Hi
This issue is already informed at ML.[1]

Current AGL platform uses qt v5.7, then the error is occurred if you use aarch64 with CONFIG_ARM64_VA_BITS=48. Though, Homescreen cannot launch.
Using CONFIG_ARM64_VA_BITS=39 is just W/A.
This bug is reported at https://bugreports.qt.io/browse/QTBUG-54822.

Recently, qt 5.7.1 is released and meta-qt5 (branch :morty-next) is applied it.[2]
[1] https://lists.linuxfoundation.org/pipermail/automotive-discussions/2016-November/002901.html
[2] https://github.com/meta-qt5/meta-qt5/commit/17abfb37eb59c7b78abe80aa45072ce0ed63491d

#I wonder this ticket is set as bug or task.

Best regards,
Renesas/ Kurokawa.