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ARM/ARM64: KVM: Emulate PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET

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The PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET functions are system-level
functions hence cannot be fully emulated by in-kernel PSCI emulation code.

To tackle this, we forward PSCI v0.2 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>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
This commit is contained in:
Anup Patel 2014-04-29 11:24:20 +05:30 • committed by Christoffer Dall
parent 8ad6b63492
commit 4b1238269e
1 changed files with 43 additions and 3 deletions
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46
arch/arm/kvm/psci.c
View file

@ -85,6 +85,23 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
return PSCI_RET_SUCCESS; return PSCI_RET_SUCCESS;
} }
static 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);
}
int kvm_psci_version(struct kvm_vcpu *vcpu) int kvm_psci_version(struct kvm_vcpu *vcpu)
{ {
if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features)) if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
@ -95,6 +112,7 @@ int kvm_psci_version(struct kvm_vcpu *vcpu)
static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
{ {
int ret = 1;
unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
unsigned long val; unsigned long val;
@ -114,13 +132,35 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
case PSCI_0_2_FN64_CPU_ON: case PSCI_0_2_FN64_CPU_ON:
val = kvm_psci_vcpu_on(vcpu); val = kvm_psci_vcpu_on(vcpu);
break; break;
case PSCI_0_2_FN_SYSTEM_OFF:
kvm_psci_system_off(vcpu);
/*
* We should'nt be going back to guest VCPU after
* receiving SYSTEM_OFF request.
*
* If user space accidently/deliberately resumes
* guest VCPU after SYSTEM_OFF request then guest
* VCPU should see internal failure from PSCI return
* value. To achieve this, we preload r0 (or x0) with
* PSCI return value INTERNAL_FAILURE.
*/
val = PSCI_RET_INTERNAL_FAILURE;
ret = 0;
break;
case PSCI_0_2_FN_SYSTEM_RESET:
kvm_psci_system_reset(vcpu);
/*
* Same reason as SYSTEM_OFF for preloading r0 (or x0)
* with PSCI return value INTERNAL_FAILURE.
*/
val = PSCI_RET_INTERNAL_FAILURE;
ret = 0;
break;
case PSCI_0_2_FN_CPU_SUSPEND: case PSCI_0_2_FN_CPU_SUSPEND:
case PSCI_0_2_FN_AFFINITY_INFO: case PSCI_0_2_FN_AFFINITY_INFO:
case PSCI_0_2_FN_MIGRATE: case PSCI_0_2_FN_MIGRATE:
case PSCI_0_2_FN_MIGRATE_INFO_TYPE: case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU: 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_CPU_SUSPEND:
case PSCI_0_2_FN64_AFFINITY_INFO: case PSCI_0_2_FN64_AFFINITY_INFO:
case PSCI_0_2_FN64_MIGRATE: case PSCI_0_2_FN64_MIGRATE:
@ -132,7 +172,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
} }
*vcpu_reg(vcpu, 0) = val; *vcpu_reg(vcpu, 0) = val;
return 1; return ret;
} }
static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)