Re: [Stratos-dev] [PATCH 1/5] hw/virtio: add boilerplate for vhost-user-i2c device

Viresh Kumar viresh.kumar@linaro.org writes:

This creates the QEMU side of the vhost-user-i2c device which connects to the remote daemon. It is based of vhost-user-fs code.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org

hw/virtio/Kconfig | 5 + hw/virtio/meson.build | 1 + hw/virtio/vhost-user-i2c.c | 286 ++++++++++++++++++++ include/hw/virtio/vhost-user-i2c.h | 37 +++ include/standard-headers/linux/virtio_ids.h | 1 + 5 files changed, 330 insertions(+) create mode 100644 hw/virtio/vhost-user-i2c.c create mode 100644 include/hw/virtio/vhost-user-i2c.h

diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig index 0eda25c4e1bf..35ab45e2095c 100644 --- a/hw/virtio/Kconfig +++ b/hw/virtio/Kconfig @@ -58,3 +58,8 @@ config VIRTIO_MEM depends on LINUX depends on VIRTIO_MEM_SUPPORTED select MEM_DEVICE

+config VHOST_USER_I2C

• bool
• default y
• depends on VIRTIO && VHOST_USER

diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build index fbff9bc9d4de..1a0d736a0db5 100644 --- a/hw/virtio/meson.build +++ b/hw/virtio/meson.build @@ -25,6 +25,7 @@ virtio_ss.add(when: 'CONFIG_VHOST_USER_VSOCK', if_true: files('vhost-user-vsock. virtio_ss.add(when: 'CONFIG_VIRTIO_RNG', if_true: files('virtio-rng.c')) virtio_ss.add(when: 'CONFIG_VIRTIO_IOMMU', if_true: files('virtio-iommu.c')) virtio_ss.add(when: 'CONFIG_VIRTIO_MEM', if_true: files('virtio-mem.c')) +virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c')) virtio_pci_ss = ss.source_set() virtio_pci_ss.add(when: 'CONFIG_VHOST_VSOCK', if_true: files('vhost-vsock-pci.c')) diff --git a/hw/virtio/vhost-user-i2c.c b/hw/virtio/vhost-user-i2c.c new file mode 100644 index 000000000000..7b0dc24412a4 --- /dev/null +++ b/hw/virtio/vhost-user-i2c.c @@ -0,0 +1,286 @@ +/*

• • Vhost-user i2c virtio device
• • Copyright (c) 2021 Viresh Kumar viresh.kumar@linaro.org
• • SPDX-License-Identifier: GPL-2.0-or-later
• */

+#include "qemu/osdep.h" +#include "qapi/error.h" +#include "hw/qdev-properties.h" +#include "hw/virtio/virtio-bus.h" +#include "hw/virtio/vhost-user-i2c.h" +#include "qemu/error-report.h" +#include "standard-headers/linux/virtio_ids.h"

+static void vu_i2c_start(VirtIODevice *vdev) +{

• VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
• BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
• VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
• int ret;
• int i;
• if (!k->set_guest_notifiers) {

•    error_report("binding does not support guest notifiers");
  

•    return;
  

• }
• ret = vhost_dev_enable_notifiers(&i2c->vhost_dev, vdev);
• if (ret < 0) {

•    error_report("Error enabling host notifiers: %d", -ret);
  

•    return;
  

• }
• ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, true);
• if (ret < 0) {

•    error_report("Error binding guest notifier: %d", -ret);
  

•    goto err_host_notifiers;
  

• }
• i2c->vhost_dev.acked_features = vdev->guest_features;
• ret = vhost_dev_start(&i2c->vhost_dev, vdev);
• if (ret < 0) {

•    error_report("Error starting vhost-user-i2c: %d", -ret);
  

•    goto err_guest_notifiers;
  

• }
• /*

• * guest_notifier_mask/pending not used yet, so just unmask
  

• * everything here. virtio-pci will do the right thing by
  

• * enabling/disabling irqfd.
  

• */
  

• for (i = 0; i < i2c->vhost_dev.nvqs; i++) {

•    vhost_virtqueue_mask(&i2c->vhost_dev, vdev, i, false);
  

• }
• return;

+err_guest_notifiers:

• k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false);

+err_host_notifiers:

• vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev);

+}

+static void vu_i2c_stop(VirtIODevice *vdev) +{

• VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
• BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
• VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
• int ret;
• if (!k->set_guest_notifiers) {

•    return;
  

• }
• vhost_dev_stop(&i2c->vhost_dev, vdev);
• ret = k->set_guest_notifiers(qbus->parent, i2c->vhost_dev.nvqs, false);
• if (ret < 0) {

•    error_report("vhost guest notifier cleanup failed: %d", ret);
  

•    return;
  

• }
• vhost_dev_disable_notifiers(&i2c->vhost_dev, vdev);

+}

+static void vu_i2c_set_status(VirtIODevice *vdev, uint8_t status) +{

• VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
• bool should_start = status & VIRTIO_CONFIG_S_DRIVER_OK;
• if (!vdev->vm_running) {

•    should_start = false;
  

• }
• if (i2c->vhost_dev.started == should_start) {

•    return;
  

• }
• if (should_start) {

•    vu_i2c_start(vdev);
  

• } else {

•    vu_i2c_stop(vdev);
  

• }

+}

+static uint64_t vu_i2c_get_features(VirtIODevice *vdev,

•                                uint64_t requested_features, Error **errp)
  

+{

• /* No feature bits used yet */
• return requested_features;

+}

+static void vu_i2c_handle_output(VirtIODevice *vdev, VirtQueue *vq) +{

• /*

• * Not normally called; it's the daemon that handles the queue;
  

• * however virtio's cleanup path can call this.
  

• */
  

+}

+static void vu_i2c_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask) +{

• VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
• vhost_virtqueue_mask(&i2c->vhost_dev, vdev, idx, mask);

+}

+static bool vu_i2c_guest_notifier_pending(VirtIODevice *vdev, int idx) +{

• VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
• return vhost_virtqueue_pending(&i2c->vhost_dev, idx);

+}

+static void do_vhost_user_cleanup(VirtIODevice *vdev, VHostUserI2C *i2c) +{

• vhost_user_cleanup(&i2c->vhost_user);
• virtio_delete_queue(i2c->req_vq);
• g_free(i2c->vhost_dev.vqs);
• virtio_cleanup(vdev);
• g_free(i2c->vhost_dev.vqs);

This is a double free of the same queue.

• i2c->vhost_dev.vqs = NULL;

+}

+static int vu_i2c_connect(DeviceState *dev) +{

• VirtIODevice *vdev = VIRTIO_DEVICE(dev);
• VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
• if (i2c->connected) {

•    return 0;
  

• }
• i2c->connected = true;
• /* restore vhost state */
• if (virtio_device_started(vdev, vdev->status)) {

•    vu_i2c_start(vdev);
  

• }
• return 0;

+}

+static void vu_i2c_disconnect(DeviceState *dev) +{

• VirtIODevice *vdev = VIRTIO_DEVICE(dev);
• VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
• if (!i2c->connected) {

•    return;
  

• }
• i2c->connected = false;
• if (i2c->vhost_dev.started) {

•    vu_i2c_stop(vdev);
  

• }

+}

+static void vu_i2c_event(void *opaque, QEMUChrEvent event) +{

• DeviceState *dev = opaque;
• VirtIODevice *vdev = VIRTIO_DEVICE(dev);
• VHostUserI2C *i2c = VHOST_USER_I2C(vdev);
• switch (event) {
• case CHR_EVENT_OPENED:

•    if (vu_i2c_connect(dev) < 0) {
  

•        qemu_chr_fe_disconnect(&i2c->conf.chardev);
  

•        return;
  

•    }
  

•    break;
  

• case CHR_EVENT_CLOSED:

•    vu_i2c_disconnect(dev);
  

•    break;
  

• case CHR_EVENT_BREAK:
• case CHR_EVENT_MUX_IN:
• case CHR_EVENT_MUX_OUT:

•    /* Ignore */
  

•    break;
  

• }

+}

+static void vu_i2c_device_realize(DeviceState *dev, Error **errp) +{

• VirtIODevice *vdev = VIRTIO_DEVICE(dev);
• VHostUserI2C *i2c = VHOST_USER_I2C(dev);
• int ret;
• if (!i2c->conf.chardev.chr) {

•    error_setg(errp, "missing chardev");
  

•    return;
  

• }
• if (!vhost_user_init(&i2c->vhost_user, &i2c->conf.chardev, errp)) {

•    return;
  

• }
• virtio_init(vdev, "vhost-user-i2c", VIRTIO_ID_I2C, 0);
• i2c->req_vq = virtio_add_queue(vdev, 3, vu_i2c_handle_output);
• i2c->vhost_dev.nvqs = 1;
• i2c->vhost_dev.vqs = g_new0(struct vhost_virtqueue, i2c->vhost_dev.nvqs);
• ret = vhost_dev_init(&i2c->vhost_dev, &i2c->vhost_user,

•                     VHOST_BACKEND_TYPE_USER, 0);
  

• if (ret < 0) {

•    error_setg_errno(errp, -ret, "vhost_dev_init() failed");
  

•    do_vhost_user_cleanup(vdev, i2c);
  

• }
• qemu_chr_fe_set_handlers(&i2c->conf.chardev, NULL, NULL, vu_i2c_event, NULL,

•                         dev, NULL, true);
  

+}

+static void vu_i2c_device_unrealize(DeviceState *dev) +{

• VirtIODevice *vdev = VIRTIO_DEVICE(dev);
• VHostUserI2C *i2c = VHOST_USER_I2C(dev);
• /* This will stop vhost backend if appropriate. */
• vu_i2c_set_status(vdev, 0);
• vhost_dev_cleanup(&i2c->vhost_dev);
• do_vhost_user_cleanup(vdev, i2c);

+}

+static const VMStateDescription vu_i2c_vmstate = {

• .name = "vhost-user-i2c",
• .unmigratable = 1,

+};

+static Property vu_i2c_properties[] = {

• DEFINE_PROP_CHR("chardev", VHostUserI2C, conf.chardev),
• DEFINE_PROP_END_OF_LIST(),

+};

+static void vu_i2c_class_init(ObjectClass *klass, void *data) +{

• DeviceClass *dc = DEVICE_CLASS(klass);
• VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
• device_class_set_props(dc, vu_i2c_properties);
• dc->vmsd = &vu_i2c_vmstate;
• set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
• vdc->realize = vu_i2c_device_realize;
• vdc->unrealize = vu_i2c_device_unrealize;
• vdc->get_features = vu_i2c_get_features;
• vdc->set_status = vu_i2c_set_status;
• vdc->guest_notifier_mask = vu_i2c_guest_notifier_mask;
• vdc->guest_notifier_pending = vu_i2c_guest_notifier_pending;

+}

+static const TypeInfo vu_i2c_info = {

• .name = TYPE_VHOST_USER_I2C,
• .parent = TYPE_VIRTIO_DEVICE,
• .instance_size = sizeof(VHostUserI2C),
• .class_init = vu_i2c_class_init,

+};

+static void vu_i2c_register_types(void) +{

• type_register_static(&vu_i2c_info);

+}

+type_init(vu_i2c_register_types) diff --git a/include/hw/virtio/vhost-user-i2c.h b/include/hw/virtio/vhost-user-i2c.h new file mode 100644 index 000000000000..a5fffcb6096c --- /dev/null +++ b/include/hw/virtio/vhost-user-i2c.h @@ -0,0 +1,37 @@ +/*

• • Vhost-user i2c virtio device
• • Copyright (c) 2021 Viresh Kumar viresh.kumar@linaro.org
• • SPDX-License-Identifier: GPL-2.0-or-later
• */

+#ifndef _QEMU_VHOST_USER_I2C_H +#define _QEMU_VHOST_USER_I2C_H

+#include "hw/virtio/virtio.h" +#include "hw/virtio/vhost.h" +#include "hw/virtio/vhost-user.h" +#include "chardev/char-fe.h"

+#define TYPE_VHOST_USER_I2C "vhost-user-i2c-device" +OBJECT_DECLARE_SIMPLE_TYPE(VHostUserI2C, VHOST_USER_I2C)

+typedef struct {

• CharBackend chardev;

+} VHostUserI2CConf;

+struct VHostUserI2C {

• /*< private >*/
• VirtIODevice parent;
• VHostUserI2CConf conf;
• struct vhost_virtqueue *vhost_vq;
• struct vhost_dev vhost_dev;
• VhostUserState vhost_user;
• VirtQueue *req_vq;
• bool connected;
• /*< public >*/

+};

+#endif /* _QEMU_VHOST_USER_I2C_H */ diff --git a/include/standard-headers/linux/virtio_ids.h b/include/standard-headers/linux/virtio_ids.h index bc1c0621f5ed..aba00c54b9cd 100644 --- a/include/standard-headers/linux/virtio_ids.h +++ b/include/standard-headers/linux/virtio_ids.h @@ -54,5 +54,6 @@ #define VIRTIO_ID_FS 26 /* virtio filesystem */ #define VIRTIO_ID_PMEM 27 /* virtio pmem */ #define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */ +#define VIRTIO_ID_I2C 34 /* virtio i2c */

This should come in as a separate patch. Generally I run:

./scripts/update-linux-headers.sh ~/lsrc/linux.git

and tag the patch as (!MERGE) as a place holder until it can get picked up with one of the regular UAPI updates.

#endif /* _LINUX_VIRTIO_IDS_H */