From: Will Deacon Date: Fri, 8 Oct 2021 13:58:35 +0000 (+0100) Subject: arm64: Prevent kexec and hibernation if is_protected_kvm_enabled() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=8f4566f18db5d1257fc2d5442e16274424a529c1;p=linux.git arm64: Prevent kexec and hibernation if is_protected_kvm_enabled() When pKVM is enabled, the hypervisor code at EL2 and its data structures are inaccessible to the host kernel and cannot be torn down or replaced as this would defeat the integrity properies which pKVM aims to provide. Furthermore, the ABI between the host and EL2 is flexible and private to whatever the current implementation of KVM requires and so booting a new kernel with an old EL2 component is very likely to end in disaster. In preparation for uninstalling the hyp stub calls which are relied upon to reset EL2, disable kexec and hibernation in the host when protected KVM is enabled. Cc: Marc Zyngier Cc: Quentin Perret Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20211008135839.1193-3-will@kernel.org --- diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 6f6ff072acbde..44369b99a57ee 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -1128,5 +1128,6 @@ bool cpus_are_stuck_in_kernel(void) { bool smp_spin_tables = (num_possible_cpus() > 1 && !have_cpu_die()); - return !!cpus_stuck_in_kernel || smp_spin_tables; + return !!cpus_stuck_in_kernel || smp_spin_tables || + is_protected_kvm_enabled(); }