feat: device connection

Add a connection to devicetree devices via vfio.

Signed-off-by: Pascal Bauer <pascal.bauer@rwth-aachen.de>

common/include/villas/kernel/devices/device_connection.hpp

@@ -0,0 +1,79 @@
+/* Vfio connection to a device.
+ *
+ * Author: Pascal Bauer <pascal.bauer@rwth-aachen.de>
+ *
+ * SPDX-FileCopyrightText: 2024-25 Pascal Bauer <pascal.bauer@rwth-aachen.de>
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+
+#include <memory>
+
+#include <villas/kernel/vfio_device.hpp>
+#include <villas/kernel/devices/linux_driver.hpp>
+
+namespace villas {
+namespace kernel {
+namespace devices {
+
+class DeviceConnection {
+public:
+  Logger logger;
+  const std::shared_ptr<kernel::vfio::Device> vfio_device;
+
+private:
+  DeviceConnection(std::shared_ptr<kernel::vfio::Device> vfio_device)
+      : logger(villas::Log::get("DeviceConnection")),
+        vfio_device(vfio_device){};
+
+public:
+  static DeviceConnection
+  from(const villas::kernel::devices::Device& device,
+       std::shared_ptr<kernel::vfio::Container> vfio_container) {
+    auto logger = villas::Log::get("Builder: DeviceConnection");
+
+    // Bind to driver
+    LinuxDriver driver(
+        std::filesystem::path("/sys/bus/platform/drivers/vfio-platform"));
+    driver.attach(device);
+
+    // Attach group to container
+    const int iommu_group = device.iommu_group().value();
+    auto vfio_group = vfio_container->getOrAttachGroup(iommu_group);
+    logger->debug("Device: {}, Iommu: {}", device.name(), iommu_group);
+
+    // Open Vfio Device
+    auto vfio_device = std::make_shared<kernel::vfio::Device>(
+        device.name(), vfio_group->getFileDescriptor());
+
+    // Attach device to group
+    vfio_group->attachDevice(vfio_device);
+
+    return DeviceConnection(vfio_device);
+  }
+
+  void add_to_memorygraph() const {
+    // Map vfio device memory to process
+    const void *mapping = this->vfio_device->regionMap(0);
+    if (mapping == MAP_FAILED) {
+      logger->error("Failed to mmap() device");
+    }
+    logger->debug("memory mapped: {}", this->vfio_device->getName());
+
+    // Create memorygraph edge from process to vfio device
+    auto &mm = MemoryManager::get();
+    size_t srcVertexId = mm.getProcessAddressSpace();
+    const size_t mem_size = this->vfio_device->regionGetSize(0);
+    size_t targetVertexId =
+        mm.getOrCreateAddressSpace(this->vfio_device->getName());
+    mm.createMapping(reinterpret_cast<uintptr_t>(mapping), 0, mem_size,
+                     "process to vfio", srcVertexId, targetVertexId);
+    logger->debug("create edge from process to {}",
+                  this->vfio_device->getName());
+  }
+};
+
+} // namespace devices
+} // namespace kernel
+} // namespace villas