ARM/ARM64: KVM: Add base for PSCI v0.2 emulation

Currently, the in-kernel PSCI emulation provides PSCI v0.1 interface to
VCPUs. This patch extends current in-kernel PSCI emulation to provide
PSCI v0.2 interface to VCPUs.

By default, ARM/ARM64 KVM will always provide PSCI v0.1 interface for
keeping the ABI backward-compatible.

To select PSCI v0.2 interface for VCPUs, the user space (i.e. QEMU or
KVMTOOL) will have to set KVM_ARM_VCPU_PSCI_0_2 feature when doing VCPU
init using KVM_ARM_VCPU_INIT ioctl.

Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

3 files changed, 11 insertions, 5 deletions

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 09af14999c9b..193ceaf01bfd 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -36,7 +36,7 @@
 #define KVM_COALESCED_MMIO_PAGE_OFFSET 1
 #define KVM_HAVE_ONE_REG
 
-#define KVM_VCPU_MAX_FEATURES 1
+#define KVM_VCPU_MAX_FEATURES 2
 
 #include <kvm/arm_vgic.h>
 
diff --git a/arch/arm/include/asm/kvm_psci.h b/arch/arm/include/asm/kvm_psci.h
index 9a83d98bf170..4c0e3e1d1597 100644
--- a/arch/arm/include/asm/kvm_psci.h
+++ b/arch/arm/include/asm/kvm_psci.h
@@ -18,6 +18,10 @@
 #ifndef __ARM_KVM_PSCI_H__
 #define __ARM_KVM_PSCI_H__
 
+#define KVM_ARM_PSCI_0_1        1
+#define KVM_ARM_PSCI_0_2        2
+
+int kvm_psci_version(struct kvm_vcpu *vcpu);
 bool kvm_psci_call(struct kvm_vcpu *vcpu);
 
 #endif /* __ARM_KVM_PSCI_H__ */
diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index ef0c8785ba16..e6ebdd3471e5 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -20,6 +20,7 @@
 #define __ARM_KVM_H__
 
 #include <linux/types.h>
+#include <linux/psci.h>
 #include <asm/ptrace.h>
 
 #define __KVM_HAVE_GUEST_DEBUG
@@ -83,6 +84,7 @@ struct kvm_regs {
 #define KVM_VGIC_V2_CPU_SIZE            0x2000
 
 #define KVM_ARM_VCPU_POWER_OFF          0 /* CPU is started in OFF state */
+#define KVM_ARM_VCPU_PSCI_0_2           1 /* CPU uses PSCI v0.2 */
 
 struct kvm_vcpu_init {
         __u32 target;
@@ -201,9 +203,9 @@ struct kvm_arch_memory_slot {
 #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)
+#define KVM_PSCI_RET_SUCCESS            PSCI_RET_SUCCESS
+#define KVM_PSCI_RET_NI                 PSCI_RET_NOT_SUPPORTED
+#define KVM_PSCI_RET_INVAL              PSCI_RET_INVALID_PARAMS
+#define KVM_PSCI_RET_DENIED             PSCI_RET_DENIED
 
 #endif /* __ARM_KVM_H__ */