The library provides igt_device_get_pci_device() function that allows to
get access to a PCI device from an open DRM device file descriptor. It
can be used on VF devices as long as a DRM driver is bound to them.
However, SR-IOV tests may want to exercise VF PCI devices created by a PF
without binding any DRM driver to them.
While keeping the API of igt_device_get_pci_device() untouched, extend API
of its underlying helper __igt_device_get_pci_device() with an extra
argument for specifying VF ID of the requested PCI device and expose this
function as public.
v2: refresh on top of IGT libpciaccess wrappers and drop previously added
but no longer needed error unwind path and recommendations for users
on calling pci_system_cleanup() after use (Chris),
- fix incorrect validation of snprintf() result and misaligned
formatting of igt_warn_on_f() arguments.
v3: follow VF numbering convention of Linux PCI ABI (Chris),
- fix and improve DOC.
Signed-off-by: Janusz Krzysztofik <[email protected]>
Reviewed-by: Chris Wilson <[email protected]> # v2
---
lib/igt_device.c | 33 +++++++++++++++++++++++++++------
lib/igt_device.h | 1 +
2 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/lib/igt_device.c b/lib/igt_device.c
index c50bf4a1f7..46b7dbc490 100644
--- a/lib/igt_device.c
+++ b/lib/igt_device.c
@@ -149,9 +149,9 @@ struct igt_pci_addr {
unsigned int function;
};
-static int igt_device_get_pci_addr(int fd, struct igt_pci_addr *pci)
+static int igt_device_get_pci_addr(int fd, int vf_id, struct igt_pci_addr *pci)
{
- char path[IGT_DEV_PATH_LEN];
+ char link[20], path[IGT_DEV_PATH_LEN];
char *buf;
int sysfs;
int len;
@@ -159,11 +159,21 @@ static int igt_device_get_pci_addr(int fd, struct
igt_pci_addr *pci)
if (!igt_device_is_pci(fd))
return -ENODEV;
+ if (vf_id < 0)
+ len = snprintf(link, sizeof(link), "device");
+ else
+ len = snprintf(link, sizeof(link), "device/virtfn%u", vf_id);
+ if (igt_warn_on_f(len >= sizeof(link),
+ "IGT bug: insufficient buffer space for rendering PCI
device link name\n"))
+ return -ENOSPC;
+ else if (igt_debug_on_f(len < 0, "unexpected failure from
snprintf()\n"))
+ return len;
+
sysfs = igt_sysfs_open(fd);
if (sysfs == -1)
return -ENOENT;
- len = readlinkat(sysfs, "device", path, sizeof(path) - 1);
+ len = readlinkat(sysfs, link, path, sizeof(path) - 1);
close(sysfs);
if (len == -1)
return -ENOENT;
@@ -183,12 +193,23 @@ static int igt_device_get_pci_addr(int fd, struct
igt_pci_addr *pci)
return 0;
}
-static struct pci_device *__igt_device_get_pci_device(int fd)
+/**
+ * __igt_device_get_pci_device:
+ *
+ * @fd: DRM device file descriptor
+ * @vf_id: PCI virtual function number or -1 if native or PF itself
+ *
+ * Looks up a PCI interface of a DRM device or a VF PCI device of the DRM PF
using libpciaccess.
+ *
+ * Returns:
+ * The pci_device, NULL on any failures.
+ */
+struct pci_device *__igt_device_get_pci_device(int fd, int vf_id)
{
struct igt_pci_addr pci_addr;
struct pci_device *pci_dev;
- if (igt_device_get_pci_addr(fd, &pci_addr)) {
+ if (igt_device_get_pci_addr(fd, vf_id, &pci_addr)) {
igt_warn("Unable to find device PCI address\n");
return NULL;
}
@@ -231,7 +252,7 @@ struct pci_device *igt_device_get_pci_device(int fd)
{
struct pci_device *pci_dev;
- pci_dev = __igt_device_get_pci_device(fd);
+ pci_dev = __igt_device_get_pci_device(fd, -1);
igt_require(pci_dev);
return pci_dev;
diff --git a/lib/igt_device.h b/lib/igt_device.h
index 278ba7a9b3..00da853e71 100644
--- a/lib/igt_device.h
+++ b/lib/igt_device.h
@@ -33,5 +33,6 @@ void igt_device_drop_master(int fd);
int igt_device_get_card_index(int fd);
struct pci_device *igt_device_get_pci_device(int fd);
+struct pci_device *__igt_device_get_pci_device(int fd, int vf_id);
#endif /* __IGT_DEVICE_H__ */
--
2.25.1
