I am trying to create a shielded VM on an NVMe drive which is claimed by my custom NVMe driver. Upon debugging, I found that shielded VM creation is failing due to DMA data transfer error.
The “AlignmentMask” member of PORT_CONFIGURATION_INFORMATION in my driver is (0x1) WORD aligned. When I changed it to (0x7)QUAD aligned, there is no data transfer error and shielded VM creation is successful. I have a couple of queries.
- How “AlignmentMask” is affecting the data transfer/creation of shielded VM?
- In normal IOs using IOmeter, no data transfer errors are observed. Why this “AlignmentMask” is affecting the data transfer only in creation of shielded VM?
Link about shielded VM : https://docs.microsoft.com/en-us/windows-server/security/guarded-fabric-shielded-vm/guarded-fabric-and-shielded-vms
Regards,
Sony