KVM: arm64: Handle DABT caused by LS64* instructions on unsupported memory

KVM: arm64: Handle DABT caused by LS64* instructions on unsupported memory

If FEAT_LS64WB not supported, FEAT_LS64* instructions only support
to access Device/Uncacheable memory, otherwise a data abort for
unsupported Exclusive or atomic access (0x35, UAoEF) is generated
per spec. It's implementation defined whether the target exception
level is routed and is possible to implemented as route to EL2 on a
VHE VM according to DDI0487L.b Section C3.2.6 Single-copy atomic
64-byte load/store.

If it's implemented as generate the DABT to the final enabled stage
(stage-2), inject the UAoEF back to the guest after checking the
memslot is valid.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Zhou Wang <wangzhou1@hisilicon.com>
Signed-off-by: Will Deacon <will@kernel.org>