The PSCI SYSTEM_OFF and SYSTEM_RESET functions are system-level
functions hence cannot be fully emulated by the in-kernel PSCI
emulation code.
To tackle this, we forward PSCI SYSTEM_OFF and SYSTEM_RESET function
calls from guest to user space (i.e. QEMU or KVMTOOL) via KVM run
structure using KVM_EXIT_SHUTDOWN and KVM_EXIT_RESET exit reasons.
Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxx>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx>
---
arch/arm/include/asm/kvm_psci.h | 2 +-
arch/arm/include/uapi/asm/kvm.h | 2 ++
arch/arm/kvm/handle_exit.c | 7 ++++++-
arch/arm/kvm/psci.c | 38 +++++++++++++++++++++++++++++--------
arch/arm64/include/asm/kvm_psci.h | 2 +-
arch/arm64/include/uapi/asm/kvm.h | 2 ++
arch/arm64/kvm/handle_exit.c | 10 ++++++----
7 files changed, 48 insertions(+), 15 deletions(-)
diff --git a/arch/arm/include/asm/kvm_psci.h b/arch/arm/include/asm/kvm_psci.h
index 9a83d98..992d7f1 100644
--- a/arch/arm/include/asm/kvm_psci.h
+++ b/arch/arm/include/asm/kvm_psci.h
@@ -18,6 +18,6 @@
#ifndef __ARM_KVM_PSCI_H__
#define __ARM_KVM_PSCI_H__
-bool kvm_psci_call(struct kvm_vcpu *vcpu);
+int 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 c498b60..f4de20c 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -172,6 +172,8 @@ struct kvm_arch_memory_slot {
#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_FN_SYSTEM_OFF KVM_PSCI_FN(4)
+#define KVM_PSCI_FN_SYSTEM_RESET KVM_PSCI_FN(5)
#define KVM_PSCI_RET_SUCCESS 0
#define KVM_PSCI_RET_NI ((unsigned long)-1)
diff --git a/arch/arm/kvm/handle_exit.c b/arch/arm/kvm/handle_exit.c
index a920790..c96c7e8 100644
--- a/arch/arm/kvm/handle_exit.c
+++ b/arch/arm/kvm/handle_exit.c
@@ -40,11 +40,16 @@ static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
+ int ret;
+
trace_kvm_hvc(*vcpu_pc(vcpu), *vcpu_reg(vcpu, 0),
kvm_vcpu_hvc_get_imm(vcpu));
- if (kvm_psci_call(vcpu))
+ ret = kvm_psci_call(vcpu);
+ if (ret == 0)
return 1;
+ else if (ret > 0)
+ return 0;
kvm_inject_undefined(vcpu);
return 1;
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
index 0881bf1..c8d3fcd 100644
--- a/arch/arm/kvm/psci.c
+++ b/arch/arm/kvm/psci.c
@@ -84,18 +84,31 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
return KVM_PSCI_RET_SUCCESS;
}
+static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
+{
+ vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN;
+}
+
+static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
+{
+ vcpu->run->exit_reason = KVM_EXIT_RESET;
+}
+
/**
* 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.
+ * The calling convention is similar to SMC calls to the secure world
+ * where the function number is placed in r0 and function number
+ * specified in r0 is withing the PSCI range.
+ *
+ * This function returns: 0 (success), > 0 (success but exit to user
+ * space), and < 0 (failure)
*/
-bool kvm_psci_call(struct kvm_vcpu *vcpu)
+int kvm_psci_call(struct kvm_vcpu *vcpu)
{
+ int ret = 0;
unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
unsigned long val;
@@ -111,11 +124,20 @@ bool kvm_psci_call(struct kvm_vcpu *vcpu)
case KVM_PSCI_FN_MIGRATE:
val = KVM_PSCI_RET_NI;
break;
-
+ case KVM_PSCI_FN_SYSTEM_OFF:
+ kvm_psci_system_off(vcpu);
+ val = KVM_PSCI_RET_SUCCESS;
+ ret = 1;
+ break;
+ case KVM_PSCI_FN_SYSTEM_RESET:
+ kvm_psci_system_reset(vcpu);
+ val = KVM_PSCI_RET_SUCCESS;
+ ret = 1;
+ break;
default:
- return false;
+ return -EINVAL;
}
*vcpu_reg(vcpu, 0) = val;
- return true;
+ return ret;
}
diff --git a/arch/arm64/include/asm/kvm_psci.h b/arch/arm64/include/asm/kvm_psci.h
index e301a48..9bd0ee8 100644
--- a/arch/arm64/include/asm/kvm_psci.h
+++ b/arch/arm64/include/asm/kvm_psci.h
@@ -18,6 +18,6 @@
#ifndef __ARM64_KVM_PSCI_H__
#define __ARM64_KVM_PSCI_H__
-bool kvm_psci_call(struct kvm_vcpu *vcpu);
+int 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 d9f026b..f678902 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -158,6 +158,8 @@ struct kvm_arch_memory_slot {
#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_FN_SYSTEM_OFF KVM_PSCI_FN(4)
+#define KVM_PSCI_FN_SYSTEM_RESET KVM_PSCI_FN(5)
#define KVM_PSCI_RET_SUCCESS 0
#define KVM_PSCI_RET_NI ((unsigned long)-1)
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 8da5606..a5b5b6a 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -30,8 +30,13 @@ typedef int (*exit_handle_fn)(struct kvm_vcpu *, struct kvm_run *);
static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
- if (kvm_psci_call(vcpu))
+ int ret;
+
+ ret = kvm_psci_call(vcpu);
+ if (ret == 0)
return 1;
+ else if (ret > 0)
+ return 0;
kvm_inject_undefined(vcpu);
return 1;
@@ -39,9 +44,6 @@ static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
- if (kvm_psci_call(vcpu))
- return 1;
-
kvm_inject_undefined(vcpu);
return 1;
}
--
1.7.9.5
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