KVM: PPC: Book3S: Fix CONFIG_TRANSACTIONAL_MEM=n crash
authorNicholas Piggin <npiggin@gmail.com>
Fri, 16 Jul 2021 02:43:09 +0000 (12:43 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Sat, 17 Jul 2021 04:33:17 +0000 (14:33 +1000)
commitbd31ecf44b8e18ccb1e5f6b50f85de6922a60de3
treede056f1c39deb16d8a237c2e51d0bf2697cf02a5
parente44fbdb68049539de9923ce4bad2d277aef54892
KVM: PPC: Book3S: Fix CONFIG_TRANSACTIONAL_MEM=n crash

When running CPU_FTR_P9_TM_HV_ASSIST, HFSCR[TM] is set for the guest
even if the host has CONFIG_TRANSACTIONAL_MEM=n, which causes it to be
unprepared to handle guest exits while transactional.

Normal guests don't have a problem because the HTM capability will not
be advertised, but a rogue or buggy one could crash the host.

Fixes: 4bb3c7a0208f ("KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210716024310.164448-1-npiggin@gmail.com
arch/powerpc/kvm/book3s_hv.c