KVM: ARM: Power State Coordination Interface implementation

Implement the PSCI specification (ARM DEN 0022A) to control
virtual CPUs being "powered" on or off.

PSCI/KVM is detected using the KVM_CAP_ARM_PSCI capability.

A virtual CPU can now be initialized in a "powered off" state,
using the KVM_ARM_VCPU_POWER_OFF feature flag.

The guest can use either SMC or HVC to execute a PSCI function.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index bbb6b2328004..3303ff5adbf3 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -65,6 +65,8 @@ struct kvm_regs {
 #define KVM_ARM_TARGET_CORTEX_A15       0
 #define KVM_ARM_NUM_TARGETS             1
 
+#define KVM_ARM_VCPU_POWER_OFF          0 /* CPU is started in OFF state */
+
 struct kvm_vcpu_init {
         __u32 target;
         __u32 features[7];
@@ -145,4 +147,18 @@ struct kvm_arch_memory_slot {
 /* Highest supported SPI, from VGIC_NR_IRQS */
 #define KVM_ARM_IRQ_GIC_MAX             127
 
+/* PSCI interface */
+#define KVM_PSCI_FN_BASE                0x95c1ba5e
+#define KVM_PSCI_FN(n)                  (KVM_PSCI_FN_BASE + (n))
+
+#define KVM_PSCI_FN_CPU_SUSPEND         KVM_PSCI_FN(0)
+#define KVM_PSCI_FN_CPU_OFF             KVM_PSCI_FN(1)
+#define KVM_PSCI_FN_CPU_ON              KVM_PSCI_FN(2)
+#define KVM_PSCI_FN_MIGRATE             KVM_PSCI_FN(3)
+
+#define KVM_PSCI_RET_SUCCESS            0
+#define KVM_PSCI_RET_NI                 ((unsigned long)-1)
+#define KVM_PSCI_RET_INVAL              ((unsigned long)-2)
+#define KVM_PSCI_RET_DENIED             ((unsigned long)-3)
+
 #endif /* __ARM_KVM_H__ */