Re: [PATCH v11 13/22] vfio: Introduce common function to add capabilities

From: Alexey Kardashevskiy
Date: Tue Nov 08 2016 - 02:29:40 EST


On 05/11/16 08:10, Kirti Wankhede wrote:
> Vendor driver using mediated device framework should use
> vfio_info_add_capability() to add capabilities.
> Introduced this function to reduce code duplication in vendor drivers.
>
> Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
> Signed-off-by: Neo Jia <cjia@xxxxxxxxxx>
> Change-Id: I6fca329fa2291f37a2c859d0bc97574d9e2ce1a6
> ---
> drivers/vfio/vfio.c | 60 +++++++++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/vfio.h | 3 +++
> 2 files changed, 62 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 4ed1a6a247c6..9a03be0942a1 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -1797,8 +1797,66 @@ void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset)
> for (tmp = caps->buf; tmp->next; tmp = (void *)tmp + tmp->next - offset)
> tmp->next += offset;
> }
> -EXPORT_SYMBOL_GPL(vfio_info_cap_shift);
> +EXPORT_SYMBOL(vfio_info_cap_shift);


Why this change?


>
> +static int sparse_mmap_cap(struct vfio_info_cap *caps, void *cap_type)
> +{
> + struct vfio_info_cap_header *header;
> + struct vfio_region_info_cap_sparse_mmap *sparse_cap, *sparse = cap_type;
> + size_t size;
> +
> + size = sizeof(*sparse) + sparse->nr_areas * sizeof(*sparse->areas);
> + header = vfio_info_cap_add(caps, size,
> + VFIO_REGION_INFO_CAP_SPARSE_MMAP, 1);
> + if (IS_ERR(header))
> + return PTR_ERR(header);
> +
> + sparse_cap = container_of(header,
> + struct vfio_region_info_cap_sparse_mmap, header);
> + sparse_cap->nr_areas = sparse->nr_areas;
> + memcpy(sparse_cap->areas, sparse->areas,
> + sparse->nr_areas * sizeof(*sparse->areas));
> + return 0;
> +}
> +
> +static int region_type_cap(struct vfio_info_cap *caps, void *cap_type)
> +{
> + struct vfio_info_cap_header *header;
> + struct vfio_region_info_cap_type *type_cap, *cap = cap_type;
> +
> + header = vfio_info_cap_add(caps, sizeof(*cap),
> + VFIO_REGION_INFO_CAP_TYPE, 1);
> + if (IS_ERR(header))
> + return PTR_ERR(header);
> +
> + type_cap = container_of(header, struct vfio_region_info_cap_type,
> + header);
> + type_cap->type = cap->type;
> + type_cap->subtype = cap->subtype;
> + return 0;
> +}
> +
> +int vfio_info_add_capability(struct vfio_info_cap *caps, int cap_type_id,
> + void *cap_type)
> +{
> + int ret = -EINVAL;
> +
> + if (!cap_type)
> + return 0;
> +
> + switch (cap_type_id) {
> + case VFIO_REGION_INFO_CAP_SPARSE_MMAP:
> + ret = sparse_mmap_cap(caps, cap_type);
> + break;
> +
> + case VFIO_REGION_INFO_CAP_TYPE:
> + ret = region_type_cap(caps, cap_type);
> + break;
> + }
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(vfio_info_add_capability);
>
> /*
> * Pin a set of guest PFNs and return their associated host PFNs for local
> diff --git a/include/linux/vfio.h b/include/linux/vfio.h
> index dcda8fccefab..cf90393a11e2 100644
> --- a/include/linux/vfio.h
> +++ b/include/linux/vfio.h
> @@ -113,6 +113,9 @@ extern struct vfio_info_cap_header *vfio_info_cap_add(
> struct vfio_info_cap *caps, size_t size, u16 id, u16 version);
> extern void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
>
> +extern int vfio_info_add_capability(struct vfio_info_cap *caps,
> + int cap_type_id, void *cap_type);
> +


It would make it easier to review and bisect if 14/22 was squashed into
this one. In the resulting patch, vfio_info_cap_add() can be made static as
it will only be used in drivers/vfio/vfio.c from now.




> struct pci_dev;
> #ifdef CONFIG_EEH
> extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
>


--
Alexey