This is a rework of an initial patch posted a couple of days back[1]

While working on enabling KVM on "reduced IPA size" systems, I realise
we have a couple of issues, some of while do impact userspace.

The first issue is that we accept the creation of a "default IPA size"
VM (40 bits) even when the HW doesn't support it. Not good.

The second one is that we disallow a memslot to end right where the
IPA limit is. One page less and you're good, but that's not quite what
it should be.

I intend for both patches to be backported to -stable.

Thanks,

	M.

* From v1:
  - Don't try to cap the default IPA size. If userspace uses 0 with an
    expectation that it will get 40bits, we should abide by it and
    return an error immediately (noticed by Andrew)
  - Added a new patch to fix the exclusive nature of the IPA limit
  
[1] https://lore.kernel.org/r/20210308174643.761100-1-maz@kernel.org (local)

Marc Zyngier (2):
  KVM: arm64: Reject VM creation when the default IPA size is
    unsupported
  KVM: arm64: Fix exclusive limit for IPA size

 Documentation/virt/kvm/api.rst |  3 +++
 arch/arm64/kvm/mmu.c           |  3 +--
 arch/arm64/kvm/reset.c         | 12 ++++++++----
 3 files changed, 12 insertions(+), 6 deletions(-)

-- 
2.29.2


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