If a vCPU is caught running 32-bit code on a system with mismatched support at EL0, then we should kill it. Acked-by: Marc Zyngier <maz@xxxxxxxxxx> Signed-off-by: Will Deacon <will@xxxxxxxxxx> --- arch/arm64/kvm/arm.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 5750ec34960e..d322ac0f4a8e 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -633,6 +633,15 @@ static void check_vcpu_requests(struct kvm_vcpu *vcpu) } } +static bool vcpu_mode_is_bad_32bit(struct kvm_vcpu *vcpu) +{ + if (likely(!vcpu_mode_is_32bit(vcpu))) + return false; + + return !system_supports_32bit_el0() || + static_branch_unlikely(&arm64_mismatched_32bit_el0); +} + /** * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code * @vcpu: The VCPU pointer @@ -816,7 +825,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) * with the asymmetric AArch32 case), return to userspace with * a fatal error. */ - if (!system_supports_32bit_el0() && vcpu_mode_is_32bit(vcpu)) { + if (vcpu_mode_is_bad_32bit(vcpu)) { /* * As we have caught the guest red-handed, decide that * it isn't fit for purpose anymore by making the vcpu -- 2.29.2.454.gaff20da3a2-goog