KVM: PPC: Book3S PR: Handle hyp doorbell exits

If we're running PR KVM in HV mode, we may get hypervisor doorbell interrupts.
Handle those the same way we treat normal doorbells.

Signed-off-by: Alexander Graf <agraf@suse.de>
KVM: PPC: Book3S HV: Fix ABIv2 indirect branch issue

To establish addressability quickly, ABIv2 requires the target
address of the function being called to be in r12.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
KVM: PPC: Assembly functions exported to modules need _GLOBAL_TOC()

Both kvmppc_hv_entry_trampoline and kvmppc_entry_trampoline are
assembly functions that are exported to modules and also require
a valid r2.

As such we need to use _GLOBAL_TOC so we provide a global entry
point that establishes the TOC (r2).

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
KVM: PPC: Book3S PR: Fix ABIv2 on LE

We switched to ABIv2 on Little Endian systems now which gets rid of the
dotted function names. Branch to the actual functions when we see such
a system.

Signed-off-by: Alexander Graf <agraf@suse.de>
KVM: PPC: Book3S PR: Fix sparse endian checks

While sending sparse with endian checks over the code base, it triggered at
some places that were missing casts or had wrong types. Fix them up.

Signed-off-by: Alexander Graf <agraf@suse.de>