diff mbox series

[PULL,1/7] Revert "hw/virtio: Add support for VDPA network simulation devices"

Message ID 4034159c1a4f5c433ae4987ff35e037a071272b7.1712647890.git.mst@redhat.com
State New
Headers show
Series [PULL,1/7] Revert "hw/virtio: Add support for VDPA network simulation devices" | expand

Commit Message

Michael S. Tsirkin April 9, 2024, 7:32 a.m. UTC
This reverts commit cd341fd1ffded978b2aa0b5309b00be7c42e347c.

The patch adds non-upstream code in
include/standard-headers/linux/virtio_pci.h
which would make maintainance harder.

Revert for now.

Suggested-by: Jason Wang <jasowang@redhat.com>
Message-Id: <df6b6b465753e754a19459e8cd61416548f89a42.1712569644.git.mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 include/hw/virtio/virtio-pci.h              |   5 -
 include/hw/virtio/virtio.h                  |  19 --
 include/standard-headers/linux/virtio_pci.h |   7 -
 hw/net/virtio-net.c                         |  16 --
 hw/virtio/virtio-pci.c                      | 189 +-------------------
 hw/virtio/virtio.c                          |  39 ----
 MAINTAINERS                                 |   5 -
 docs/system/device-emulation.rst            |   1 -
 docs/system/devices/vdpa-net.rst            | 121 -------------
 9 files changed, 3 insertions(+), 399 deletions(-)
 delete mode 100644 docs/system/devices/vdpa-net.rst
diff mbox series

Patch

diff --git a/include/hw/virtio/virtio-pci.h b/include/hw/virtio/virtio-pci.h
index 4d57a9c751..59d88018c1 100644
--- a/include/hw/virtio/virtio-pci.h
+++ b/include/hw/virtio/virtio-pci.h
@@ -43,7 +43,6 @@  enum {
     VIRTIO_PCI_FLAG_INIT_FLR_BIT,
     VIRTIO_PCI_FLAG_AER_BIT,
     VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT,
-    VIRTIO_PCI_FLAG_VDPA_BIT,
 };
 
 /* Need to activate work-arounds for buggy guests at vmstate load. */
@@ -90,9 +89,6 @@  enum {
 #define VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED \
   (1 << VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT)
 
-/* VDPA supported flags */
-#define VIRTIO_PCI_FLAG_VDPA (1 << VIRTIO_PCI_FLAG_VDPA_BIT)
-
 typedef struct {
     MSIMessage msg;
     int virq;
@@ -144,7 +140,6 @@  struct VirtIOPCIProxy {
         };
         VirtIOPCIRegion regs[5];
     };
-    VirtIOPCIRegion lm;
     MemoryRegion modern_bar;
     MemoryRegion io_bar;
     uint32_t legacy_io_bar_idx;
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index b3c74a1bca..c8f72850bc 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -35,9 +35,6 @@ 
                                 (0x1ULL << VIRTIO_F_NOTIFY_ON_EMPTY) | \
                                 (0x1ULL << VIRTIO_F_ANY_LAYOUT))
 
-#define LM_DISABLE      0x00
-#define LM_ENABLE       0x01
-
 struct VirtQueue;
 
 static inline hwaddr vring_align(hwaddr addr,
@@ -98,11 +95,6 @@  enum virtio_device_endian {
     VIRTIO_DEVICE_ENDIAN_BIG,
 };
 
-typedef struct BitmapMemoryRegionCaches {
-    struct rcu_head rcu;
-    MemoryRegionCache bitmap;
-} BitmapMemoryRegionCaches;
-
 /**
  * struct VirtIODevice - common VirtIO structure
  * @name: name of the device
@@ -136,14 +128,6 @@  struct VirtIODevice
     uint32_t generation;
     int nvectors;
     VirtQueue *vq;
-    uint8_t lm_logging_ctrl;
-    uint32_t lm_base_addr_low;
-    uint32_t lm_base_addr_high;
-    uint32_t lm_end_addr_low;
-    uint32_t lm_end_addr_high;
-
-    BitmapMemoryRegionCaches *caches;
-
     MemoryListener listener;
     uint16_t device_id;
     /* @vm_running: current VM running state via virtio_vmstate_change() */
@@ -395,11 +379,8 @@  hwaddr virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
 hwaddr virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
 hwaddr virtio_queue_get_used_size(VirtIODevice *vdev, int n);
 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
-unsigned int virtio_queue_get_vring_states(VirtIODevice *vdev, int n);
 void virtio_queue_set_last_avail_idx(VirtIODevice *vdev, int n,
                                      unsigned int idx);
-void virtio_queue_set_vring_states(VirtIODevice *vdev, int n,
-                                   unsigned int idx);
 void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n);
 void virtio_queue_invalidate_signalled_used(VirtIODevice *vdev, int n);
 void virtio_queue_update_used_idx(VirtIODevice *vdev, int n);
diff --git a/include/standard-headers/linux/virtio_pci.h b/include/standard-headers/linux/virtio_pci.h
index 86733278ba..3e2bc2c97e 100644
--- a/include/standard-headers/linux/virtio_pci.h
+++ b/include/standard-headers/linux/virtio_pci.h
@@ -221,13 +221,6 @@  struct virtio_pci_cfg_cap {
 #define VIRTIO_PCI_COMMON_ADM_Q_IDX	60
 #define VIRTIO_PCI_COMMON_ADM_Q_NUM	62
 
-#define LM_LOGGING_CTRL                 0
-#define LM_BASE_ADDR_LOW                4
-#define LM_BASE_ADDR_HIGH               8
-#define LM_END_ADDR_LOW                 12
-#define LM_END_ADDR_HIGH                16
-#define LM_VRING_STATE_OFFSET           0x20
-
 #endif /* VIRTIO_PCI_NO_MODERN */
 
 /* Admin command status. */
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 58014a92ad..24e5e7d347 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -2039,22 +2039,6 @@  static ssize_t virtio_net_receive_rcu(NetClientState *nc, const uint8_t *buf,
             goto err;
         }
 
-        /* Mark dirty page's bitmap of guest memory */
-        if (vdev->lm_logging_ctrl == LM_ENABLE) {
-            uint64_t chunk = elem->in_addr[i] / VHOST_LOG_CHUNK;
-            /* Get chunk index */
-            BitmapMemoryRegionCaches *caches = qatomic_rcu_read(&vdev->caches);
-            uint64_t index = chunk / 8;
-            uint64_t shift = chunk % 8;
-            uint8_t val = 0;
-            address_space_read_cached(&caches->bitmap, index, &val,
-                                      sizeof(val));
-            val |= 1 << shift;
-            address_space_write_cached(&caches->bitmap, index, &val,
-                                       sizeof(val));
-            address_space_cache_invalidate(&caches->bitmap, index, sizeof(val));
-        }
-
         elems[i] = elem;
         lens[i] = total;
         i++;
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index eaaf86402c..cb6940fc0e 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1442,155 +1442,6 @@  int virtio_pci_add_shm_cap(VirtIOPCIProxy *proxy,
     return virtio_pci_add_mem_cap(proxy, &cap.cap);
 }
 
-/* Called within call_rcu().  */
-static void bitmap_free_region_cache(BitmapMemoryRegionCaches *caches)
-{
-    assert(caches != NULL);
-    address_space_cache_destroy(&caches->bitmap);
-    g_free(caches);
-}
-
-static void lm_disable(VirtIODevice *vdev)
-{
-    BitmapMemoryRegionCaches *caches;
-    caches = qatomic_read(&vdev->caches);
-    qatomic_rcu_set(&vdev->caches, NULL);
-    if (caches) {
-        call_rcu(caches, bitmap_free_region_cache, rcu);
-    }
-}
-
-static void lm_enable(VirtIODevice *vdev)
-{
-    BitmapMemoryRegionCaches *old = vdev->caches;
-    BitmapMemoryRegionCaches *new = NULL;
-    hwaddr addr, end, size;
-    int64_t len;
-
-    addr = vdev->lm_base_addr_low | ((hwaddr)(vdev->lm_base_addr_high) << 32);
-    end = vdev->lm_end_addr_low | ((hwaddr)(vdev->lm_end_addr_high) << 32);
-    size = end - addr;
-    if (size <= 0) {
-        error_report("Invalid lm size.");
-        return;
-    }
-
-    new = g_new0(BitmapMemoryRegionCaches, 1);
-    len = address_space_cache_init(&new->bitmap, vdev->dma_as, addr, size,
-                                   true);
-    if (len < size) {
-        virtio_error(vdev, "Cannot map bitmap");
-        goto err_bitmap;
-    }
-    qatomic_rcu_set(&vdev->caches, new);
-
-    if (old) {
-        call_rcu(old, bitmap_free_region_cache, rcu);
-    }
-
-    return;
-
-err_bitmap:
-    address_space_cache_destroy(&new->bitmap);
-    g_free(new);
-}
-
-static uint64_t virtio_pci_lm_read(void *opaque, hwaddr addr,
-                                       unsigned size)
-{
-    VirtIOPCIProxy *proxy = opaque;
-    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
-    hwaddr offset_end = LM_VRING_STATE_OFFSET +
-                        virtio_pci_queue_mem_mult(proxy) * VIRTIO_QUEUE_MAX;
-    uint32_t val;
-    int qid;
-
-    if (vdev == NULL) {
-        return UINT64_MAX;
-    }
-    switch (addr) {
-    case LM_LOGGING_CTRL:
-        val = vdev->lm_logging_ctrl;
-        break;
-    case LM_BASE_ADDR_LOW:
-        val = vdev->lm_base_addr_low;
-        break;
-    case LM_BASE_ADDR_HIGH:
-        val = vdev->lm_base_addr_high;
-        break;
-    case LM_END_ADDR_LOW:
-        val = vdev->lm_end_addr_low;
-        break;
-    case LM_END_ADDR_HIGH:
-        val = vdev->lm_end_addr_high;
-        break;
-    default:
-        if (addr >= LM_VRING_STATE_OFFSET && addr <= offset_end) {
-            qid = (addr - LM_VRING_STATE_OFFSET) /
-                  virtio_pci_queue_mem_mult(proxy);
-            val = virtio_queue_get_vring_states(vdev, qid);
-        } else
-            val = 0;
-
-        break;
-    }
-
-    return val;
-}
-
-static void virtio_pci_lm_write(void *opaque, hwaddr addr,
-                                    uint64_t val, unsigned size)
-{
-    VirtIOPCIProxy *proxy = opaque;
-    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
-    hwaddr offset_end = LM_VRING_STATE_OFFSET +
-                        virtio_pci_queue_mem_mult(proxy) * VIRTIO_QUEUE_MAX;
-    int qid;
-
-    if (vdev == NULL) {
-        return;
-    }
-
-    switch (addr) {
-    case LM_LOGGING_CTRL:
-        vdev->lm_logging_ctrl = val;
-        switch (val) {
-        case LM_DISABLE:
-            lm_disable(vdev);
-            break;
-        case LM_ENABLE:
-            lm_enable(vdev);
-            break;
-        default:
-            virtio_error(vdev, "Unsupport LM_LOGGING_CTRL value: %"PRIx64,
-                         val);
-                break;
-        };
-
-        break;
-    case LM_BASE_ADDR_LOW:
-        vdev->lm_base_addr_low = val;
-        break;
-    case LM_BASE_ADDR_HIGH:
-        vdev->lm_base_addr_high = val;
-        break;
-    case LM_END_ADDR_LOW:
-        vdev->lm_end_addr_low = val;
-        break;
-    case LM_END_ADDR_HIGH:
-        vdev->lm_end_addr_high = val;
-        break;
-    default:
-        if (addr >= LM_VRING_STATE_OFFSET && addr <= offset_end) {
-            qid = (addr - LM_VRING_STATE_OFFSET) /
-                  virtio_pci_queue_mem_mult(proxy);
-            virtio_queue_set_vring_states(vdev, qid, val);
-        } else
-            virtio_error(vdev, "Unsupport addr: %"PRIx64, addr);
-        break;
-    }
-}
-
 static uint64_t virtio_pci_common_read(void *opaque, hwaddr addr,
                                        unsigned size)
 {
@@ -1972,15 +1823,6 @@  static void virtio_pci_modern_regions_init(VirtIOPCIProxy *proxy,
         },
         .endianness = DEVICE_LITTLE_ENDIAN,
     };
-    static const MemoryRegionOps lm_ops = {
-        .read = virtio_pci_lm_read,
-        .write = virtio_pci_lm_write,
-        .impl = {
-            .min_access_size = 1,
-            .max_access_size = 4,
-        },
-        .endianness = DEVICE_LITTLE_ENDIAN,
-    };
     g_autoptr(GString) name = g_string_new(NULL);
 
     g_string_printf(name, "virtio-pci-common-%s", vdev_name);
@@ -2017,14 +1859,6 @@  static void virtio_pci_modern_regions_init(VirtIOPCIProxy *proxy,
                           proxy,
                           name->str,
                           proxy->notify_pio.size);
-    if (proxy->flags & VIRTIO_PCI_FLAG_VDPA) {
-        g_string_printf(name, "virtio-pci-lm-%s", vdev_name);
-        memory_region_init_io(&proxy->lm.mr, OBJECT(proxy),
-                          &lm_ops,
-                          proxy,
-                          name->str,
-                          proxy->lm.size);
-    }
 }
 
 static void virtio_pci_modern_region_map(VirtIOPCIProxy *proxy,
@@ -2187,10 +2021,6 @@  static void virtio_pci_device_plugged(DeviceState *d, Error **errp)
         virtio_pci_modern_mem_region_map(proxy, &proxy->isr, &cap);
         virtio_pci_modern_mem_region_map(proxy, &proxy->device, &cap);
         virtio_pci_modern_mem_region_map(proxy, &proxy->notify, &notify.cap);
-        if (proxy->flags & VIRTIO_PCI_FLAG_VDPA) {
-            memory_region_add_subregion(&proxy->modern_bar,
-                                        proxy->lm.offset, &proxy->lm.mr);
-        }
 
         if (modern_pio) {
             memory_region_init(&proxy->io_bar, OBJECT(proxy),
@@ -2260,9 +2090,6 @@  static void virtio_pci_device_unplugged(DeviceState *d)
         virtio_pci_modern_mem_region_unmap(proxy, &proxy->isr);
         virtio_pci_modern_mem_region_unmap(proxy, &proxy->device);
         virtio_pci_modern_mem_region_unmap(proxy, &proxy->notify);
-        if (proxy->flags & VIRTIO_PCI_FLAG_VDPA) {
-            memory_region_del_subregion(&proxy->modern_bar, &proxy->lm.mr);
-        }
         if (modern_pio) {
             virtio_pci_modern_io_region_unmap(proxy, &proxy->notify_pio);
         }
@@ -2317,17 +2144,9 @@  static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp)
     proxy->notify_pio.type = VIRTIO_PCI_CAP_NOTIFY_CFG;
 
     /* subclasses can enforce modern, so do this unconditionally */
-    if (!(proxy->flags & VIRTIO_PCI_FLAG_VDPA)) {
-        memory_region_init(&proxy->modern_bar, OBJECT(proxy), "virtio-pci",
-                           /* PCI BAR regions must be powers of 2 */
-                           pow2ceil(proxy->notify.offset + proxy->notify.size));
-    } else {
-        proxy->lm.offset = proxy->notify.offset + proxy->notify.size;
-        proxy->lm.size = 0x20 + VIRTIO_QUEUE_MAX * 4;
-        memory_region_init(&proxy->modern_bar, OBJECT(proxy), "virtio-pci",
-                           /* PCI BAR regions must be powers of 2 */
-                           pow2ceil(proxy->lm.offset + proxy->lm.size));
-    }
+    memory_region_init(&proxy->modern_bar, OBJECT(proxy), "virtio-pci",
+                       /* PCI BAR regions must be powers of 2 */
+                       pow2ceil(proxy->notify.offset + proxy->notify.size));
 
     if (proxy->disable_legacy == ON_OFF_AUTO_AUTO) {
         proxy->disable_legacy = pcie_port ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF;
@@ -2482,8 +2301,6 @@  static Property virtio_pci_properties[] = {
                     VIRTIO_PCI_FLAG_INIT_FLR_BIT, true),
     DEFINE_PROP_BIT("aer", VirtIOPCIProxy, flags,
                     VIRTIO_PCI_FLAG_AER_BIT, false),
-    DEFINE_PROP_BIT("vdpa", VirtIOPCIProxy, flags,
-                    VIRTIO_PCI_FLAG_VDPA_BIT, false),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index fb6b4ccd83..d229755eae 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3368,18 +3368,6 @@  static uint16_t virtio_queue_split_get_last_avail_idx(VirtIODevice *vdev,
     return vdev->vq[n].last_avail_idx;
 }
 
-static uint32_t virtio_queue_split_get_vring_states(VirtIODevice *vdev,
-                                                      int n)
-{
-    struct VirtQueue *vq = &vdev->vq[n];
-    uint16_t avail, used;
-
-    avail = vq->last_avail_idx;
-    used = vq->used_idx;
-
-    return avail | (uint32_t)used << 16;
-}
-
 unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
 {
     if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
@@ -3389,33 +3377,6 @@  unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n)
     }
 }
 
-unsigned int virtio_queue_get_vring_states(VirtIODevice *vdev, int n)
-{
-    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
-        return -1;
-    } else {
-        return virtio_queue_split_get_vring_states(vdev, n);
-    }
-}
-
-static void virtio_queue_split_set_vring_states(VirtIODevice *vdev,
-                                                int n, uint32_t idx)
-{
-    struct VirtQueue *vq = &vdev->vq[n];
-    vq->last_avail_idx = (uint16_t)(idx & 0xffff);
-    vq->shadow_avail_idx = (uint16_t)(idx & 0xffff);
-    vq->used_idx = (uint16_t)(idx >> 16);
-}
-
-void virtio_queue_set_vring_states(VirtIODevice *vdev, int n, uint32_t idx)
-{
-    if (virtio_vdev_has_feature(vdev, VIRTIO_F_RING_PACKED)) {
-        return;
-    } else {
-        virtio_queue_split_set_vring_states(vdev, n, idx);
-    }
-}
-
 static void virtio_queue_packed_set_last_avail_idx(VirtIODevice *vdev,
                                                    int n, unsigned int idx)
 {
diff --git a/MAINTAINERS b/MAINTAINERS
index e71183eef9..249b678fc6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2370,11 +2370,6 @@  F: hw/virtio/vhost-user-scmi*
 F: include/hw/virtio/vhost-user-scmi.h
 F: tests/qtest/libqos/virtio-scmi.*
 
-vdpa-net
-M: Hao Chen <chenh@yusur.tech>
-S: Maintained
-F: docs/system/devices/vdpa-net.rst
-
 virtio-crypto
 M: Gonglei <arei.gonglei@huawei.com>
 S: Supported
diff --git a/docs/system/device-emulation.rst b/docs/system/device-emulation.rst
index e4a27f53c8..f19777411c 100644
--- a/docs/system/device-emulation.rst
+++ b/docs/system/device-emulation.rst
@@ -99,4 +99,3 @@  Emulated Devices
    devices/canokey.rst
    devices/usb-u2f.rst
    devices/igb.rst
-   devices/vdpa-net.rst
diff --git a/docs/system/devices/vdpa-net.rst b/docs/system/devices/vdpa-net.rst
deleted file mode 100644
index 323d8c926a..0000000000
--- a/docs/system/devices/vdpa-net.rst
+++ /dev/null
@@ -1,121 +0,0 @@ 
-vdpa net
-============
-
-This document explains the setup and usage of the vdpa network device.
-The vdpa network device is a paravirtualized vdpa emulate device.
-
-Description
------------
-
-VDPA net devices support dirty page bitmap mark and vring state saving and recovery.
-
-Users can use this VDPA device for live migration simulation testing in a nested virtualization environment.
-
-Registers layout
-----------------
-
-The vdpa device add live migrate registers layout as follow::
-
-  Offset       Register Name	        Bitwidth     Associated vq
-  0x0          LM_LOGGING_CTRL          4bits
-  0x10         LM_BASE_ADDR_LOW         32bits
-  0x14         LM_BASE_ADDR_HIGH        32bits
-  0x18         LM_END_ADDR_LOW          32bits
-  0x1c         LM_END_ADDR_HIGH         32bits
-  0x20         LM_RING_STATE_OFFSET	32bits       vq0
-  0x24         LM_RING_STATE_OFFSET	32bits       vq1
-  0x28         LM_RING_STATE_OFFSET	32bits       vq2
-  ......
-  0x20+1023*4  LM_RING_STATE_OFFSET     32bits       vq1023
-
-These registers are extended at the end of the notify bar space.
-
-Architecture diagram
---------------------
-::
-
-  |------------------------------------------------------------------------|
-  | guest-L1-user-space                                                    |
-  |                                                                        |
-  |                               |----------------------------------------|
-  |                               |       [virtio-net driver]              |
-  |                               |              ^  guest-L2-src(iommu=on) |
-  |                               |--------------|-------------------------|
-  |                               |              |  qemu-L2-src(viommu)    |
-  | [dpdk-vdpa]<->[vhost socket]<-+->[vhost-user backend(iommu=on)]        |
-  --------------------------------------------------------------------------
-  --------------------------------------------------------------------------
-  |       ^                             guest-L1-kernel-space              |
-  |       |                                                                |
-  |    [VFIO]                                                              |
-  |       ^                                                                |
-  |       |                             guest-L1-src(iommu=on)             |
-  --------|-----------------------------------------------------------------
-  --------|-----------------------------------------------------------------
-  | [vdpa net device(iommu=on)]        [manager nic device]                |
-  |          |                                    |                        |
-  |          |                                    |                        |
-  |     [tap device]     qemu-L1-src(viommu)      |                        |
-  ------------------------------------------------+-------------------------
-                                                  |
-                                                  |
-                        ---------------------     |
-                        | kernel net bridge |<-----
-                        |     virbr0        |<----------------------------------
-                        ---------------------                                  |
-                                                                               |
-                                                                               |
-  --------------------------------------------------------------------------   |
-  | guest-L1-user-space                                                    |   |
-  |                                                                        |   |
-  |                               |----------------------------------------|   |
-  |                               |       [virtio-net driver]              |   |
-  |                               |              ^  guest-L2-dst(iommu=on) |   |
-  |                               |--------------|-------------------------|   |
-  |                               |              |  qemu-L2-dst(viommu)    |   |
-  | [dpdk-vdpa]<->[vhost socket]<-+->[vhost-user backend(iommu=on)]        |   |
-  --------------------------------------------------------------------------   |
-  --------------------------------------------------------------------------   |
-  |       ^                             guest-L1-kernel-space              |   |
-  |       |                                                                |   |
-  |    [VFIO]                                                              |   |
-  |       ^                                                                |   |
-  |       |                             guest-L1-dst(iommu=on)             |   |
-  --------|-----------------------------------------------------------------   |
-  --------|-----------------------------------------------------------------   |
-  | [vdpa net device(iommu=on)]        [manager nic device]----------------+----
-  |          |                                                             |
-  |          |                                                             |
-  |     [tap device]     qemu-L1-dst(viommu)                               |
-  --------------------------------------------------------------------------
-
-
-Device properties
------------------
-
-The Virtio vdpa device can be configured with the following properties:
-
- * ``vdpa=on`` open vdpa device emulated.
-
-Usages
---------
-This patch add virtio sriov support and vdpa live migrate support.
-You can open vdpa by set xml file as follow::
-
-  <qemu:commandline  xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
-  <qemu:arg value='-device'/>
-  <qemu:arg value='intel-iommu,intremap=on,device-iotlb=on,aw-bits=48'/>
-  <qemu:arg value='-netdev'/>
-  <qemu:arg value='tap,id=hostnet1,script=no,downscript=no,vhost=off'/>
-  <qemu:arg value='-device'/>
-  <qemu:arg value='virtio-net-pci,netdev=hostnet1,id=net1,mac=56:4a:b7:4f:4d:a9,bus=pci.6,addr=0x0,iommu_platform=on,ats=on,vdpa=on'/>
-  </qemu:commandline>
-
-Limitations
------------
-1. Dependent on tap device with param ``vhost=off``.
-2. Nested virtualization environment only supports ``q35`` machines.
-3. Current only support split vring live migrate.
-
-
-