diff --git a/block/export/meson.build b/block/export/meson.build
index 19526435d8..135b356775 100644
--- a/block/export/meson.build
+++ b/block/export/meson.build
@@ -1,2 +1,5 @@
 blockdev_ss.add(files('export.c'))
-blockdev_ss.add(when: 'CONFIG_VHOST_USER_BLK_SERVER', if_true: files('vhost-user-blk-server.c'))
+
+if have_vhost_user_blk_server
+    blockdev_ss.add(files('vhost-user-blk-server.c'))
+endif
diff --git a/configure b/configure
index 4cef321d9d..3fbc2a0c68 100755
--- a/configure
+++ b/configure
@@ -328,8 +328,8 @@ vhost_net=""
 vhost_crypto=""
 vhost_scsi=""
 vhost_vsock=""
-vhost_user=""
-vhost_user_blk_server=""
+vhost_user="no"
+vhost_user_blk_server="auto"
 vhost_user_fs=""
 kvm="auto"
 hax="auto"
@@ -718,7 +718,6 @@ fi
 case $targetos in
 MINGW32*)
   mingw32="yes"
-  vhost_user="no"
   audio_possible_drivers="dsound sdl"
   if check_include dsound.h; then
     audio_drv_list="dsound"
@@ -797,6 +796,7 @@ Linux)
   audio_possible_drivers="oss alsa sdl pa"
   linux="yes"
   linux_user="yes"
+  vhost_user="yes"
 ;;
 esac
 
@@ -1247,9 +1247,9 @@ for opt do
   ;;
   --enable-vhost-vsock) vhost_vsock="yes"
   ;;
-  --disable-vhost-user-blk-server) vhost_user_blk_server="no"
+  --disable-vhost-user-blk-server) vhost_user_blk_server="disabled"
   ;;
-  --enable-vhost-user-blk-server) vhost_user_blk_server="yes"
+  --enable-vhost-user-blk-server) vhost_user_blk_server="enabled"
   ;;
   --disable-vhost-user-fs) vhost_user_fs="no"
   ;;
@@ -2341,9 +2341,8 @@ fi
 # vhost interdependencies and host support
 
 # vhost backends
-test "$vhost_user" = "" && vhost_user=yes
-if test "$vhost_user" = "yes" && test "$mingw32" = "yes"; then
-  error_exit "vhost-user isn't available on win32"
+if test "$vhost_user" = "yes" && test "$linux" != "yes"; then
+  error_exit "vhost-user is only available on Linux"
 fi
 test "$vhost_vdpa" = "" && vhost_vdpa=$linux
 if test "$vhost_vdpa" = "yes" && test "$linux" != "yes"; then
@@ -2390,12 +2389,6 @@ if test "$vhost_net" = ""; then
   test "$vhost_kernel" = "yes" && vhost_net=yes
 fi
 
-# libvhost-user is Linux-only
-test "$vhost_user_blk_server" = "" && vhost_user_blk_server=$linux
-if test "$vhost_user_blk_server" = "yes" && test "$linux" = "no"; then
-  error_exit "--enable-vhost-user-blk-server is only available on Linux"
-fi
-
 ##########################################
 # pkg-config probe
 
@@ -6289,9 +6282,6 @@ fi
 if test "$vhost_vdpa" = "yes" ; then
   echo "CONFIG_VHOST_VDPA=y" >> $config_host_mak
 fi
-if test "$vhost_user_blk_server" = "yes" ; then
-  echo "CONFIG_VHOST_USER_BLK_SERVER=y" >> $config_host_mak
-fi
 if test "$vhost_user_fs" = "yes" ; then
   echo "CONFIG_VHOST_USER_FS=y" >> $config_host_mak
 fi
@@ -7012,6 +7002,7 @@ NINJA=$ninja $meson setup \
         -Dcapstone=$capstone -Dslirp=$slirp -Dfdt=$fdt \
         -Diconv=$iconv -Dcurses=$curses -Dlibudev=$libudev\
         -Ddocs=$docs -Dsphinx_build=$sphinx_build -Dinstall_blobs=$blobs \
+        -Dvhost_user_blk_server=$vhost_user_blk_server \
         $cross_arg \
         "$PWD" "$source_path"
 
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index bfec8a881a..5c73ffdd6b 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -701,7 +701,7 @@ vu_add_mem_reg(VuDev *dev, VhostUserMsg *vmsg) {
         return false;
     }
 
-    DPRINT("Adding region: %d\n", dev->nregions);
+    DPRINT("Adding region: %u\n", dev->nregions);
     DPRINT("    guest_phys_addr: 0x%016"PRIx64"\n",
            msg_region->guest_phys_addr);
     DPRINT("    memory_size:     0x%016"PRIx64"\n",
@@ -848,7 +848,7 @@ vu_set_mem_table_exec_postcopy(VuDev *dev, VhostUserMsg *vmsg)
     VhostUserMemory m = vmsg->payload.memory, *memory = &m;
     dev->nregions = memory->nregions;
 
-    DPRINT("Nregions: %d\n", memory->nregions);
+    DPRINT("Nregions: %u\n", memory->nregions);
     for (i = 0; i < dev->nregions; i++) {
         void *mmap_addr;
         VhostUserMemoryRegion *msg_region = &memory->regions[i];
@@ -938,7 +938,7 @@ vu_set_mem_table_exec(VuDev *dev, VhostUserMsg *vmsg)
         return vu_set_mem_table_exec_postcopy(dev, vmsg);
     }
 
-    DPRINT("Nregions: %d\n", memory->nregions);
+    DPRINT("Nregions: %u\n", memory->nregions);
     for (i = 0; i < dev->nregions; i++) {
         void *mmap_addr;
         VhostUserMemoryRegion *msg_region = &memory->regions[i];
@@ -1049,8 +1049,8 @@ vu_set_vring_num_exec(VuDev *dev, VhostUserMsg *vmsg)
     unsigned int index = vmsg->payload.state.index;
     unsigned int num = vmsg->payload.state.num;
 
-    DPRINT("State.index: %d\n", index);
-    DPRINT("State.num:   %d\n", num);
+    DPRINT("State.index: %u\n", index);
+    DPRINT("State.num:   %u\n", num);
     dev->vq[index].vring.num = num;
 
     return false;
@@ -1105,8 +1105,8 @@ vu_set_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
     unsigned int index = vmsg->payload.state.index;
     unsigned int num = vmsg->payload.state.num;
 
-    DPRINT("State.index: %d\n", index);
-    DPRINT("State.num:   %d\n", num);
+    DPRINT("State.index: %u\n", index);
+    DPRINT("State.num:   %u\n", num);
     dev->vq[index].shadow_avail_idx = dev->vq[index].last_avail_idx = num;
 
     return false;
@@ -1117,7 +1117,7 @@ vu_get_vring_base_exec(VuDev *dev, VhostUserMsg *vmsg)
 {
     unsigned int index = vmsg->payload.state.index;
 
-    DPRINT("State.index: %d\n", index);
+    DPRINT("State.index: %u\n", index);
     vmsg->payload.state.num = dev->vq[index].last_avail_idx;
     vmsg->size = sizeof(vmsg->payload.state);
 
@@ -1478,8 +1478,8 @@ vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
     unsigned int index = vmsg->payload.state.index;
     unsigned int enable = vmsg->payload.state.num;
 
-    DPRINT("State.index: %d\n", index);
-    DPRINT("State.enable:   %d\n", enable);
+    DPRINT("State.index: %u\n", index);
+    DPRINT("State.enable:   %u\n", enable);
 
     if (index >= dev->max_queues) {
         vu_panic(dev, "Invalid vring_enable index: %u", index);
@@ -1728,7 +1728,7 @@ vu_handle_vring_kick(VuDev *dev, VhostUserMsg *vmsg)
         return false;
     }
 
-    DPRINT("Got kick message: handler:%p idx:%d\n",
+    DPRINT("Got kick message: handler:%p idx:%u\n",
            dev->vq[index].handler, index);
 
     if (!dev->vq[index].started) {
@@ -1772,7 +1772,7 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
     DPRINT("Request: %s (%d)\n", vu_request_to_string(vmsg->request),
            vmsg->request);
     DPRINT("Flags:   0x%x\n", vmsg->flags);
-    DPRINT("Size:    %d\n", vmsg->size);
+    DPRINT("Size:    %u\n", vmsg->size);
 
     if (vmsg->fd_num) {
         int i;
diff --git a/contrib/libvhost-user/libvhost-user.h b/contrib/libvhost-user/libvhost-user.h
index a1539dbb69..7d47f1364a 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -136,7 +136,7 @@ typedef struct VhostUserMemory {
 } VhostUserMemory;
 
 typedef struct VhostUserMemRegMsg {
-    uint32_t padding;
+    uint64_t padding;
     VhostUserMemoryRegion region;
 } VhostUserMemRegMsg;
 
diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c
index caad88637e..dc981bf945 100644
--- a/contrib/vhost-user-blk/vhost-user-blk.c
+++ b/contrib/vhost-user-blk/vhost-user-blk.c
@@ -476,7 +476,7 @@ static int unix_sock_new(char *unix_fn)
     assert(unix_fn);
 
     sock = socket(AF_UNIX, SOCK_STREAM, 0);
-    if (sock <= 0) {
+    if (sock < 0) {
         perror("socket");
         return -1;
     }
diff --git a/contrib/vhost-user-scsi/vhost-user-scsi.c b/contrib/vhost-user-scsi/vhost-user-scsi.c
index 3c912384e9..0f9ba4b2a2 100644
--- a/contrib/vhost-user-scsi/vhost-user-scsi.c
+++ b/contrib/vhost-user-scsi/vhost-user-scsi.c
@@ -320,7 +320,7 @@ static int unix_sock_new(char *unix_fn)
     assert(unix_fn);
 
     sock = socket(AF_UNIX, SOCK_STREAM, 0);
-    if (sock <= 0) {
+    if (sock < 0) {
         perror("socket");
         return -1;
     }
diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
index 988f154144..6d4025ba6a 100644
--- a/docs/interop/vhost-user.rst
+++ b/docs/interop/vhost-user.rst
@@ -131,6 +131,23 @@ A region is:
 
 :mmap offset: 64-bit offset where region starts in the mapped memory
 
+Single memory region description
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
++---------+---------------+------+--------------+-------------+
+| padding | guest address | size | user address | mmap offset |
++---------+---------------+------+--------------+-------------+
+
+:padding: 64-bit
+
+:guest address: a 64-bit guest address of the region
+
+:size: a 64-bit size
+
+:user address: a 64-bit user address
+
+:mmap offset: 64-bit offset where region starts in the mapped memory
+
 Log description
 ^^^^^^^^^^^^^^^
 
@@ -1281,7 +1298,7 @@ Master message types
 ``VHOST_USER_ADD_MEM_REG``
   :id: 37
   :equivalent ioctl: N/A
-  :slave payload: memory region
+  :slave payload: single memory region description
 
   When the ``VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS`` protocol
   feature has been successfully negotiated, this message is submitted
@@ -1296,7 +1313,7 @@ Master message types
 ``VHOST_USER_REM_MEM_REG``
   :id: 38
   :equivalent ioctl: N/A
-  :slave payload: memory region
+  :slave payload: single memory region description
 
   When the ``VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS`` protocol
   feature has been successfully negotiated, this message is submitted
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 9c5b4f7fbc..2fdd5daf74 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -149,7 +149,7 @@ typedef struct VhostUserMemory {
 } VhostUserMemory;
 
 typedef struct VhostUserMemRegMsg {
-    uint32_t padding;
+    uint64_t padding;
     VhostUserMemoryRegion region;
 } VhostUserMemRegMsg;
 
@@ -800,8 +800,7 @@ static int vhost_user_add_remove_regions(struct vhost_dev *dev,
     uint64_t shadow_pcb[VHOST_USER_MAX_RAM_SLOTS] = {};
     int nr_add_reg, nr_rem_reg;
 
-    msg->hdr.size = sizeof(msg->payload.mem_reg.padding) +
-        sizeof(VhostUserMemoryRegion);
+    msg->hdr.size = sizeof(msg->payload.mem_reg);
 
     /* Find the regions which need to be removed or added. */
     scrub_shadow_regions(dev, add_reg, &nr_add_reg, rem_reg, &nr_rem_reg,
diff --git a/meson.build b/meson.build
index 132bc49782..10132eeae0 100644
--- a/meson.build
+++ b/meson.build
@@ -756,6 +756,19 @@ statx_test = '''
 
 has_statx = cc.links(statx_test)
 
+have_vhost_user_blk_server = (targetos == 'linux' and
+    'CONFIG_VHOST_USER' in config_host)
+
+if get_option('vhost_user_blk_server').enabled()
+    if targetos != 'linux'
+        error('vhost_user_blk_server requires linux')
+    elif 'CONFIG_VHOST_USER' not in config_host
+        error('vhost_user_blk_server requires vhost-user support')
+    endif
+elif get_option('vhost_user_blk_server').disabled() or not have_system
+    have_vhost_user_blk_server = false
+endif
+
 #################
 # config-host.h #
 #################
@@ -780,6 +793,7 @@ config_host_data.set('CONFIG_MPATH_NEW_API', mpathpersist_new_api)
 config_host_data.set('CONFIG_CURSES', curses.found())
 config_host_data.set('CONFIG_SDL', sdl.found())
 config_host_data.set('CONFIG_SDL_IMAGE', sdl_image.found())
+config_host_data.set('CONFIG_VHOST_USER_BLK_SERVER', have_vhost_user_blk_server)
 config_host_data.set('CONFIG_VNC', vnc.found())
 config_host_data.set('CONFIG_VNC_JPEG', jpeg.found())
 config_host_data.set('CONFIG_VNC_PNG', png.found())
@@ -2109,6 +2123,7 @@ summary_info += {'vhost-crypto support': config_host.has_key('CONFIG_VHOST_CRYPT
 summary_info += {'vhost-scsi support': config_host.has_key('CONFIG_VHOST_SCSI')}
 summary_info += {'vhost-vsock support': config_host.has_key('CONFIG_VHOST_VSOCK')}
 summary_info += {'vhost-user support': config_host.has_key('CONFIG_VHOST_USER')}
+summary_info += {'vhost-user-blk server support': have_vhost_user_blk_server}
 summary_info += {'vhost-user-fs support': config_host.has_key('CONFIG_VHOST_USER_FS')}
 summary_info += {'vhost-vdpa support': config_host.has_key('CONFIG_VHOST_VDPA')}
 summary_info += {'Trace backends':    config_host['TRACE_BACKENDS']}
diff --git a/meson_options.txt b/meson_options.txt
index b4f1801875..f6f64785fe 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -64,6 +64,8 @@ option('xkbcommon', type : 'feature', value : 'auto',
        description: 'xkbcommon support')
 option('virtiofsd', type: 'feature', value: 'auto',
        description: 'build virtiofs daemon (virtiofsd)')
+option('vhost_user_blk_server', type: 'feature', value: 'auto',
+       description: 'build vhost-user-blk server')
 
 option('capstone', type: 'combo', value: 'auto',
        choices: ['disabled', 'enabled', 'auto', 'system', 'internal'],