* Kirti Wankhede <kwankh...@nvidia.com> [2016-11-15 20:59:48 +0530]:
Hi Kirti,
> Added APIs for pining and unpining set of pages. These call back into
> backend iommu module to actually pin and unpin pages.
> Added two new callback functions to struct vfio_iommu_driver_ops. Backend
> IOMMU module that supports pining and unpinning pages for mdev devices
> should provide these functions.
>
> Renamed static functions in vfio_type1_iommu.c to resolve conflicts
>
> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
> Signed-off-by: Neo Jia <c...@nvidia.com>
> Change-Id: Ia7417723aaae86bec2959ad9ae6c2915ddd340e0
> ---
> drivers/vfio/vfio.c | 103
> ++++++++++++++++++++++++++++++++++++++++
> drivers/vfio/vfio_iommu_type1.c | 20 ++++----
> include/linux/vfio.h | 14 +++++-
> 3 files changed, 126 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 2e83bdf007fe..3bf8a01bf67b 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -1799,6 +1799,109 @@ void vfio_info_cap_shift(struct vfio_info_cap *caps,
> size_t offset)
> }
> EXPORT_SYMBOL_GPL(vfio_info_cap_shift);
>
> +
> +/*
> + * Pin a set of guest PFNs and return their associated host PFNs for local
> + * domain only.
> + * @dev [in] : device
> + * @user_pfn [in]: array of user/guest PFNs to be unpinned. Number of
> user/guest
> + * PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
Move the second sentence to the @npage section?
> + * @npage [in] :count of elements in array. This count should not be greater
> + * than PAGE_SIZE.
And remove the second sentence here.
> + * @prot [in] : protection flags
> + * @phys_pfn[out] : array of host PFNs
nit:
I saw three differnt styles here:
@xxx [in] :xxxxxxx
@xxx [in]: xxxxxxx
@xxx[out]: xxxxxxx
Frankly speeking, I didn't think the [in|out] flags helps much.
> + * Return error or number of pages pinned.
> + */
> +int vfio_pin_pages(struct device *dev, unsigned long *user_pfn, int npage,
> + int prot, unsigned long *phys_pfn)
> +{
> + struct vfio_container *container;
> + struct vfio_group *group;
> + struct vfio_iommu_driver *driver;
> + int ret;
> +
> + if (!dev || !user_pfn || !phys_pfn || !npage)
> + return -EINVAL;
> +
> + if (npage > VFIO_PIN_PAGES_MAX_ENTRIES)
> + return -E2BIG;
> +
> + group = vfio_group_get_from_dev(dev);
> + if (IS_ERR(group))
> + return PTR_ERR(group);
> +
> + ret = vfio_group_add_container_user(group);
> + if (ret)
> + goto err_pin_pages;
> +
> + container = group->container;
> + down_read(&container->group_lock);
> +
> + driver = container->iommu_driver;
> + if (likely(driver && driver->ops->pin_pages))
> + ret = driver->ops->pin_pages(container->iommu_data, user_pfn,
> + npage, prot, phys_pfn);
> + else
> + ret = -ENOTTY;
> +
> + up_read(&container->group_lock);
> + vfio_group_try_dissolve_container(group);
> +
> +err_pin_pages:
> + vfio_group_put(group);
> + return ret;
> +}
> +EXPORT_SYMBOL(vfio_pin_pages);
> +
> +/*
> + * Unpin set of host PFNs for local domain only.
> + * @dev [in] : device
> + * @user_pfn [in]: array of user/guest PFNs to be unpinned. Number of
> user/guest
> + * PFNs should not be greater than VFIO_PIN_PAGES_MAX_ENTRIES.
> + * @npage [in] :count of elements in array. This count should not be greater
> + * than PAGE_SIZE.
Same nits as above here.
> + * Return error or number of pages unpinned.
> + */
[...]
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index 0ecae0b1cd34..420cdc928786 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -75,7 +75,11 @@ struct vfio_iommu_driver_ops {
> struct iommu_group *group);
> void (*detach_group)(void *iommu_data,
> struct iommu_group *group);
> -
> + int (*pin_pages)(void *iommu_data, unsigned long *user_pfn,
> + int npage, int prot,
> + unsigned long *phys_pfn);
> + int (*unpin_pages)(void *iommu_data,
> + unsigned long *user_pfn, int npage);
> };
>
> extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops
> *ops);
> @@ -127,6 +131,14 @@ static inline long vfio_spapr_iommu_eeh_ioctl(struct
> iommu_group *group,
> }
> #endif /* CONFIG_EEH */
>
> +#define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))
> +
> +extern int vfio_pin_pages(struct device *dev, unsigned long *user_pfn,
> + int npage, int prot, unsigned long *phys_pfn);
> +
> +extern int vfio_unpin_pages(struct device *dev, unsigned long *user_pfn,
> + int npage);
> +
Move this hunk up to the "External user API" section?
> /*
> * IRQfd - generic
> */
> --
> 2.7.0
>
The code looks good to me.
--
Dong Jia
