In some architectural corner cases, AT instructions can generate an exception, which KVM is not really ready to handle properly. Teach the code to handle this situation gracefully. This is a backport of the respective upstream patches to v5.8(.5). James prepared and tested these already, but we were lacking the upstream commit ID so far. I am sending this on his behalf, since he is off this week. The last two of the originally three patches were tagged Cc: stable already, but 2/3 did not apply cleanly, hence this specific backport. 3/3 has already been added to stable-queue, so I am dropping it from this post. Cheers, Andre. James Morse (2): KVM: arm64: Add kvm_extable for vaxoricism code KVM: arm64: Survive synchronous exceptions caused by AT instructions arch/arm64/include/asm/kvm_asm.h | 43 +++++++++++++++++++++ arch/arm64/kernel/vmlinux.lds.S | 8 ++++ arch/arm64/kvm/hyp/entry.S | 15 +++++--- arch/arm64/kvm/hyp/hyp-entry.S | 65 ++++++++++++++++++++------------ arch/arm64/kvm/hyp/switch.c | 39 +++++++++++++++++-- 5 files changed, 136 insertions(+), 34 deletions(-) -- 2.17.1
