[VIRT-263 # ARMv8.1-VHE Virtual Host Extensions ]

Got to "kvm enabled with vhe" kernel message, but then the kernel hangs there. Irritatingly works with the kernel I built myself, but not a distro supplied kernel. Need to track down the config difference so I can continue using gdbstub.

[VIRT-344 # ARMv8.5-MemTag, Memory Tagging Extension ]

Regenerated an mte+linux-user branch for Google engineers to use to develop llvm. This is code previously posted, but my current branch striped out linux-user for ease of review of the system code.

[VIRT-327 # Richard's upstream QEMU work ]

Fixed mmap assert, signal handler method. Fixed constant folding of extract2. Fixed aarch64 host output of extract2. Posted pull request for those.

Started reviewing the GSoC risugen patches, v3 for avx.

r~