LM regression: fce886a60207 KVM: arm64: Plumb the pKVM MMU in KVM

[Sebastian Ott]

Hey,

Doing back and forth migrations currently fails on arm after a couple iterations.
During the failing migration KVM_RUN exits via guest_abort and returns -ENOMEM.
I can reliably reproduce this by migrating between 2 qemu instances on an ampere
altra machine. This fails after < 5 iterations. In this case qemu would spit out
smth like this (other than that - nothing in the logs):

error: kvm run failed Cannot allocate memory
  PC=0000aaaae7d48590 X00=0000aaaae80a2e00 X01=0000aaaae7ea2fc0
X02=0000000001d3a5d0 X03=0000aaaae7eace8c X04=000000003b9aca00
X05=000000000000004a X06=000000000000004a X07=0000000028000000
X08=0000000000001d70 X09=0000000000000018 X10=000144b7d0000000
X11=00ffffffffffffff X12=000000008378f367 X13=0000aaab1a202d70
X14=0000000000000000 X15=0000000000000000 X16=0000ffffa2e2f7a8
X17=0000ffffa2541f20 X18=000000000000a000 X19=84bfda6288cf2dd6
X20=0000aaab1a1f1ce0 X21=000000007fffffff X22=0000ffffc5431788
X23=0000aaab1a17db60 X24=0000ffffc5431770 X25=0000000100000000
X26=0000004100000000 X27=0000000000000001 X28=0000aaab1a1f1c20
X29=0000ffffc54316d0 X30=0000aaaae7f8cd24  SP=0000ffffc5431650
PSTATE=20001000 --C- EL0t

Guest and host are otherwise idle, kvm is in normal VHE mode.

Git bisect points to (fce886a60207 "KVM: arm64: Plumb the pKVM MMU in KVM")
I also double checked that by reverting this commit on top of 6.14.

Sebastian
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