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-rw-r--r--hw/virtio/virtio-bus.c372
1 files changed, 372 insertions, 0 deletions
diff --git a/hw/virtio/virtio-bus.c b/hw/virtio/virtio-bus.c
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--- /dev/null
+++ b/hw/virtio/virtio-bus.c
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+/*
+ * VirtioBus
+ *
+ * Copyright (C) 2012 : GreenSocs Ltd
+ * http://www.greensocs.com/ , email: info@greensocs.com
+ *
+ * Developed by :
+ * Frederic Konrad <fred.konrad@greensocs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "qapi/error.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio.h"
+#include "exec/address-spaces.h"
+
+/* #define DEBUG_VIRTIO_BUS */
+
+#ifdef DEBUG_VIRTIO_BUS
+#define DPRINTF(fmt, ...) \
+do { printf("virtio_bus: " fmt , ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) do { } while (0)
+#endif
+
+/* A VirtIODevice is being plugged */
+void virtio_bus_device_plugged(VirtIODevice *vdev, Error **errp)
+{
+ DeviceState *qdev = DEVICE(vdev);
+ BusState *qbus = BUS(qdev_get_parent_bus(qdev));
+ VirtioBusState *bus = VIRTIO_BUS(qbus);
+ VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
+ VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+ bool has_iommu = virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
+ bool vdev_has_iommu;
+ Error *local_err = NULL;
+
+ DPRINTF("%s: plug device.\n", qbus->name);
+
+ if (klass->pre_plugged != NULL) {
+ klass->pre_plugged(qbus->parent, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+ }
+
+ /* Get the features of the plugged device. */
+ assert(vdc->get_features != NULL);
+ vdev->host_features = vdc->get_features(vdev, vdev->host_features,
+ &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+
+ if (klass->device_plugged != NULL) {
+ klass->device_plugged(qbus->parent, &local_err);
+ }
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return;
+ }
+
+ vdev->dma_as = &address_space_memory;
+ if (has_iommu) {
+ vdev_has_iommu = virtio_host_has_feature(vdev, VIRTIO_F_IOMMU_PLATFORM);
+ /*
+ * Present IOMMU_PLATFORM to the driver iff iommu_plattform=on and
+ * device operational. If the driver does not accept IOMMU_PLATFORM
+ * we fail the device.
+ */
+ virtio_add_feature(&vdev->host_features, VIRTIO_F_IOMMU_PLATFORM);
+ if (klass->get_dma_as) {
+ vdev->dma_as = klass->get_dma_as(qbus->parent);
+ if (!vdev_has_iommu && vdev->dma_as != &address_space_memory) {
+ error_setg(errp,
+ "iommu_platform=true is not supported by the device");
+ return;
+ }
+ }
+ }
+}
+
+/* Reset the virtio_bus */
+void virtio_bus_reset(VirtioBusState *bus)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+
+ DPRINTF("%s: reset device.\n", BUS(bus)->name);
+ virtio_bus_stop_ioeventfd(bus);
+ if (vdev != NULL) {
+ virtio_reset(vdev);
+ }
+}
+
+/* A VirtIODevice is being unplugged */
+void virtio_bus_device_unplugged(VirtIODevice *vdev)
+{
+ DeviceState *qdev = DEVICE(vdev);
+ BusState *qbus = BUS(qdev_get_parent_bus(qdev));
+ VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(qbus);
+
+ DPRINTF("%s: remove device.\n", qbus->name);
+
+ if (vdev != NULL) {
+ if (klass->device_unplugged != NULL) {
+ klass->device_unplugged(qbus->parent);
+ }
+ }
+}
+
+/* Get the device id of the plugged device. */
+uint16_t virtio_bus_get_vdev_id(VirtioBusState *bus)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+ assert(vdev != NULL);
+ return vdev->device_id;
+}
+
+/* Get the config_len field of the plugged device. */
+size_t virtio_bus_get_vdev_config_len(VirtioBusState *bus)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+ assert(vdev != NULL);
+ return vdev->config_len;
+}
+
+/* Get bad features of the plugged device. */
+uint32_t virtio_bus_get_vdev_bad_features(VirtioBusState *bus)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+ VirtioDeviceClass *k;
+
+ assert(vdev != NULL);
+ k = VIRTIO_DEVICE_GET_CLASS(vdev);
+ if (k->bad_features != NULL) {
+ return k->bad_features(vdev);
+ } else {
+ return 0;
+ }
+}
+
+/* Get config of the plugged device. */
+void virtio_bus_get_vdev_config(VirtioBusState *bus, uint8_t *config)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+ VirtioDeviceClass *k;
+
+ assert(vdev != NULL);
+ k = VIRTIO_DEVICE_GET_CLASS(vdev);
+ if (k->get_config != NULL) {
+ k->get_config(vdev, config);
+ }
+}
+
+/* Set config of the plugged device. */
+void virtio_bus_set_vdev_config(VirtioBusState *bus, uint8_t *config)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+ VirtioDeviceClass *k;
+
+ assert(vdev != NULL);
+ k = VIRTIO_DEVICE_GET_CLASS(vdev);
+ if (k->set_config != NULL) {
+ k->set_config(vdev, config);
+ }
+}
+
+/* On success, ioeventfd ownership belongs to the caller. */
+int virtio_bus_grab_ioeventfd(VirtioBusState *bus)
+{
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
+
+ /* vhost can be used even if ioeventfd=off in the proxy device,
+ * so do not check k->ioeventfd_enabled.
+ */
+ if (!k->ioeventfd_assign) {
+ return -ENOSYS;
+ }
+
+ if (bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
+ virtio_bus_stop_ioeventfd(bus);
+ /* Remember that we need to restart ioeventfd
+ * when ioeventfd_grabbed becomes zero.
+ */
+ bus->ioeventfd_started = true;
+ }
+ bus->ioeventfd_grabbed++;
+ return 0;
+}
+
+void virtio_bus_release_ioeventfd(VirtioBusState *bus)
+{
+ assert(bus->ioeventfd_grabbed != 0);
+ if (--bus->ioeventfd_grabbed == 0 && bus->ioeventfd_started) {
+ /* Force virtio_bus_start_ioeventfd to act. */
+ bus->ioeventfd_started = false;
+ virtio_bus_start_ioeventfd(bus);
+ }
+}
+
+int virtio_bus_start_ioeventfd(VirtioBusState *bus)
+{
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
+ DeviceState *proxy = DEVICE(BUS(bus)->parent);
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+ VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+ int r;
+
+ if (!k->ioeventfd_assign || !k->ioeventfd_enabled(proxy)) {
+ return -ENOSYS;
+ }
+ if (bus->ioeventfd_started) {
+ return 0;
+ }
+
+ /* Only set our notifier if we have ownership. */
+ if (!bus->ioeventfd_grabbed) {
+ r = vdc->start_ioeventfd(vdev);
+ if (r < 0) {
+ error_report("%s: failed. Fallback to userspace (slower).", __func__);
+ return r;
+ }
+ }
+ bus->ioeventfd_started = true;
+ return 0;
+}
+
+void virtio_bus_stop_ioeventfd(VirtioBusState *bus)
+{
+ VirtIODevice *vdev;
+ VirtioDeviceClass *vdc;
+
+ if (!bus->ioeventfd_started) {
+ return;
+ }
+
+ /* Only remove our notifier if we have ownership. */
+ if (!bus->ioeventfd_grabbed) {
+ vdev = virtio_bus_get_device(bus);
+ vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
+ vdc->stop_ioeventfd(vdev);
+ }
+ bus->ioeventfd_started = false;
+}
+
+bool virtio_bus_ioeventfd_enabled(VirtioBusState *bus)
+{
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
+ DeviceState *proxy = DEVICE(BUS(bus)->parent);
+
+ return k->ioeventfd_assign && k->ioeventfd_enabled(proxy);
+}
+
+/*
+ * This function switches ioeventfd on/off in the device.
+ * The caller must set or clear the handlers for the EventNotifier.
+ */
+int virtio_bus_set_host_notifier(VirtioBusState *bus, int n, bool assign)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+ VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(bus);
+ DeviceState *proxy = DEVICE(BUS(bus)->parent);
+ VirtQueue *vq = virtio_get_queue(vdev, n);
+ EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
+ int r = 0;
+
+ if (!k->ioeventfd_assign) {
+ return -ENOSYS;
+ }
+
+ if (assign) {
+ r = event_notifier_init(notifier, 1);
+ if (r < 0) {
+ error_report("%s: unable to init event notifier: %s (%d)",
+ __func__, strerror(-r), r);
+ return r;
+ }
+ r = k->ioeventfd_assign(proxy, notifier, n, true);
+ if (r < 0) {
+ error_report("%s: unable to assign ioeventfd: %d", __func__, r);
+ virtio_bus_cleanup_host_notifier(bus, n);
+ }
+ } else {
+ k->ioeventfd_assign(proxy, notifier, n, false);
+ }
+
+ if (r == 0) {
+ virtio_queue_set_host_notifier_enabled(vq, assign);
+ }
+
+ return r;
+}
+
+void virtio_bus_cleanup_host_notifier(VirtioBusState *bus, int n)
+{
+ VirtIODevice *vdev = virtio_bus_get_device(bus);
+ VirtQueue *vq = virtio_get_queue(vdev, n);
+ EventNotifier *notifier = virtio_queue_get_host_notifier(vq);
+
+ /* Test and clear notifier after disabling event,
+ * in case poll callback didn't have time to run.
+ */
+ virtio_queue_host_notifier_read(notifier);
+ event_notifier_cleanup(notifier);
+}
+
+static char *virtio_bus_get_dev_path(DeviceState *dev)
+{
+ BusState *bus = qdev_get_parent_bus(dev);
+ DeviceState *proxy = DEVICE(bus->parent);
+ return qdev_get_dev_path(proxy);
+}
+
+static char *virtio_bus_get_fw_dev_path(DeviceState *dev)
+{
+ return NULL;
+}
+
+bool virtio_bus_device_iommu_enabled(VirtIODevice *vdev)
+{
+ DeviceState *qdev = DEVICE(vdev);
+ BusState *qbus = BUS(qdev_get_parent_bus(qdev));
+ VirtioBusState *bus = VIRTIO_BUS(qbus);
+ VirtioBusClass *klass = VIRTIO_BUS_GET_CLASS(bus);
+
+ if (!klass->iommu_enabled) {
+ return false;
+ }
+
+ return klass->iommu_enabled(qbus->parent);
+}
+
+static void virtio_bus_class_init(ObjectClass *klass, void *data)
+{
+ BusClass *bus_class = BUS_CLASS(klass);
+ bus_class->get_dev_path = virtio_bus_get_dev_path;
+ bus_class->get_fw_dev_path = virtio_bus_get_fw_dev_path;
+}
+
+static const TypeInfo virtio_bus_info = {
+ .name = TYPE_VIRTIO_BUS,
+ .parent = TYPE_BUS,
+ .instance_size = sizeof(VirtioBusState),
+ .abstract = true,
+ .class_size = sizeof(VirtioBusClass),
+ .class_init = virtio_bus_class_init
+};
+
+static void virtio_register_types(void)
+{
+ type_register_static(&virtio_bus_info);
+}
+
+type_init(virtio_register_types)
generated by cgit v1.2.3 (git 2.39.1) at 2025-07-28 07:44:03 +0000