This article is intended for Citrix administrators and technical teams only. Non-admin users must contact their company’s Help Desk/IT support team and can refer to CTX297149 for more information.



After connecting a Linux VDA desktop, "Devices" tab might be missing from Windows Receiver toolbar, which indicates USB redirection doesn't take place.

Verify the following configurations:

1. Ensure DDC policy setting "Client USB Device Redirection: Allowed" (for workstation hosts only).

• Get information about current kernel 

• Get information about VHCI module

3. Rebuild the VHCI module to consistent with Linux kernel
    1) In Linux VDA, verify if Module.symvers file exists under /usr/src/linux-headers-4.4.0-21-generic. If not, run apt-get install linux-headers$(uname -r) to install the kernel header files and create Module.symvers. 
    2) Download "Linux Virtual Delivery Agent (sources)" from the Citrix download site.
    3) Extract vhci-hcd-1.15 from citrix-linux-vda-sources.zip file and copy it to Linux VDA.
    4) Edit vhci-hcd-1.15/Makefile, comment original KDIR assignment and set it to kernel directory,
           #KDIR = $(BUILD_PREFIX)/lib/modules/$(KVERSION)/build
​           KDIR = /usr/src/linux-headers-4.4.0-21-generic

    5) In the folder vhci-hcd-1.15/, run make to build the VHCI kernel. If the build was successful, usb-vhci-hcd.ko and usb-vhci-iocifc.ko are created in the vhci-hcd-1.15/ folder.
    6) Replace the kernel module with the newly built one: cp -f usb-vhci-*.ko /opt/Citrix/VDA/lib64/
    7) Restart the USB service: service ctxusbsd restart
    8) Check VHCI module again, and version consistent with kernel version
      
    9) Log off and log on to the the session again. Check to see if USB redirection is functioning 

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Problem Cause

USB redirection depends on the VHCI kernel modules (usb-vhci-hcd.ko and usb-vhci-iocif.ko). These modules are part of the Linux VDA RPM package and compiled based on the official Linux distribution kernel. If kernel of Linux distribution is not compatible with VHCI driver provided by Linux VDA, Citrix USB redirection won't take effect. 

The article describes a detailed troubleshooting steps against missing "Devices" tab from Receiver toolbar.