Hi Stefano, Thanks!
I am exploring both options here, modification of framebuffer source file & setting up x11vnc server in guest. Other than these I would like to share a few findings with you. 1. If i keep "CONFIG_XEN_FBDEV_FRONTEND=y" then xen-fbfront.ko is not generating but if i keep "CONFIG_XEN_FBDEV_FRONTEND=m" then could see xen-fbfront.ko & its loading also. Same things with other frontend/backend drivers also. Do we need to configure these drivers as a module(m) only? 2. I could see xenstored service is running for the host but it's always failing for the guest machine. I could see it in bootup logs & via systemctl status also. Below are the logs: *[ OK ] Reached target Basic System.[ OK ] Started Kernel Logging Service.[ OK ] Started System Logging Service. Starting D-Bus System Message Bus... Starting User Login Management... Starting Permit User Sessions... Starting The Xen xenstore... Starting OpenSSH Key Generation...[FAILED] Failed to start The Xen xenstore.See 'systemctl status xenstored.service' for details.[DEPEND] Dependency failed for qemu for xen dom0 disk backend.[DEPEND] Dependency failed for Xend…p guests on boot and shutdown.[DEPEND] Dependency failed for xen-…des, JSON configuration stub).[DEPEND] Dependency failed for Xenc…guest consoles and hypervisor.[ OK ] Finished Permit User Sessions.[ OK ] Started Getty on tty1.[ OK ] Started Serial Getty on hvc0.[ OK ] Started Serial Getty on ttyS0.[ OK ] Reached target Login Prompts. Starting Xen-watchdog - run xen watchdog daemon...[ OK ] Started D-Bus System Message Bus.[ OK ] Started Xen-watchdog - run xen watchdog daemon.[ OK ] Finished OpenSSH Key Generation.[ OK ] Started User Login Management.[ OK ] Reached target Multi-User System. Starting Record Runlevel Change in UTMP...[ OK ] Finished Record Runlevel Change in UTMP.fbcon: Taking over consolePoky (Yocto Project Reference Distro) 4.0.4 raspberrypi4-64 hvc0raspberrypi4-64 login: rootroot@raspberrypi4-64:~#root@raspberrypi4-64:~#root@raspberrypi4-64:~# systemctl status xenstored.servicex xenstored.service - The Xen xenstore Loaded: loaded (/lib/systemd/system/xenstored.service; enabled; vendor preset: enabled) Active: failed (Result: exit-code) since Thu 2022-12-01 06:12:05 UTC; 26s ago Process: 195 ExecStartPre=/bin/grep -q control_d /proc/xen/capabilities (code=exited, status=1/FAILURE)Dec 01 06:12:04 raspberrypi4-64 systemd[1]: Starting The Xen xenstore...Dec 01 06:12:05 raspberrypi4-64 systemd[1]: xenstored.service: Control pro...UREDec 01 06:12:05 raspberrypi4-64 systemd[1]: xenstored.service: Failed with...e'.Dec 01 06:12:05 raspberrypi4-64 systemd[1]: Failed to start The Xen xenstore.Hint: Some lines were ellipsized, use -l to show in full.* *root@raspberrypi4-64:~# * Any input on these? Thanks & Regards, Vipul Kumar On Wed, Nov 23, 2022 at 5:41 AM Stefano Stabellini <sstabell...@kernel.org> wrote: > Hi Vipul, > > I cannot spot any issue in the configuration, in particual you have: > > CONFIG_XEN_FBDEV_FRONTEND=y > > which is what you need. > > The only thing I can suggest is to add printks to the Linux frontend > driver (the one running in the domU) which is > drivers/video/fbdev/xen-fbfront.c and printfs to the QEMU backend > (running in Dom0) which is hw/display/xenfb.c to figure out what is > going on. > > > Alternatively, you can setup PV network with the domU, such as: > > vif=[''] > > and then run x11 and a x11vnc server in your domU. You should be able to > connect to it using vncviewer at the network IP of your domU. > > Basically you are skipping the problem because instead of using the PV > framebuffer protocol, you just use VNC over the network with the domU. > > > Cheers, > > Stefano > > > On Tue, 22 Nov 2022, Vipul Suneja wrote: > > Hi Stefano, > > Thanks for the support! > > > > Looks like I have tried all the combinations & possible ways to get > display up but failed. Is there any document or pdf for porting xen on > > raspberrypi4. > > I could find lot's of links telling the same but couldn't see any > official user guide or document from the xen community on the same. If > > there is something to refer > > to please share with me. > > I am attaching the kernel configuration file also, just take a look if i > have missed anything. > > Any other suggestions or input from your end could be really helpful? > > > > Regards, > > Vipul Kumar > > > > On Fri, Nov 11, 2022 at 6:40 AM Stefano Stabellini < > sstabell...@kernel.org> wrote: > > Hi Vipul, > > > > Sorry for the late reply. From the earlier logs that you sent, it > looks > > like everything should be working correctly. Specifically: > > > > 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" > > > > state "4" means "connected". So I would expect that you should be > able > > to connect to the vnc server using vncviewer. You might not see > anything > > (black screen) but you should definitely be able to connect. > > > > I wouldn't try to launch x11 in the guest just yet. fbcon in Linux > is > > enough to render something on the screen. You should be able to > see the > > Linux text-based console rendered graphically, connecting to it > via vnc. > > > > Sorry for the basic question, but have you tried all the following? > > > > vncviewer 127.0.0.1:0 > > vncviewer 127.0.0.1:1 > > vncviewer 127.0.0.1:2 > > vncviewer 127.0.0.1:5900 > > vncviewer 127.0.0.1:5901 > > vncviewer 127.0.0.1:5902 > > > > Given that from the xenstore-ls logs everything seems to work > correctly > > I am not sure what else to suggest. You might have to add printf > to QEMU > > ui/vnc.c and hw/display/xenfb.c to see what is going wrong. > > > > Cheers, > > > > Stefano > > > > > > On Mon, 7 Nov 2022, Vipul Suneja wrote: > > > Hi Stefano, > > > Thanks! > > > > > > Any input further on "xenstore-ls" logs? > > > > > > I am trying to run the x0vncserver & x11vnc server manually on > guest machine(xen_guest_image_minimal) image but it's failing > > with the below > > > error. > > > > > > root@raspberrypi4-64:/usr/bin# x0vncserver > > > x0vncserver: unable to open display "" > > > root@raspberrypi4-64:/usr/bin# > > > root@raspberrypi4-64:/usr/bin# x11vnc > > > ############################################################### > > > #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@# > > > #@ @# > > > #@ ** WARNING ** WARNING ** WARNING ** WARNING ** @# > > > #@ @# > > > #@ YOU ARE RUNNING X11VNC WITHOUT A PASSWORD!! @# > > > #@ @# > > > #@ This means anyone with network access to this computer @# > > > #@ may be able to view and control your desktop. @# > > > #@ @# > > > #@ >>> If you did not mean to do this Press CTRL-C now!! <<< @# > > > #@ @# > > > #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@# > > > #@ @# > > > #@ You can create an x11vnc password file by running: @# > > > #@ @# > > > #@ x11vnc -storepasswd password /path/to/passfile @# > > > #@ or x11vnc -storepasswd /path/to/passfile @# > > > #@ or x11vnc -storepasswd @# > > > #@ @# > > > #@ (the last one will use ~/.vnc/passwd) @# > > > #@ @# > > > #@ and then starting x11vnc via: @# > > > #@ @# > > > #@ x11vnc -rfbauth /path/to/passfile @# > > > #@ @# > > > #@ an existing ~/.vnc/passwd file from another VNC @# > > > #@ application will work fine too. @# > > > #@ @# > > > #@ You can also use the -passwdfile or -passwd options. @# > > > #@ (note -passwd is unsafe if local users are not trusted) @# > > > #@ @# > > > #@ Make sure any -rfbauth and -passwdfile password files @# > > > #@ cannot be read by untrusted users. @# > > > #@ @# > > > #@ Use x11vnc -usepw to automatically use your @# > > > #@ ~/.vnc/passwd or ~/.vnc/passwdfile password files. @# > > > #@ (and prompt you to create ~/.vnc/passwd if neither @# > > > #@ file exists.) Under -usepw, x11vnc will exit if it @# > > > #@ cannot find a password to use. @# > > > #@ @# > > > #@ @# > > > #@ Even with a password, the subsequent VNC traffic is @# > > > #@ sent in the clear. Consider tunnelling via ssh(1): @# > > > #@ @# > > > #@ http://www.karlrunge.com/x11vnc/#tunnelling @# > > > #@ @# > > > #@ Or using the x11vnc SSL options: -ssl and -stunnel @# > > > #@ @# > > > #@ Please Read the documentation for more info about @# > > > #@ passwords, security, and encryption. @# > > > #@ @# > > > #@ http://www.karlrunge.com/x11vnc/faq.html#faq-passwd @# > > > #@ @# > > > #@ To disable this warning use the -nopw option, or put @# > > > #@ 'nopw' on a line in your ~/.x11vncrc file. @# > > > #@ @# > > > #@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@# > > > ############################################################### > > > 09/03/2018 12:58:41 x11vnc version: 0.9.16 lastmod: 2019-01-05 > pid: 424 > > > 09/03/2018 12:58:41 XOpenDisplay("") failed. > > > 09/03/2018 12:58:41 Trying again with > XAUTHLOCALHOSTNAME=localhost ... > > > 09/03/2018 12:58:41 > > > 09/03/2018 12:58:41 *** XOpenDisplay failed. No -display or > DISPLAY. > > > 09/03/2018 12:58:41 *** Trying ":0" in 4 seconds. Press Ctrl-C > to abort. > > > 09/03/2018 12:58:41 *** 1 2 3 4 > > > 09/03/2018 12:58:45 XOpenDisplay(":0") failed. > > > 09/03/2018 12:58:45 Trying again with > XAUTHLOCALHOSTNAME=localhost ... > > > 09/03/2018 12:58:45 XOpenDisplay(":0") failed. > > > 09/03/2018 12:58:45 Trying again with unset XAUTHLOCALHOSTNAME > ... > > > 09/03/2018 12:58:45 > > > > > > 09/03/2018 12:58:45 *************************************** > > > 09/03/2018 12:58:45 *** XOpenDisplay failed (:0) > > > > > > *** x11vnc was unable to open the X DISPLAY: ":0", it cannot > continue. > > > *** There may be "Xlib:" error messages above with details about > the failure. > > > > > > Some tips and guidelines: > > > > > > ** An X server (the one you wish to view) must be running before > x11vnc is > > > started: x11vnc does not start the X server. (however, see > the -create > > > option if that is what you really want). > > > > > > ** You must use -display <disp>, -OR- set and export your > $DISPLAY > > > environment variable to refer to the display of the desired X > server. > > > - Usually the display is simply ":0" (in fact x11vnc uses this > if you forget > > > to specify it), but in some multi-user situations it could be > ":1", ":2", > > > or even ":137". Ask your administrator or a guru if you are > having > > > difficulty determining what your X DISPLAY is. > > > > > > ** Next, you need to have sufficient permissions (Xauthority) > > > to connect to the X DISPLAY. Here are some Tips: > > > > > > - Often, you just need to run x11vnc as the user logged into > the X session. > > > So make sure to be that user when you type x11vnc. > > > - Being root is usually not enough because the incorrect > MIT-MAGIC-COOKIE > > > file may be accessed. The cookie file contains the secret > key that > > > allows x11vnc to connect to the desired X DISPLAY. > > > - You can explicitly indicate which MIT-MAGIC-COOKIE file > should be used > > > by the -auth option, e.g.: > > > x11vnc -auth /home/someuser/.Xauthority -display :0 > > > x11vnc -auth /tmp/.gdmzndVlR -display :0 > > > you must have read permission for the auth file. > > > See also '-auth guess' and '-findauth' discussed below. > > > > > > ** If NO ONE is logged into an X session yet, but there is a > greeter login > > > program like "gdm", "kdm", "xdm", or "dtlogin" running, you > will need > > > to find and use the raw display manager MIT-MAGIC-COOKIE file. > > > Some examples for various display managers: > > > > > > gdm: -auth /var/gdm/:0.Xauth > > > -auth /var/lib/gdm/:0.Xauth > > > kdm: -auth /var/lib/kdm/A:0-crWk72 > > > -auth /var/run/xauth/A:0-crWk72 > > > xdm: -auth /var/lib/xdm/authdir/authfiles/A:0-XQvaJk > > > dtlogin: -auth /var/dt/A:0-UgaaXa > > > > > > Sometimes the command "ps wwwwaux | grep auth" can reveal the > file location. > > > > > > Starting with x11vnc 0.9.9 you can have it try to guess by > using: > > > > > > -auth guess > > > > > > (see also the x11vnc -findauth option.) > > > > > > Only root will have read permission for the file, and so > x11vnc must be run > > > as root (or copy it). The random characters in the filenames > will of course > > > change and the directory the cookie file resides in is system > dependent. > > > > > > See also: http://www.karlrunge.com/x11vnc/faq.html > > > > > > Regards, > > > Vipul Kumar > > > > > > On Thu, Nov 3, 2022 at 10:27 PM Vipul Suneja < > vsunej...@gmail.com> wrote: > > > 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-ls > > > tool = "" > > > 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 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
