Hello,
I just hit a Windows bug while testing the XCP-ng Windows Guest Drivers and Tools. If you have a Windows 10 (1803) VM and installed PV-Drivers (CITRIX or XCP-ng) you may get a bluescreen like this:
Cause
"Addresses an issue that ignores the MM_DONT_ZERO_ALLOCATION flag. This issue leads to degraded performance, and, occasionally, error 0x139 appears." (https://support.microsoft.com/en-us/help/4458469/windows-10-update-kb4458469)
This bluescreen above is the exact error 0x139 --> KERNEL_SECURITY_CHECK_FAILURE
I opened the created minidump in Visual Studio 2019 and was at the exact location, where xenvif hits the bug:
Solution
Install latest Windows Updates bevore installing the Windows Guest Tools and Drivers!
That's also recommended by CITRIX: "If your VM operating system is Windows 10 1803, you must install the latest Windows Updates before installing this [xenvif 8.2.1.175 and above] version of the Management Agent. For more information, see https://support.microsoft.com/en-us/help/4458469/windows-10-update-kb4458469." (https://support.citrix.com/article/CTX235403)
Edit:
I added a hint in the wiki: https://github.com/xcp-ng/xcp/wiki/Guest-Tools#state-of-822200-rc1-and-822-beta