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

On 2026/07/24 7:30, Connor Kite wrote:
> 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);

The signature of the stub for !defined(CONFIG_VHOST_USER) is not 
updated, breaking builds.

Regards,
Akihiko Odaki

>   
>   /**
>    * 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);
>   }
>