[PATCH v7 resend 0/4] add generic vDPA device support

[PATCH v7 resend 0/4] 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 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) (4):
  virtio: get class_id and pci device id by the virtio id
  vdpa: add vdpa-dev support
  vdpa: add vdpa-dev-pci support
  docs: Add generic vhost-vdpa device documentation

 docs/system/devices/vhost-vdpa-device.rst |  43 +++
 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, 665 insertions(+)
 create mode 100644 docs/system/devices/vhost-vdpa-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 v7 resend 1/4] 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 34db51e241..3469b88d43 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"
@@ -213,6 +214,90 @@ 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);
@@ -1683,6 +1768,9 @@ 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 2446dcd9ae..d95b1a13a5 100644
--- a/include/hw/virtio/virtio-pci.h
+++ b/include/hw/virtio/virtio-pci.h
@@ -146,6 +146,8 @@ 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;
@@ -179,6 +181,9 @@ 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 v7 resend 2/4] 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         | 377 +++++++++++++++++++++++++++++++++++
 include/hw/virtio/vdpa-dev.h |  43 ++++
 4 files changed, 426 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..62d83d3423
--- /dev/null
+++ b/hw/virtio/vdpa-dev.c
@@ -0,0 +1,377 @@
+/*
+ * 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);
+    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);
+
+    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",
+    .unmigratable = 1,
+    .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 v7 resend 3/4] 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 v7 resend 4/4] docs: Add generic vhost-vdpa device documentation

[Longpeng(Mike) via]

From: Longpeng <longpeng2@huawei.com>

Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 docs/system/devices/vhost-vdpa-device.rst | 43 +++++++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 docs/system/devices/vhost-vdpa-device.rst

diff --git a/docs/system/devices/vhost-vdpa-device.rst b/docs/system/devices/vhost-vdpa-device.rst
new file mode 100644
index 0000000000..b758c4fce6
--- /dev/null
+++ b/docs/system/devices/vhost-vdpa-device.rst
@@ -0,0 +1,43 @@
+
+=========================
+generic vhost-vdpa device
+=========================
+
+This document explains the usage of the generic vhost vdpa 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 "generic vdpa device" which is
+type insensitive (likes vfio-pci).
+
+Examples
+--------
+
+Prepare the vhost-vdpa backends first:
+
+::
+  host# ls -l /dev/vhost-vdpa-*
+  crw------- 1 root root 236, 0 Nov  2 00:49 /dev/vhost-vdpa-0
+
+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 v7 resend 0/4] add generic vDPA device support

[Michael S. Tsirkin]

On Sat, Nov 05, 2022 at 04:36:25PM +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.

With this kind of passthrough migration is completely MIA right?
Better add a blocker...
And given this is there an advantage over 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 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) (4):
>   virtio: get class_id and pci device id by the virtio id
>   vdpa: add vdpa-dev support
>   vdpa: add vdpa-dev-pci support
>   docs: Add generic vhost-vdpa device documentation
> 
>  docs/system/devices/vhost-vdpa-device.rst |  43 +++
>  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, 665 insertions(+)
>  create mode 100644 docs/system/devices/vhost-vdpa-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 v7 resend 0/4] add generic vDPA device support

[longpeng2--- via]

在 2022/11/6 0:43, Michael S. Tsirkin 写道:
> On Sat, Nov 05, 2022 at 04:36:25PM +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.
> 
> With this kind of passthrough migration is completely MIA right?
> Better add a blocker...

Oh, I missed the "vdpa-dev: mark the device as unmigratable" since v4 
and I'll add it in the next version.

We'll support passthrough migration in the next step. We have already 
written a demo that can migrate between some offloading cards.

> And given this is there an advantage over VFIO?

I think the answer is the same as "why we need vDPA" if we compare it 
with 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 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) (4):
>>    virtio: get class_id and pci device id by the virtio id
>>    vdpa: add vdpa-dev support
>>    vdpa: add vdpa-dev-pci support
>>    docs: Add generic vhost-vdpa device documentation
>>
>>   docs/system/devices/vhost-vdpa-device.rst |  43 +++
>>   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, 665 insertions(+)
>>   create mode 100644 docs/system/devices/vhost-vdpa-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 v7 resend 0/4] add generic vDPA device support

[Michael S. Tsirkin]

On Sun, Nov 06, 2022 at 08:17:07AM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote:
> 
> 
> 在 2022/11/6 0:43, Michael S. Tsirkin 写道:
> > On Sat, Nov 05, 2022 at 04:36:25PM +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.
> > 
> > With this kind of passthrough migration is completely MIA right?
> > Better add a blocker...
> 
> Oh, I missed the "vdpa-dev: mark the device as unmigratable" since v4 and
> I'll add it in the next version.
> 
> We'll support passthrough migration in the next step. We have already
> written a demo that can migrate between some offloading cards.

Hmm ok. Backend disconnect can't work though, can it? State
is by necessity lost when backend crashes.

> > And given this is there an advantage over VFIO?
> 
> I think the answer is the same as "why we need vDPA" if we compare it with
> VFIO.

The answer is mostly because you can migrate and support backend
disconnect, no?

> > 
> > > 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 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) (4):
> > >    virtio: get class_id and pci device id by the virtio id
> > >    vdpa: add vdpa-dev support
> > >    vdpa: add vdpa-dev-pci support
> > >    docs: Add generic vhost-vdpa device documentation
> > > 
> > >   docs/system/devices/vhost-vdpa-device.rst |  43 +++
> > >   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, 665 insertions(+)
> > >   create mode 100644 docs/system/devices/vhost-vdpa-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 v7 resend 0/4] add generic vDPA device support

[longpeng2--- via]

在 2022/11/6 13:22, Michael S. Tsirkin 写道:
> On Sun, Nov 06, 2022 at 08:17:07AM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote:
>>
>>
>> 在 2022/11/6 0:43, Michael S. Tsirkin 写道:
>>> On Sat, Nov 05, 2022 at 04:36:25PM +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.
>>>
>>> With this kind of passthrough migration is completely MIA right?
>>> Better add a blocker...
>>
>> Oh, I missed the "vdpa-dev: mark the device as unmigratable" since v4 and
>> I'll add it in the next version.
>>
>> We'll support passthrough migration in the next step. We have already
>> written a demo that can migrate between some offloading cards.
> 
> Hmm ok. Backend disconnect can't work though, can it? State
> is by necessity lost when backend crashes.
>Yes, it can't.

>>> And given this is there an advantage over VFIO?
>>
>> I think the answer is the same as "why we need vDPA" if we compare it with
>> VFIO.
> 
> The answer is mostly because you can migrate and support backend
> disconnect, no?
>
Migrating between different hardware is the first consideration in our 
requirement, supporting backend disconnect is a low priority.

>>>
>>>> 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 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) (4):
>>>>     virtio: get class_id and pci device id by the virtio id
>>>>     vdpa: add vdpa-dev support
>>>>     vdpa: add vdpa-dev-pci support
>>>>     docs: Add generic vhost-vdpa device documentation
>>>>
>>>>    docs/system/devices/vhost-vdpa-device.rst |  43 +++
>>>>    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, 665 insertions(+)
>>>>    create mode 100644 docs/system/devices/vhost-vdpa-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 v7 resend 0/4] add generic vDPA device support

[Michael S. Tsirkin]

On Sun, Nov 06, 2022 at 09:11:39PM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote:
> 
> 
> 在 2022/11/6 13:22, Michael S. Tsirkin 写道:
> > On Sun, Nov 06, 2022 at 08:17:07AM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote:
> > > 
> > > 
> > > 在 2022/11/6 0:43, Michael S. Tsirkin 写道:
> > > > On Sat, Nov 05, 2022 at 04:36:25PM +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.
> > > > 
> > > > With this kind of passthrough migration is completely MIA right?
> > > > Better add a blocker...
> > > 
> > > Oh, I missed the "vdpa-dev: mark the device as unmigratable" since v4 and
> > > I'll add it in the next version.
> > > 
> > > We'll support passthrough migration in the next step. We have already
> > > written a demo that can migrate between some offloading cards.
> > 
> > Hmm ok. Backend disconnect can't work though, can it? State
> > is by necessity lost when backend crashes.
> > Yes, it can't.
> 
> > > > And given this is there an advantage over VFIO?
> > > 
> > > I think the answer is the same as "why we need vDPA" if we compare it with
> > > VFIO.
> > 
> > The answer is mostly because you can migrate and support backend
> > disconnect, no?
> > 
> Migrating between different hardware is the first consideration in our
> requirement, supporting backend disconnect is a low priority.

I dislike non-orthogonal features though ...
And the advantage of keeping it out of process with qemu is
I presume security?

> > > > 
> > > > > 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 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) (4):
> > > > >     virtio: get class_id and pci device id by the virtio id
> > > > >     vdpa: add vdpa-dev support
> > > > >     vdpa: add vdpa-dev-pci support
> > > > >     docs: Add generic vhost-vdpa device documentation
> > > > > 
> > > > >    docs/system/devices/vhost-vdpa-device.rst |  43 +++
> > > > >    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, 665 insertions(+)
> > > > >    create mode 100644 docs/system/devices/vhost-vdpa-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 v7 resend 0/4] add generic vDPA device support

[longpeng2--- via]

在 2022/11/6 21:47, Michael S. Tsirkin 写道:
> On Sun, Nov 06, 2022 at 09:11:39PM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote:
>>
>>
>> 在 2022/11/6 13:22, Michael S. Tsirkin 写道:
>>> On Sun, Nov 06, 2022 at 08:17:07AM +0800, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote:
>>>>
>>>>
>>>> 在 2022/11/6 0:43, Michael S. Tsirkin 写道:
>>>>> On Sat, Nov 05, 2022 at 04:36:25PM +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.
>>>>>
>>>>> With this kind of passthrough migration is completely MIA right?
>>>>> Better add a blocker...
>>>>
>>>> Oh, I missed the "vdpa-dev: mark the device as unmigratable" since v4 and
>>>> I'll add it in the next version.
>>>>
>>>> We'll support passthrough migration in the next step. We have already
>>>> written a demo that can migrate between some offloading cards.
>>>
>>> Hmm ok. Backend disconnect can't work though, can it? State
>>> is by necessity lost when backend crashes.
>>> Yes, it can't.
>>
>>>>> And given this is there an advantage over VFIO?
>>>>
>>>> I think the answer is the same as "why we need vDPA" if we compare it with
>>>> VFIO.
>>>
>>> The answer is mostly because you can migrate and support backend
>>> disconnect, no?
>>>
>> Migrating between different hardware is the first consideration in our
>> requirement, supporting backend disconnect is a low priority.
> 
> I dislike non-orthogonal features though ...
> And the advantage of keeping it out of process with qemu is
> I presume security?
> 

Yes, this is one of the reasons. The TCB of the generic vdpa device is 
smaller than the existing vdpa device (needs to use the 
virtio-net/blk/scsi emulation codes).

Besides, the generic vdpa device can support any virtio device, but the 
existing vdpa device only supports virtio-net yet.

Though the existing vdpa device is more powerful and the generic vdpa 
device would miss some features, it can be an alternative for some users.


>>>>>
>>>>>> 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 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) (4):
>>>>>>      virtio: get class_id and pci device id by the virtio id
>>>>>>      vdpa: add vdpa-dev support
>>>>>>      vdpa: add vdpa-dev-pci support
>>>>>>      docs: Add generic vhost-vdpa device documentation
>>>>>>
>>>>>>     docs/system/devices/vhost-vdpa-device.rst |  43 +++
>>>>>>     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, 665 insertions(+)
>>>>>>     create mode 100644 docs/system/devices/vhost-vdpa-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
>>>>>
>>>>> .
>>>
>>>
>>> .
> 
> 
> .