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 vcpu to user space (i.e. QEMU or KVMTOOL) via kvm_run structure using KVM_EXIT_SYSTEM_EVENT exit reasons.
Signed-off-by: Anup Patel anup.patel@linaro.org Signed-off-by: Pranavkumar Sawargaonkar pranavkumar@linaro.org --- arch/arm/include/asm/kvm_psci.h | 2 +- arch/arm/include/uapi/asm/kvm.h | 2 ++ arch/arm/kvm/handle_exit.c | 13 +++++++--- arch/arm/kvm/psci.c | 48 ++++++++++++++++++++++++++++++------- arch/arm64/include/asm/kvm_psci.h | 2 +- arch/arm64/include/uapi/asm/kvm.h | 2 ++ arch/arm64/kvm/handle_exit.c | 12 +++++++--- 7 files changed, 65 insertions(+), 16 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..c3f0e72 100644 --- a/arch/arm/kvm/handle_exit.c +++ b/arch/arm/kvm/handle_exit.c @@ -40,14 +40,21 @@ 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 ret; + else if (ret == -EINVAL) { + kvm_inject_undefined(vcpu); return 1; + } + + return ret;
- kvm_inject_undefined(vcpu); - return 1; }
static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run) diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 0881bf1..8e246d6 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -84,18 +84,41 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) return KVM_PSCI_RET_SUCCESS; }
+static inline void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) +{ + memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); + vcpu->run->system_event.type = type; + vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT; +} + +static void kvm_psci_system_off(struct kvm_vcpu *vcpu) +{ + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN); +} + +static void kvm_psci_system_reset(struct kvm_vcpu *vcpu) +{ + kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_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 (errors) + * + * Errors: + * -EINVAL: Unrecognized PSCI function */ -bool kvm_psci_call(struct kvm_vcpu *vcpu) +int kvm_psci_call(struct kvm_vcpu *vcpu) { + int ret = 1; unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long val;
@@ -111,11 +134,20 @@ 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 = 0; + break; + case KVM_PSCI_FN_SYSTEM_RESET: + kvm_psci_system_reset(vcpu); + val = KVM_PSCI_RET_SUCCESS; + ret = 0; + 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 df84d7b..e382eb8 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -30,11 +30,17 @@ 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 ret; + else if (ret == -EINVAL) { + kvm_inject_undefined(vcpu); return 1; + }
- kvm_inject_undefined(vcpu); - return 1; + return ret; }
static int handle_smc(struct kvm_vcpu *vcpu, struct kvm_run *run)