On 21/03/17 12:29, Christoffer Dall wrote:
> On Tue, Mar 21, 2017 at 12:05:30PM +0000, Marc Zyngier wrote:
>> On 20/03/17 10:58, Christoffer Dall wrote:
>>> Implement early initialization for both the distributor and the CPU
>>> interfaces. The basic idea is that even though the VGIC is not
>>> functional or not requested from user space, the critical path of the
>>> run loop can still call VGIC functions that just won't do anything,
>>> without them having to check additional initialization flags to ensure
>>> they don't look at uninitialized data structures.
>>>
>>> Signed-off-by: Christoffer Dall <[email protected]>
>>> ---
>>> virt/kvm/arm/vgic/vgic-init.c | 96
>>> +++++++++++++++++++++++++------------------
>>> 1 file changed, 56 insertions(+), 40 deletions(-)
>>>
>>> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
>>> index 3762fd1..25fd1b9 100644
>>> --- a/virt/kvm/arm/vgic/vgic-init.c
>>> +++ b/virt/kvm/arm/vgic/vgic-init.c
>>> @@ -24,7 +24,12 @@
>>>
>>> /*
>>> * Initialization rules: there are multiple stages to the vgic
>>> - * initialization, both for the distributor and the CPU interfaces.
>>> + * initialization, both for the distributor and the CPU interfaces. The
>>> basic
>>> + * idea is that even though the VGIC is not functional or not requested
>>> from
>>> + * user space, the critical path of the run loop can still call VGIC
>>> functions
>>> + * that just won't do anything, without them having to check additional
>>> + * initialization flags to ensure they don't look at uninitialized data
>>> + * structures.
>>> *
>>> * Distributor:
>>> *
>>> @@ -39,23 +44,67 @@
>>> *
>>> * CPU Interface:
>>> *
>>> - * - kvm_vgic_cpu_early_init(): initialization of static data that
>>> + * - kvm_vgic_vcpu_early_init(): initialization of static data that
>>> * doesn't depend on any sizing information or emulation type. No
>>> * allocation is allowed there.
>>> */
>>>
>>> /* EARLY INIT */
>>>
>>> -/*
>>> - * Those 2 functions should not be needed anymore but they
>>> - * still are called from arm.c
>>> +/**
>>> + * kvm_vgic_early_init() - Initialize static VGIC VCPU data structures
>>> + * @kvm: The VM whose VGIC districutor should be initialized
>>> + *
>>> + * Only do initialization of static structures that don't require any
>>> + * allocation or sizing information from userspace. vgic_init() called
>>> + * kvm_vgic_dist_init() which takes care of the rest.
>>> */
>>> void kvm_vgic_early_init(struct kvm *kvm)
>>> {
>>> + struct vgic_dist *dist = &kvm->arch.vgic;
>>> +
>>> + INIT_LIST_HEAD(&dist->lpi_list_head);
>>> + spin_lock_init(&dist->lpi_list_lock);
>>> }
>>>
>>> +/**
>>> + * kvm_vgic_vcpu_early_init() - Initialize static VGIC VCPU data structures
>>> + * @vcpu: The VCPU whose VGIC data structures whould be initialized
>>> + *
>>> + * Only do initialization, but do not actually enable the VGIC CPU
>>> interface
>>> + * yet.
>>> + */
>>> void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu)
>>> {
>>> + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>>> + int i;
>>> +
>>> + INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
>>> + spin_lock_init(&vgic_cpu->ap_list_lock);
>>> +
>>> + /*
>>> + * Enable and configure all SGIs to be edge-triggered and
>>> + * configure all PPIs as level-triggered.
>>> + */
>>> + for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
>>> + struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
>>> +
>>> + INIT_LIST_HEAD(&irq->ap_list);
>>> + spin_lock_init(&irq->irq_lock);
>>> + irq->intid = i;
>>> + irq->vcpu = NULL;
>>> + irq->target_vcpu = vcpu;
>>> + irq->targets = 1U << vcpu->vcpu_id;
>>> + kref_init(&irq->refcount);
>>> + if (vgic_irq_is_sgi(i)) {
>>> + /* SGIs */
>>> + irq->enabled = 1;
>>> + irq->config = VGIC_CONFIG_EDGE;
>>> + } else {
>>> + /* PPIs */
>>> + irq->config = VGIC_CONFIG_LEVEL;
>>> + }
>>> + }
>>> }
>>>
>>> /* CREATION */
>>> @@ -148,9 +197,6 @@ static int kvm_vgic_dist_init(struct kvm *kvm, unsigned
>>> int nr_spis)
>>> struct kvm_vcpu *vcpu0 = kvm_get_vcpu(kvm, 0);
>>> int i;
>>>
>>> - INIT_LIST_HEAD(&dist->lpi_list_head);
>>> - spin_lock_init(&dist->lpi_list_lock);
>>> -
>>> dist->spis = kcalloc(nr_spis, sizeof(struct vgic_irq), GFP_KERNEL);
>>> if (!dist->spis)
>>> return -ENOMEM;
>>> @@ -181,41 +227,11 @@ static int kvm_vgic_dist_init(struct kvm *kvm,
>>> unsigned int nr_spis)
>>> }
>>>
>>> /**
>>> - * kvm_vgic_vcpu_init: initialize the vcpu data structures and
>>> - * enable the VCPU interface
>>> - * @vcpu: the VCPU which's VGIC should be initialized
>>> + * kvm_vgic_vcpu_init() - Enable the VCPU interface
>>> + * @vcpu: the VCPU which's VGIC should be enabled
>>> */
>>> static void kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
>>> {
>>> - struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>>> - int i;
>>> -
>>> - INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
>>> - spin_lock_init(&vgic_cpu->ap_list_lock);
>>> -
>>> - /*
>>> - * Enable and configure all SGIs to be edge-triggered and
>>> - * configure all PPIs as level-triggered.
>>> - */
>>> - for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
>>> - struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
>>> -
>>> - INIT_LIST_HEAD(&irq->ap_list);
>>> - spin_lock_init(&irq->irq_lock);
>>> - irq->intid = i;
>>> - irq->vcpu = NULL;
>>> - irq->target_vcpu = vcpu;
>>> - irq->targets = 1U << vcpu->vcpu_id;
>>> - kref_init(&irq->refcount);
>>> - if (vgic_irq_is_sgi(i)) {
>>> - /* SGIs */
>>> - irq->enabled = 1;
>>> - irq->config = VGIC_CONFIG_EDGE;
>>> - } else {
>>> - /* PPIs */
>>> - irq->config = VGIC_CONFIG_LEVEL;
>>> - }
>>> - }
>>> if (kvm_vgic_global_state.type == VGIC_V2)
>>> vgic_v2_enable(vcpu);
>>> else
>>>
>>
>> Since this function is now about enabling the vgic on a given vcpu,
>> shouldn't the name reflect this? Other than that:
>
> The v3 version does something which is a bit of a mix between
> initialization and enabling, plus it would add even more churn, so, meh,
> not really sure. If you feel it should be kvm_vgic_vcpu_enable(), I'm
> okay with changing it.
Ah, indeed, this is a slightly busier function. Never mind.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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