On 11/16/2016 8:33 AM, Dong Jia Shi wrote:
> * Kirti Wankhede <kwankhede@xxxxxxxxxx> [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 <kwankhede@xxxxxxxxxx>
>> Signed-off-by: Neo Jia <cjia@xxxxxxxxxx>
>> 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?
>
Ok
>> /*
>> * IRQfd - generic
>> */
>> --
>> 2.7.0
>>
>
> The code looks good to me.
>
Thanks.
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