[PATCH v7 1/2] vfio: add get device info API

[Mingjin Ye <mingjinx.ye@intel.com>]

This patch adds an API to support getting device information.

The driver can use the "rte_vfio_get_device_info" helper to get
device information from EAL.

Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>
---
 lib/eal/include/rte_vfio.h | 29 +++++++++++++++++++++++++++++
 lib/eal/linux/eal_vfio.c   | 27 +++++++++++++++++++++++++++
 lib/eal/version.map        |  3 +++
 3 files changed, 59 insertions(+)

diff --git a/lib/eal/include/rte_vfio.h b/lib/eal/include/rte_vfio.h
index 22832afd0f..50c4f5b617 100644
--- a/lib/eal/include/rte_vfio.h
+++ b/lib/eal/include/rte_vfio.h
@@ -17,6 +17,8 @@ extern "C" {
 #include <stdbool.h>
 #include <stdint.h>
 
+#include <rte_compat.h>
+
 /*
  * determine if VFIO is present on the system
  */
@@ -239,6 +241,33 @@ int
 rte_vfio_get_group_num(const char *sysfs_base,
 		      const char *dev_addr, int *iommu_group_num);
 
+/**
+ * Get device information
+ *
+ * This function is only relevant to linux and will return
+ * an error on BSD.
+ *
+ * @param sysfs_base
+ *   sysfs path prefix.
+ *
+ * @param dev_addr
+ *   device location.
+ *
+ * @param vfio_dev_fd
+ *   VFIO fd.
+ *
+ * @param device_info
+ *   Device information.
+ *
+ * @return
+ *   0 on success.
+ *   <0 on failure.
+ */
+__rte_experimental
+int
+rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
+			int *vfio_dev_fd, struct vfio_device_info *device_info);
+
 /**
  * Open a new VFIO container fd
  *
diff --git a/lib/eal/linux/eal_vfio.c b/lib/eal/linux/eal_vfio.c
index ad3c1654b2..05a0091006 100644
--- a/lib/eal/linux/eal_vfio.c
+++ b/lib/eal/linux/eal_vfio.c
@@ -1222,6 +1222,33 @@ vfio_set_iommu_type(int vfio_container_fd)
 	return NULL;
 }
 
+int
+rte_vfio_get_device_info(const char *sysfs_base, const char *dev_addr,
+			int *vfio_dev_fd, struct vfio_device_info *device_info)
+{
+	int ret;
+
+	if (!device_info || *vfio_dev_fd < 0)
+		return -1;
+
+	if (*vfio_dev_fd == 0) {
+		ret = rte_vfio_setup_device(sysfs_base, dev_addr,
+				vfio_dev_fd, device_info);
+		if (ret)
+			return -1;
+	} else {
+		ret = ioctl(*vfio_dev_fd, VFIO_DEVICE_GET_INFO, device_info);
+		if (ret) {
+			RTE_LOG(ERR, EAL, "%s cannot get device info, "
+					"error %i (%s)\n", dev_addr, errno,
+					strerror(errno));
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
 int
 vfio_has_supported_extensions(int vfio_container_fd)
 {
diff --git a/lib/eal/version.map b/lib/eal/version.map
index 5e0cd47c82..c06ceaad50 100644
--- a/lib/eal/version.map
+++ b/lib/eal/version.map
@@ -393,6 +393,9 @@ EXPERIMENTAL {
 	# added in 23.07
 	rte_memzone_max_get;
 	rte_memzone_max_set;
+
+	# added in 23.11
+	rte_vfio_get_device_info; # WINDOWS_NO_EXPORT
 };
 
 INTERNAL {
-- 
2.25.1