[PATCH] Test case for VFIO_PLATFORM returning device tree info

[PATCH] Test case for VFIO_PLATFORM returning device tree info

[Antonios Motakis]

This is a test case complementing the patch series:
[RFC 0/4] VFIO: PLATFORM: Return device tree info for a platform device node

This test case is based on the ARM PL330 DMA controller and shows how device
node properties can be accessed from userspace.

It doesn't apply on anything in particular, sent in a patch format on the ML 
merely for reading convenience. It can be pulled from:
git-9UaJU3cA/F/QT0dZR+AlfA@public.gmane.org:virtualopensystems/vfio-devtree-test.git

---
 vfio-dt.c | 172 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 vfio-dt.c

diff --git a/vfio-dt.c b/vfio-dt.c
new file mode 100644
index 0000000..6e671dd
--- /dev/null
+++ b/vfio-dt.c
@@ -0,0 +1,172 @@
+#include <stdio.h>
+#include <sys/fcntl.h>
+#include <sys/mman.h>
+#include <linux/vfio.h>
+#include <sys/eventfd.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+
+#define VFIO_DEVICE_FLAGS_DEVTREE	(1 << 3) /* device tree metadata */
+
+struct vfio_devtree_info {
+	__u32	argsz;
+	__u32	type;
+#define VFIO_DEVTREE_PROP_NAMES		0
+#define VFIO_DEVTREE_ARR_TYPE_STRING	1
+#define VFIO_DEVTREE_ARR_TYPE_U8	2
+#define VFIO_DEVTREE_ARR_TYPE_U16	3
+#define VFIO_DEVTREE_ARR_TYPE_U32	4
+	__u32	length;
+	__u8	data[];
+};
+#define VFIO_DEVICE_GET_DEVTREE_INFO	_IO(VFIO_TYPE, VFIO_BASE + 17)
+
+static void vfio_pr_devtree_prop(int device, char *name, unsigned int type)
+{
+	static unsigned int length = 0;
+	static struct vfio_devtree_info *devtree = NULL;
+	int ret;
+
+	if (length < strlen(name) + 1)
+		length = strlen(name) + 1;
+
+	while (1) {
+		unsigned int argsz = sizeof(struct vfio_devtree_info) + length;
+		devtree = realloc(devtree, argsz);
+		devtree->argsz = argsz;
+		devtree->type = type;
+		strcpy(devtree->data, name);
+
+		ret = ioctl(device, VFIO_DEVICE_GET_DEVTREE_INFO, devtree);
+
+		if (length < devtree->length)
+			length = devtree->length;
+		else
+			break;
+	}
+
+	if (ret) {
+		printf("%s = error %d\n", name, ret);
+	} else if (type == VFIO_DEVTREE_ARR_TYPE_STRING ||
+			type == VFIO_DEVTREE_PROP_NAMES) {
+		int i;
+		printf("%s =", name);
+		for (i=0; i < devtree->length; i += strlen(devtree->data + i) + 1)
+			printf(" \"%s\"", devtree->data + i);
+		printf("\n");
+
+	} else if (type == VFIO_DEVTREE_ARR_TYPE_U32 ||
+		   type == VFIO_DEVTREE_ARR_TYPE_U16 ||
+		   type == VFIO_DEVTREE_ARR_TYPE_U8) {
+		long unsigned int *uarr = (long unsigned int *) devtree->data;
+
+		printf("%s =", name);
+		while (uarr < devtree->data + devtree->length) {
+			printf(" 0x%lx", *uarr);
+			uarr++;
+		}
+		printf("\n");
+	}
+}
+
+int main (int argc, char **argv) {
+
+	int container, group, device;
+	unsigned int i;
+
+	struct vfio_group_status group_status = { .argsz = sizeof(group_status) };
+	struct vfio_iommu_type1_info iommu_info = { .argsz = sizeof(iommu_info) };
+	struct vfio_iommu_type1_dma_map dma_map = { .argsz = sizeof(dma_map) };
+	struct vfio_device_info device_info = { .argsz = sizeof(device_info) };
+
+	int ret;
+
+	if (argc != 3) {
+		printf("Usage: ./vfio-dt /dev/vfio/${group_id} device_id\n");
+		return 2;
+	}
+
+	/* Create a new container */
+	container = open("/dev/vfio/vfio", O_RDWR);
+
+	if (ioctl(container, VFIO_GET_API_VERSION) != VFIO_API_VERSION) {
+		printf("Unknown API version\n");
+		return 1;
+	}
+
+	if (!ioctl(container, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU)) {
+		printf("Doesn't support the IOMMU driver we want\n");
+		return 1;
+	}
+
+	/* Open the group */
+	group = open(argv[1], O_RDWR);
+
+	/* Test the group is viable and available */
+	ioctl(group, VFIO_GROUP_GET_STATUS, &group_status);
+
+	if (!(group_status.flags & VFIO_GROUP_FLAGS_VIABLE)) {
+		printf("Group is not viable (not all devices bound for vfio)\n");
+		return 1;
+	}
+
+	/* Add the group to the container */
+	ioctl(group, VFIO_GROUP_SET_CONTAINER, &container);
+
+	/* Enable the IOMMU model we want */
+	ioctl(container, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU);
+
+	/* Get addition IOMMU info */
+	ioctl(container, VFIO_IOMMU_GET_INFO, &iommu_info);
+
+	/* Get a file descriptor for the device */
+	device = ioctl(group, VFIO_GROUP_GET_DEVICE_FD, argv[2]);
+	printf("=== VFIO device file descriptor %d ===\n", device);
+
+	/* Test and setup the device */
+	ret = ioctl(device, VFIO_DEVICE_GET_INFO, &device_info);
+
+	if(ret) {
+		printf("Could not get VFIO device\n");
+		return 1;
+	}
+
+	/* devtree tests */
+
+	/* Get available property names */
+	vfio_pr_devtree_prop(device, "props", VFIO_DEVTREE_PROP_NAMES);
+
+	/* these should return an error */
+	vfio_pr_devtree_prop(device, "invalid", VFIO_DEVTREE_ARR_TYPE_STRING);
+	vfio_pr_devtree_prop(device, "invalid", VFIO_DEVTREE_ARR_TYPE_U32);
+
+	/* fetch some strings */
+	vfio_pr_devtree_prop(device, "name", VFIO_DEVTREE_ARR_TYPE_STRING);
+	vfio_pr_devtree_prop(device, "clock-names", VFIO_DEVTREE_ARR_TYPE_STRING);
+	vfio_pr_devtree_prop(device, "compatible", VFIO_DEVTREE_ARR_TYPE_STRING);
+
+	/* u32 arrays */
+	vfio_pr_devtree_prop(device, "reg", VFIO_DEVTREE_ARR_TYPE_U32);
+	vfio_pr_devtree_prop(device, "interrupts", VFIO_DEVTREE_ARR_TYPE_U32);
+	vfio_pr_devtree_prop(device, "phandle", VFIO_DEVTREE_ARR_TYPE_U32);
+	vfio_pr_devtree_prop(device, "linux,phandle", VFIO_DEVTREE_ARR_TYPE_U32);
+	vfio_pr_devtree_prop(device, "clocks", VFIO_DEVTREE_ARR_TYPE_U32);
+	vfio_pr_devtree_prop(device, "#dma-cells", VFIO_DEVTREE_ARR_TYPE_U32);
+	vfio_pr_devtree_prop(device, "#stream-id-cells", VFIO_DEVTREE_ARR_TYPE_U32);
+
+	/* VFIO also exposes full_name which includes the path. Should only
+	 * work as a string. */
+	vfio_pr_devtree_prop(device, "full_name", VFIO_DEVTREE_ARR_TYPE_STRING);
+	vfio_pr_devtree_prop(device, "full_name", VFIO_DEVTREE_ARR_TYPE_U32);
+
+	/* the pl330 device tree doesn't include 16 and 8 bit types, so
+	 * a proper test cannot be done for now */
+	/* get reg but as 16 bit type */
+	vfio_pr_devtree_prop(device, "reg", VFIO_DEVTREE_ARR_TYPE_U16);
+	/* get reg but as 8 bit type */
+	vfio_pr_devtree_prop(device, "reg", VFIO_DEVTREE_ARR_TYPE_U8);
+
+	return 0;
+}
-- 
1.8.3.2