KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte

KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte

If a protected vCPU faults on an IPA which appears to be mapped, query
the hypervisor to determine whether or not the faulting pte has been
poisoned by a forceful reclaim. If the pte has been poisoned, return
-EFAULT back to userspace rather than retrying the instruction forever.

Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-28-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>