As-per PSCI v0.2, the source CPU provides physical address of "entry point" and "context id" for starting a target CPU. Also, if target CPU is already running then we should return ALREADY_ON.
Current emulation of CPU_ON function does not consider physical address of "context id" and returns INVALID_PARAMETERS if target CPU is already running.
This patch updates kvm_psci_vcpu_on() such that it works for both PSCI v0.1 and PSCI v0.2.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org Acked-by: Marc Zyngier marc.zyngier@arm.com --- arch/arm/kvm/psci.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index d04a47b..b582e99 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -48,6 +48,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) struct kvm_vcpu *vcpu = NULL, *tmp; wait_queue_head_t *wq; unsigned long cpu_id; + unsigned long context_id; unsigned long mpidr; phys_addr_t target_pc; int i; @@ -68,10 +69,17 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) * Make sure the caller requested a valid CPU and that the CPU is * turned off. */ - if (!vcpu || !vcpu->arch.pause) + if (!vcpu) return PSCI_RET_INVALID_PARAMS; + if (!vcpu->arch.pause) { + if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1) + return PSCI_RET_ALREADY_ON; + else + return PSCI_RET_INVALID_PARAMS; + }
target_pc = *vcpu_reg(source_vcpu, 2); + context_id = *vcpu_reg(source_vcpu, 3);
kvm_reset_vcpu(vcpu);
@@ -86,6 +94,11 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) kvm_vcpu_set_be(vcpu);
*vcpu_pc(vcpu) = target_pc; + /* + * NOTE: We always update r0 (or x0) because for PSCI v0.1 + * the general puspose registers are undefined upon CPU_ON. + */ + *vcpu_reg(vcpu, 0) = context_id; vcpu->arch.pause = false; smp_mb(); /* Make sure the above is visible */