On Mon, Apr 21 2014 at 2:00:01 pm BST, Anup Patel <anup.patel@xxxxxxxxxx> wrote:
> The PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET functions are system-level
> functions hence cannot be fully emulated by in-kernel PSCI emulation code.
>
> To tackle this, we forward PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET function
> calls from vcpu to user space (i.e. QEMU or KVMTOOL) via kvm_run structure
> using KVM_EXIT_SYSTEM_EVENT exit reasons.
>
> Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxx>
> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx>
> Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
> ---
> arch/arm/kvm/psci.c | 32 +++++++++++++++++++++++++++++---
> 1 file changed, 29 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
> index 14e6fa6..4486d0f 100644
> --- a/arch/arm/kvm/psci.c
> +++ b/arch/arm/kvm/psci.c
> @@ -85,6 +85,23 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> return PSCI_RET_SUCCESS;
> }
>
> +static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
> +{
> + memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
> + vcpu->run->system_event.type = type;
> + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
> +}
> +
> +static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
> +{
> + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
> +}
> +
> +static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
> +{
> + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
> +}
> +
> int kvm_psci_version(struct kvm_vcpu *vcpu)
> {
> if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
> @@ -95,6 +112,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu)
>
> static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
> {
> + int ret = 1;
> unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
> unsigned long val;
>
> @@ -114,13 +132,21 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
> case PSCI_0_2_FN64_CPU_ON:
> val = kvm_psci_vcpu_on(vcpu);
> break;
> + case PSCI_0_2_FN_SYSTEM_OFF:
> + kvm_psci_system_off(vcpu);
> + val = PSCI_RET_INTERNAL_FAILURE;
> + ret = 0;
> + break;
> + case PSCI_0_2_FN_SYSTEM_RESET:
> + kvm_psci_system_reset(vcpu);
> + val = PSCI_RET_INTERNAL_FAILURE;
> + ret = 0;
> + break;
Maybe add a comment about why we set INTERNAL_FAILURE here (we shouldn't
be able to come back from such a PSCI call).
> case PSCI_0_2_FN_CPU_SUSPEND:
> case PSCI_0_2_FN_AFFINITY_INFO:
> case PSCI_0_2_FN_MIGRATE:
> case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
> case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
> - case PSCI_0_2_FN_SYSTEM_OFF:
> - case PSCI_0_2_FN_SYSTEM_RESET:
> case PSCI_0_2_FN64_CPU_SUSPEND:
> case PSCI_0_2_FN64_AFFINITY_INFO:
> case PSCI_0_2_FN64_MIGRATE:
> @@ -132,7 +158,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
> }
>
> *vcpu_reg(vcpu, 0) = val;
> - return 1;
> + return ret;
> }
>
> static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
Aside from this minor comment:
Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
M.
--
Jazz is not dead. It just smells funny.
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