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| author | Anup Patel <anup.patel@linaro.org> | 2014-04-29 11:24:20 +0530 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2014-04-30 04:18:58 -0700 |
| commit | 4b1238269ed340d59ef829fd9c30a39cfb2923a8 (patch) | |
| tree | 8e2fcecc8c6e7678a6c70337f892284e487ce8f0 /arch/arm/kvm | |
| parent | 8ad6b634928a25971dc42dce101808b1491f87ec (diff) | |
| download | linux-4b1238269ed340d59ef829fd9c30a39cfb2923a8.tar.gz linux-4b1238269ed340d59ef829fd9c30a39cfb2923a8.tar.bz2 linux-4b1238269ed340d59ef829fd9c30a39cfb2923a8.zip | |
ARM/ARM64: KVM: Emulate PSCI v0.2 SYSTEM_OFF and SYSTEM_RESET
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>
Diffstat (limited to 'arch/arm/kvm')
| -rw-r--r-- | arch/arm/kvm/psci.c | 46 |
1 files changed, 43 insertions, 3 deletions
diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 14e6fa6c8e35..59362131b79f 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -85,6 +85,23 @@ static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) 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) { 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) { + int ret = 1; unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); 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: val = kvm_psci_vcpu_on(vcpu); 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_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: @@ -132,7 +172,7 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) } *vcpu_reg(vcpu, 0) = val; - return 1; + return ret; } static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu) |