[PATCH v12 13/22] vfio: Introduce common function to add capabilities

From: Kirti Wankhede
Date: Mon Nov 14 2016 - 10:46:01 EST


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.

vfio_info_cap_shift() manipulated a data buffer to add an offset to each
element in a chain. This data buffer is documented in a uapi header.
Changing vfio_info_cap_shift symbol to be available to all 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 388a3cbddbd9..3648fd74aa30 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);

+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 123e089388e9..b1aaf69cb470 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -111,6 +111,9 @@ 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);
+
struct pci_dev;
#ifdef CONFIG_EEH
extern void vfio_spapr_pci_eeh_open(struct pci_dev *pdev);
--
2.7.0