The SMCCC does not allow the SMC64 calling convention to be used from AArch32. While KVM checks to see if the calling convention is allowed in PSCI_1_0_FN_PSCI_FEATURES, it does not actually prevent calls to unadvertised PSCI v1.0+ functions. Check to see if the requested function is allowed from the guest's execution state. Deny the call if it is not. Fixes: d43583b890e7 ("KVM: arm64: Expose PSCI SYSTEM_RESET2 call to the guest") Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Oliver Upton <oupton@xxxxxxxxxx> --- arch/arm64/kvm/psci.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm64/kvm/psci.c b/arch/arm64/kvm/psci.c index cd3ee947485f..0d771468b708 100644 --- a/arch/arm64/kvm/psci.c +++ b/arch/arm64/kvm/psci.c @@ -318,6 +318,10 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) if (minor > 1) return -EINVAL; + val = kvm_psci_check_allowed_function(vcpu, psci_fn); + if (val) + goto out; + switch(psci_fn) { case PSCI_0_2_FN_PSCI_VERSION: val = minor == 0 ? KVM_ARM_PSCI_1_0 : KVM_ARM_PSCI_1_1; @@ -378,6 +382,7 @@ static int kvm_psci_1_x_call(struct kvm_vcpu *vcpu, u32 minor) return kvm_psci_0_2_call(vcpu); } +out: smccc_set_retval(vcpu, val, 0, 0, 0); return ret; } -- 2.35.1.894.gb6a874cedc-goog