The nVHE percpu data is partially linked but the nVHE linker script did
not align the percpu section.  The PERCPU_INPUT macro would then align
the data to a page boundary:

  #define PERCPU_INPUT(cacheline)					\
  	__per_cpu_start = .;						\
  	*(.data..percpu..first)						\
  	. = ALIGN(PAGE_SIZE);						\
  	*(.data..percpu..page_aligned)					\
  	. = ALIGN(cacheline);						\
  	*(.data..percpu..read_mostly)					\
  	. = ALIGN(cacheline);						\
  	*(.data..percpu)						\
  	*(.data..percpu..shared_aligned)				\
  	PERCPU_DECRYPTED_SECTION					\
  	__per_cpu_end = .;

but then when the final vmlinux linking happens the hypervisor percpu
data is included after page alignment and so the offsets potentially
don't match.  On my build I saw that the .hyp.data..percpu section was
at address 0x20 and then the percpu data would begin at 0x1000 (because
of the page alignment in PERCPU_INPUT), but when linked into vmlinux,
everything would be shifted down by 0x20 bytes.

This manifests as one of the CPUs getting lost when running
kvm-unit-tests or starting any VM and subsequent soft lockup on a Cortex
A72 device.

Fixes: 30c95391 ("kvm: arm64: Set up hyp percpu data for nVHE")
Signed-off-by: Jamie Iles <jamie@nuviainc.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: David Brazdil <dbrazdil@google.com>
Cc: David Brazdil <dbrazdil@google.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201113150406.14314-1-jamie@nuviainc.com