Hi Stefano, Thanks!
I used xen-guest-image-minimal(simple console based image) as a guest with fbcon & fbdev enabled in kernel configurations but still the same error can't open the display. below are the outcome of "xenstore-ls": *root@raspberrypi4-64:~/guest1# xenstore-lstool = "" xenstored = ""local = "" domain = "" 0 = "" control = "" feature-poweroff = "1" feature-reboot = "1" domid = "0" name = "Domain-0" device-model = "" 0 = "" backends = "" console = "" vkbd = "" vfb = "" qnic = "" state = "running" 1 = "" backends = "" console = "" vkbd = "" vfb = "" qnic = "" state = "running" backend = "" vbd = "" 1 = "" 51712 = "" frontend = "/local/domain/1/device/vbd/51712" params = "/home/root/guest2/xen-guest-image-minimal-raspberrypi4-64.ext3" script = "/etc/xen/scripts/block" frontend-id = "1" online = "1" removable = "0" bootable = "1" state = "4" dev = "xvda" type = "phy" mode = "w" device-type = "disk" discard-enable = "1" feature-max-indirect-segments = "256" multi-queue-max-queues = "4" max-ring-page-order = "4" node = "/dev/loop0" physical-device = "7:0" physical-device-path = "/dev/loop0" hotplug-status = "connected" feature-flush-cache = "1" discard-granularity = "4096" discard-alignment = "0" discard-secure = "0" feature-discard = "1" feature-barrier = "1" feature-persistent = "1" sectors = "1794048" info = "0" sector-size = "512" physical-sector-size = "512" vfb = "" 1 = "" 0 = "" frontend = "/local/domain/1/device/vfb/0" frontend-id = "1" online = "1" state = "4" vnc = "1" vnclisten = "127.0.0.1" vncdisplay = "0" vncunused = "1" sdl = "0" opengl = "0" feature-resize = "1" hotplug-status = "connected" request-update = "1" vkbd = "" 1 = "" 0 = "" frontend = "/local/domain/1/device/vkbd/0" frontend-id = "1" online = "1" state = "4" feature-abs-pointer = "1" feature-raw-pointer = "1" hotplug-status = "connected" console = "" 1 = "" 0 = "" frontend = "/local/domain/1/console" frontend-id = "1" online = "1" state = "1" protocol = "vt100" vif = "" 1 = "" 0 = "" frontend = "/local/domain/1/device/vif/0" frontend-id = "1" online = "1" state = "4" script = "/etc/xen/scripts/vif-bridge" mac = "e4:5f:01:cd:7b:dd" bridge = "xenbr0" handle = "0" type = "vif" hotplug-status = "connected" feature-sg = "1" feature-gso-tcpv4 = "1" feature-gso-tcpv6 = "1" feature-ipv6-csum-offload = "1" feature-rx-copy = "1" feature-xdp-headroom = "1" feature-rx-flip = "0" feature-multicast-control = "1" feature-dynamic-multicast-control = "1" feature-split-event-channels = "1" multi-queue-max-queues = "4" feature-ctrl-ring = "1" 1 = "" vm = "/vm/d81ec5a9-5bf9-4f2b-89e8-0f60d6da948f" name = "guest2" cpu = "" 0 = "" availability = "online" 1 = "" availability = "online" memory = "" static-max = "2097152" target = "2097152" videoram = "0" device = "" suspend = "" event-channel = "" vbd = "" 51712 = "" backend = "/local/domain/0/backend/vbd/1/51712" backend-id = "0" state = "4" virtual-device = "51712" device-type = "disk" multi-queue-num-queues = "2" queue-0 = "" ring-ref = "8" event-channel = "4" queue-1 = "" ring-ref = "9" event-channel = "5" protocol = "arm-abi" feature-persistent = "1" vfb = "" 0 = "" backend = "/local/domain/0/backend/vfb/1/0" backend-id = "0" state = "4" page-ref = "275022" event-channel = "3" protocol = "arm-abi" feature-update = "1" vkbd = "" 0 = "" backend = "/local/domain/0/backend/vkbd/1/0" backend-id = "0" state = "4" request-abs-pointer = "1" page-ref = "275322" page-gref = "1284" event-channel = "10" vif = "" 0 = "" backend = "/local/domain/0/backend/vif/1/0" backend-id = "0" state = "4" handle = "0" mac = "e4:5f:01:cd:7b:dd" mtu = "1500" xdp-headroom = "0" multi-queue-num-queues = "2" queue-0 = "" tx-ring-ref = "1280" rx-ring-ref = "1281" event-channel-tx = "6" event-channel-rx = "7" queue-1 = "" tx-ring-ref = "1282" rx-ring-ref = "1283" event-channel-tx = "8" event-channel-rx = "9" request-rx-copy = "1" feature-rx-notify = "1" feature-sg = "1" feature-gso-tcpv4 = "1" feature-gso-tcpv6 = "1" feature-ipv6-csum-offload = "1" control = "" shutdown = "" feature-poweroff = "1" feature-reboot = "1" feature-suspend = "" sysrq = "" platform-feature-multiprocessor-suspend = "1" platform-feature-xs_reset_watches = "1" data = "" drivers = "" feature = "" attr = "" error = "" domid = "1" store = "" port = "1" ring-ref = "233473" console = "" backend = "/local/domain/0/backend/console/1/0" backend-id = "0" limit = "1048576" type = "xenconsoled" output = "pty" tty = "/dev/pts/1" port = "2" ring-ref = "233472" vnc-listen = "127.0.0.1" vnc-port = "5900" image = "" device-model-pid = "788"vm = "" d81ec5a9-5bf9-4f2b-89e8-0f60d6da948f = "" name = "guest2" uuid = "d81ec5a9-5bf9-4f2b-89e8-0f60d6da948f" start_time = "1520600274.27"libxl = "" 1 = "" device = "" vbd = "" 51712 = "" frontend = "/local/domain/1/device/vbd/51712" backend = "/local/domain/0/backend/vbd/1/51712" params = "/home/root/guest2/xen-guest-image-minimal-raspberrypi4-64.ext3" script = "/etc/xen/scripts/block" frontend-id = "1" online = "1" removable = "0" bootable = "1" state = "1" dev = "xvda" type = "phy" mode = "w" device-type = "disk" discard-enable = "1" vfb = "" 0 = "" frontend = "/local/domain/1/device/vfb/0" backend = "/local/domain/0/backend/vfb/1/0" frontend-id = "1" online = "1" state = "1" vnc = "1" vnclisten = "127.0.0.1" vncdisplay = "0" vncunused = "1" sdl = "0" opengl = "0" vkbd = "" 0 = "" frontend = "/local/domain/1/device/vkbd/0" backend = "/local/domain/0/backend/vkbd/1/0" frontend-id = "1" online = "1" state = "1" console = "" 0 = "" frontend = "/local/domain/1/console" backend = "/local/domain/0/backend/console/1/0" frontend-id = "1" online = "1" state = "1" protocol = "vt100" vif = "" 0 = "" frontend = "/local/domain/1/device/vif/0" backend = "/local/domain/0/backend/vif/1/0" frontend-id = "1" online = "1" state = "1" script = "/etc/xen/scripts/vif-bridge" mac = "e4:5f:01:cd:7b:dd" bridge = "xenbr0" handle = "0" type = "vif" hotplug-status = "" type = "pvh" dm-version = "qemu_xen"root@raspberrypi4-64:~/guest1#* Any input as per above? Looking forward to hearing from you. Regards, Vipul Kumar On Wed, Oct 26, 2022 at 5:21 AM Stefano Stabellini <sstabell...@kernel.org> wrote: > Hi Vipul, > > If you look at the QEMU logs, it says: > > VNC server running on 127.0.0.1:5900 > > That is the VNC server you need to connect to. So in theory: > > vncviewer 127.0.0.1:5900 > > should work correctly. > > > If you have: > > vfb = ["type=vnc"] > > in your xl config file and you have "fbdev" in your Linux guest, it > should work. > > If you connect to the VNC server but you get a black screen, it might be > a guest configuration issue. I would try with a simpler guest, text only > (no X11, no Wayland) and enable the fbdev console (fbcon). See > Documentation/fb/fbcon.rst in Linux. You should be able to see a > graphical console over VNC. > > If that works, then you know that the fbdev kernel driver (xen-fbfront) > works correctly. > > If it doesn't work, the output of "xenstore-ls" would be interesting. > > Cheers, > > Stefano > > > On Wed, 19 Oct 2022, Vipul Suneja wrote: > > Hi Stefano, > > > > Thanks for the response! > > > > I am following the same link you shared from the beginning. Tried the > command "vncviewer localhost:0" in DOM0 but same issue "Can't open > > display", below are the logs: > > > > root@raspberrypi4-64:~# vncviewer localhost:0 > > > > TigerVNC Viewer 64-bit v1.11.0 > > Built on: 2020-09-08 12:16 > > Copyright (C) 1999-2020 TigerVNC Team and many others (see README.rst) > > See https://www.tigervnc.org for information on TigerVNC. > > Can't open display: > > > > Below are the netstat logs, i couldn't see anything running at port 5900 > or 5901: > > > > root@raspberrypi4-64:~# netstat -tuwx > > Active Internet connections (w/o servers) > > Proto Recv-Q Send-Q Local Address Foreign Address > State > > tcp 0 164 192.168.1.39:ssh 192.168.1.38:37472 > ESTABLISHED > > Active UNIX domain sockets (w/o servers) > > Proto RefCnt Flags Type State I-Node Path > > unix 8 [ ] DGRAM CONNECTED 10565 /dev/log > > unix 3 [ ] STREAM CONNECTED 10891 > /var/run/xenstored/socket > > unix 3 [ ] STREAM CONNECTED 13791 > > unix 3 [ ] STREAM CONNECTED 10843 > /var/run/xenstored/socket > > unix 3 [ ] STREAM CONNECTED 10573 > /var/run/xenstored/socket > > unix 2 [ ] DGRAM CONNECTED 14510 > > unix 3 [ ] STREAM CONNECTED 13249 > > unix 2 [ ] DGRAM CONNECTED 13887 > > unix 2 [ ] DGRAM CONNECTED 10599 > > unix 3 [ ] STREAM CONNECTED 14005 > > unix 3 [ ] STREAM CONNECTED 13258 > > unix 3 [ ] STREAM CONNECTED 13248 > > unix 3 [ ] STREAM CONNECTED 14003 > > unix 3 [ ] STREAM CONNECTED 10572 > /var/run/xenstored/socket > > unix 3 [ ] STREAM CONNECTED 10786 > /var/run/xenstored/socket > > unix 3 [ ] DGRAM CONNECTED 13186 > > unix 3 [ ] STREAM CONNECTED 10864 > /var/run/xenstored/socket > > unix 3 [ ] STREAM CONNECTED 10812 > /var/run/xenstored/socket > > unix 2 [ ] DGRAM CONNECTED 14083 > > unix 3 [ ] STREAM CONNECTED 10813 > /var/run/xenstored/socket > > unix 3 [ ] STREAM CONNECTED 14068 > > unix 3 [ ] STREAM CONNECTED 13256 > > unix 3 [ ] STREAM CONNECTED 10571 > /var/run/xenstored/socket > > unix 3 [ ] STREAM CONNECTED 10842 > > unix 3 [ ] STREAM CONNECTED 13985 > > unix 3 [ ] DGRAM CONNECTED 13185 > > unix 2 [ ] STREAM CONNECTED 13884 > > unix 2 [ ] DGRAM CONNECTED 14528 > > unix 2 [ ] DGRAM CONNECTED 13785 > > unix 3 [ ] STREAM CONNECTED 14034 > > > > Attaching xen log files of /var/log/xen. > > I didn't get the role of QEMU here because as mentioned earlier, I am > porting in raspberrypi 4B. > > > > Regards, > > Vipul Kumar > > > > On Wed, Oct 19, 2022 at 12:43 AM Stefano Stabellini < > sstabell...@kernel.org> wrote: > > It usually works the way it is described in the guide: > > > > > https://www.virtuatopia.com/index.php?title=Configuring_a_VNC_based_Graphical_Console_for_a_Xen_Paravirtualized_domainU_Guest > > > > You don't need to install any VNC-related server software because > it is > > already provided by Xen (to be precise it is provided by QEMU > working > > together with Xen.) > > > > You only need the vnc client in dom0 so that you can connect, but > you > > could also run the vnc client outside from another host. So > basically > > the following should work when executed in Dom0 after creating > DomU: > > > > vncviewer localhost:0 > > > > Can you attach the Xen and QEMU logs (/var/log/xen/*)? And also use > > netstat -taunp to check if there is anything running at port 5900 > or > > 5901? > > > > Cheers, > > > > Stefano > > > > > > On Tue, 18 Oct 2022, Vipul Suneja wrote: > > > Hi Stefano, > > > > > > Thanks for the response! > > > > > > I could install tigerVNC, x11vnc & libvncserver in Dom0 > xen-image-minimal but only manage to install libvncserver(couldn't > > install tigervnc > > > & x11vnc because of x11 > > > support missing, it's wayland) in DOMU custom graphical image. I > tried running vncviewer with IP address & port in dom0 to > > access the domu > > > graphical image display as per below commands. > > > > > > vncviewer 192.168.1.42:5901 > > > > > > But it showing can't open display, below are the logs: > > > > > > root@raspberrypi4-64:~/guest1# vncviewer 192.168.1.42:5901 > > > > > > TigerVNC Viewer 64-bit v1.11.0 > > > Built on: 2020-09-08 12:16 > > > Copyright (C) 1999-2020 TigerVNC Team and many others (see > README.rst) > > > See https://www.tigervnc.org for information on TigerVNC. > > > Can't open display: > > > root@raspberrypi4-64:~/guest1# > > > > > > I am not exactly sure what the issue is but I thought only > libvncserver in DOMU could work to get access but it did not > > work. > > > If TigerVNC is the issue here then is there any other VNC source > which could be installed for both x11 & wayland supported > > images? > > > > > > Regards, > > > Vipul Kumar > > > > > > On Tue, Oct 18, 2022 at 2:40 AM Stefano Stabellini < > sstabell...@kernel.org> wrote: > > > VNC is typically easier to setup, because SDL needs extra > libraries at > > > build time and runtime. If QEMU is built without SDL > support it won't > > > start when you ask for SDL. > > > > > > VNC should work with both x11 and wayland in your domU. It > doesn't work > > > at the x11 level, it exposes a special fbdev device in > your domU that > > > should work with: > > > - a graphical console in Linux domU > > > - x11 > > > - wayland (but I haven't tested this so I am not 100% sure > about it) > > > > > > When you say "it doesn't work", what do you mean? Do you > get a black > > > window? > > > > > > You need CONFIG_XEN_FBDEV_FRONTEND in Linux domU > > > (drivers/video/fbdev/xen-fbfront.c). I would try to get a > graphical text > > > console up and running in your domU before attempting > x11/wayland. > > > > > > Cheers, > > > > > > Stefano > > > > > > On Mon, 17 Oct 2022, Vipul Suneja wrote: > > > > Hi, > > > > Thanks! > > > > > > > > I have ported xen minimal image as DOM0 & custom wayland > GUI based image as DOMU in raspberry pi4B. I am trying to > > make GUI > > > display up > > > > for guest machine. I tried using sdl, included below > line in guest.conf file > > > > vfb= [ 'sdl=1' ] > > > > > > > > But it is throwing below error: > > > > > > > > root@raspberrypi4-64:~/guest1# xl create -c guest1.cfg > > > > Parsing config from guest1.cfg > > > > libxl: error: libxl_qmp.c:1400:qmp_ev_fd_callback: > Domain 3:error on QMP socket: Connection reset by peer > > > > libxl: error: libxl_qmp.c:1439:qmp_ev_fd_callback: > Domain 3:Error happened with the QMP connection to QEMU > > > > libxl: error: > libxl_dm.c:3351:device_model_postconfig_done: Domain 3:Post DM startup > configs failed, rc=-26 > > > > libxl: error: > libxl_create.c:1867:domcreate_devmodel_started: Domain 3:device model did > not start: -26 > > > > libxl: error: libxl_aoutils.c:646:libxl__kill_xs_path: > Device Model already exited > > > > libxl: error: libxl_domain.c:1183:libxl__destroy_domid: > Domain 3:Non-existant domain > > > > libxl: error: > libxl_domain.c:1137:domain_destroy_callback: Domain 3:Unable to destroy > guest > > > > libxl: error: libxl_domain.c:1064:domain_destroy_cb: > Domain 3:Destruction of domain failed > > > > > > > > Another way is VNC, i could install tigervnc in DOM0 but > same i couldn't in guest machine because it doesn't support > > > x11(supports wayland > > > > only). I am completely blocked here, Need your support > to enable the display up. > > > > Any alternative of VNC which could work in both x11 & > wayland supported images? > > > > > > > > Any input on VNC, SDL or any other way to proceed on > this? Looking forward to hearing from you. > > > > > > > > Regards, > > > > Vipul Kumar > > > > > > > > > > > > > > >