On Tue, Apr 15 2014 at 7:14:10 am BST, Anup Patel anup.patel@linaro.org 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@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org Reviewed-by: Christoffer Dall christoffer.dall@linaro.org
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..b964aa4 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 inline void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
Loose the "inline". This is not performance critical, and the compiler does a pretty good job doing that for you.
+{
- 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_SUCCESS;ret = 0;break;- case PSCI_0_2_FN_SYSTEM_RESET:
kvm_psci_system_reset(vcpu);val = PSCI_RET_SUCCESS;ret = 0;break;
What is the significance of setting val to PSCI_RET_SUCCESS here? We're exiting to userspace, so surely only the platform emulation can set that. Am I missing something?
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)