use this functionality on a data
> >> path flow when a direct access to the BAR is needed.
> >>
> >> Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
> >> ---
> >> drivers/vfio/pci/vfio_pci_rdwr.c | 10 ++++++----
> >> include/linux/vfio_pci_core.h | 19 +++++++++++++++++++
> >> 2 files changed, 25 insertions(+), 4 deletions(-)
> >
> > I don't follow the inconsistency between this and the previous patch.
> > Why did we move and rename the code to setup the barmap but we export
> > the ioread/write functions in place? Thanks,
> >
> > Alex
>
> The mount of code for barmap setup was quite small compared to the
> ioread/write functions.
>
> However, I agree, we can be consistent here and export in both cases the
> functions in place as part of vfio_pci_rdwr.c which is already part of
> vfio_pci_core.ko
>
> I may also rename in current patch vfio_pci_iowrite/read<xxx> to have
> the 'core' prefix as part of the functions names (i.e.
> vfio_pci_core_iowrite/read<xxx>) to be consistent with other exported
> core functions and adapt the callers to this name.
>
> Makes sense ?

Yep. Thanks,

Alex

> >> diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
> >> index 6f08b3ecbb89..817ec9a89123 100644
> >> --- a/drivers/vfio/pci/vfio_pci_rdwr.c
> >> +++ b/drivers/vfio/pci/vfio_pci_rdwr.c
> >> @@ -38,7 +38,7 @@
> >> #define vfio_iowrite8 iowrite8
> >>
> >> #define VFIO_IOWRITE(size) \
> >> -static int vfio_pci_iowrite##size(struct vfio_pci_core_device *vdev, \
> >> +int vfio_pci_iowrite##size(struct vfio_pci_core_device *vdev, \
> >> bool test_mem, u##size val, void __iomem *io) \
> >> { \
> >> if (test_mem) { \
> >> @@ -55,7 +55,8 @@ static int vfio_pci_iowrite##size(struct vfio_pci_core_device *vdev, \
> >> up_read(&vdev->memory_lock); \
> >> \
> >> return 0; \
> >> -}
> >> +} \
> >> +EXPORT_SYMBOL_GPL(vfio_pci_iowrite##size);
> >>
> >> VFIO_IOWRITE(8)
> >> VFIO_IOWRITE(16)
> >> @@ -65,7 +66,7 @@ VFIO_IOWRITE(64)
> >> #endif
> >>
> >> #define VFIO_IOREAD(size) \
> >> -static int vfio_pci_ioread##size(struct vfio_pci_core_device *vdev, \
> >> +int vfio_pci_ioread##size(struct vfio_pci_core_device *vdev, \
> >> bool test_mem, u##size *val, void __iomem *io) \
> >> { \
> >> if (test_mem) { \
> >> @@ -82,7 +83,8 @@ static int vfio_pci_ioread##size(struct vfio_pci_core_device *vdev, \
> >> up_read(&vdev->memory_lock); \
> >> \
> >> return 0; \
> >> -}
> >> +} \
> >> +EXPORT_SYMBOL_GPL(vfio_pci_ioread##size);
> >>
> >> VFIO_IOREAD(8)
> >> VFIO_IOREAD(16)
> >> diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
> >> index 67ac58e20e1d..22c915317788 100644
> >> --- a/include/linux/vfio_pci_core.h
> >> +++ b/include/linux/vfio_pci_core.h
> >> @@ -131,4 +131,23 @@ int vfio_pci_core_setup_barmap(struct vfio_pci_core_device *vdev, int bar);
> >> pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev,
> >> pci_channel_state_t state);
> >>
> >> +#define VFIO_IOWRITE_DECLATION(size) \
> >> +int vfio_pci_iowrite##size(struct vfio_pci_core_device *vdev, \
> >> + bool test_mem, u##size val, void __iomem *io);
> >> +
> >> +VFIO_IOWRITE_DECLATION(8)
> >> +VFIO_IOWRITE_DECLATION(16)
> >> +VFIO_IOWRITE_DECLATION(32)
> >> +#ifdef iowrite64
> >> +VFIO_IOWRITE_DECLATION(64)
> >> +#endif
> >> +
> >> +#define VFIO_IOREAD_DECLATION(size) \
> >> +int vfio_pci_ioread##size(struct vfio_pci_core_device *vdev, \
> >> + bool test_mem, u##size *val, void __iomem *io);
> >> +
> >> +VFIO_IOREAD_DECLATION(8)
> >> +VFIO_IOREAD_DECLATION(16)
> >> +VFIO_IOREAD_DECLATION(32)
> >> +
> >> #endif /* VFIO_PCI_CORE_H */
> >
>