[RFC PATCH kvmtool 01/10] vfio: Associate vm instance with vfio fd

["Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>]

This is needed for followup patches

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 vfio/core.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/vfio/core.c b/vfio/core.c
index 3ff2c0b075df..c6b305c30cf7 100644
--- a/vfio/core.c
+++ b/vfio/core.c
@@ -9,6 +9,7 @@
 #define IOMMU_GROUP_DIR		"/sys/kernel/iommu_groups"
 
 static int vfio_container;
+static int kvm_vfio_device;
 static LIST_HEAD(vfio_groups);
 static struct vfio_device *vfio_devices;
 
@@ -437,8 +438,19 @@ static int vfio_configure_groups(struct kvm *kvm)
 		ret = vfio_configure_reserved_regions(kvm, group);
 		if (ret)
 			return ret;
-	}
 
+		struct kvm_device_attr attr = {
+			.group = KVM_DEV_VFIO_FILE,
+			.attr = KVM_DEV_VFIO_FILE_ADD,
+			.addr = (__u64)&group->fd,
+		};
+
+		if (ioctl(kvm_vfio_device, KVM_SET_DEVICE_ATTR, &attr)) {
+			pr_err("Failed KVM_SET_DEVICE_ATTR for KVM_DEV_VFIO_FILE");
+			return -ENODEV;
+		}
+
+	}
 	return 0;
 }
 
@@ -656,6 +668,16 @@ static int vfio__init(struct kvm *kvm)
 	if (!vfio_devices)
 		return -ENOMEM;
 
+	struct kvm_create_device device = {
+		.type = KVM_DEV_TYPE_VFIO,
+	};
+
+	if (ioctl(kvm->vm_fd, KVM_CREATE_DEVICE, &device)) {
+		pr_err("Failed KVM_CREATE_DEVICE ioctl");
+		return -ENODEV;
+	}
+	kvm_vfio_device = device.fd;
+
 	ret = vfio_container_init(kvm);
 	if (ret)
 		return ret;
-- 
2.43.0