[PATCH 03/16] ARM/ARM64: KVM: Add base for PSCI v0.2 emulation

Christoffer Dall
2014-05-25T18:19:16Z

From: Anup Patel <anup.patel@linaro.org>

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>
---
arch/arm/include/asm/kvm_host.h | 2 +-
arch/arm/include/asm/kvm_psci.h | 4 ++
arch/arm/include/uapi/asm/kvm.h | 10 +++--
arch/arm/kvm/psci.c | 93 ++++++++++++++++++++++++++++++++-------
arch/arm64/include/asm/kvm_host.h | 2 +-
arch/arm64/include/asm/kvm_psci.h | 4 ++
arch/arm64/include/uapi/asm/kvm.h | 10 +++--
7 files changed, 99 insertions(+), 26 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..e6ebdd3 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__ */
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 448f60e..8c42596c 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -59,7 +59,7 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
* turned off.
*/
if (!vcpu || !vcpu->arch.pause)
- return KVM_PSCI_RET_INVAL;
+ return PSCI_RET_INVALID_PARAMS;

target_pc = *vcpu_reg(source_vcpu, 2);

@@ -82,20 +82,60 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
wq = kvm_arch_vcpu_wq(vcpu);
wake_up_interruptible(wq);

- return KVM_PSCI_RET_SUCCESS;
+ return 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 PSCI_0_2_FN_PSCI_VERSION:
+ /*
+ * Bits[31:16] = Major Version = 0
+ * Bits[15:0] = Minor Version = 2
+ */
+ val = 2;
+ break;
+ case PSCI_0_2_FN_CPU_OFF:
+ kvm_psci_vcpu_off(vcpu);
+ val = PSCI_RET_SUCCESS;
+ break;
+ case PSCI_0_2_FN_CPU_ON:
+ case PSCI_0_2_FN64_CPU_ON:
+ val = kvm_psci_vcpu_on(vcpu);
+ break;
+ 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:
+ case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
+ val = PSCI_RET_NOT_SUPPORTED;
+ 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;
@@ -103,16 +143,15 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
switch (psci_fn) {
case KVM_PSCI_FN_CPU_OFF:
kvm_psci_vcpu_off(vcpu);
- val = KVM_PSCI_RET_SUCCESS;
+ val = PSCI_RET_SUCCESS;
break;
case KVM_PSCI_FN_CPU_ON:
val = kvm_psci_vcpu_on(vcpu);
break;
case KVM_PSCI_FN_CPU_SUSPEND:
case KVM_PSCI_FN_MIGRATE:
- val = KVM_PSCI_RET_NI;
+ val = PSCI_RET_NOT_SUPPORTED;
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 eaf54a3..e6471da 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -31,6 +31,7 @@
#define KVM_NR_SPSR 5

#ifndef __ASSEMBLY__
+#include <linux/psci.h>
#include <asm/types.h>
#include <asm/ptrace.h>

@@ -77,6 +78,7 @@ 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;
@@ -186,10 +188,10 @@ 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

--
1.8.5.2