VMs used to execute hvc #0 for the psci call. However, when we come to provide virtual EL2 to the VM, the host OS inside the VM also calls kvm_call_hyp which is also hvc #0. So, it's hard to differentiate between them from the host hypervisor's point of view.
So, let the VM execute smc for the psci call. On ARMv8.3, even if EL3 is not implemented, a smc instruction executed at non-secure EL1 is trapped to EL2 if HCR_EL2.TSC==1, rather than being treated as UNDEFINED. So, the host hypervisor can handle this psci call without any confusion. Signed-off-by: Jintack Lim <[email protected]> --- arch/arm64/kvm/handle_exit.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index 208be16..ce6d2ef 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -64,8 +64,27 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run) static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) { - kvm_inject_undefined(vcpu); - return 1; + int ret; + + /* If imm is non-zero, it's not defined */ + if (kvm_vcpu_hvc_get_imm(vcpu)) { + kvm_inject_undefined(vcpu); + return 1; + } + + /* + * If imm is zero, it's a psci call. + * Note that on ARMv8.3, even if EL3 is not implemented, SMC executed + * at Non-secure EL1 is trapped to EL2 if HCR_EL2.TSC==1, rather than + * being treated as UNDEFINED. + */ + ret = kvm_psci_call(vcpu); + if (ret < 0) { + kvm_inject_undefined(vcpu); + return 1; + } + + return ret; } /** -- 1.9.1
