[PATCH v3 1/4] ARM/ARM64: KVM: Add support for PSCI v0.2 emulation

Anup Patel anup.patel at linaro.org
Tue Feb 4 04:48:13 EST 2014


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.

Please note that we do not provide all mandatory functions required
by PSCI v0.2 which makes this implemenation as a base for extension
by subsequent patches. This also means KVM_ARM_VCPU_PSCI_0_2 feature
is experimental and will not be available to user space untill all
PSCI v0.2 mandatory functions are provided by KVM ARM/ARM64.

Signed-off-by: Anup Patel <anup.patel at linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
---
 arch/arm/include/asm/kvm_host.h   |    2 +-
 arch/arm/include/asm/kvm_psci.h   |    4 ++
 arch/arm/include/uapi/asm/kvm.h   |   35 ++++++++++++++-
 arch/arm/kvm/guest.c              |    3 ++
 arch/arm/kvm/psci.c               |   85 +++++++++++++++++++++++++++++++------
 arch/arm64/include/asm/kvm_host.h |    2 +-
 arch/arm64/include/asm/kvm_psci.h |    4 ++
 arch/arm64/include/uapi/asm/kvm.h |   35 ++++++++++++++-
 arch/arm64/kvm/guest.c            |    3 ++
 9 files changed, 157 insertions(+), 16 deletions(-)

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 09af149..193ceaf 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 9a83d98..4c0e3e1 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 ef0c878..9c922d9 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -83,6 +83,7 @@ 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;
@@ -192,7 +193,7 @@ struct kvm_arch_memory_slot {
 /* Highest supported SPI, from VGIC_NR_IRQS */
 #define KVM_ARM_IRQ_GIC_MAX		127
 
-/* PSCI interface */
+/* PSCI v0.1 interface */
 #define KVM_PSCI_FN_BASE		0x95c1ba5e
 #define KVM_PSCI_FN(n)			(KVM_PSCI_FN_BASE + (n))
 
@@ -201,9 +202,41 @@ struct kvm_arch_memory_slot {
 #define KVM_PSCI_FN_CPU_ON		KVM_PSCI_FN(2)
 #define KVM_PSCI_FN_MIGRATE		KVM_PSCI_FN(3)
 
+/* PSCI v0.2 interface */
+#define KVM_PSCI_0_2_FN_BASE		0x84000000
+#define KVM_PSCI_0_2_FN(n)		(KVM_PSCI_0_2_FN_BASE + (n))
+#define KVM_PSCI_0_2_FN64_BASE		0xC4000000
+#define KVM_PSCI_0_2_FN64(n)		(KVM_PSCI_0_2_FN64_BASE + (n))
+
+#define KVM_PSCI_0_2_FN_PSCI_VERSION	KVM_PSCI_0_2_FN(0)
+#define KVM_PSCI_0_2_FN_CPU_SUSPEND	KVM_PSCI_0_2_FN(1)
+#define KVM_PSCI_0_2_FN_CPU_OFF		KVM_PSCI_0_2_FN(2)
+#define KVM_PSCI_0_2_FN_CPU_ON		KVM_PSCI_0_2_FN(3)
+#define KVM_PSCI_0_2_FN_AFFINITY_INFO	KVM_PSCI_0_2_FN(4)
+#define KVM_PSCI_0_2_FN_MIGRATE		KVM_PSCI_0_2_FN(5)
+#define KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE \
+					KVM_PSCI_0_2_FN(6)
+#define KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU \
+					KVM_PSCI_0_2_FN(7)
+#define KVM_PSCI_0_2_FN_SYSTEM_OFF	KVM_PSCI_0_2_FN(8)
+#define KVM_PSCI_0_2_FN_SYSTEM_RESET	KVM_PSCI_0_2_FN(9)
+
+#define KVM_PSCI_0_2_FN64_CPU_SUSPEND	KVM_PSCI_0_2_FN64(1)
+#define KVM_PSCI_0_2_FN64_CPU_ON	KVM_PSCI_0_2_FN64(3)
+#define KVM_PSCI_0_2_FN64_AFFINITY_INFO	KVM_PSCI_0_2_FN64(4)
+#define KVM_PSCI_0_2_FN64_MIGRATE	KVM_PSCI_0_2_FN64(5)
+#define KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU \
+					KVM_PSCI_0_2_FN64(7)
+
+/* PSCI return values */
 #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_ALREADY_ON		((unsigned long)-4)
+#define KVM_PSCI_RET_ON_PENDING		((unsigned long)-5)
+#define KVM_PSCI_RET_INTERNAL_FAILURE	((unsigned long)-6)
+#define KVM_PSCI_RET_NOT_PRESENT	((unsigned long)-7)
+#define KVM_PSCI_RET_DISABLED		((unsigned long)-8)
 
 #endif /* __ARM_KVM_H__ */
diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index b23a59c..89929b6 100644
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -307,6 +307,9 @@ int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 		if (test_bit(i, (void *)init->features)) {
 			if (i >= KVM_VCPU_MAX_FEATURES)
 				return -ENOENT;
+			/* Don't allow setting experimental features */
+			if (i == KVM_ARM_VCPU_PSCI_0_2)
+				return -ENOENT;
 			set_bit(i, vcpu->arch.features);
 		}
 	}
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 448f60e..e4ec4af 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -85,17 +85,57 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
 	return KVM_PSCI_RET_SUCCESS;
 }
 
-/**
- * kvm_psci_call - handle PSCI call if r0 value is in range
- * @vcpu: Pointer to the VCPU struct
- *
- * Handle PSCI calls from guests through traps from HVC instructions.
- * The calling convention is similar to SMC calls to the secure world where
- * the function number is placed in r0 and this function returns true if the
- * function number specified in r0 is withing the PSCI range, and false
- * otherwise.
- */
-bool kvm_psci_call(struct kvm_vcpu *vcpu)
+int kvm_psci_version(struct kvm_vcpu *vcpu)
+{
+	if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
+		return KVM_ARM_PSCI_0_2;
+
+	return KVM_ARM_PSCI_0_1;
+}
+
+static bool kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
+{
+	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
+	unsigned long val;
+
+	switch (psci_fn) {
+	case KVM_PSCI_0_2_FN_PSCI_VERSION:
+		/*
+		 * Bits[31:16] = Major Version = 0
+		 * Bits[15:0] = Minor Version = 2
+		 */
+		val = 2;
+		break;
+	case KVM_PSCI_0_2_FN_CPU_OFF:
+		kvm_psci_vcpu_off(vcpu);
+		val = KVM_PSCI_RET_SUCCESS;
+		break;
+	case KVM_PSCI_0_2_FN_CPU_ON:
+	case KVM_PSCI_0_2_FN64_CPU_ON:
+		val = kvm_psci_vcpu_on(vcpu);
+		break;
+	case KVM_PSCI_0_2_FN_CPU_SUSPEND:
+	case KVM_PSCI_0_2_FN_AFFINITY_INFO:
+	case KVM_PSCI_0_2_FN_MIGRATE:
+	case KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE:
+	case KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
+	case KVM_PSCI_0_2_FN_SYSTEM_OFF:
+	case KVM_PSCI_0_2_FN_SYSTEM_RESET:
+	case KVM_PSCI_0_2_FN64_CPU_SUSPEND:
+	case KVM_PSCI_0_2_FN64_AFFINITY_INFO:
+	case KVM_PSCI_0_2_FN64_MIGRATE:
+	case KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
+		val = KVM_PSCI_RET_NI;
+		break;
+	default:
+		return false;
+	}
+
+	*vcpu_reg(vcpu, 0) = val;
+	return true;
+}
+
+static bool kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
 {
 	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
 	unsigned long val;
@@ -112,7 +152,6 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
 	case KVM_PSCI_FN_MIGRATE:
 		val = KVM_PSCI_RET_NI;
 		break;
-
 	default:
 		return false;
 	}
@@ -120,3 +159,25 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
 	*vcpu_reg(vcpu, 0) = val;
 	return true;
 }
+
+/**
+ * kvm_psci_call - handle PSCI call if r0 value is in range
+ * @vcpu: Pointer to the VCPU struct
+ *
+ * Handle PSCI calls from guests through traps from HVC instructions.
+ * The calling convention is similar to SMC calls to the secure world where
+ * the function number is placed in r0 and this function returns true if the
+ * function number specified in r0 is withing the PSCI range, and false
+ * otherwise.
+ */
+bool kvm_psci_call(struct kvm_vcpu *vcpu)
+{
+	switch (kvm_psci_version(vcpu)) {
+	case KVM_ARM_PSCI_0_2:
+		return kvm_psci_0_2_call(vcpu);
+	case KVM_ARM_PSCI_0_1:
+		return kvm_psci_0_1_call(vcpu);
+	default:
+		return false;
+	};
+}
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 0a1d697..92242ce 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -39,7 +39,7 @@
 #include <kvm/arm_vgic.h>
 #include <kvm/arm_arch_timer.h>
 
-#define KVM_VCPU_MAX_FEATURES 2
+#define KVM_VCPU_MAX_FEATURES 3
 
 struct kvm_vcpu;
 int kvm_target_cpu(void);
diff --git a/arch/arm64/include/asm/kvm_psci.h b/arch/arm64/include/asm/kvm_psci.h
index e301a48..e25c658 100644
--- a/arch/arm64/include/asm/kvm_psci.h
+++ b/arch/arm64/include/asm/kvm_psci.h
@@ -18,6 +18,10 @@
 #ifndef __ARM64_KVM_PSCI_H__
 #define __ARM64_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 /* __ARM64_KVM_PSCI_H__ */
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 495ab6f..31c2f54 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -77,6 +77,7 @@ struct kvm_regs {
 
 #define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */
 #define KVM_ARM_VCPU_EL1_32BIT		1 /* CPU running a 32bit VM */
+#define KVM_ARM_VCPU_PSCI_0_2		2 /* CPU uses PSCI v0.2 */
 
 struct kvm_vcpu_init {
 	__u32 target;
@@ -168,7 +169,7 @@ struct kvm_arch_memory_slot {
 /* Highest supported SPI, from VGIC_NR_IRQS */
 #define KVM_ARM_IRQ_GIC_MAX		127
 
-/* PSCI interface */
+/* PSCI v0.1 interface */
 #define KVM_PSCI_FN_BASE		0x95c1ba5e
 #define KVM_PSCI_FN(n)			(KVM_PSCI_FN_BASE + (n))
 
@@ -177,10 +178,42 @@ struct kvm_arch_memory_slot {
 #define KVM_PSCI_FN_CPU_ON		KVM_PSCI_FN(2)
 #define KVM_PSCI_FN_MIGRATE		KVM_PSCI_FN(3)
 
+/* PSCI v0.2 interface */
+#define KVM_PSCI_0_2_FN_BASE		0x84000000
+#define KVM_PSCI_0_2_FN(n)		(KVM_PSCI_0_2_FN_BASE + (n))
+#define KVM_PSCI_0_2_FN64_BASE		0xC4000000
+#define KVM_PSCI_0_2_FN64(n)		(KVM_PSCI_0_2_FN64_BASE + (n))
+
+#define KVM_PSCI_0_2_FN_PSCI_VERSION	KVM_PSCI_0_2_FN(0)
+#define KVM_PSCI_0_2_FN_CPU_SUSPEND	KVM_PSCI_0_2_FN(1)
+#define KVM_PSCI_0_2_FN_CPU_OFF		KVM_PSCI_0_2_FN(2)
+#define KVM_PSCI_0_2_FN_CPU_ON		KVM_PSCI_0_2_FN(3)
+#define KVM_PSCI_0_2_FN_AFFINITY_INFO	KVM_PSCI_0_2_FN(4)
+#define KVM_PSCI_0_2_FN_MIGRATE		KVM_PSCI_0_2_FN(5)
+#define KVM_PSCI_0_2_FN_MIGRATE_INFO_TYPE \
+					KVM_PSCI_0_2_FN(6)
+#define KVM_PSCI_0_2_FN_MIGRATE_INFO_UP_CPU \
+					KVM_PSCI_0_2_FN(7)
+#define KVM_PSCI_0_2_FN_SYSTEM_OFF	KVM_PSCI_0_2_FN(8)
+#define KVM_PSCI_0_2_FN_SYSTEM_RESET	KVM_PSCI_0_2_FN(9)
+
+#define KVM_PSCI_0_2_FN64_CPU_SUSPEND	KVM_PSCI_0_2_FN64(1)
+#define KVM_PSCI_0_2_FN64_CPU_ON	KVM_PSCI_0_2_FN64(3)
+#define KVM_PSCI_0_2_FN64_AFFINITY_INFO	KVM_PSCI_0_2_FN64(4)
+#define KVM_PSCI_0_2_FN64_MIGRATE	KVM_PSCI_0_2_FN64(5)
+#define KVM_PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU \
+					KVM_PSCI_0_2_FN64(7)
+
+/* PSCI return values */
 #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_ALREADY_ON		((unsigned long)-4)
+#define KVM_PSCI_RET_ON_PENDING		((unsigned long)-5)
+#define KVM_PSCI_RET_INTERNAL_FAILURE	((unsigned long)-6)
+#define KVM_PSCI_RET_NOT_PRESENT	((unsigned long)-7)
+#define KVM_PSCI_RET_DISABLED		((unsigned long)-8)
 
 #endif
 
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 0874557..b27877c 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -246,6 +246,9 @@ int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 		if (init->features[i / 32] & (1 << (i % 32))) {
 			if (i >= KVM_VCPU_MAX_FEATURES)
 				return -ENOENT;
+			/* Don't allow setting experimental features */
+			if (i == KVM_ARM_VCPU_PSCI_0_2)
+				return -ENOENT;
 			set_bit(i, vcpu->arch.features);
 		}
 	}
-- 
1.7.9.5




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