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Commit aa8aeefe authored by Anup Patel's avatar Anup Patel Committed by Christoffer Dall
Browse files

ARM/ARM64: KVM: Fix CPU_ON emulation for PSCI v0.2 



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: default avatarAnup Patel <anup.patel@linaro.org>
Signed-off-by: default avatarPranavkumar Sawargaonkar <pranavkumar@linaro.org>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent bab0b430

arch/arm/kvm/psci.c

+14 −1
Original line number Diff line number Diff line
@@ -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 */