FROMLIST: KVM: arm64: Fix-up hyp stage-1 refcounts for all pages mapped at EL2

In order to allow unmapping arbitrary memory pages from the hypervisor
stage-1 page-table, fix-up the initial refcount for pages that have been
mapped before the 'vmemmap' array was up and running so that it
accurately accounts for all existing hypervisor mappings.

This is achieved by traversing the entire hypervisor stage-1 page-table
during initialisation of EL2 and updating the corresponding
'struct hyp_page' for each valid mapping.

Tested-by: Vincent Donnefort <vdonnefort@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20221020133827.5541-5-will@kernel.org


Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Change-Id: I10df07bab97198ac4fd9477091b2e9340cc441b0
Signed-off-by: Quentin Perret <qperret@google.com>