[PATCH v10 0/5] add generic vDPA device support

[PATCH v10 0/5] add generic vDPA device support

[Longpeng(Mike) via]

From: Longpeng <longpeng2@huawei.com>

Hi guys,

With the generic vDPA device, QEMU won't need to touch the device
types any more, such like vfio.

We can use the generic vDPA device as follow:
  -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-X
  Or
  -M microvm -m 512m -smp 2 -kernel ... -initrd ... -device \
  vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-x

Changes v10 -> v9:
    - optimize the doc [Jason]

Changes v9 -> v8:
    - rename vhost-vdpa-device.rst to vhost-vdpa-generic-device.rst [Jason, Stefano]
    - emphasize the vhost-vDPA generic device in doc [Jason]

Changes v8 -> v7:
    - add migration blocker. [Michael]

Changes v6 -> v7:
    (v6: https://mail.gnu.org/archive/html/qemu-devel/2022-05/msg02821.html)
    - rebase. [Jason]
    - add documentation . [Stefan]

Changes v5 -> v6:
  Patch 2:
    - Turn to the original approach in the RFC to initialize the
      virtio_pci_id_info array. [Michael]
	  https://lore.kernel.org/all/20220105005900.860-2-longpeng2@huawei.com/
  Patch 3:
    - Fix logical error of exception handler around the post_init.
      [Stefano]
    - Fix some coding style warnings. [Stefano]
  Patch 4:
    - Fix some coding style warnings. [Stefano]

Changes v4 -> v5:
  Patch 3:
    - remove vhostfd [Jason]
    - support virtio-mmio [Jason]

Changes v3 -> v4:
  v3: https://www.mail-archive.com/qemu-devel@nongnu.org/msg877015.html
  - reorganize the series [Stefano]
  - fix some typos [Stefano]
  - fix logical error in vhost_vdpa_device_realize [Stefano]

Changes v2 -> v3
  Patch 4 & 5:
    - only call vdpa ioctls in vdpa-dev.c [Stefano, Longpeng]
    - s/VQS_NUM/VQS_COUNT  [Stefano]
    - check both vdpa_dev_fd and vdpa_dev [Stefano]
  Patch 6:
    - move all steps into vhost_vdpa_device_unrealize. [Stefano]

Changes RFC -> v2
  Patch 1:
    - rename 'pdev_id' to 'trans_devid'  [Michael]
    - only use transitional device id for the devices
      listed in the spec  [Michael]
    - use macros to make the id_info table clearer  [Longpeng]
    - add some modern devices in the id_info table  [Longpeng]
  Patch 2:
    - remove the GET_VECTORS_NUM command  [Jason]
  Patch 4:
    - expose vdpa_dev_fd as a QOM preperty  [Stefan]
    - introduce vhost_vdpa_device_get_u32 as a common
      function to make the code clearer  [Stefan]
    - fix the misleading description of 'dc->desc'  [Stefano]
  Patch 5:
    - check returned number of virtqueues  [Stefan]
  Patch 6:
    - init s->num_queues  [Stefano]
    - free s->dev.vqs  [Stefano]

Longpeng (Mike) (5):
  virtio: get class_id and pci device id by the virtio id
  vdpa: add vdpa-dev support
  vdpa: add vdpa-dev-pci support
  vdpa-dev: mark the device as unmigratable
  docs: Add generic vhost-vdpa device documentation

 .../devices/vhost-vdpa-generic-device.rst     |  66 +++
 hw/virtio/Kconfig                             |   5 +
 hw/virtio/meson.build                         |   2 +
 hw/virtio/vdpa-dev-pci.c                      | 102 +++++
 hw/virtio/vdpa-dev.c                          | 377 ++++++++++++++++++
 hw/virtio/virtio-pci.c                        |  88 ++++
 include/hw/virtio/vdpa-dev.h                  |  43 ++
 include/hw/virtio/virtio-pci.h                |   5 +
 8 files changed, 688 insertions(+)
 create mode 100644 docs/system/devices/vhost-vdpa-generic-device.rst
 create mode 100644 hw/virtio/vdpa-dev-pci.c
 create mode 100644 hw/virtio/vdpa-dev.c
 create mode 100644 include/hw/virtio/vdpa-dev.h

-- 
2.23.0

[PATCH v10 1/5] virtio: get class_id and pci device id by the virtio id

[Longpeng(Mike) via]

From: Longpeng <longpeng2@huawei.com>

Add helpers to get the "Transitional PCI Device ID" and "class_id"
of the device specified by the "Virtio Device ID".

These helpers will be used to build the generic vDPA device later.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 hw/virtio/virtio-pci.c         | 88 ++++++++++++++++++++++++++++++++++
 include/hw/virtio/virtio-pci.h |  5 ++
 2 files changed, 93 insertions(+)

diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index a1c9dfa7bb..a602f670ca 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -19,6 +19,7 @@
 
 #include "exec/memop.h"
 #include "standard-headers/linux/virtio_pci.h"
+#include "standard-headers/linux/virtio_ids.h"
 #include "hw/boards.h"
 #include "hw/virtio/virtio.h"
 #include "migration/qemu-file-types.h"
@@ -224,6 +225,90 @@ static int virtio_pci_load_queue(DeviceState *d, int n, QEMUFile *f)
     return 0;
 }
 
+typedef struct VirtIOPCIIDInfo {
+    /* virtio id */
+    uint16_t vdev_id;
+    /* pci device id for the transitional device */
+    uint16_t trans_devid;
+    uint16_t class_id;
+} VirtIOPCIIDInfo;
+
+static const VirtIOPCIIDInfo virtio_pci_id_info[] = {
+    {
+        .vdev_id = VIRTIO_ID_CRYPTO,
+        .class_id = PCI_CLASS_OTHERS,
+    }, {
+        .vdev_id = VIRTIO_ID_FS,
+        .class_id = PCI_CLASS_STORAGE_OTHER,
+    }, {
+        .vdev_id = VIRTIO_ID_NET,
+        .trans_devid = PCI_DEVICE_ID_VIRTIO_NET,
+        .class_id = PCI_CLASS_NETWORK_ETHERNET,
+    }, {
+        .vdev_id = VIRTIO_ID_BLOCK,
+        .trans_devid = PCI_DEVICE_ID_VIRTIO_BLOCK,
+        .class_id = PCI_CLASS_STORAGE_SCSI,
+    }, {
+        .vdev_id = VIRTIO_ID_CONSOLE,
+        .trans_devid = PCI_DEVICE_ID_VIRTIO_CONSOLE,
+        .class_id = PCI_CLASS_COMMUNICATION_OTHER,
+    }, {
+        .vdev_id = VIRTIO_ID_SCSI,
+        .trans_devid = PCI_DEVICE_ID_VIRTIO_SCSI,
+        .class_id = PCI_CLASS_STORAGE_SCSI
+    }, {
+        .vdev_id = VIRTIO_ID_9P,
+        .trans_devid = PCI_DEVICE_ID_VIRTIO_9P,
+        .class_id = PCI_BASE_CLASS_NETWORK,
+    }, {
+        .vdev_id = VIRTIO_ID_BALLOON,
+        .trans_devid = PCI_DEVICE_ID_VIRTIO_BALLOON,
+        .class_id = PCI_CLASS_OTHERS,
+    }, {
+        .vdev_id = VIRTIO_ID_RNG,
+        .trans_devid = PCI_DEVICE_ID_VIRTIO_RNG,
+        .class_id = PCI_CLASS_OTHERS,
+    },
+};
+
+static const VirtIOPCIIDInfo *virtio_pci_get_id_info(uint16_t vdev_id)
+{
+    const VirtIOPCIIDInfo *info = NULL;
+    int i;
+
+    for (i = 0; i < ARRAY_SIZE(virtio_pci_id_info); i++) {
+        if (virtio_pci_id_info[i].vdev_id == vdev_id) {
+            info = &virtio_pci_id_info[i];
+            break;
+        }
+    }
+
+    if (!info) {
+        /* The device id is invalid or not added to the id_info yet. */
+        error_report("Invalid virtio device(id %u)", vdev_id);
+        abort();
+    }
+
+    return info;
+}
+
+/*
+ * Get the Transitional Device ID for the specific device, return
+ * zero if the device is non-transitional.
+ */
+uint16_t virtio_pci_get_trans_devid(uint16_t device_id)
+{
+    return virtio_pci_get_id_info(device_id)->trans_devid;
+}
+
+/*
+ * Get the Class ID for the specific device.
+ */
+uint16_t virtio_pci_get_class_id(uint16_t device_id)
+{
+    return virtio_pci_get_id_info(device_id)->class_id;
+}
+
 static bool virtio_pci_ioeventfd_enabled(DeviceState *d)
 {
     VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
@@ -1729,6 +1814,9 @@ static void virtio_pci_device_plugged(DeviceState *d, Error **errp)
          * is set to PCI_SUBVENDOR_ID_REDHAT_QUMRANET by default.
          */
         pci_set_word(config + PCI_SUBSYSTEM_ID, virtio_bus_get_vdev_id(bus));
+        if (proxy->trans_devid) {
+            pci_config_set_device_id(config, proxy->trans_devid);
+        }
     } else {
         /* pure virtio-1.0 */
         pci_set_word(config + PCI_VENDOR_ID,
diff --git a/include/hw/virtio/virtio-pci.h b/include/hw/virtio/virtio-pci.h
index 938799e8f6..24fba1604b 100644
--- a/include/hw/virtio/virtio-pci.h
+++ b/include/hw/virtio/virtio-pci.h
@@ -151,6 +151,8 @@ struct VirtIOPCIProxy {
     bool disable_modern;
     bool ignore_backend_features;
     OnOffAuto disable_legacy;
+    /* Transitional device id */
+    uint16_t trans_devid;
     uint32_t class_code;
     uint32_t nvectors;
     uint32_t dfselect;
@@ -184,6 +186,9 @@ static inline void virtio_pci_disable_modern(VirtIOPCIProxy *proxy)
     proxy->disable_modern = true;
 }
 
+uint16_t virtio_pci_get_trans_devid(uint16_t device_id);
+uint16_t virtio_pci_get_class_id(uint16_t device_id);
+
 /*
  * virtio-input-pci: This extends VirtioPCIProxy.
  */
-- 
2.23.0

[PATCH v10 2/5] vdpa: add vdpa-dev support

[Longpeng(Mike) via]

From: Longpeng <longpeng2@huawei.com>

Supports vdpa-dev, we can use the deivce directly:

-M microvm -m 512m -smp 2 -kernel ... -initrd ... -device \
vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-x

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 hw/virtio/Kconfig            |   5 +
 hw/virtio/meson.build        |   1 +
 hw/virtio/vdpa-dev.c         | 376 +++++++++++++++++++++++++++++++++++
 include/hw/virtio/vdpa-dev.h |  43 ++++
 4 files changed, 425 insertions(+)
 create mode 100644 hw/virtio/vdpa-dev.c
 create mode 100644 include/hw/virtio/vdpa-dev.h

diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index cbfd8c7173..89e9e426d8 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -85,3 +85,8 @@ config VHOST_USER_GPIO
     bool
     default y
     depends on VIRTIO && VHOST_USER
+
+config VHOST_VDPA_DEV
+    bool
+    default y
+    depends on VIRTIO && VHOST_VDPA && LINUX
diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index dfed1e7af5..54d6d29af7 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -31,6 +31,7 @@ virtio_ss.add(when: 'CONFIG_VHOST_USER_I2C', if_true: files('vhost-user-i2c.c'))
 virtio_ss.add(when: 'CONFIG_VHOST_USER_RNG', if_true: files('vhost-user-rng.c'))
 virtio_ss.add(when: 'CONFIG_VHOST_USER_GPIO', if_true: files('vhost-user-gpio.c'))
 virtio_ss.add(when: ['CONFIG_VIRTIO_PCI', 'CONFIG_VHOST_USER_GPIO'], if_true: files('vhost-user-gpio-pci.c'))
+virtio_ss.add(when: 'CONFIG_VHOST_VDPA_DEV', if_true: files('vdpa-dev.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/vdpa-dev.c b/hw/virtio/vdpa-dev.c
new file mode 100644
index 0000000000..dbc4f8001d
--- /dev/null
+++ b/hw/virtio/vdpa-dev.c
@@ -0,0 +1,376 @@
+/*
+ * Vhost Vdpa Device
+ *
+ * Copyright (c) Huawei Technologies Co., Ltd. 2022. All Rights Reserved.
+ *
+ * Authors:
+ *   Longpeng <longpeng2@huawei.com>
+ *
+ * Largely based on the "vhost-user-blk-pci.c" and "vhost-user-blk.c"
+ * implemented by:
+ *   Changpeng Liu <changpeng.liu@intel.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include <sys/ioctl.h>
+#include <linux/vhost.h>
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/cutils.h"
+#include "hw/qdev-core.h"
+#include "hw/qdev-properties.h"
+#include "hw/qdev-properties-system.h"
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-access.h"
+#include "hw/virtio/vdpa-dev.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/runstate.h"
+
+static void
+vhost_vdpa_device_dummy_handle_output(VirtIODevice *vdev, VirtQueue *vq)
+{
+    /* Nothing to do */
+}
+
+static uint32_t
+vhost_vdpa_device_get_u32(int fd, unsigned long int cmd, Error **errp)
+{
+    uint32_t val = (uint32_t)-1;
+
+    if (ioctl(fd, cmd, &val) < 0) {
+        error_setg(errp, "vhost-vdpa-device: cmd 0x%lx failed: %s",
+                   cmd, strerror(errno));
+    }
+
+    return val;
+}
+
+static void vhost_vdpa_device_realize(DeviceState *dev, Error **errp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VhostVdpaDevice *v = VHOST_VDPA_DEVICE(vdev);
+    uint16_t max_queue_size;
+    struct vhost_virtqueue *vqs;
+    int i, ret;
+
+    if (!v->vhostdev) {
+        error_setg(errp, "vhost-vdpa-device: vhostdev are missing");
+        return;
+    }
+
+    v->vhostfd = qemu_open(v->vhostdev, O_RDWR, errp);
+    if (*errp) {
+        return;
+    }
+    v->vdpa.device_fd = v->vhostfd;
+
+    v->vdev_id = vhost_vdpa_device_get_u32(v->vhostfd,
+                                           VHOST_VDPA_GET_DEVICE_ID, errp);
+    if (*errp) {
+        goto out;
+    }
+
+    max_queue_size = vhost_vdpa_device_get_u32(v->vhostfd,
+                                               VHOST_VDPA_GET_VRING_NUM, errp);
+    if (*errp) {
+        goto out;
+    }
+
+    if (v->queue_size > max_queue_size) {
+        error_setg(errp, "vhost-vdpa-device: invalid queue_size: %u (max:%u)",
+                   v->queue_size, max_queue_size);
+        goto out;
+    } else if (!v->queue_size) {
+        v->queue_size = max_queue_size;
+    }
+
+    v->num_queues = vhost_vdpa_device_get_u32(v->vhostfd,
+                                              VHOST_VDPA_GET_VQS_COUNT, errp);
+    if (*errp) {
+        goto out;
+    }
+
+    if (!v->num_queues || v->num_queues > VIRTIO_QUEUE_MAX) {
+        error_setg(errp, "invalid number of virtqueues: %u (max:%u)",
+                   v->num_queues, VIRTIO_QUEUE_MAX);
+        goto out;
+    }
+
+    v->dev.nvqs = v->num_queues;
+    vqs = g_new0(struct vhost_virtqueue, v->dev.nvqs);
+    v->dev.vqs = vqs;
+    v->dev.vq_index = 0;
+    v->dev.vq_index_end = v->dev.nvqs;
+    v->dev.backend_features = 0;
+    v->started = false;
+
+    ret = vhost_dev_init(&v->dev, &v->vdpa, VHOST_BACKEND_TYPE_VDPA, 0, NULL);
+    if (ret < 0) {
+        error_setg(errp, "vhost-vdpa-device: vhost initialization failed: %s",
+                   strerror(-ret));
+        goto free_vqs;
+    }
+
+    v->config_size = vhost_vdpa_device_get_u32(v->vhostfd,
+                                               VHOST_VDPA_GET_CONFIG_SIZE,
+                                               errp);
+    if (*errp) {
+        goto vhost_cleanup;
+    }
+
+    /*
+     * Invoke .post_init() to initialize the transport-specific fields
+     * before calling virtio_init().
+     */
+    if (v->post_init && v->post_init(v, errp) < 0) {
+        goto vhost_cleanup;
+    }
+
+    v->config = g_malloc0(v->config_size);
+
+    ret = vhost_dev_get_config(&v->dev, v->config, v->config_size, NULL);
+    if (ret < 0) {
+        error_setg(errp, "vhost-vdpa-device: get config failed");
+        goto free_config;
+    }
+
+    virtio_init(vdev, v->vdev_id, v->config_size);
+
+    v->virtqs = g_new0(VirtQueue *, v->dev.nvqs);
+    for (i = 0; i < v->dev.nvqs; i++) {
+        v->virtqs[i] = virtio_add_queue(vdev, v->queue_size,
+                                        vhost_vdpa_device_dummy_handle_output);
+    }
+
+    return;
+
+free_config:
+    g_free(v->config);
+vhost_cleanup:
+    vhost_dev_cleanup(&v->dev);
+free_vqs:
+    g_free(vqs);
+out:
+    qemu_close(v->vhostfd);
+    v->vhostfd = -1;
+}
+
+static void vhost_vdpa_device_unrealize(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    int i;
+
+    virtio_set_status(vdev, 0);
+
+    for (i = 0; i < s->num_queues; i++) {
+        virtio_delete_queue(s->virtqs[i]);
+    }
+    g_free(s->virtqs);
+    virtio_cleanup(vdev);
+
+    g_free(s->config);
+    g_free(s->dev.vqs);
+    vhost_dev_cleanup(&s->dev);
+    qemu_close(s->vhostfd);
+    s->vhostfd = -1;
+}
+
+static void
+vhost_vdpa_device_get_config(VirtIODevice *vdev, uint8_t *config)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+
+    memcpy(config, s->config, s->config_size);
+}
+
+static void
+vhost_vdpa_device_set_config(VirtIODevice *vdev, const uint8_t *config)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    int ret;
+
+    ret = vhost_dev_set_config(&s->dev, s->config, 0, s->config_size,
+                               VHOST_SET_CONFIG_TYPE_MASTER);
+    if (ret) {
+        error_report("set device config space failed");
+        return;
+    }
+}
+
+static uint64_t vhost_vdpa_device_get_features(VirtIODevice *vdev,
+                                               uint64_t features,
+                                               Error **errp)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    uint64_t backend_features = s->dev.features;
+
+    if (!virtio_has_feature(features, VIRTIO_F_IOMMU_PLATFORM)) {
+        virtio_clear_feature(&backend_features, VIRTIO_F_IOMMU_PLATFORM);
+    }
+
+    return backend_features;
+}
+
+static int vhost_vdpa_device_start(VirtIODevice *vdev, Error **errp)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    int i, ret;
+
+    if (!k->set_guest_notifiers) {
+        error_setg(errp, "binding does not support guest notifiers");
+        return -ENOSYS;
+    }
+
+    ret = vhost_dev_enable_notifiers(&s->dev, vdev);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error enabling host notifiers");
+        return ret;
+    }
+
+    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, true);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error binding guest notifier");
+        goto err_host_notifiers;
+    }
+
+    s->dev.acked_features = vdev->guest_features;
+
+    ret = vhost_dev_start(&s->dev, vdev, false);
+    if (ret < 0) {
+        error_setg_errno(errp, -ret, "Error starting vhost");
+        goto err_guest_notifiers;
+    }
+    s->started = true;
+
+    /*
+     * 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 < s->dev.nvqs; i++) {
+        vhost_virtqueue_mask(&s->dev, vdev, i, false);
+    }
+
+    return ret;
+
+err_guest_notifiers:
+    k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
+err_host_notifiers:
+    vhost_dev_disable_notifiers(&s->dev, vdev);
+    return ret;
+}
+
+static void vhost_vdpa_device_stop(VirtIODevice *vdev)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev)));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+    int ret;
+
+    if (!s->started) {
+        return;
+    }
+    s->started = false;
+
+    if (!k->set_guest_notifiers) {
+        return;
+    }
+
+    vhost_dev_stop(&s->dev, vdev, false);
+
+    ret = k->set_guest_notifiers(qbus->parent, s->dev.nvqs, false);
+    if (ret < 0) {
+        error_report("vhost guest notifier cleanup failed: %d", ret);
+        return;
+    }
+
+    vhost_dev_disable_notifiers(&s->dev, vdev);
+}
+
+static void vhost_vdpa_device_set_status(VirtIODevice *vdev, uint8_t status)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(vdev);
+    bool should_start = virtio_device_started(vdev, status);
+    Error *local_err = NULL;
+    int ret;
+
+    if (!vdev->vm_running) {
+        should_start = false;
+    }
+
+    if (s->started == should_start) {
+        return;
+    }
+
+    if (should_start) {
+        ret = vhost_vdpa_device_start(vdev, &local_err);
+        if (ret < 0) {
+            error_reportf_err(local_err, "vhost-vdpa-device: start failed: ");
+        }
+    } else {
+        vhost_vdpa_device_stop(vdev);
+    }
+}
+
+static Property vhost_vdpa_device_properties[] = {
+    DEFINE_PROP_STRING("vhostdev", VhostVdpaDevice, vhostdev),
+    DEFINE_PROP_UINT16("queue-size", VhostVdpaDevice, queue_size, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static const VMStateDescription vmstate_vhost_vdpa_device = {
+    .name = "vhost-vdpa-device",
+    .minimum_version_id = 1,
+    .version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_VIRTIO_DEVICE,
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static void vhost_vdpa_device_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+
+    device_class_set_props(dc, vhost_vdpa_device_properties);
+    dc->desc = "VDPA-based generic device assignment";
+    dc->vmsd = &vmstate_vhost_vdpa_device;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    vdc->realize = vhost_vdpa_device_realize;
+    vdc->unrealize = vhost_vdpa_device_unrealize;
+    vdc->get_config = vhost_vdpa_device_get_config;
+    vdc->set_config = vhost_vdpa_device_set_config;
+    vdc->get_features = vhost_vdpa_device_get_features;
+    vdc->set_status = vhost_vdpa_device_set_status;
+}
+
+static void vhost_vdpa_device_instance_init(Object *obj)
+{
+    VhostVdpaDevice *s = VHOST_VDPA_DEVICE(obj);
+
+    device_add_bootindex_property(obj, &s->bootindex, "bootindex",
+                                  NULL, DEVICE(obj));
+}
+
+static const TypeInfo vhost_vdpa_device_info = {
+    .name = TYPE_VHOST_VDPA_DEVICE,
+    .parent = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(VhostVdpaDevice),
+    .class_init = vhost_vdpa_device_class_init,
+    .instance_init = vhost_vdpa_device_instance_init,
+};
+
+static void register_vhost_vdpa_device_type(void)
+{
+    type_register_static(&vhost_vdpa_device_info);
+}
+
+type_init(register_vhost_vdpa_device_type);
diff --git a/include/hw/virtio/vdpa-dev.h b/include/hw/virtio/vdpa-dev.h
new file mode 100644
index 0000000000..4dbf98195c
--- /dev/null
+++ b/include/hw/virtio/vdpa-dev.h
@@ -0,0 +1,43 @@
+/*
+ * Vhost Vdpa Device
+ *
+ * Copyright (c) Huawei Technologies Co., Ltd. 2022. All Rights Reserved.
+ *
+ * Authors:
+ *   Longpeng <longpeng2@huawei.com>
+ *
+ * Largely based on the "vhost-user-blk.h" implemented by:
+ *   Changpeng Liu <changpeng.liu@intel.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+#ifndef _VHOST_VDPA_DEVICE_H
+#define _VHOST_VDPA_DEVICE_H
+
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-vdpa.h"
+#include "qom/object.h"
+
+
+#define TYPE_VHOST_VDPA_DEVICE "vhost-vdpa-device"
+OBJECT_DECLARE_SIMPLE_TYPE(VhostVdpaDevice, VHOST_VDPA_DEVICE)
+
+struct VhostVdpaDevice {
+    VirtIODevice parent_obj;
+    char *vhostdev;
+    int vhostfd;
+    int32_t bootindex;
+    uint32_t vdev_id;
+    uint32_t num_queues;
+    struct vhost_dev dev;
+    struct vhost_vdpa vdpa;
+    VirtQueue **virtqs;
+    uint8_t *config;
+    int config_size;
+    uint16_t queue_size;
+    bool started;
+    int (*post_init)(VhostVdpaDevice *v, Error **errp);
+};
+
+#endif
-- 
2.23.0

[PATCH v10 3/5] vdpa: add vdpa-dev-pci support

[Longpeng(Mike) via]

From: Longpeng <longpeng2@huawei.com>

Supports vdpa-dev-pci, we can use the device as follow:

-device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-X

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 hw/virtio/meson.build    |   1 +
 hw/virtio/vdpa-dev-pci.c | 102 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+)
 create mode 100644 hw/virtio/vdpa-dev-pci.c

diff --git a/hw/virtio/meson.build b/hw/virtio/meson.build
index 54d6d29af7..559b80cb28 100644
--- a/hw/virtio/meson.build
+++ b/hw/virtio/meson.build
@@ -57,6 +57,7 @@ virtio_pci_ss.add(when: 'CONFIG_VIRTIO_SERIAL', if_true: files('virtio-serial-pc
 virtio_pci_ss.add(when: 'CONFIG_VIRTIO_PMEM', if_true: files('virtio-pmem-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VIRTIO_IOMMU', if_true: files('virtio-iommu-pci.c'))
 virtio_pci_ss.add(when: 'CONFIG_VIRTIO_MEM', if_true: files('virtio-mem-pci.c'))
+virtio_pci_ss.add(when: 'CONFIG_VHOST_VDPA_DEV', if_true: files('vdpa-dev-pci.c'))
 
 virtio_ss.add_all(when: 'CONFIG_VIRTIO_PCI', if_true: virtio_pci_ss)
 
diff --git a/hw/virtio/vdpa-dev-pci.c b/hw/virtio/vdpa-dev-pci.c
new file mode 100644
index 0000000000..5446e6b393
--- /dev/null
+++ b/hw/virtio/vdpa-dev-pci.c
@@ -0,0 +1,102 @@
+/*
+ * Vhost Vdpa Device PCI Bindings
+ *
+ * Copyright (c) Huawei Technologies Co., Ltd. 2022. All Rights Reserved.
+ *
+ * Authors:
+ *   Longpeng <longpeng2@huawei.com>
+ *
+ * Largely based on the "vhost-user-blk-pci.c" and "vhost-user-blk.c"
+ * implemented by:
+ *   Changpeng Liu <changpeng.liu@intel.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include <sys/ioctl.h>
+#include <linux/vhost.h>
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/vdpa-dev.h"
+#include "hw/pci/pci.h"
+#include "hw/qdev-properties.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/module.h"
+#include "hw/virtio/virtio-pci.h"
+#include "qom/object.h"
+
+
+typedef struct VhostVdpaDevicePCI VhostVdpaDevicePCI;
+
+#define TYPE_VHOST_VDPA_DEVICE_PCI "vhost-vdpa-device-pci-base"
+DECLARE_INSTANCE_CHECKER(VhostVdpaDevicePCI, VHOST_VDPA_DEVICE_PCI,
+                         TYPE_VHOST_VDPA_DEVICE_PCI)
+
+struct VhostVdpaDevicePCI {
+    VirtIOPCIProxy parent_obj;
+    VhostVdpaDevice vdev;
+};
+
+static void vhost_vdpa_device_pci_instance_init(Object *obj)
+{
+    VhostVdpaDevicePCI *dev = VHOST_VDPA_DEVICE_PCI(obj);
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VHOST_VDPA_DEVICE);
+    object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
+                              "bootindex");
+}
+
+static Property vhost_vdpa_device_pci_properties[] = {
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static int vhost_vdpa_device_pci_post_init(VhostVdpaDevice *v, Error **errp)
+{
+    VhostVdpaDevicePCI *dev = container_of(v, VhostVdpaDevicePCI, vdev);
+    VirtIOPCIProxy *vpci_dev = &dev->parent_obj;
+
+    vpci_dev->class_code = virtio_pci_get_class_id(v->vdev_id);
+    vpci_dev->trans_devid = virtio_pci_get_trans_devid(v->vdev_id);
+    /* one for config vector */
+    vpci_dev->nvectors = v->num_queues + 1;
+
+    return 0;
+}
+
+static void
+vhost_vdpa_device_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VhostVdpaDevicePCI *dev = VHOST_VDPA_DEVICE_PCI(vpci_dev);
+
+    dev->vdev.post_init = vhost_vdpa_device_pci_post_init;
+    qdev_realize(DEVICE(&dev->vdev), BUS(&vpci_dev->bus), errp);
+}
+
+static void vhost_vdpa_device_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    device_class_set_props(dc, vhost_vdpa_device_pci_properties);
+    k->realize = vhost_vdpa_device_pci_realize;
+}
+
+static const VirtioPCIDeviceTypeInfo vhost_vdpa_device_pci_info = {
+    .base_name               = TYPE_VHOST_VDPA_DEVICE_PCI,
+    .generic_name            = "vhost-vdpa-device-pci",
+    .transitional_name       = "vhost-vdpa-device-pci-transitional",
+    .non_transitional_name   = "vhost-vdpa-device-pci-non-transitional",
+    .instance_size  = sizeof(VhostVdpaDevicePCI),
+    .instance_init  = vhost_vdpa_device_pci_instance_init,
+    .class_init     = vhost_vdpa_device_pci_class_init,
+};
+
+static void vhost_vdpa_device_pci_register(void)
+{
+    virtio_pci_types_register(&vhost_vdpa_device_pci_info);
+}
+
+type_init(vhost_vdpa_device_pci_register);
-- 
2.23.0

[PATCH v10 4/5] vdpa-dev: mark the device as unmigratable

[Longpeng(Mike) via]

From: Longpeng <longpeng2@huawei.com>

The generic vDPA device doesn't support migration currently, so
mark it as unmigratable temporarily.

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 hw/virtio/vdpa-dev.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/virtio/vdpa-dev.c b/hw/virtio/vdpa-dev.c
index dbc4f8001d..db6ba61152 100644
--- a/hw/virtio/vdpa-dev.c
+++ b/hw/virtio/vdpa-dev.c
@@ -327,6 +327,7 @@ static Property vhost_vdpa_device_properties[] = {
 
 static const VMStateDescription vmstate_vhost_vdpa_device = {
     .name = "vhost-vdpa-device",
+    .unmigratable = 1,
     .minimum_version_id = 1,
     .version_id = 1,
     .fields = (VMStateField[]) {
-- 
2.23.0

[PATCH v10 5/5] docs: Add generic vhost-vdpa device documentation

[Longpeng(Mike) via]

From: Longpeng <longpeng2@huawei.com>

Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 .../devices/vhost-vdpa-generic-device.rst     | 66 +++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 docs/system/devices/vhost-vdpa-generic-device.rst

diff --git a/docs/system/devices/vhost-vdpa-generic-device.rst b/docs/system/devices/vhost-vdpa-generic-device.rst
new file mode 100644
index 0000000000..7d13359ea1
--- /dev/null
+++ b/docs/system/devices/vhost-vdpa-generic-device.rst
@@ -0,0 +1,66 @@
+
+=========================
+vhost-vDPA generic device
+=========================
+
+This document explains the usage of the vhost-vDPA generic device.
+
+Description
+-----------
+
+vDPA(virtio data path acceleration) device is a device that uses a datapath
+which complies with the virtio specifications with vendor specific control
+path.
+
+QEMU provides two types of vhost-vDPA devices to enable the vDPA device, one
+is type sensitive which means QEMU needs to know the actual device type
+(e.g. net, blk, scsi) and another is called "vhost-vDPA generic device" which
+is type insensitive.
+
+The vhost-vDPA generic device builds on the vhost-vdpa subsystem and virtio
+subsystem. It is quite small, but it can support any type of virtio device.
+
+Examples
+--------
+
+1. Please make sure the modules listed bellow are installed:
+    vhost.ko
+    vhost_iotlb.ko
+    vdpa.ko
+    vhost_vdpa.ko
+
+
+2. Prepare the vhost-vDPA backends, here is an example using vdpa_sim_blk
+   device:
+
+::
+  host# modprobe vdpa_sim_blk
+  host# vdpa dev add mgmtdev vdpasim_blk name blk0
+  (...you can see the vhost-vDPA device under /dev directory now...)
+  host# ls -l /dev/vhost-vdpa-*
+  crw------- 1 root root 236, 0 Nov  2 00:49 /dev/vhost-vdpa-0
+
+Note:
+It needs some vendor-specific steps to provision the vDPA device if you're
+using real HW devices, such as installing the vendor-specific vDPA driver
+and binding the device to the driver.
+
+
+3. Start the virtual machine:
+
+Start QEMU with virtio-mmio bus:
+
+::
+  host# qemu-system                                                  \
+      -M microvm -m 512 -smp 2 -kernel ... -initrd ...               \
+      -device vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-0           \
+      ...
+
+
+Start QEMU with virtio-pci bus:
+
+::
+  host# qemu-system                                                  \
+      -M pc -m 512 -smp 2                                            \
+      -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-0       \
+      ...
-- 
2.23.0

Re: [PATCH v10 5/5] docs: Add generic vhost-vdpa device documentation

[Stefano Garzarella]

On Mon, Dec 05, 2022 at 04:49:43PM +0800, Longpeng(Mike) wrote:
>From: Longpeng <longpeng2@huawei.com>
>
>Signed-off-by: Longpeng <longpeng2@huawei.com>
>---
> .../devices/vhost-vdpa-generic-device.rst     | 66 +++++++++++++++++++
> 1 file changed, 66 insertions(+)
> create mode 100644 docs/system/devices/vhost-vdpa-generic-device.rst
>
>diff --git a/docs/system/devices/vhost-vdpa-generic-device.rst b/docs/system/devices/vhost-vdpa-generic-device.rst
>new file mode 100644
>index 0000000000..7d13359ea1
>--- /dev/null
>+++ b/docs/system/devices/vhost-vdpa-generic-device.rst
>@@ -0,0 +1,66 @@
>+
>+=========================
>+vhost-vDPA generic device
>+=========================
>+
>+This document explains the usage of the vhost-vDPA generic device.
>+
>+Description
>+-----------
>+
>+vDPA(virtio data path acceleration) device is a device that uses a datapath
>+which complies with the virtio specifications with vendor specific control
>+path.
>+
>+QEMU provides two types of vhost-vDPA devices to enable the vDPA device, one
>+is type sensitive which means QEMU needs to know the actual device type
>+(e.g. net, blk, scsi) and another is called "vhost-vDPA generic device" which
>+is type insensitive.
>+
>+The vhost-vDPA generic device builds on the vhost-vdpa subsystem and virtio
>+subsystem. It is quite small, but it can support any type of virtio device.
>+

Maybe we can also add a minimum requirement section (e.g. we needs at 
least Linux v5.18 for VHOST_VDPA_GET_VQS_COUNT)

>+Examples
>+--------
>+
>+1. Please make sure the modules listed bellow are installed:
>+    vhost.ko
>+    vhost_iotlb.ko
>+    vdpa.ko
>+    vhost_vdpa.ko
>+
>+
>+2. Prepare the vhost-vDPA backends, here is an example using vdpa_sim_blk
>+   device:
>+
>+::

Should we add also a `modprobe vhost-vdpa` step?

>+  host# modprobe vdpa_sim_blk
>+  host# vdpa dev add mgmtdev vdpasim_blk name blk0
>+  (...you can see the vhost-vDPA device under /dev directory now...)
>+  host# ls -l /dev/vhost-vdpa-*
>+  crw------- 1 root root 236, 0 Nov  2 00:49 /dev/vhost-vdpa-0
>+
>+Note:
>+It needs some vendor-specific steps to provision the vDPA device if you're
>+using real HW devices, such as installing the vendor-specific vDPA driver
>+and binding the device to the driver.
>+
>+
>+3. Start the virtual machine:
>+
>+Start QEMU with virtio-mmio bus:
>+
>+::
>+  host# qemu-system                                                  \
>+      -M microvm -m 512 -smp 2 -kernel ... -initrd ...               \
>+      -device vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-0           \
>+      ...
>+
>+
>+Start QEMU with virtio-pci bus:
>+
>+::
>+  host# qemu-system                                                  \
>+      -M pc -m 512 -smp 2                                            \
>+      -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-0       \
>+      ...
>-- 
>2.23.0
>

Re: [PATCH v10 5/5] docs: Add generic vhost-vdpa device documentation

[longpeng2--- via]

在 2022/12/13 22:35, Stefano Garzarella 写道:
> On Mon, Dec 05, 2022 at 04:49:43PM +0800, Longpeng(Mike) wrote:
>> From: Longpeng <longpeng2@huawei.com>
>>
>> Signed-off-by: Longpeng <longpeng2@huawei.com>
>> ---
>> .../devices/vhost-vdpa-generic-device.rst     | 66 +++++++++++++++++++
>> 1 file changed, 66 insertions(+)
>> create mode 100644 docs/system/devices/vhost-vdpa-generic-device.rst
>>
>> diff --git a/docs/system/devices/vhost-vdpa-generic-device.rst 
>> b/docs/system/devices/vhost-vdpa-generic-device.rst
>> new file mode 100644
>> index 0000000000..7d13359ea1
>> --- /dev/null
>> +++ b/docs/system/devices/vhost-vdpa-generic-device.rst
>> @@ -0,0 +1,66 @@
>> +
>> +=========================
>> +vhost-vDPA generic device
>> +=========================
>> +
>> +This document explains the usage of the vhost-vDPA generic device.
>> +
>> +Description
>> +-----------
>> +
>> +vDPA(virtio data path acceleration) device is a device that uses a 
>> datapath
>> +which complies with the virtio specifications with vendor specific 
>> control
>> +path.
>> +
>> +QEMU provides two types of vhost-vDPA devices to enable the vDPA 
>> device, one
>> +is type sensitive which means QEMU needs to know the actual device type
>> +(e.g. net, blk, scsi) and another is called "vhost-vDPA generic 
>> device" which
>> +is type insensitive.
>> +
>> +The vhost-vDPA generic device builds on the vhost-vdpa subsystem and 
>> virtio
>> +subsystem. It is quite small, but it can support any type of virtio 
>> device.
>> +
> 
> Maybe we can also add a minimum requirement section (e.g. we needs at 
> least Linux v5.18 for VHOST_VDPA_GET_VQS_COUNT)
> 
Ok.

>> +Examples
>> +--------
>> +
>> +1. Please make sure the modules listed bellow are installed:
>> +    vhost.ko
>> +    vhost_iotlb.ko
>> +    vdpa.ko
>> +    vhost_vdpa.ko
>> +
>> +
>> +2. Prepare the vhost-vDPA backends, here is an example using 
>> vdpa_sim_blk
>> +   device:
>> +
>> +::
> 
> Should we add also a `modprobe vhost-vdpa` step?
> 
This is already described in Step 1.

>> +  host# modprobe vdpa_sim_blk
>> +  host# vdpa dev add mgmtdev vdpasim_blk name blk0
>> +  (...you can see the vhost-vDPA device under /dev directory now...)
>> +  host# ls -l /dev/vhost-vdpa-*
>> +  crw------- 1 root root 236, 0 Nov  2 00:49 /dev/vhost-vdpa-0
>> +
>> +Note:
>> +It needs some vendor-specific steps to provision the vDPA device if 
>> you're
>> +using real HW devices, such as installing the vendor-specific vDPA 
>> driver
>> +and binding the device to the driver.
>> +
>> +
>> +3. Start the virtual machine:
>> +
>> +Start QEMU with virtio-mmio bus:
>> +
>> +::
>> +  host# qemu-system                                                  \
>> +      -M microvm -m 512 -smp 2 -kernel ... -initrd ...               \
>> +      -device vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-0           \
>> +      ...
>> +
>> +
>> +Start QEMU with virtio-pci bus:
>> +
>> +::
>> +  host# qemu-system                                                  \
>> +      -M pc -m 512 -smp 2                                            \
>> +      -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-0       \
>> +      ...
>> -- 
>> 2.23.0
>>
> 
> .

Re: [PATCH v10 5/5] docs: Add generic vhost-vdpa device documentation

[Stefano Garzarella]

On Tue, Dec 13, 2022 at 11:37:35PM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote:
>
>
>在 2022/12/13 22:35, Stefano Garzarella 写道:
>>On Mon, Dec 05, 2022 at 04:49:43PM +0800, Longpeng(Mike) wrote:
>>>From: Longpeng <longpeng2@huawei.com>
>>>
>>>Signed-off-by: Longpeng <longpeng2@huawei.com>
>>>---
>>>.../devices/vhost-vdpa-generic-device.rst     | 66 +++++++++++++++++++
>>>1 file changed, 66 insertions(+)
>>>create mode 100644 docs/system/devices/vhost-vdpa-generic-device.rst
>>>
>>>diff --git a/docs/system/devices/vhost-vdpa-generic-device.rst 
>>>b/docs/system/devices/vhost-vdpa-generic-device.rst
>>>new file mode 100644
>>>index 0000000000..7d13359ea1
>>>--- /dev/null
>>>+++ b/docs/system/devices/vhost-vdpa-generic-device.rst
>>>@@ -0,0 +1,66 @@
>>>+
>>>+=========================
>>>+vhost-vDPA generic device
>>>+=========================
>>>+
>>>+This document explains the usage of the vhost-vDPA generic device.
>>>+
>>>+Description
>>>+-----------
>>>+
>>>+vDPA(virtio data path acceleration) device is a device that uses 
>>>a datapath
>>>+which complies with the virtio specifications with vendor 
>>>specific control
>>>+path.
>>>+
>>>+QEMU provides two types of vhost-vDPA devices to enable the vDPA 
>>>device, one
>>>+is type sensitive which means QEMU needs to know the actual device type
>>>+(e.g. net, blk, scsi) and another is called "vhost-vDPA generic 
>>>device" which
>>>+is type insensitive.
>>>+
>>>+The vhost-vDPA generic device builds on the vhost-vdpa subsystem 
>>>and virtio
>>>+subsystem. It is quite small, but it can support any type of 
>>>virtio device.
>>>+
>>
>>Maybe we can also add a minimum requirement section (e.g. we needs 
>>at least Linux v5.18 for VHOST_VDPA_GET_VQS_COUNT)
>>
>Ok.
>
>>>+Examples
>>>+--------
>>>+
>>>+1. Please make sure the modules listed bellow are installed:
>>>+    vhost.ko
>>>+    vhost_iotlb.ko
>>>+    vdpa.ko
>>>+    vhost_vdpa.ko
>>>+
>>>+
>>>+2. Prepare the vhost-vDPA backends, here is an example using 
>>>vdpa_sim_blk
>>>+   device:
>>>+
>>>+::
>>
>>Should we add also a `modprobe vhost-vdpa` step?
>>
>This is already described in Step 1.

Ah sorry, I had interpreted it as having those modules compiled and 
available, not loaded.
Maybe better to replace "installed", with "loaded".

Although IMHO we can remove "Step 1" and add "modprobe vhost-vdpa" here.
The others are all dependencies that are automatically loaded.

Thanks,
Stefano

Re: [PATCH v10 0/5] add generic vDPA device support

[Michael S. Tsirkin]

On Mon, Dec 05, 2022 at 04:49:38PM +0800, Longpeng(Mike) wrote:
> From: Longpeng <longpeng2@huawei.com>
> 
> Hi guys,
> 
> With the generic vDPA device, QEMU won't need to touch the device
> types any more, such like vfio.

Fails build:
Warning, treated as error:
/scm/qemu/docs/system/devices/vhost-vdpa-generic-device.rst:document isn't included in any toctree




> We can use the generic vDPA device as follow:
>   -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-X
>   Or
>   -M microvm -m 512m -smp 2 -kernel ... -initrd ... -device \
>   vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-x
> 
> Changes v10 -> v9:
>     - optimize the doc [Jason]
> 
> Changes v9 -> v8:
>     - rename vhost-vdpa-device.rst to vhost-vdpa-generic-device.rst [Jason, Stefano]
>     - emphasize the vhost-vDPA generic device in doc [Jason]
> 
> Changes v8 -> v7:
>     - add migration blocker. [Michael]
> 
> Changes v6 -> v7:
>     (v6: https://mail.gnu.org/archive/html/qemu-devel/2022-05/msg02821.html)
>     - rebase. [Jason]
>     - add documentation . [Stefan]
> 
> Changes v5 -> v6:
>   Patch 2:
>     - Turn to the original approach in the RFC to initialize the
>       virtio_pci_id_info array. [Michael]
> 	  https://lore.kernel.org/all/20220105005900.860-2-longpeng2@huawei.com/
>   Patch 3:
>     - Fix logical error of exception handler around the post_init.
>       [Stefano]
>     - Fix some coding style warnings. [Stefano]
>   Patch 4:
>     - Fix some coding style warnings. [Stefano]
> 
> Changes v4 -> v5:
>   Patch 3:
>     - remove vhostfd [Jason]
>     - support virtio-mmio [Jason]
> 
> Changes v3 -> v4:
>   v3: https://www.mail-archive.com/qemu-devel@nongnu.org/msg877015.html
>   - reorganize the series [Stefano]
>   - fix some typos [Stefano]
>   - fix logical error in vhost_vdpa_device_realize [Stefano]
> 
> Changes v2 -> v3
>   Patch 4 & 5:
>     - only call vdpa ioctls in vdpa-dev.c [Stefano, Longpeng]
>     - s/VQS_NUM/VQS_COUNT  [Stefano]
>     - check both vdpa_dev_fd and vdpa_dev [Stefano]
>   Patch 6:
>     - move all steps into vhost_vdpa_device_unrealize. [Stefano]
> 
> Changes RFC -> v2
>   Patch 1:
>     - rename 'pdev_id' to 'trans_devid'  [Michael]
>     - only use transitional device id for the devices
>       listed in the spec  [Michael]
>     - use macros to make the id_info table clearer  [Longpeng]
>     - add some modern devices in the id_info table  [Longpeng]
>   Patch 2:
>     - remove the GET_VECTORS_NUM command  [Jason]
>   Patch 4:
>     - expose vdpa_dev_fd as a QOM preperty  [Stefan]
>     - introduce vhost_vdpa_device_get_u32 as a common
>       function to make the code clearer  [Stefan]
>     - fix the misleading description of 'dc->desc'  [Stefano]
>   Patch 5:
>     - check returned number of virtqueues  [Stefan]
>   Patch 6:
>     - init s->num_queues  [Stefano]
>     - free s->dev.vqs  [Stefano]
> 
> Longpeng (Mike) (5):
>   virtio: get class_id and pci device id by the virtio id
>   vdpa: add vdpa-dev support
>   vdpa: add vdpa-dev-pci support
>   vdpa-dev: mark the device as unmigratable
>   docs: Add generic vhost-vdpa device documentation
> 
>  .../devices/vhost-vdpa-generic-device.rst     |  66 +++
>  hw/virtio/Kconfig                             |   5 +
>  hw/virtio/meson.build                         |   2 +
>  hw/virtio/vdpa-dev-pci.c                      | 102 +++++
>  hw/virtio/vdpa-dev.c                          | 377 ++++++++++++++++++
>  hw/virtio/virtio-pci.c                        |  88 ++++
>  include/hw/virtio/vdpa-dev.h                  |  43 ++
>  include/hw/virtio/virtio-pci.h                |   5 +
>  8 files changed, 688 insertions(+)
>  create mode 100644 docs/system/devices/vhost-vdpa-generic-device.rst
>  create mode 100644 hw/virtio/vdpa-dev-pci.c
>  create mode 100644 hw/virtio/vdpa-dev.c
>  create mode 100644 include/hw/virtio/vdpa-dev.h
> 
> -- 
> 2.23.0

Re: [PATCH v10 5/5] docs: Add generic vhost-vdpa device documentation

[Michael S. Tsirkin]

On Mon, Dec 05, 2022 at 04:49:43PM +0800, Longpeng(Mike) wrote:
> From: Longpeng <longpeng2@huawei.com>
> 
> Signed-off-by: Longpeng <longpeng2@huawei.com>

Dropped 5/5 for now due to comments and build errors.

> ---
>  .../devices/vhost-vdpa-generic-device.rst     | 66 +++++++++++++++++++
>  1 file changed, 66 insertions(+)
>  create mode 100644 docs/system/devices/vhost-vdpa-generic-device.rst
> 
> diff --git a/docs/system/devices/vhost-vdpa-generic-device.rst b/docs/system/devices/vhost-vdpa-generic-device.rst
> new file mode 100644
> index 0000000000..7d13359ea1
> --- /dev/null
> +++ b/docs/system/devices/vhost-vdpa-generic-device.rst
> @@ -0,0 +1,66 @@
> +
> +=========================
> +vhost-vDPA generic device
> +=========================
> +
> +This document explains the usage of the vhost-vDPA generic device.
> +
> +Description
> +-----------
> +
> +vDPA(virtio data path acceleration) device is a device that uses a datapath
> +which complies with the virtio specifications with vendor specific control
> +path.
> +
> +QEMU provides two types of vhost-vDPA devices to enable the vDPA device, one
> +is type sensitive which means QEMU needs to know the actual device type
> +(e.g. net, blk, scsi) and another is called "vhost-vDPA generic device" which
> +is type insensitive.
> +
> +The vhost-vDPA generic device builds on the vhost-vdpa subsystem and virtio
> +subsystem. It is quite small, but it can support any type of virtio device.
> +
> +Examples
> +--------
> +
> +1. Please make sure the modules listed bellow are installed:
> +    vhost.ko
> +    vhost_iotlb.ko
> +    vdpa.ko
> +    vhost_vdpa.ko
> +
> +
> +2. Prepare the vhost-vDPA backends, here is an example using vdpa_sim_blk
> +   device:
> +
> +::
> +  host# modprobe vdpa_sim_blk
> +  host# vdpa dev add mgmtdev vdpasim_blk name blk0
> +  (...you can see the vhost-vDPA device under /dev directory now...)
> +  host# ls -l /dev/vhost-vdpa-*
> +  crw------- 1 root root 236, 0 Nov  2 00:49 /dev/vhost-vdpa-0
> +
> +Note:
> +It needs some vendor-specific steps to provision the vDPA device if you're
> +using real HW devices, such as installing the vendor-specific vDPA driver
> +and binding the device to the driver.
> +
> +
> +3. Start the virtual machine:
> +
> +Start QEMU with virtio-mmio bus:
> +
> +::
> +  host# qemu-system                                                  \
> +      -M microvm -m 512 -smp 2 -kernel ... -initrd ...               \
> +      -device vhost-vdpa-device,vhostdev=/dev/vhost-vdpa-0           \
> +      ...
> +
> +
> +Start QEMU with virtio-pci bus:
> +
> +::
> +  host# qemu-system                                                  \
> +      -M pc -m 512 -smp 2                                            \
> +      -device vhost-vdpa-device-pci,vhostdev=/dev/vhost-vdpa-0       \
> +      ...
> -- 
> 2.23.0