KVM: arm64: Populate level on S1PTW SEA injection

KVM: arm64: Populate level on S1PTW SEA injection

Our fault injection mechanism is mildly primitive, and doesn't
really implement the architecture when it comes to reporting
the level of a failing S1 PTW (we blindly report a SEA outside
of a PTW).

Now that we can walk the S1 page tables and look for a particular
IPA in the descriptors, it is pretty easy to improve the SEA
injection code.

Note that we only do it for AArch64 guests, and that 32bit guests
are left to their own device (oddly enough, I don't fancy writing
a 32bit PTW...).

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>