[PATCH RFC 05/15] vhost-user: add memory_isolation to VhostUserState

Connor Kite <[email protected]> Thu, 23 Jul 2026 15:30:04 -0700
Newsgroups dev.linux.lists.virtio-fs,org.nongnu.qemu-devel
Message-ID <[email protected]>
Add a memory_isolation bool to the VhostUserState struct. This
bool is set within vhost_user_init(), which takes a
memory_isolation bool as an argument.

Refactor all call locations of vhost_user_init to include the new
argument.

Signed-off-by: Connor Kite <[email protected]>
---
 backends/cryptodev-vhost-user.c     |  2 +-
 backends/vhost-user.c               |  4 ++--
 hw/block/vhost-user-blk.c           |  3 ++-
 hw/display/vhost-user-gpu.c         |  3 ++-
 hw/scsi/vhost-user-scsi.c           |  3 ++-
 hw/virtio/vhost-stub.c              |  3 ++-
 hw/virtio/vhost-user-base.c         |  3 ++-
 hw/virtio/vhost-user-fs.c           |  3 ++-
 hw/virtio/vhost-user-scmi.c         |  3 ++-
 hw/virtio/vhost-user-vsock.c        |  3 ++-
 hw/virtio/vhost-user.c              |  5 ++++-
 include/hw/virtio/vhost-user.h      |  6 +++++-
 include/system/vhost-user-backend.h |  3 ++-
 net/passt.c                         | 13 ++++++++-----
 net/vhost-user.c                    |  9 +++++----
 15 files changed, 43 insertions(+), 23 deletions(-)

diff --git a/backends/cryptodev-vhost-user.c b/backends/cryptodev-vhost-user.c
index e0547c5d40..328d7fbdfe 100644
--- a/backends/cryptodev-vhost-user.c
+++ b/backends/cryptodev-vhost-user.c
@@ -214,7 +214,7 @@ static void cryptodev_vhost_user_init(
         }
     }
 
-    if (!vhost_user_init(&s->vhost_user, &s->chr, errp)) {
+    if (!vhost_user_init(&s->vhost_user, &s->chr, s->memory_isolation, errp)) {
         return;
     }
 
diff --git a/backends/vhost-user.c b/backends/vhost-user.c
index 380d825023..470eba1775 100644
--- a/backends/vhost-user.c
+++ b/backends/vhost-user.c
@@ -22,13 +22,13 @@
 
 int
 vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev,
-                            unsigned nvqs, Error **errp)
+                            unsigned nvqs, bool memory_isolation, Error **errp)
 {
     int ret;
 
     assert(!b->vdev && vdev);
 
-    if (!vhost_user_init(&b->vhost_user, &b->chr, errp)) {
+    if (!vhost_user_init(&b->vhost_user, &b->chr, memory_isolation, errp)) {
         return -1;
     }
 
diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
index 9830dc6c35..5c1a19eb50 100644
--- a/hw/block/vhost-user-blk.c
+++ b/hw/block/vhost-user-blk.c
@@ -505,7 +505,8 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (!vhost_user_init(&s->vhost_user, &s->chardev, errp)) {
+    if (!vhost_user_init(&s->vhost_user, &s->chardev,
+                         s->memory_isolation, errp)) {
         return;
     }
 
diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c
index 6d0ede672a..b44c989f58 100644
--- a/hw/display/vhost-user-gpu.c
+++ b/hw/display/vhost-user-gpu.c
@@ -625,7 +625,8 @@ vhost_user_gpu_device_realize(DeviceState *qdev, Error **errp)
     VirtIODevice *vdev = VIRTIO_DEVICE(g);
 
     vhost_dev_set_config_notifier(&g->vhost->dev, &config_ops);
-    if (vhost_user_backend_dev_init(g->vhost, vdev, 2, errp) < 0) {
+    if (vhost_user_backend_dev_init(g->vhost, vdev, 2, g->memory_isolation,
+                                    errp) < 0) {
         return;
     }
 
diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
index c1a0393220..5a19182f2b 100644
--- a/hw/scsi/vhost-user-scsi.c
+++ b/hw/scsi/vhost-user-scsi.c
@@ -276,7 +276,8 @@ static void vhost_user_scsi_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (!vhost_user_init(&s->vhost_user, &vs->conf.chardev, errp)) {
+    if (!vhost_user_init(&s->vhost_user, &vs->conf.chardev,
+                         vs->conf.memory_isolation, errp)) {
         goto free_virtio;
     }
 
diff --git a/hw/virtio/vhost-stub.c b/hw/virtio/vhost-stub.c
index 7321dc9210..d1e1075a31 100644
--- a/hw/virtio/vhost-stub.c
+++ b/hw/virtio/vhost-stub.c
@@ -12,7 +12,8 @@ unsigned int vhost_get_free_memslots(void)
     return UINT_MAX;
 }
 
-bool vhost_user_init(VhostUserState *user, CharFrontend *chr, Error **errp)
+bool vhost_user_init(VhostUserState *user, CharFrontend *chr,
+                     bool memory_isolation, Error **errp)
 {
     return false;
 }
diff --git a/hw/virtio/vhost-user-base.c b/hw/virtio/vhost-user-base.c
index d2a74a2860..11864a3f08 100644
--- a/hw/virtio/vhost-user-base.c
+++ b/hw/virtio/vhost-user-base.c
@@ -317,7 +317,8 @@ static void vub_device_realize(DeviceState *dev, Error **errp)
         vub->vhost_user.supports_config = true;
     }
 
-    if (!vhost_user_init(&vub->vhost_user, &vub->chardev, errp)) {
+    if (!vhost_user_init(&vub->vhost_user, &vub->chardev,
+                         vub->memory_isolation, errp)) {
         return;
     }
 
diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c
index 3d980d814b..07ff2a35e0 100644
--- a/hw/virtio/vhost-user-fs.c
+++ b/hw/virtio/vhost-user-fs.c
@@ -238,7 +238,8 @@ static void vuf_device_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (!vhost_user_init(&fs->vhost_user, &fs->conf.chardev, errp)) {
+    if (!vhost_user_init(&fs->vhost_user, &fs->conf.chardev,
+                         fs->conf.memory_isolation, errp)) {
         return;
     }
 
diff --git a/hw/virtio/vhost-user-scmi.c b/hw/virtio/vhost-user-scmi.c
index d514d89392..2c1dbb723e 100644
--- a/hw/virtio/vhost-user-scmi.c
+++ b/hw/virtio/vhost-user-scmi.c
@@ -244,7 +244,8 @@ static void vu_scmi_device_realize(DeviceState *dev, Error **errp)
 
     vdev->host_features |= (1ULL << VIRTIO_SCMI_F_P2A_CHANNELS);
 
-    if (!vhost_user_init(&scmi->vhost_user, &scmi->chardev, errp)) {
+    if (!vhost_user_init(&scmi->vhost_user, &scmi->chardev,
+                         scmi->memory_isolation, errp)) {
         return;
     }
 
diff --git a/hw/virtio/vhost-user-vsock.c b/hw/virtio/vhost-user-vsock.c
index 89aa789e22..33ab3b69e6 100644
--- a/hw/virtio/vhost-user-vsock.c
+++ b/hw/virtio/vhost-user-vsock.c
@@ -106,7 +106,8 @@ static void vuv_device_realize(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (!vhost_user_init(&vsock->vhost_user, &vsock->conf.chardev, errp)) {
+    if (!vhost_user_init(&vsock->vhost_user, &vsock->conf.chardev,
+                         vsock->conf.memory_isolation, errp)) {
         return;
     }
 
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 517cc4ca71..f296b63fb9 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -3118,13 +3118,16 @@ static void vhost_user_state_destroy(gpointer data)
     vhost_user_host_notifier_remove(n, NULL, true);
 }
 
-bool vhost_user_init(VhostUserState *user, CharFrontend *chr, Error **errp)
+bool vhost_user_init(VhostUserState *user, CharFrontend *chr,
+                     bool memory_isolation,
+                     Error **errp)
 {
     if (user->chr) {
         error_setg(errp, "Cannot initialize vhost-user state");
         return false;
     }
     user->chr = chr;
+    user->memory_isolation = memory_isolation;
     user->memory_slots = 0;
     user->notifiers = g_ptr_array_new_full(VIRTIO_QUEUE_MAX / 4,
                                            &vhost_user_state_destroy);
diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h
index 06c360af18..72b5787efe 100644
--- a/include/hw/virtio/vhost-user.h
+++ b/include/hw/virtio/vhost-user.h
@@ -66,6 +66,7 @@ typedef struct VhostUserHostNotifier {
  * @chr: the character backend for the socket
  * @notifiers: GPtrArray of @VhostUserHostnotifier
  * @memory_slots:
+ * @memory_isolation: determines whether data is shared or copied
  */
 typedef struct VhostUserState {
     CharFrontend *chr;
@@ -73,12 +74,14 @@ typedef struct VhostUserState {
     int memory_slots;
     bool supports_config;
     bool supports_inflight_migration;
+    bool memory_isolation;
 } VhostUserState;
 
 /**
  * vhost_user_init() - initialise shared vhost_user state
  * @user: allocated area for storing shared state
  * @chr: the chardev for the vhost socket
+ * @memory_isolation: disables device access to guest memory
  * @errp: error handle
  *
  * User can either directly g_new() space for the state or embed
@@ -87,7 +90,8 @@ typedef struct VhostUserState {
  *
  * Return: true on success, false on error while setting errp.
  */
-bool vhost_user_init(VhostUserState *user, CharFrontend *chr, Error **errp);
+bool vhost_user_init(VhostUserState *user, CharFrontend *chr,
+                     bool memory_isolation, Error **errp);
 
 /**
  * vhost_user_cleanup() - cleanup state
diff --git a/include/system/vhost-user-backend.h b/include/system/vhost-user-backend.h
index 3184c8e799..c23f689182 100644
--- a/include/system/vhost-user-backend.h
+++ b/include/system/vhost-user-backend.h
@@ -41,7 +41,8 @@ struct VhostUserBackend {
 };
 
 int vhost_user_backend_dev_init(VhostUserBackend *b, VirtIODevice *vdev,
-                                unsigned nvqs, Error **errp);
+                                unsigned nvqs, bool memory_isolation,
+                                Error **errp);
 void vhost_user_backend_start(VhostUserBackend *b);
 int vhost_user_backend_stop(VhostUserBackend *b);
 
diff --git a/net/passt.c b/net/passt.c
index ce80186883..a3021f37ef 100644
--- a/net/passt.c
+++ b/net/passt.c
@@ -433,7 +433,9 @@ static void passt_vhost_user_event(void *opaque, QEMUChrEvent event)
     }
 }
 
-static int net_passt_vhost_user_init(NetPasstState *s, Error **errp)
+static int net_passt_vhost_user_init(NetPasstState *s,
+                                     bool memory_isolation,
+                                     Error **errp)
 {
     Chardev *chr;
     int sv[2];
@@ -457,7 +459,8 @@ static int net_passt_vhost_user_init(NetPasstState *s, Error **errp)
 
     s->vhost_user = g_new0(struct VhostUserState, 1);
     if (!qemu_chr_fe_init(&s->vhost_chr, chr, errp) ||
-        !vhost_user_init(s->vhost_user, &s->vhost_chr, errp)) {
+        !vhost_user_init(s->vhost_user, &s->vhost_chr, memory_isolation,
+                         errp)) {
         goto err;
     }
 
@@ -735,14 +738,14 @@ int net_init_passt(const Netdev *netdev, const char *name,
     s->pidfile = pidfile;
 
     if (netdev->u.passt.has_vhost_user && netdev->u.passt.vhost_user) {
-        bool memory_isolation G_GNUC_UNUSED = false;
+        bool memory_isolation = false;
 
         if (netdev->u.passt.has_memory_isolation &&
-           netdev->u.passt.memory_isolation) {
+            netdev->u.passt.memory_isolation) {
             memory_isolation = true;
         }
 
-        if (net_passt_vhost_user_init(s, errp) == -1) {
+        if (net_passt_vhost_user_init(s, memory_isolation, errp) == -1) {
             qemu_del_net_client(nc);
             return -1;
         }
diff --git a/net/vhost-user.c b/net/vhost-user.c
index 8fa303f901..722ab20228 100644
--- a/net/vhost-user.c
+++ b/net/vhost-user.c
@@ -370,7 +370,7 @@ static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
 
 static int net_vhost_user_init(NetClientState *peer, const char *device,
                                const char *name, Chardev *chr,
-                               int queues)
+                               int queues, bool memory_isolation)
 {
     Error *err = NULL;
     NetClientState *nc, *nc0 = NULL;
@@ -390,7 +390,7 @@ static int net_vhost_user_init(NetClientState *peer, const char *device,
             nc0 = nc;
             s = DO_UPCAST(NetVhostUserState, nc, nc);
             if (!qemu_chr_fe_init(&s->chr, chr, &err) ||
-                !vhost_user_init(user, &s->chr, &err)) {
+                !vhost_user_init(user, &s->chr, memory_isolation, &err)) {
                 error_report_err(err);
                 goto err;
             }
@@ -459,7 +459,7 @@ int net_init_vhost_user(const Netdev *netdev, const char *name,
     int queues;
     const NetdevVhostUserOptions *vhost_user_opts;
     Chardev *chr;
-    bool memory_isolation G_GNUC_UNUSED;
+    bool memory_isolation;
 
     assert(netdev->type == NET_CLIENT_DRIVER_VHOST_USER);
     vhost_user_opts = &netdev->u.vhost_user;
@@ -480,5 +480,6 @@ int net_init_vhost_user(const Netdev *netdev, const char *name,
     memory_isolation = vhost_user_opts->has_memory_isolation ?
                        vhost_user_opts->memory_isolation : false;
 
-    return net_vhost_user_init(peer, "vhost_user", name, chr, queues);
+    return net_vhost_user_init(peer, "vhost_user", name, chr, queues,
+                               memory_isolation);
 }

-- 
2.43.0