To avoid a race between turning VCPUs off and turning them on, make sure that only the VCPU threat itself turns off the VCPU. When other threads want to turn of a VCPU, they now do this via a request.
Signed-off-by: Christoffer Dall <christoffer.d...@arm.com> Acked-by: Marc Zyngier <marc.zyng...@arm.com> --- arch/arm/include/asm/kvm_host.h | 2 ++ arch/arm64/include/asm/kvm_host.h | 2 ++ virt/kvm/arm/arm.c | 8 ++++++-- virt/kvm/arm/psci.c | 11 ++--------- 4 files changed, 12 insertions(+), 11 deletions(-) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 50e89869178a..b1cfae222441 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -49,6 +49,8 @@ KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) #define KVM_REQ_IRQ_PENDING KVM_ARCH_REQ(1) #define KVM_REQ_VCPU_RESET KVM_ARCH_REQ(2) +#define KVM_REQ_VCPU_OFF \ + KVM_ARCH_REQ_FLAGS(3, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use); diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index da3fc7324d68..d43b13421987 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -49,6 +49,8 @@ KVM_ARCH_REQ_FLAGS(0, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) #define KVM_REQ_IRQ_PENDING KVM_ARCH_REQ(1) #define KVM_REQ_VCPU_RESET KVM_ARCH_REQ(2) +#define KVM_REQ_VCPU_OFF \ + KVM_ARCH_REQ_FLAGS(3, KVM_REQUEST_WAIT | KVM_REQUEST_NO_WAKEUP) DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use); diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 9c486fad3f9f..785076176814 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -404,8 +404,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) static void vcpu_power_off(struct kvm_vcpu *vcpu) { - vcpu->arch.power_off = true; - kvm_make_request(KVM_REQ_SLEEP, vcpu); + kvm_make_request(KVM_REQ_VCPU_OFF, vcpu); kvm_vcpu_kick(vcpu); } @@ -646,6 +645,11 @@ static void check_vcpu_requests(struct kvm_vcpu *vcpu) if (kvm_check_request(KVM_REQ_SLEEP, vcpu)) vcpu_req_sleep(vcpu); + if (kvm_check_request(KVM_REQ_VCPU_OFF, vcpu)) { + vcpu->arch.power_off = true; + vcpu_req_sleep(vcpu); + } + if (kvm_check_request(KVM_REQ_VCPU_RESET, vcpu)) kvm_reset_vcpu(vcpu); diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index b9cff1d4b06d..20255319e193 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -97,9 +97,7 @@ static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) { - vcpu->arch.power_off = true; - kvm_make_request(KVM_REQ_SLEEP, vcpu); - kvm_vcpu_kick(vcpu); + kvm_make_request(KVM_REQ_VCPU_OFF, vcpu); } static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) @@ -198,9 +196,6 @@ static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu) static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) { - int i; - struct kvm_vcpu *tmp; - /* * The KVM ABI specifies that a system event exit may call KVM_RUN * again and may perform shutdown/reboot at a later time that when the @@ -210,9 +205,7 @@ static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type) * after this call is handled and before the VCPUs have been * re-initialized. */ - kvm_for_each_vcpu(i, tmp, vcpu->kvm) - tmp->arch.power_off = true; - kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP); + kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_VCPU_OFF); memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event)); vcpu->run->system_event.type = type; -- 2.18.0 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm