[PATCH for 8.0 v8 00/12] ASID support in vhost-vdpa net

[PATCH for 8.0 v8 00/12] ASID support in vhost-vdpa net

[Eugenio Pérez]

Control VQ is the way net devices use to send changes to the device state, like
the number of active queues or its mac address.

QEMU needs to intercept this queue so it can track these changes and is able to
migrate the device. It can do it from 1576dbb5bbc4 ("vdpa: Add x-svq to
NetdevVhostVDPAOptions"). However, to enable x-svq implies to shadow all VirtIO
device's virtqueues, which will damage performance.

This series adds address space isolation, so the device and the guest
communicate directly with them (passthrough) and CVQ communication is split in
two: The guest communicates with QEMU and QEMU forwards the commands to the
device.

This patch add new features so is targeted for qemu 8.0.

Comments are welcome. Thanks!

v8:
- Do not allocate iova_tree on net_init_vhost_vdpa if only CVQ is
  shadowed. Move the iova_tree allocation to
  vhost_vdpa_net_cvq_start and vhost_vdpa_net_cvq_stop in this case.

v7:
- Never ask for number of address spaces, just react if isolation is not
  possible.
- Return ASID ioctl errors instead of masking them as if the device has
  no asid.
- Rename listener_shadow_vq to shadow_data
- Move comment on zero initailization of vhost_vdpa_dma_map above the
  functions.
- Add VHOST_VDPA_GUEST_PA_ASID macro.

v6:
- Do not allocate SVQ resources like file descriptors if SVQ cannot be used.
- Disable shadow CVQ if the device does not support it because of net
  features.

v5:
- Move vring state in vhost_vdpa_get_vring_group instead of using a
  parameter.
- Rename VHOST_VDPA_NET_CVQ_PASSTHROUGH to VHOST_VDPA_NET_DATA_ASID

v4:
- Rebased on last CVQ start series, that allocated CVQ cmd bufs at load
- Squash vhost_vdpa_cvq_group_is_independent.
- Do not check for cvq index on vhost_vdpa_net_prepare, we only have one
  that callback registered in that NetClientInfo.
- Add comment specifying behavior if device does not support _F_ASID
- Update headers to a later Linux commit to not to remove SETUP_RNG_SEED

v3:
- Do not return an error but just print a warning if vdpa device initialization
  returns failure while getting AS num of VQ groups
- Delete extra newline

v2:
- Much as commented on series [1], handle vhost_net backend through
  NetClientInfo callbacks instead of directly.
- Fix not freeing SVQ properly when device does not support CVQ
- Add BIT_ULL missed checking device's backend feature for _F_ASID.

Eugenio Pérez (12):
  vdpa: use v->shadow_vqs_enabled in vhost_vdpa_svqs_start & stop
  vhost: set SVQ device call handler at SVQ start
  vhost: allocate SVQ device file descriptors at device start
  vhost: move iova_tree set to vhost_svq_start
  vdpa: add vhost_vdpa_net_valid_svq_features
  vdpa: extract vhost_vdpa_svq_allocate_iova_tree
  vdpa: move SVQ vring features check to net/
  vdpa: allocate SVQ array unconditionally
  vdpa: add asid parameter to vhost_vdpa_dma_map/unmap
  vdpa: store x-svq parameter in VhostVDPAState
  vdpa: add shadow_data to vhost_vdpa
  vdpa: always start CVQ in SVQ mode if possible

 hw/virtio/vhost-shadow-virtqueue.h |   5 +-
 include/hw/virtio/vhost-vdpa.h     |  16 ++-
 hw/virtio/vhost-shadow-virtqueue.c |  44 ++------
 hw/virtio/vhost-vdpa.c             | 126 ++++++++++-----------
 net/vhost-vdpa.c                   | 172 ++++++++++++++++++++++++-----
 hw/virtio/trace-events             |   4 +-
 6 files changed, 236 insertions(+), 131 deletions(-)

-- 
2.31.1

[PATCH for 8.0 v8 01/12] vdpa: use v->shadow_vqs_enabled in vhost_vdpa_svqs_start & stop

[Eugenio Pérez]

This function used to trust in v->shadow_vqs != NULL to know if it must
start svq or not.

This is not going to be valid anymore, as qemu is going to allocate svq
array unconditionally (but it will only start them conditionally).

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-vdpa.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 7468e44b87..7f0ff4df5b 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -1029,7 +1029,7 @@ static bool vhost_vdpa_svqs_start(struct vhost_dev *dev)
     Error *err = NULL;
     unsigned i;
 
-    if (!v->shadow_vqs) {
+    if (!v->shadow_vqs_enabled) {
         return true;
     }
 
@@ -1082,7 +1082,7 @@ static void vhost_vdpa_svqs_stop(struct vhost_dev *dev)
 {
     struct vhost_vdpa *v = dev->opaque;
 
-    if (!v->shadow_vqs) {
+    if (!v->shadow_vqs_enabled) {
         return;
     }
 
-- 
2.31.1

[PATCH for 8.0 v8 02/12] vhost: set SVQ device call handler at SVQ start

[Eugenio Pérez]

By the end of this series CVQ is shadowed as long as the features
support it.

Since we don't know at the beginning of qemu running if this is
supported, move the event notifier handler setting to the start of the
SVQ, instead of the start of qemu run. This will avoid to create them if
the device does not support SVQ.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-shadow-virtqueue.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index 5bd14cad96..264ddc166d 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -648,6 +648,7 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
 {
     size_t desc_size, driver_size, device_size;
 
+    event_notifier_set_handler(&svq->hdev_call, vhost_svq_handle_call);
     svq->next_guest_avail_elem = NULL;
     svq->shadow_avail_idx = 0;
     svq->shadow_used_idx = 0;
@@ -704,6 +705,7 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq)
     g_free(svq->desc_state);
     qemu_vfree(svq->vring.desc);
     qemu_vfree(svq->vring.used);
+    event_notifier_set_handler(&svq->hdev_call, NULL);
 }
 
 /**
@@ -740,7 +742,6 @@ VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree,
     }
 
     event_notifier_init_fd(&svq->svq_kick, VHOST_FILE_UNBIND);
-    event_notifier_set_handler(&svq->hdev_call, vhost_svq_handle_call);
     svq->iova_tree = iova_tree;
     svq->ops = ops;
     svq->ops_opaque = ops_opaque;
@@ -763,7 +764,6 @@ void vhost_svq_free(gpointer pvq)
     VhostShadowVirtqueue *vq = pvq;
     vhost_svq_stop(vq);
     event_notifier_cleanup(&vq->hdev_kick);
-    event_notifier_set_handler(&vq->hdev_call, NULL);
     event_notifier_cleanup(&vq->hdev_call);
     g_free(vq);
 }
-- 
2.31.1

[PATCH for 8.0 v8 03/12] vhost: allocate SVQ device file descriptors at device start

[Eugenio Pérez]

The next patches will start control SVQ if possible. However, we don't
know if that will be possible at qemu boot anymore.

Delay device file descriptors until we know it at device start. This
will avoid to create them if the device does not support SVQ.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-shadow-virtqueue.c | 31 ++------------------------
 hw/virtio/vhost-vdpa.c             | 35 ++++++++++++++++++++++++------
 2 files changed, 30 insertions(+), 36 deletions(-)

diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index 264ddc166d..3b05bab44d 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -715,43 +715,18 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq)
  * @iova_tree: Tree to perform descriptors translations
  * @ops: SVQ owner callbacks
  * @ops_opaque: ops opaque pointer
- *
- * Returns the new virtqueue or NULL.
- *
- * In case of error, reason is reported through error_report.
  */
 VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree,
                                     const VhostShadowVirtqueueOps *ops,
                                     void *ops_opaque)
 {
-    g_autofree VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1);
-    int r;
-
-    r = event_notifier_init(&svq->hdev_kick, 0);
-    if (r != 0) {
-        error_report("Couldn't create kick event notifier: %s (%d)",
-                     g_strerror(errno), errno);
-        goto err_init_hdev_kick;
-    }
-
-    r = event_notifier_init(&svq->hdev_call, 0);
-    if (r != 0) {
-        error_report("Couldn't create call event notifier: %s (%d)",
-                     g_strerror(errno), errno);
-        goto err_init_hdev_call;
-    }
+    VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1);
 
     event_notifier_init_fd(&svq->svq_kick, VHOST_FILE_UNBIND);
     svq->iova_tree = iova_tree;
     svq->ops = ops;
     svq->ops_opaque = ops_opaque;
-    return g_steal_pointer(&svq);
-
-err_init_hdev_call:
-    event_notifier_cleanup(&svq->hdev_kick);
-
-err_init_hdev_kick:
-    return NULL;
+    return svq;
 }
 
 /**
@@ -763,7 +738,5 @@ void vhost_svq_free(gpointer pvq)
 {
     VhostShadowVirtqueue *vq = pvq;
     vhost_svq_stop(vq);
-    event_notifier_cleanup(&vq->hdev_kick);
-    event_notifier_cleanup(&vq->hdev_call);
     g_free(vq);
 }
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 7f0ff4df5b..3df2775760 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -428,15 +428,11 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
 
     shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free);
     for (unsigned n = 0; n < hdev->nvqs; ++n) {
-        g_autoptr(VhostShadowVirtqueue) svq;
+        VhostShadowVirtqueue *svq;
 
         svq = vhost_svq_new(v->iova_tree, v->shadow_vq_ops,
                             v->shadow_vq_ops_opaque);
-        if (unlikely(!svq)) {
-            error_setg(errp, "Cannot create svq %u", n);
-            return -1;
-        }
-        g_ptr_array_add(shadow_vqs, g_steal_pointer(&svq));
+        g_ptr_array_add(shadow_vqs, svq);
     }
 
     v->shadow_vqs = g_steal_pointer(&shadow_vqs);
@@ -864,11 +860,23 @@ static int vhost_vdpa_svq_set_fds(struct vhost_dev *dev,
     const EventNotifier *event_notifier = &svq->hdev_kick;
     int r;
 
+    r = event_notifier_init(&svq->hdev_kick, 0);
+    if (r != 0) {
+        error_setg_errno(errp, -r, "Couldn't create kick event notifier");
+        goto err_init_hdev_kick;
+    }
+
+    r = event_notifier_init(&svq->hdev_call, 0);
+    if (r != 0) {
+        error_setg_errno(errp, -r, "Couldn't create call event notifier");
+        goto err_init_hdev_call;
+    }
+
     file.fd = event_notifier_get_fd(event_notifier);
     r = vhost_vdpa_set_vring_dev_kick(dev, &file);
     if (unlikely(r != 0)) {
         error_setg_errno(errp, -r, "Can't set device kick fd");
-        return r;
+        goto err_init_set_dev_fd;
     }
 
     event_notifier = &svq->hdev_call;
@@ -876,8 +884,18 @@ static int vhost_vdpa_svq_set_fds(struct vhost_dev *dev,
     r = vhost_vdpa_set_vring_dev_call(dev, &file);
     if (unlikely(r != 0)) {
         error_setg_errno(errp, -r, "Can't set device call fd");
+        goto err_init_set_dev_fd;
     }
 
+    return 0;
+
+err_init_set_dev_fd:
+    event_notifier_set_handler(&svq->hdev_call, NULL);
+
+err_init_hdev_call:
+    event_notifier_cleanup(&svq->hdev_kick);
+
+err_init_hdev_kick:
     return r;
 }
 
@@ -1089,6 +1107,9 @@ static void vhost_vdpa_svqs_stop(struct vhost_dev *dev)
     for (unsigned i = 0; i < v->shadow_vqs->len; ++i) {
         VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, i);
         vhost_vdpa_svq_unmap_rings(dev, svq);
+
+        event_notifier_cleanup(&svq->hdev_kick);
+        event_notifier_cleanup(&svq->hdev_call);
     }
 }
 
-- 
2.31.1

[PATCH for 8.0 v8 04/12] vhost: move iova_tree set to vhost_svq_start

[Eugenio Pérez]

Since we don't know if we will use SVQ at qemu initialization, let's
allocate iova_tree only if needed. To do so, accept it at SVQ start, not
at initialization.

This will avoid to create it if the device does not support SVQ.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 hw/virtio/vhost-shadow-virtqueue.h | 5 ++---
 hw/virtio/vhost-shadow-virtqueue.c | 9 ++++-----
 hw/virtio/vhost-vdpa.c             | 5 ++---
 3 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h
index d04c34a589..926a4897b1 100644
--- a/hw/virtio/vhost-shadow-virtqueue.h
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -126,11 +126,10 @@ size_t vhost_svq_driver_area_size(const VhostShadowVirtqueue *svq);
 size_t vhost_svq_device_area_size(const VhostShadowVirtqueue *svq);
 
 void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
-                     VirtQueue *vq);
+                     VirtQueue *vq, VhostIOVATree *iova_tree);
 void vhost_svq_stop(VhostShadowVirtqueue *svq);
 
-VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree,
-                                    const VhostShadowVirtqueueOps *ops,
+VhostShadowVirtqueue *vhost_svq_new(const VhostShadowVirtqueueOps *ops,
                                     void *ops_opaque);
 
 void vhost_svq_free(gpointer vq);
diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index 3b05bab44d..4307296358 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -642,9 +642,10 @@ void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd)
  * @svq: Shadow Virtqueue
  * @vdev: VirtIO device
  * @vq: Virtqueue to shadow
+ * @iova_tree: Tree to perform descriptors translations
  */
 void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
-                     VirtQueue *vq)
+                     VirtQueue *vq, VhostIOVATree *iova_tree)
 {
     size_t desc_size, driver_size, device_size;
 
@@ -655,6 +656,7 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
     svq->last_used_idx = 0;
     svq->vdev = vdev;
     svq->vq = vq;
+    svq->iova_tree = iova_tree;
 
     svq->vring.num = virtio_queue_get_num(vdev, virtio_get_queue_index(vq));
     driver_size = vhost_svq_driver_area_size(svq);
@@ -712,18 +714,15 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq)
  * Creates vhost shadow virtqueue, and instructs the vhost device to use the
  * shadow methods and file descriptors.
  *
- * @iova_tree: Tree to perform descriptors translations
  * @ops: SVQ owner callbacks
  * @ops_opaque: ops opaque pointer
  */
-VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree,
-                                    const VhostShadowVirtqueueOps *ops,
+VhostShadowVirtqueue *vhost_svq_new(const VhostShadowVirtqueueOps *ops,
                                     void *ops_opaque)
 {
     VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1);
 
     event_notifier_init_fd(&svq->svq_kick, VHOST_FILE_UNBIND);
-    svq->iova_tree = iova_tree;
     svq->ops = ops;
     svq->ops_opaque = ops_opaque;
     return svq;
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 3df2775760..691bcc811a 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -430,8 +430,7 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
     for (unsigned n = 0; n < hdev->nvqs; ++n) {
         VhostShadowVirtqueue *svq;
 
-        svq = vhost_svq_new(v->iova_tree, v->shadow_vq_ops,
-                            v->shadow_vq_ops_opaque);
+        svq = vhost_svq_new(v->shadow_vq_ops, v->shadow_vq_ops_opaque);
         g_ptr_array_add(shadow_vqs, svq);
     }
 
@@ -1063,7 +1062,7 @@ static bool vhost_vdpa_svqs_start(struct vhost_dev *dev)
             goto err;
         }
 
-        vhost_svq_start(svq, dev->vdev, vq);
+        vhost_svq_start(svq, dev->vdev, vq, v->iova_tree);
         ok = vhost_vdpa_svq_map_rings(dev, svq, &addr, &err);
         if (unlikely(!ok)) {
             goto err_map;
-- 
2.31.1

[PATCH for 8.0 v8 05/12] vdpa: add vhost_vdpa_net_valid_svq_features

[Eugenio Pérez]

It will be reused at vdpa device start so let's extract in its own
function.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 net/vhost-vdpa.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 2b4b85d8f8..88e0eec5fa 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -107,6 +107,22 @@ VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc)
     return s->vhost_net;
 }
 
+static bool vhost_vdpa_net_valid_svq_features(uint64_t features, Error **errp)
+{
+    uint64_t invalid_dev_features =
+        features & ~vdpa_svq_device_features &
+        /* Transport are all accepted at this point */
+        ~MAKE_64BIT_MASK(VIRTIO_TRANSPORT_F_START,
+                         VIRTIO_TRANSPORT_F_END - VIRTIO_TRANSPORT_F_START);
+
+    if (invalid_dev_features) {
+        error_setg(errp, "vdpa svq does not work with features 0x%" PRIx64,
+                   invalid_dev_features);
+    }
+
+    return !invalid_dev_features;
+}
+
 static int vhost_vdpa_net_check_device_id(struct vhost_net *net)
 {
     uint32_t device_id;
@@ -676,15 +692,7 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
     if (opts->x_svq) {
         struct vhost_vdpa_iova_range iova_range;
 
-        uint64_t invalid_dev_features =
-            features & ~vdpa_svq_device_features &
-            /* Transport are all accepted at this point */
-            ~MAKE_64BIT_MASK(VIRTIO_TRANSPORT_F_START,
-                             VIRTIO_TRANSPORT_F_END - VIRTIO_TRANSPORT_F_START);
-
-        if (invalid_dev_features) {
-            error_setg(errp, "vdpa svq does not work with features 0x%" PRIx64,
-                       invalid_dev_features);
+        if (!vhost_vdpa_net_valid_svq_features(features, errp)) {
             goto err_svq;
         }
 
-- 
2.31.1

[PATCH for 8.0 v8 06/12] vdpa: extract vhost_vdpa_svq_allocate_iova_tree

[Eugenio Pérez]

It can be allocated either if all virtqueues must be shadowed or if
vdpa-net detects it can shadow only cvq.

Extract in its own function so we can reuse it.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 net/vhost-vdpa.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 88e0eec5fa..9ee3bc4cd3 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -240,6 +240,22 @@ static NetClientInfo net_vhost_vdpa_info = {
         .check_peer_type = vhost_vdpa_check_peer_type,
 };
 
+static int vhost_vdpa_get_iova_range(int fd,
+                                     struct vhost_vdpa_iova_range *iova_range)
+{
+    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
+
+    return ret < 0 ? -errno : 0;
+}
+
+static VhostIOVATree *vhost_vdpa_svq_allocate_iova_tree(int vdpa_device_fd)
+{
+    struct vhost_vdpa_iova_range iova_range;
+
+    vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
+    return vhost_iova_tree_new(iova_range.first, iova_range.last);
+}
+
 static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
 {
     VhostIOVATree *tree = v->iova_tree;
@@ -587,14 +603,6 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
     return nc;
 }
 
-static int vhost_vdpa_get_iova_range(int fd,
-                                     struct vhost_vdpa_iova_range *iova_range)
-{
-    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
-
-    return ret < 0 ? -errno : 0;
-}
-
 static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp)
 {
     int ret = ioctl(fd, VHOST_GET_FEATURES, features);
@@ -690,14 +698,11 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
     }
 
     if (opts->x_svq) {
-        struct vhost_vdpa_iova_range iova_range;
-
         if (!vhost_vdpa_net_valid_svq_features(features, errp)) {
             goto err_svq;
         }
 
-        vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
-        iova_tree = vhost_iova_tree_new(iova_range.first, iova_range.last);
+        iova_tree = vhost_vdpa_svq_allocate_iova_tree(vdpa_device_fd);
     }
 
     ncs = g_malloc0(sizeof(*ncs) * queue_pairs);
-- 
2.31.1

[PATCH for 8.0 v8 07/12] vdpa: move SVQ vring features check to net/

[Eugenio Pérez]

The next patches will start control SVQ if possible. However, we don't
know if that will be possible at qemu boot anymore.

Since the moved checks will be already evaluated at net/ to know if it
is ok to shadow CVQ, move them.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-vdpa.c | 33 ++-------------------------------
 net/vhost-vdpa.c       |  3 ++-
 2 files changed, 4 insertions(+), 32 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 691bcc811a..6f2dabd0bf 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -402,29 +402,9 @@ static int vhost_vdpa_get_dev_features(struct vhost_dev *dev,
     return ret;
 }
 
-static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
-                               Error **errp)
+static void vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v)
 {
     g_autoptr(GPtrArray) shadow_vqs = NULL;
-    uint64_t dev_features, svq_features;
-    int r;
-    bool ok;
-
-    if (!v->shadow_vqs_enabled) {
-        return 0;
-    }
-
-    r = vhost_vdpa_get_dev_features(hdev, &dev_features);
-    if (r != 0) {
-        error_setg_errno(errp, -r, "Can't get vdpa device features");
-        return r;
-    }
-
-    svq_features = dev_features;
-    ok = vhost_svq_valid_features(svq_features, errp);
-    if (unlikely(!ok)) {
-        return -1;
-    }
 
     shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free);
     for (unsigned n = 0; n < hdev->nvqs; ++n) {
@@ -435,7 +415,6 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
     }
 
     v->shadow_vqs = g_steal_pointer(&shadow_vqs);
-    return 0;
 }
 
 static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
@@ -460,11 +439,7 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
     dev->opaque =  opaque ;
     v->listener = vhost_vdpa_memory_listener;
     v->msg_type = VHOST_IOTLB_MSG_V2;
-    ret = vhost_vdpa_init_svq(dev, v, errp);
-    if (ret) {
-        goto err;
-    }
-
+    vhost_vdpa_init_svq(dev, v);
     vhost_vdpa_get_iova_range(v);
 
     if (!vhost_vdpa_first_dev(dev)) {
@@ -475,10 +450,6 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
                                VIRTIO_CONFIG_S_DRIVER);
 
     return 0;
-
-err:
-    ram_block_discard_disable(false);
-    return ret;
 }
 
 static void vhost_vdpa_host_notifier_uninit(struct vhost_dev *dev,
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 9ee3bc4cd3..b47acf5a2d 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -118,9 +118,10 @@ static bool vhost_vdpa_net_valid_svq_features(uint64_t features, Error **errp)
     if (invalid_dev_features) {
         error_setg(errp, "vdpa svq does not work with features 0x%" PRIx64,
                    invalid_dev_features);
+        return false;
     }
 
-    return !invalid_dev_features;
+    return vhost_svq_valid_features(features, errp);
 }
 
 static int vhost_vdpa_net_check_device_id(struct vhost_net *net)
-- 
2.31.1

[PATCH for 8.0 v8 08/12] vdpa: allocate SVQ array unconditionally

[Eugenio Pérez]

SVQ may run or not in a device depending on runtime conditions (for
example, if the device can move CVQ to its own group or not).

Allocate the SVQ array unconditionally at startup, since its hard to
move this allocation elsewhere.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 hw/virtio/vhost-vdpa.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 6f2dabd0bf..ed360b7fdf 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -546,10 +546,6 @@ static void vhost_vdpa_svq_cleanup(struct vhost_dev *dev)
     struct vhost_vdpa *v = dev->opaque;
     size_t idx;
 
-    if (!v->shadow_vqs) {
-        return;
-    }
-
     for (idx = 0; idx < v->shadow_vqs->len; ++idx) {
         vhost_svq_stop(g_ptr_array_index(v->shadow_vqs, idx));
     }
-- 
2.31.1

[PATCH for 8.0 v8 09/12] vdpa: add asid parameter to vhost_vdpa_dma_map/unmap

[Eugenio Pérez]

So the caller can choose which ASID is destined.

No need to update the batch functions as they will always be called from
memory listener updates at the moment. Memory listener updates will
always update ASID 0, as it's the passthrough ASID.

All vhost devices's ASID are 0 at this moment.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
v7:
* Move comment on zero initailization of vhost_vdpa_dma_map above the
  functions.
* Add VHOST_VDPA_GUEST_PA_ASID macro.

v5:
* Solve conflict, now vhost_vdpa_svq_unmap_ring returns void
* Change comment on zero initialization.

v4: Add comment specifying behavior if device does not support _F_ASID

v3: Deleted unneeded space
---
 include/hw/virtio/vhost-vdpa.h | 14 ++++++++++---
 hw/virtio/vhost-vdpa.c         | 36 +++++++++++++++++++++++-----------
 net/vhost-vdpa.c               |  6 +++---
 hw/virtio/trace-events         |  4 ++--
 4 files changed, 41 insertions(+), 19 deletions(-)

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 1111d85643..e57dfa1fd1 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -19,6 +19,12 @@
 #include "hw/virtio/virtio.h"
 #include "standard-headers/linux/vhost_types.h"
 
+/*
+ * ASID dedicated to map guest's addresses.  If SVQ is disabled it maps GPA to
+ * qemu's IOVA.  If SVQ is enabled it maps also the SVQ vring here
+ */
+#define VHOST_VDPA_GUEST_PA_ASID 0
+
 typedef struct VhostVDPAHostNotifier {
     MemoryRegion mr;
     void *addr;
@@ -29,6 +35,7 @@ typedef struct vhost_vdpa {
     int index;
     uint32_t msg_type;
     bool iotlb_batch_begin_sent;
+    uint32_t address_space_id;
     MemoryListener listener;
     struct vhost_vdpa_iova_range iova_range;
     uint64_t acked_features;
@@ -42,8 +49,9 @@ typedef struct vhost_vdpa {
     VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
 } VhostVDPA;
 
-int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
-                       void *vaddr, bool readonly);
-int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova, hwaddr size);
+int vhost_vdpa_dma_map(struct vhost_vdpa *v, uint32_t asid, hwaddr iova,
+                       hwaddr size, void *vaddr, bool readonly);
+int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, uint32_t asid, hwaddr iova,
+                         hwaddr size);
 
 #endif
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index ed360b7fdf..1100cde29e 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -72,22 +72,28 @@ static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section,
     return false;
 }
 
-int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
-                       void *vaddr, bool readonly)
+/*
+ * The caller must set asid = 0 if the device does not support asid.
+ * This is not an ABI break since it is set to 0 by the initializer anyway.
+ */
+int vhost_vdpa_dma_map(struct vhost_vdpa *v, uint32_t asid, hwaddr iova,
+                       hwaddr size, void *vaddr, bool readonly)
 {
     struct vhost_msg_v2 msg = {};
     int fd = v->device_fd;
     int ret = 0;
 
     msg.type = v->msg_type;
+    msg.asid = asid;
     msg.iotlb.iova = iova;
     msg.iotlb.size = size;
     msg.iotlb.uaddr = (uint64_t)(uintptr_t)vaddr;
     msg.iotlb.perm = readonly ? VHOST_ACCESS_RO : VHOST_ACCESS_RW;
     msg.iotlb.type = VHOST_IOTLB_UPDATE;
 
-   trace_vhost_vdpa_dma_map(v, fd, msg.type, msg.iotlb.iova, msg.iotlb.size,
-                            msg.iotlb.uaddr, msg.iotlb.perm, msg.iotlb.type);
+    trace_vhost_vdpa_dma_map(v, fd, msg.type, msg.asid, msg.iotlb.iova,
+                             msg.iotlb.size, msg.iotlb.uaddr, msg.iotlb.perm,
+                             msg.iotlb.type);
 
     if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
         error_report("failed to write, fd=%d, errno=%d (%s)",
@@ -98,18 +104,24 @@ int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
     return ret;
 }
 
-int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova, hwaddr size)
+/*
+ * The caller must set asid = 0 if the device does not support asid.
+ * This is not an ABI break since it is set to 0 by the initializer anyway.
+ */
+int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, uint32_t asid, hwaddr iova,
+                         hwaddr size)
 {
     struct vhost_msg_v2 msg = {};
     int fd = v->device_fd;
     int ret = 0;
 
     msg.type = v->msg_type;
+    msg.asid = asid;
     msg.iotlb.iova = iova;
     msg.iotlb.size = size;
     msg.iotlb.type = VHOST_IOTLB_INVALIDATE;
 
-    trace_vhost_vdpa_dma_unmap(v, fd, msg.type, msg.iotlb.iova,
+    trace_vhost_vdpa_dma_unmap(v, fd, msg.type, msg.asid, msg.iotlb.iova,
                                msg.iotlb.size, msg.iotlb.type);
 
     if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
@@ -229,8 +241,8 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
     }
 
     vhost_vdpa_iotlb_batch_begin_once(v);
-    ret = vhost_vdpa_dma_map(v, iova, int128_get64(llsize),
-                             vaddr, section->readonly);
+    ret = vhost_vdpa_dma_map(v, VHOST_VDPA_GUEST_PA_ASID, iova,
+                             int128_get64(llsize), vaddr, section->readonly);
     if (ret) {
         error_report("vhost vdpa map fail!");
         goto fail_map;
@@ -303,7 +315,8 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
         vhost_iova_tree_remove(v->iova_tree, *result);
     }
     vhost_vdpa_iotlb_batch_begin_once(v);
-    ret = vhost_vdpa_dma_unmap(v, iova, int128_get64(llsize));
+    ret = vhost_vdpa_dma_unmap(v, VHOST_VDPA_GUEST_PA_ASID, iova,
+                               int128_get64(llsize));
     if (ret) {
         error_report("vhost_vdpa dma unmap error!");
     }
@@ -883,7 +896,7 @@ static void vhost_vdpa_svq_unmap_ring(struct vhost_vdpa *v, hwaddr addr)
     }
 
     size = ROUND_UP(result->size, qemu_real_host_page_size());
-    r = vhost_vdpa_dma_unmap(v, result->iova, size);
+    r = vhost_vdpa_dma_unmap(v, v->address_space_id, result->iova, size);
     if (unlikely(r < 0)) {
         error_report("Unable to unmap SVQ vring: %s (%d)", g_strerror(-r), -r);
         return;
@@ -923,7 +936,8 @@ static bool vhost_vdpa_svq_map_ring(struct vhost_vdpa *v, DMAMap *needle,
         return false;
     }
 
-    r = vhost_vdpa_dma_map(v, needle->iova, needle->size + 1,
+    r = vhost_vdpa_dma_map(v, v->address_space_id, needle->iova,
+                           needle->size + 1,
                            (void *)(uintptr_t)needle->translated_addr,
                            needle->perm == IOMMU_RO);
     if (unlikely(r != 0)) {
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index b47acf5a2d..b40b1ddf0d 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -275,7 +275,7 @@ static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
         return;
     }
 
-    r = vhost_vdpa_dma_unmap(v, map->iova, map->size + 1);
+    r = vhost_vdpa_dma_unmap(v, v->address_space_id, map->iova, map->size + 1);
     if (unlikely(r != 0)) {
         error_report("Device cannot unmap: %s(%d)", g_strerror(r), r);
     }
@@ -315,8 +315,8 @@ static int vhost_vdpa_cvq_map_buf(struct vhost_vdpa *v, void *buf, size_t size,
         return r;
     }
 
-    r = vhost_vdpa_dma_map(v, map.iova, vhost_vdpa_net_cvq_cmd_page_len(), buf,
-                           !write);
+    r = vhost_vdpa_dma_map(v, v->address_space_id, map.iova,
+                           vhost_vdpa_net_cvq_cmd_page_len(), buf, !write);
     if (unlikely(r < 0)) {
         goto dma_map_err;
     }
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 820dadc26c..0ad9390307 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -30,8 +30,8 @@ vhost_user_write(uint32_t req, uint32_t flags) "req:%d flags:0x%"PRIx32""
 vhost_user_create_notifier(int idx, void *n) "idx:%d n:%p"
 
 # vhost-vdpa.c
-vhost_vdpa_dma_map(void *vdpa, int fd, uint32_t msg_type, uint64_t iova, uint64_t size, uint64_t uaddr, uint8_t perm, uint8_t type) "vdpa:%p fd: %d msg_type: %"PRIu32" iova: 0x%"PRIx64" size: 0x%"PRIx64" uaddr: 0x%"PRIx64" perm: 0x%"PRIx8" type: %"PRIu8
-vhost_vdpa_dma_unmap(void *vdpa, int fd, uint32_t msg_type, uint64_t iova, uint64_t size, uint8_t type) "vdpa:%p fd: %d msg_type: %"PRIu32" iova: 0x%"PRIx64" size: 0x%"PRIx64" type: %"PRIu8
+vhost_vdpa_dma_map(void *vdpa, int fd, uint32_t msg_type, uint32_t asid, uint64_t iova, uint64_t size, uint64_t uaddr, uint8_t perm, uint8_t type) "vdpa:%p fd: %d msg_type: %"PRIu32" asid: %"PRIu32" iova: 0x%"PRIx64" size: 0x%"PRIx64" uaddr: 0x%"PRIx64" perm: 0x%"PRIx8" type: %"PRIu8
+vhost_vdpa_dma_unmap(void *vdpa, int fd, uint32_t msg_type, uint32_t asid, uint64_t iova, uint64_t size, uint8_t type) "vdpa:%p fd: %d msg_type: %"PRIu32" asid: %"PRIu32" iova: 0x%"PRIx64" size: 0x%"PRIx64" type: %"PRIu8
 vhost_vdpa_listener_begin_batch(void *v, int fd, uint32_t msg_type, uint8_t type)  "vdpa:%p fd: %d msg_type: %"PRIu32" type: %"PRIu8
 vhost_vdpa_listener_commit(void *v, int fd, uint32_t msg_type, uint8_t type)  "vdpa:%p fd: %d msg_type: %"PRIu32" type: %"PRIu8
 vhost_vdpa_listener_region_add(void *vdpa, uint64_t iova, uint64_t llend, void *vaddr, bool readonly) "vdpa: %p iova 0x%"PRIx64" llend 0x%"PRIx64" vaddr: %p read-only: %d"
-- 
2.31.1

[PATCH for 8.0 v8 10/12] vdpa: store x-svq parameter in VhostVDPAState

[Eugenio Pérez]

CVQ can be shadowed two ways:
- Device has x-svq=on parameter (current way)
- The device can isolate CVQ in its own vq group

QEMU needs to check for the second condition dynamically, because CVQ
index is not known before the driver ack the features. Since this is
dynamic, the CVQ isolation could vary with different conditions, making
it possible to go from "not isolated group" to "isolated".

Saving the cmdline parameter in an extra field so we never disable CVQ
SVQ in case the device was started with x-svq cmdline.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 net/vhost-vdpa.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index b40b1ddf0d..3ff149dfd9 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -38,6 +38,8 @@ typedef struct VhostVDPAState {
     void *cvq_cmd_out_buffer;
     virtio_net_ctrl_ack *status;
 
+    /* The device always have SVQ enabled */
+    bool always_svq;
     bool started;
 } VhostVDPAState;
 
@@ -583,6 +585,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
 
     s->vhost_vdpa.device_fd = vdpa_device_fd;
     s->vhost_vdpa.index = queue_pair_index;
+    s->always_svq = svq;
     s->vhost_vdpa.shadow_vqs_enabled = svq;
     s->vhost_vdpa.iova_tree = iova_tree;
     if (!is_datapath) {
-- 
2.31.1

[PATCH for 8.0 v8 11/12] vdpa: add shadow_data to vhost_vdpa

[Eugenio Pérez]

The memory listener that thells the device how to convert GPA to qemu's
va is registered against CVQ vhost_vdpa. memory listener translations
are always ASID 0, CVQ ones are ASID 1 if supported.

Let's tell the listener if it needs to register them on iova tree or
not.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
v7: Rename listener_shadow_vq to shadow_data
v5: Solve conflict about vhost_iova_tree_remove accepting mem_region by
    value.
---
 include/hw/virtio/vhost-vdpa.h | 2 ++
 hw/virtio/vhost-vdpa.c         | 6 +++---
 net/vhost-vdpa.c               | 1 +
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index e57dfa1fd1..45b969a311 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -40,6 +40,8 @@ typedef struct vhost_vdpa {
     struct vhost_vdpa_iova_range iova_range;
     uint64_t acked_features;
     bool shadow_vqs_enabled;
+    /* Vdpa must send shadow addresses as IOTLB key for data queues, not GPA */
+    bool shadow_data;
     /* IOVA mapping used by the Shadow Virtqueue */
     VhostIOVATree *iova_tree;
     GPtrArray *shadow_vqs;
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 1100cde29e..8e54c5c0fc 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -224,7 +224,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
                                          vaddr, section->readonly);
 
     llsize = int128_sub(llend, int128_make64(iova));
-    if (v->shadow_vqs_enabled) {
+    if (v->shadow_data) {
         int r;
 
         mem_region.translated_addr = (hwaddr)(uintptr_t)vaddr,
@@ -251,7 +251,7 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
     return;
 
 fail_map:
-    if (v->shadow_vqs_enabled) {
+    if (v->shadow_data) {
         vhost_iova_tree_remove(v->iova_tree, mem_region);
     }
 
@@ -296,7 +296,7 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
 
     llsize = int128_sub(llend, int128_make64(iova));
 
-    if (v->shadow_vqs_enabled) {
+    if (v->shadow_data) {
         const DMAMap *result;
         const void *vaddr = memory_region_get_ram_ptr(section->mr) +
             section->offset_within_region +
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index 3ff149dfd9..a1f1e29b7c 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -587,6 +587,7 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
     s->vhost_vdpa.index = queue_pair_index;
     s->always_svq = svq;
     s->vhost_vdpa.shadow_vqs_enabled = svq;
+    s->vhost_vdpa.shadow_data = svq;
     s->vhost_vdpa.iova_tree = iova_tree;
     if (!is_datapath) {
         s->cvq_cmd_out_buffer = qemu_memalign(qemu_real_host_page_size(),
-- 
2.31.1

[PATCH for 8.0 v8 12/12] vdpa: always start CVQ in SVQ mode if possible

[Eugenio Pérez]

Isolate control virtqueue in its own group, allowing to intercept control
commands but letting dataplane run totally passthrough to the guest.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
v8:
* Do not allocate iova_tree on net_init_vhost_vdpa if only CVQ is
  shadowed. Move the iova_tree handling in this case to
  vhost_vdpa_net_cvq_start and vhost_vdpa_net_cvq_stop.

v7:
* Never ask for number of address spaces, just react if isolation is not
  possible.
* Return ASID ioctl errors instead of masking them as if the device has
  no asid.
* Simplify net_init_vhost_vdpa logic
* Add "if possible" suffix

v6:
* Disable control SVQ if the device does not support it because of
features.

v5:
* Fixing the not adding cvq buffers when x-svq=on is specified.
* Move vring state in vhost_vdpa_get_vring_group instead of using a
  parameter.
* Rename VHOST_VDPA_NET_CVQ_PASSTHROUGH to VHOST_VDPA_NET_DATA_ASID

v4:
* Squash vhost_vdpa_cvq_group_is_independent.
* Rebased on last CVQ start series, that allocated CVQ cmd bufs at load
* Do not check for cvq index on vhost_vdpa_net_prepare, we only have one
  that callback registered in that NetClientInfo.

v3:
* Make asid related queries print a warning instead of returning an
  error and stop the start of qemu.
---
 hw/virtio/vhost-vdpa.c |   3 +-
 net/vhost-vdpa.c       | 106 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 107 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 8e54c5c0fc..45bb72d359 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -652,7 +652,8 @@ static int vhost_vdpa_set_backend_cap(struct vhost_dev *dev)
 {
     uint64_t features;
     uint64_t f = 0x1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2 |
-        0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH;
+        0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH |
+        0x1ULL << VHOST_BACKEND_F_IOTLB_ASID;
     int r;
 
     if (vhost_vdpa_call(dev, VHOST_GET_BACKEND_FEATURES, &features)) {
diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
index a1f1e29b7c..bce57fa724 100644
--- a/net/vhost-vdpa.c
+++ b/net/vhost-vdpa.c
@@ -102,6 +102,8 @@ static const uint64_t vdpa_svq_device_features =
     BIT_ULL(VIRTIO_NET_F_RSC_EXT) |
     BIT_ULL(VIRTIO_NET_F_STANDBY);
 
+#define VHOST_VDPA_NET_CVQ_ASID 1
+
 VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc)
 {
     VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
@@ -259,6 +261,40 @@ static VhostIOVATree *vhost_vdpa_svq_allocate_iova_tree(int vdpa_device_fd)
     return vhost_iova_tree_new(iova_range.first, iova_range.last);
 }
 
+static int64_t vhost_vdpa_get_vring_group(int device_fd, unsigned vq_index)
+{
+    struct vhost_vring_state state = {
+        .index = vq_index,
+    };
+    int r = ioctl(device_fd, VHOST_VDPA_GET_VRING_GROUP, &state);
+
+    if (unlikely(r < 0)) {
+        error_report("Cannot get VQ %u group: %s", vq_index,
+                     g_strerror(errno));
+        return r;
+    }
+
+    return state.num;
+}
+
+static int vhost_vdpa_set_address_space_id(struct vhost_vdpa *v,
+                                           unsigned vq_group,
+                                           unsigned asid_num)
+{
+    struct vhost_vring_state asid = {
+        .index = vq_group,
+        .num = asid_num,
+    };
+    int r;
+
+    r = ioctl(v->device_fd, VHOST_VDPA_SET_GROUP_ASID, &asid);
+    if (unlikely(r < 0)) {
+        error_report("Can't set vq group %u asid %u, errno=%d (%s)",
+                     asid.index, asid.num, errno, g_strerror(errno));
+    }
+    return r;
+}
+
 static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
 {
     VhostIOVATree *tree = v->iova_tree;
@@ -333,11 +369,71 @@ dma_map_err:
 static int vhost_vdpa_net_cvq_start(NetClientState *nc)
 {
     VhostVDPAState *s;
-    int r;
+    struct vhost_vdpa *v;
+    uint64_t backend_features;
+    int64_t cvq_group;
+    int cvq_index, r;
 
     assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
 
     s = DO_UPCAST(VhostVDPAState, nc, nc);
+    v = &s->vhost_vdpa;
+
+    v->shadow_data = s->always_svq;
+    v->shadow_vqs_enabled = s->always_svq;
+    s->vhost_vdpa.address_space_id = VHOST_VDPA_GUEST_PA_ASID;
+
+    if (s->always_svq) {
+        /* SVQ is already configured for all virtqueues */
+        goto out;
+    }
+
+    /* Backend features are not available in v->dev yet. */
+    r = ioctl(v->device_fd, VHOST_GET_BACKEND_FEATURES, &backend_features);
+    if (unlikely(r < 0)) {
+        error_report("Cannot get vdpa backend_features: %s(%d)",
+            g_strerror(errno), errno);
+        return -1;
+    }
+    if (!(backend_features & VHOST_BACKEND_F_IOTLB_ASID) ||
+        !vhost_vdpa_net_valid_svq_features(v->dev->features, NULL)) {
+        return 0;
+    }
+
+    /**
+     * Check if all the virtqueues of the virtio device are in a different vq
+     * than the last vq. VQ group of last group passed in cvq_group.
+     */
+    cvq_index = v->dev->vq_index_end - 1;
+    cvq_group = vhost_vdpa_get_vring_group(v->device_fd, cvq_index);
+    if (unlikely(cvq_group < 0)) {
+        return cvq_group;
+    }
+    for (int i = 0; i < cvq_index; ++i) {
+        int64_t group = vhost_vdpa_get_vring_group(v->device_fd, i);
+
+        if (unlikely(group < 0)) {
+            return group;
+        }
+
+        if (unlikely(group == cvq_group)) {
+            warn_report(
+                "CVQ %"PRId64" group is the same as VQ %d one (%"PRId64")",
+                cvq_group, i, group);
+            return 0;
+        }
+    }
+
+    r = vhost_vdpa_set_address_space_id(v, cvq_group, VHOST_VDPA_NET_CVQ_ASID);
+    if (unlikely(r < 0)) {
+        return r;
+    }
+
+    v->iova_tree = vhost_vdpa_svq_allocate_iova_tree(v->device_fd);
+    v->shadow_vqs_enabled = true;
+    s->vhost_vdpa.address_space_id = VHOST_VDPA_NET_CVQ_ASID;
+
+out:
     if (!s->vhost_vdpa.shadow_vqs_enabled) {
         return 0;
     }
@@ -366,6 +462,14 @@ static void vhost_vdpa_net_cvq_stop(NetClientState *nc)
     if (s->vhost_vdpa.shadow_vqs_enabled) {
         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
         vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->status);
+        if (!s->always_svq) {
+            /*
+             * If only the CVQ is shadowed we can delete this safely.
+             * If all the VQs are shadows this will be needed by the time the
+             * device is started again to register SVQ vrings and similar.
+             */
+            g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_delete);
+        }
     }
 }
 
-- 
2.31.1

Re: [PATCH for 8.0 v8 04/12] vhost: move iova_tree set to vhost_svq_start

[Jason Wang]

On Thu, Nov 24, 2022 at 11:52 PM Eugenio Pérez <eperezma@redhat.com> wrote:
>
> Since we don't know if we will use SVQ at qemu initialization, let's
> allocate iova_tree only if needed. To do so, accept it at SVQ start, not
> at initialization.
>
> This will avoid to create it if the device does not support SVQ.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>

Acked-by: Jason Wang <jasowang@redhat.com>

Thanks

> ---
>  hw/virtio/vhost-shadow-virtqueue.h | 5 ++---
>  hw/virtio/vhost-shadow-virtqueue.c | 9 ++++-----
>  hw/virtio/vhost-vdpa.c             | 5 ++---
>  3 files changed, 8 insertions(+), 11 deletions(-)
>
> diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h
> index d04c34a589..926a4897b1 100644
> --- a/hw/virtio/vhost-shadow-virtqueue.h
> +++ b/hw/virtio/vhost-shadow-virtqueue.h
> @@ -126,11 +126,10 @@ size_t vhost_svq_driver_area_size(const VhostShadowVirtqueue *svq);
>  size_t vhost_svq_device_area_size(const VhostShadowVirtqueue *svq);
>
>  void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
> -                     VirtQueue *vq);
> +                     VirtQueue *vq, VhostIOVATree *iova_tree);
>  void vhost_svq_stop(VhostShadowVirtqueue *svq);
>
> -VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree,
> -                                    const VhostShadowVirtqueueOps *ops,
> +VhostShadowVirtqueue *vhost_svq_new(const VhostShadowVirtqueueOps *ops,
>                                      void *ops_opaque);
>
>  void vhost_svq_free(gpointer vq);
> diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
> index 3b05bab44d..4307296358 100644
> --- a/hw/virtio/vhost-shadow-virtqueue.c
> +++ b/hw/virtio/vhost-shadow-virtqueue.c
> @@ -642,9 +642,10 @@ void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd)
>   * @svq: Shadow Virtqueue
>   * @vdev: VirtIO device
>   * @vq: Virtqueue to shadow
> + * @iova_tree: Tree to perform descriptors translations
>   */
>  void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
> -                     VirtQueue *vq)
> +                     VirtQueue *vq, VhostIOVATree *iova_tree)
>  {
>      size_t desc_size, driver_size, device_size;
>
> @@ -655,6 +656,7 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev,
>      svq->last_used_idx = 0;
>      svq->vdev = vdev;
>      svq->vq = vq;
> +    svq->iova_tree = iova_tree;
>
>      svq->vring.num = virtio_queue_get_num(vdev, virtio_get_queue_index(vq));
>      driver_size = vhost_svq_driver_area_size(svq);
> @@ -712,18 +714,15 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq)
>   * Creates vhost shadow virtqueue, and instructs the vhost device to use the
>   * shadow methods and file descriptors.
>   *
> - * @iova_tree: Tree to perform descriptors translations
>   * @ops: SVQ owner callbacks
>   * @ops_opaque: ops opaque pointer
>   */
> -VhostShadowVirtqueue *vhost_svq_new(VhostIOVATree *iova_tree,
> -                                    const VhostShadowVirtqueueOps *ops,
> +VhostShadowVirtqueue *vhost_svq_new(const VhostShadowVirtqueueOps *ops,
>                                      void *ops_opaque)
>  {
>      VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1);
>
>      event_notifier_init_fd(&svq->svq_kick, VHOST_FILE_UNBIND);
> -    svq->iova_tree = iova_tree;
>      svq->ops = ops;
>      svq->ops_opaque = ops_opaque;
>      return svq;
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 3df2775760..691bcc811a 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -430,8 +430,7 @@ static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
>      for (unsigned n = 0; n < hdev->nvqs; ++n) {
>          VhostShadowVirtqueue *svq;
>
> -        svq = vhost_svq_new(v->iova_tree, v->shadow_vq_ops,
> -                            v->shadow_vq_ops_opaque);
> +        svq = vhost_svq_new(v->shadow_vq_ops, v->shadow_vq_ops_opaque);
>          g_ptr_array_add(shadow_vqs, svq);
>      }
>
> @@ -1063,7 +1062,7 @@ static bool vhost_vdpa_svqs_start(struct vhost_dev *dev)
>              goto err;
>          }
>
> -        vhost_svq_start(svq, dev->vdev, vq);
> +        vhost_svq_start(svq, dev->vdev, vq, v->iova_tree);
>          ok = vhost_vdpa_svq_map_rings(dev, svq, &addr, &err);
>          if (unlikely(!ok)) {
>              goto err_map;
> --
> 2.31.1
>

Re: [PATCH for 8.0 v8 06/12] vdpa: extract vhost_vdpa_svq_allocate_iova_tree

[Jason Wang]

On Thu, Nov 24, 2022 at 11:52 PM Eugenio Pérez <eperezma@redhat.com> wrote:
>
> It can be allocated either if all virtqueues must be shadowed or if
> vdpa-net detects it can shadow only cvq.
>
> Extract in its own function so we can reuse it.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>  net/vhost-vdpa.c | 29 +++++++++++++++++------------
>  1 file changed, 17 insertions(+), 12 deletions(-)
>
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index 88e0eec5fa..9ee3bc4cd3 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -240,6 +240,22 @@ static NetClientInfo net_vhost_vdpa_info = {
>          .check_peer_type = vhost_vdpa_check_peer_type,
>  };
>
> +static int vhost_vdpa_get_iova_range(int fd,
> +                                     struct vhost_vdpa_iova_range *iova_range)
> +{
> +    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
> +
> +    return ret < 0 ? -errno : 0;
> +}

I don't get why this needs to be moved to net specific code.

Thanks

> +
> +static VhostIOVATree *vhost_vdpa_svq_allocate_iova_tree(int vdpa_device_fd)
> +{
> +    struct vhost_vdpa_iova_range iova_range;
> +
> +    vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
> +    return vhost_iova_tree_new(iova_range.first, iova_range.last);
> +}
> +
>  static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
>  {
>      VhostIOVATree *tree = v->iova_tree;
> @@ -587,14 +603,6 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
>      return nc;
>  }
>
> -static int vhost_vdpa_get_iova_range(int fd,
> -                                     struct vhost_vdpa_iova_range *iova_range)
> -{
> -    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
> -
> -    return ret < 0 ? -errno : 0;
> -}
> -
>  static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp)
>  {
>      int ret = ioctl(fd, VHOST_GET_FEATURES, features);
> @@ -690,14 +698,11 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
>      }
>
>      if (opts->x_svq) {
> -        struct vhost_vdpa_iova_range iova_range;
> -
>          if (!vhost_vdpa_net_valid_svq_features(features, errp)) {
>              goto err_svq;
>          }
>
> -        vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
> -        iova_tree = vhost_iova_tree_new(iova_range.first, iova_range.last);
> +        iova_tree = vhost_vdpa_svq_allocate_iova_tree(vdpa_device_fd);
>      }
>
>      ncs = g_malloc0(sizeof(*ncs) * queue_pairs);
> --
> 2.31.1
>

Re: [PATCH for 8.0 v8 12/12] vdpa: always start CVQ in SVQ mode if possible

[Jason Wang]

On Thu, Nov 24, 2022 at 11:52 PM Eugenio Pérez <eperezma@redhat.com> wrote:
>
> Isolate control virtqueue in its own group, allowing to intercept control
> commands but letting dataplane run totally passthrough to the guest.
>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
> v8:
> * Do not allocate iova_tree on net_init_vhost_vdpa if only CVQ is
>   shadowed. Move the iova_tree handling in this case to
>   vhost_vdpa_net_cvq_start and vhost_vdpa_net_cvq_stop.
>
> v7:
> * Never ask for number of address spaces, just react if isolation is not
>   possible.
> * Return ASID ioctl errors instead of masking them as if the device has
>   no asid.
> * Simplify net_init_vhost_vdpa logic
> * Add "if possible" suffix
>
> v6:
> * Disable control SVQ if the device does not support it because of
> features.
>
> v5:
> * Fixing the not adding cvq buffers when x-svq=on is specified.
> * Move vring state in vhost_vdpa_get_vring_group instead of using a
>   parameter.
> * Rename VHOST_VDPA_NET_CVQ_PASSTHROUGH to VHOST_VDPA_NET_DATA_ASID
>
> v4:
> * Squash vhost_vdpa_cvq_group_is_independent.
> * Rebased on last CVQ start series, that allocated CVQ cmd bufs at load
> * Do not check for cvq index on vhost_vdpa_net_prepare, we only have one
>   that callback registered in that NetClientInfo.
>
> v3:
> * Make asid related queries print a warning instead of returning an
>   error and stop the start of qemu.
> ---
>  hw/virtio/vhost-vdpa.c |   3 +-
>  net/vhost-vdpa.c       | 106 ++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 107 insertions(+), 2 deletions(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 8e54c5c0fc..45bb72d359 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -652,7 +652,8 @@ static int vhost_vdpa_set_backend_cap(struct vhost_dev *dev)
>  {
>      uint64_t features;
>      uint64_t f = 0x1ULL << VHOST_BACKEND_F_IOTLB_MSG_V2 |
> -        0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH;
> +        0x1ULL << VHOST_BACKEND_F_IOTLB_BATCH |
> +        0x1ULL << VHOST_BACKEND_F_IOTLB_ASID;
>      int r;
>
>      if (vhost_vdpa_call(dev, VHOST_GET_BACKEND_FEATURES, &features)) {
> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> index a1f1e29b7c..bce57fa724 100644
> --- a/net/vhost-vdpa.c
> +++ b/net/vhost-vdpa.c
> @@ -102,6 +102,8 @@ static const uint64_t vdpa_svq_device_features =
>      BIT_ULL(VIRTIO_NET_F_RSC_EXT) |
>      BIT_ULL(VIRTIO_NET_F_STANDBY);
>
> +#define VHOST_VDPA_NET_CVQ_ASID 1
> +
>  VHostNetState *vhost_vdpa_get_vhost_net(NetClientState *nc)
>  {
>      VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc);
> @@ -259,6 +261,40 @@ static VhostIOVATree *vhost_vdpa_svq_allocate_iova_tree(int vdpa_device_fd)
>      return vhost_iova_tree_new(iova_range.first, iova_range.last);
>  }
>
> +static int64_t vhost_vdpa_get_vring_group(int device_fd, unsigned vq_index)
> +{
> +    struct vhost_vring_state state = {
> +        .index = vq_index,
> +    };
> +    int r = ioctl(device_fd, VHOST_VDPA_GET_VRING_GROUP, &state);
> +
> +    if (unlikely(r < 0)) {
> +        error_report("Cannot get VQ %u group: %s", vq_index,
> +                     g_strerror(errno));
> +        return r;
> +    }
> +
> +    return state.num;
> +}
> +
> +static int vhost_vdpa_set_address_space_id(struct vhost_vdpa *v,
> +                                           unsigned vq_group,
> +                                           unsigned asid_num)
> +{
> +    struct vhost_vring_state asid = {
> +        .index = vq_group,
> +        .num = asid_num,
> +    };
> +    int r;
> +
> +    r = ioctl(v->device_fd, VHOST_VDPA_SET_GROUP_ASID, &asid);
> +    if (unlikely(r < 0)) {
> +        error_report("Can't set vq group %u asid %u, errno=%d (%s)",
> +                     asid.index, asid.num, errno, g_strerror(errno));
> +    }
> +    return r;
> +}
> +
>  static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
>  {
>      VhostIOVATree *tree = v->iova_tree;
> @@ -333,11 +369,71 @@ dma_map_err:
>  static int vhost_vdpa_net_cvq_start(NetClientState *nc)
>  {
>      VhostVDPAState *s;
> -    int r;
> +    struct vhost_vdpa *v;
> +    uint64_t backend_features;
> +    int64_t cvq_group;
> +    int cvq_index, r;
>
>      assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_VDPA);
>
>      s = DO_UPCAST(VhostVDPAState, nc, nc);
> +    v = &s->vhost_vdpa;
> +
> +    v->shadow_data = s->always_svq;
> +    v->shadow_vqs_enabled = s->always_svq;
> +    s->vhost_vdpa.address_space_id = VHOST_VDPA_GUEST_PA_ASID;
> +
> +    if (s->always_svq) {
> +        /* SVQ is already configured for all virtqueues */
> +        goto out;
> +    }
> +
> +    /* Backend features are not available in v->dev yet. */
> +    r = ioctl(v->device_fd, VHOST_GET_BACKEND_FEATURES, &backend_features);
> +    if (unlikely(r < 0)) {
> +        error_report("Cannot get vdpa backend_features: %s(%d)",
> +            g_strerror(errno), errno);
> +        return -1;
> +    }
> +    if (!(backend_features & VHOST_BACKEND_F_IOTLB_ASID) ||
> +        !vhost_vdpa_net_valid_svq_features(v->dev->features, NULL)) {

As discussed in v7, it would be better to add comment to explain how
migration is blocked in this case.

> +        return 0;
> +    }
> +
> +    /**
> +     * Check if all the virtqueues of the virtio device are in a different vq
> +     * than the last vq. VQ group of last group passed in cvq_group.
> +     */
> +    cvq_index = v->dev->vq_index_end - 1;
> +    cvq_group = vhost_vdpa_get_vring_group(v->device_fd, cvq_index);
> +    if (unlikely(cvq_group < 0)) {
> +        return cvq_group;
> +    }
> +    for (int i = 0; i < cvq_index; ++i) {
> +        int64_t group = vhost_vdpa_get_vring_group(v->device_fd, i);
> +
> +        if (unlikely(group < 0)) {
> +            return group;
> +        }
> +
> +        if (unlikely(group == cvq_group)) {
> +            warn_report(
> +                "CVQ %"PRId64" group is the same as VQ %d one (%"PRId64")",
> +                cvq_group, i, group);

Any reason we need a warning here? It's pretty common for the parent
that only has a single as.

Others look good.

Thanks

> +            return 0;
> +        }
> +    }
> +
> +    r = vhost_vdpa_set_address_space_id(v, cvq_group, VHOST_VDPA_NET_CVQ_ASID);
> +    if (unlikely(r < 0)) {
> +        return r;
> +    }
> +
> +    v->iova_tree = vhost_vdpa_svq_allocate_iova_tree(v->device_fd);
> +    v->shadow_vqs_enabled = true;
> +    s->vhost_vdpa.address_space_id = VHOST_VDPA_NET_CVQ_ASID;
> +
> +out:
>      if (!s->vhost_vdpa.shadow_vqs_enabled) {
>          return 0;
>      }
> @@ -366,6 +462,14 @@ static void vhost_vdpa_net_cvq_stop(NetClientState *nc)
>      if (s->vhost_vdpa.shadow_vqs_enabled) {
>          vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->cvq_cmd_out_buffer);
>          vhost_vdpa_cvq_unmap_buf(&s->vhost_vdpa, s->status);
> +        if (!s->always_svq) {
> +            /*
> +             * If only the CVQ is shadowed we can delete this safely.
> +             * If all the VQs are shadows this will be needed by the time the
> +             * device is started again to register SVQ vrings and similar.
> +             */
> +            g_clear_pointer(&s->vhost_vdpa.iova_tree, vhost_iova_tree_delete);
> +        }
>      }
>  }
>
> --
> 2.31.1
>

Re: [PATCH for 8.0 v8 06/12] vdpa: extract vhost_vdpa_svq_allocate_iova_tree

[Eugenio Perez Martin]

On Wed, Nov 30, 2022 at 7:43 AM Jason Wang <jasowang@redhat.com> wrote:
>
> On Thu, Nov 24, 2022 at 11:52 PM Eugenio Pérez <eperezma@redhat.com> wrote:
> >
> > It can be allocated either if all virtqueues must be shadowed or if
> > vdpa-net detects it can shadow only cvq.
> >
> > Extract in its own function so we can reuse it.
> >
> > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > ---
> >  net/vhost-vdpa.c | 29 +++++++++++++++++------------
> >  1 file changed, 17 insertions(+), 12 deletions(-)
> >
> > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> > index 88e0eec5fa..9ee3bc4cd3 100644
> > --- a/net/vhost-vdpa.c
> > +++ b/net/vhost-vdpa.c
> > @@ -240,6 +240,22 @@ static NetClientInfo net_vhost_vdpa_info = {
> >          .check_peer_type = vhost_vdpa_check_peer_type,
> >  };
> >
> > +static int vhost_vdpa_get_iova_range(int fd,
> > +                                     struct vhost_vdpa_iova_range *iova_range)
> > +{
> > +    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
> > +
> > +    return ret < 0 ? -errno : 0;
> > +}
>
> I don't get why this needs to be moved to net specific code.
>

It was already in net, this code just extracted it in its own function.

It's done in net because iova_tree must be the same for all queuepair
vhost, so we need to allocate before them.

Thanks!

> Thanks
>
> > +
> > +static VhostIOVATree *vhost_vdpa_svq_allocate_iova_tree(int vdpa_device_fd)
> > +{
> > +    struct vhost_vdpa_iova_range iova_range;
> > +
> > +    vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
> > +    return vhost_iova_tree_new(iova_range.first, iova_range.last);
> > +}
> > +
> >  static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
> >  {
> >      VhostIOVATree *tree = v->iova_tree;
> > @@ -587,14 +603,6 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
> >      return nc;
> >  }
> >
> > -static int vhost_vdpa_get_iova_range(int fd,
> > -                                     struct vhost_vdpa_iova_range *iova_range)
> > -{
> > -    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
> > -
> > -    return ret < 0 ? -errno : 0;
> > -}
> > -
> >  static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp)
> >  {
> >      int ret = ioctl(fd, VHOST_GET_FEATURES, features);
> > @@ -690,14 +698,11 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
> >      }
> >
> >      if (opts->x_svq) {
> > -        struct vhost_vdpa_iova_range iova_range;
> > -
> >          if (!vhost_vdpa_net_valid_svq_features(features, errp)) {
> >              goto err_svq;
> >          }
> >
> > -        vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
> > -        iova_tree = vhost_iova_tree_new(iova_range.first, iova_range.last);
> > +        iova_tree = vhost_vdpa_svq_allocate_iova_tree(vdpa_device_fd);
> >      }
> >
> >      ncs = g_malloc0(sizeof(*ncs) * queue_pairs);
> > --
> > 2.31.1
> >
>

Re: [PATCH for 8.0 v8 06/12] vdpa: extract vhost_vdpa_svq_allocate_iova_tree

[Jason Wang]

On Wed, Nov 30, 2022 at 3:40 PM Eugenio Perez Martin
<eperezma@redhat.com> wrote:
>
> On Wed, Nov 30, 2022 at 7:43 AM Jason Wang <jasowang@redhat.com> wrote:
> >
> > On Thu, Nov 24, 2022 at 11:52 PM Eugenio Pérez <eperezma@redhat.com> wrote:
> > >
> > > It can be allocated either if all virtqueues must be shadowed or if
> > > vdpa-net detects it can shadow only cvq.
> > >
> > > Extract in its own function so we can reuse it.
> > >
> > > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > > ---
> > >  net/vhost-vdpa.c | 29 +++++++++++++++++------------
> > >  1 file changed, 17 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> > > index 88e0eec5fa..9ee3bc4cd3 100644
> > > --- a/net/vhost-vdpa.c
> > > +++ b/net/vhost-vdpa.c
> > > @@ -240,6 +240,22 @@ static NetClientInfo net_vhost_vdpa_info = {
> > >          .check_peer_type = vhost_vdpa_check_peer_type,
> > >  };
> > >
> > > +static int vhost_vdpa_get_iova_range(int fd,
> > > +                                     struct vhost_vdpa_iova_range *iova_range)
> > > +{
> > > +    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
> > > +
> > > +    return ret < 0 ? -errno : 0;
> > > +}
> >
> > I don't get why this needs to be moved to net specific code.
> >
>
> It was already in net, this code just extracted it in its own function.

Ok, there's similar function that in vhost-vdpa.c:

static void vhost_vdpa_get_iova_range(struct vhost_vdpa *v)
{
    int ret = vhost_vdpa_call(v->dev, VHOST_VDPA_GET_IOVA_RANGE,
                              &v->iova_range);
    if (ret != 0) {
        v->iova_range.first = 0;
        v->iova_range.last = UINT64_MAX;
    }

    trace_vhost_vdpa_get_iova_range(v->dev, v->iova_range.first,
                                    v->iova_range.last);
}

I think we can reuse that.

Thanks

>
> It's done in net because iova_tree must be the same for all queuepair
> vhost, so we need to allocate before them.
>
> Thanks!
>
> > Thanks
> >
> > > +
> > > +static VhostIOVATree *vhost_vdpa_svq_allocate_iova_tree(int vdpa_device_fd)
> > > +{
> > > +    struct vhost_vdpa_iova_range iova_range;
> > > +
> > > +    vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
> > > +    return vhost_iova_tree_new(iova_range.first, iova_range.last);
> > > +}
> > > +
> > >  static void vhost_vdpa_cvq_unmap_buf(struct vhost_vdpa *v, void *addr)
> > >  {
> > >      VhostIOVATree *tree = v->iova_tree;
> > > @@ -587,14 +603,6 @@ static NetClientState *net_vhost_vdpa_init(NetClientState *peer,
> > >      return nc;
> > >  }
> > >
> > > -static int vhost_vdpa_get_iova_range(int fd,
> > > -                                     struct vhost_vdpa_iova_range *iova_range)
> > > -{
> > > -    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
> > > -
> > > -    return ret < 0 ? -errno : 0;
> > > -}
> > > -
> > >  static int vhost_vdpa_get_features(int fd, uint64_t *features, Error **errp)
> > >  {
> > >      int ret = ioctl(fd, VHOST_GET_FEATURES, features);
> > > @@ -690,14 +698,11 @@ int net_init_vhost_vdpa(const Netdev *netdev, const char *name,
> > >      }
> > >
> > >      if (opts->x_svq) {
> > > -        struct vhost_vdpa_iova_range iova_range;
> > > -
> > >          if (!vhost_vdpa_net_valid_svq_features(features, errp)) {
> > >              goto err_svq;
> > >          }
> > >
> > > -        vhost_vdpa_get_iova_range(vdpa_device_fd, &iova_range);
> > > -        iova_tree = vhost_iova_tree_new(iova_range.first, iova_range.last);
> > > +        iova_tree = vhost_vdpa_svq_allocate_iova_tree(vdpa_device_fd);
> > >      }
> > >
> > >      ncs = g_malloc0(sizeof(*ncs) * queue_pairs);
> > > --
> > > 2.31.1
> > >
> >
>

Re: [PATCH for 8.0 v8 06/12] vdpa: extract vhost_vdpa_svq_allocate_iova_tree

[Eugenio Perez Martin]

On Thu, Dec 1, 2022 at 9:45 AM Jason Wang <jasowang@redhat.com> wrote:
>
> On Wed, Nov 30, 2022 at 3:40 PM Eugenio Perez Martin
> <eperezma@redhat.com> wrote:
> >
> > On Wed, Nov 30, 2022 at 7:43 AM Jason Wang <jasowang@redhat.com> wrote:
> > >
> > > On Thu, Nov 24, 2022 at 11:52 PM Eugenio Pérez <eperezma@redhat.com> wrote:
> > > >
> > > > It can be allocated either if all virtqueues must be shadowed or if
> > > > vdpa-net detects it can shadow only cvq.
> > > >
> > > > Extract in its own function so we can reuse it.
> > > >
> > > > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > > > ---
> > > >  net/vhost-vdpa.c | 29 +++++++++++++++++------------
> > > >  1 file changed, 17 insertions(+), 12 deletions(-)
> > > >
> > > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> > > > index 88e0eec5fa..9ee3bc4cd3 100644
> > > > --- a/net/vhost-vdpa.c
> > > > +++ b/net/vhost-vdpa.c
> > > > @@ -240,6 +240,22 @@ static NetClientInfo net_vhost_vdpa_info = {
> > > >          .check_peer_type = vhost_vdpa_check_peer_type,
> > > >  };
> > > >
> > > > +static int vhost_vdpa_get_iova_range(int fd,
> > > > +                                     struct vhost_vdpa_iova_range *iova_range)
> > > > +{
> > > > +    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
> > > > +
> > > > +    return ret < 0 ? -errno : 0;
> > > > +}
> > >
> > > I don't get why this needs to be moved to net specific code.
> > >
> >
> > It was already in net, this code just extracted it in its own function.
>
> Ok, there's similar function that in vhost-vdpa.c:
>
> static void vhost_vdpa_get_iova_range(struct vhost_vdpa *v)
> {
>     int ret = vhost_vdpa_call(v->dev, VHOST_VDPA_GET_IOVA_RANGE,
>                               &v->iova_range);
>     if (ret != 0) {
>         v->iova_range.first = 0;
>         v->iova_range.last = UINT64_MAX;
>     }
>
>     trace_vhost_vdpa_get_iova_range(v->dev, v->iova_range.first,
>                                     v->iova_range.last);
> }
>
> I think we can reuse that.
>

That's right, but I'd do the reverse: I would store iova_min, iova_max
in VhostVDPAState and would set it to vhost_vdpa at
net_vhost_vdpa_init. That way, we only have one ioctl call at the
beginning instead of having (#vq pairs + cvq) calls each time the
device starts. I can send it in a new change if you see it ok.

There are a few functions like that we can reuse in net/. To get the
features and the backend features are two other examples. Even if we
don't cache them since device initialization mandates the read, we
could reduce code duplication that way.

However, they use vhost_dev or vhost_vdpa instead of directly the file
descriptor. Not a big deal but it's an extra step.

What do you think?

Thanks!

Re: [PATCH for 8.0 v8 06/12] vdpa: extract vhost_vdpa_svq_allocate_iova_tree

[Jason Wang]

On Thu, Dec 1, 2022 at 5:50 PM Eugenio Perez Martin <eperezma@redhat.com> wrote:
>
> On Thu, Dec 1, 2022 at 9:45 AM Jason Wang <jasowang@redhat.com> wrote:
> >
> > On Wed, Nov 30, 2022 at 3:40 PM Eugenio Perez Martin
> > <eperezma@redhat.com> wrote:
> > >
> > > On Wed, Nov 30, 2022 at 7:43 AM Jason Wang <jasowang@redhat.com> wrote:
> > > >
> > > > On Thu, Nov 24, 2022 at 11:52 PM Eugenio Pérez <eperezma@redhat.com> wrote:
> > > > >
> > > > > It can be allocated either if all virtqueues must be shadowed or if
> > > > > vdpa-net detects it can shadow only cvq.
> > > > >
> > > > > Extract in its own function so we can reuse it.
> > > > >
> > > > > Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> > > > > ---
> > > > >  net/vhost-vdpa.c | 29 +++++++++++++++++------------
> > > > >  1 file changed, 17 insertions(+), 12 deletions(-)
> > > > >
> > > > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
> > > > > index 88e0eec5fa..9ee3bc4cd3 100644
> > > > > --- a/net/vhost-vdpa.c
> > > > > +++ b/net/vhost-vdpa.c
> > > > > @@ -240,6 +240,22 @@ static NetClientInfo net_vhost_vdpa_info = {
> > > > >          .check_peer_type = vhost_vdpa_check_peer_type,
> > > > >  };
> > > > >
> > > > > +static int vhost_vdpa_get_iova_range(int fd,
> > > > > +                                     struct vhost_vdpa_iova_range *iova_range)
> > > > > +{
> > > > > +    int ret = ioctl(fd, VHOST_VDPA_GET_IOVA_RANGE, iova_range);
> > > > > +
> > > > > +    return ret < 0 ? -errno : 0;
> > > > > +}
> > > >
> > > > I don't get why this needs to be moved to net specific code.
> > > >
> > >
> > > It was already in net, this code just extracted it in its own function.
> >
> > Ok, there's similar function that in vhost-vdpa.c:
> >
> > static void vhost_vdpa_get_iova_range(struct vhost_vdpa *v)
> > {
> >     int ret = vhost_vdpa_call(v->dev, VHOST_VDPA_GET_IOVA_RANGE,
> >                               &v->iova_range);
> >     if (ret != 0) {
> >         v->iova_range.first = 0;
> >         v->iova_range.last = UINT64_MAX;
> >     }
> >
> >     trace_vhost_vdpa_get_iova_range(v->dev, v->iova_range.first,
> >                                     v->iova_range.last);
> > }
> >
> > I think we can reuse that.
> >
>
> That's right, but I'd do the reverse: I would store iova_min, iova_max
> in VhostVDPAState and would set it to vhost_vdpa at
> net_vhost_vdpa_init. That way, we only have one ioctl call at the
> beginning instead of having (#vq pairs + cvq) calls each time the
> device starts. I can send it in a new change if you see it ok.
>
> There are a few functions like that we can reuse in net/. To get the
> features and the backend features are two other examples. Even if we
> don't cache them since device initialization mandates the read, we
> could reduce code duplication that way.
>
> However, they use vhost_dev or vhost_vdpa instead of directly the file
> descriptor. Not a big deal but it's an extra step.
>
> What do you think?

I'm fine with this.

Thanks

>
> Thanks!
>