Re: [RFC PATCH 40/45] KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init

Christoffer Dall
2016-03-31T17:58:26Z

On Fri, Mar 25, 2016 at 02:05:03AM +0000, Andre Przywara wrote:
> From: Eric Auger <eric.auger@linaro.org>
>
> This patch allocates and initializes the data structures used
> to model the vgic distributor and virtual cpu interfaces. At that
> stage the number of IRQs and number of virtual CPUs is frozen.
>
> The following realy_init functions are kept since they are called from
> arm.c. However they may disappear in subsequent patches since
> they are void.
>
> vgic_[v2|v3]_enable still is stubbed at this stage.

early init ?

>
> Signed-off-by: Eric Auger <eric.auger@linaro.org>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> include/kvm/vgic/vgic.h | 7 +-
> virt/kvm/arm/vgic/vgic-v2.c | 5 +
> virt/kvm/arm/vgic/vgic-v3.c | 5 +
> virt/kvm/arm/vgic/vgic.c | 5 +
> virt/kvm/arm/vgic/vgic.h | 8 ++
> virt/kvm/arm/vgic/vgic_init.c | 214 ++++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 243 insertions(+), 1 deletion(-)
>
> diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
> index 536582b..4a51582 100644
> --- a/include/kvm/vgic/vgic.h
> +++ b/include/kvm/vgic/vgic.h
> @@ -115,6 +115,7 @@ struct vgic_io_device {
> struct vgic_dist {
> bool in_kernel;
> bool ready;
> + bool initialized;
>
> /* vGIC model the kernel emulates for the guest (GICv2 or GICv3) */
> u32 vgic_model;
> @@ -195,7 +196,11 @@ struct vgic_cpu {
> };
>
> int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
> +void kvm_vgic_early_init(struct kvm *kvm);
> int kvm_vgic_create(struct kvm *kvm, u32 type);
> +void kvm_vgic_destroy(struct kvm *kvm);
> +void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu);
> +void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
> int kvm_vgic_hyp_init(void);
>
> int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
> @@ -204,7 +209,7 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
> int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
>
> #define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel))
> -#define vgic_initialized(k) (false)
> +#define vgic_initialized(k) ((k)->arch.vgic.initialized)
> #define vgic_ready(k) ((k)->arch.vgic.ready)
> #define vgic_valid_spi(k,i) (((i) >= VGIC_NR_PRIVATE_IRQS) && \
> ((i) < (k)->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS))
> diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
> index 0cb5c4f..c48dbd4 100644
> --- a/virt/kvm/arm/vgic/vgic-v2.c
> +++ b/virt/kvm/arm/vgic/vgic-v2.c
> @@ -234,6 +234,11 @@ void vgic_v2_irq_change_affinity(struct kvm *kvm, u32 intid, u8 new_targets)
> spin_unlock(&irq->irq_lock);
> }
>
> +/* not yet implemented */
> +void vgic_v2_enable(struct kvm_vcpu *vcpu)
> +{
> +}
> +
> /**
> * vgic_v2_probe - probe for a GICv2 compatible interrupt controller in DT
> * @node: pointer to the DT node
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 1a53141..3155680 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -220,6 +220,11 @@ void vgic_v3_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
> vmcrp->pmr = (vmcr & ICH_VMCR_PMR_MASK) >> ICH_VMCR_PMR_SHIFT;
> }
>
> +/* not yet implemented */
> +void vgic_v3_enable(struct kvm_vcpu *vcpu)
> +{
> +}
> +
> /**
> * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
> * @node: pointer to the DT node
> diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c
> index 8c19379..4ade7c0 100644
> --- a/virt/kvm/arm/vgic/vgic.c
> +++ b/virt/kvm/arm/vgic/vgic.c
> @@ -268,6 +268,11 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int intid,
> bool level)
> {
> struct kvm_vcpu *vcpu;
> + int ret;
> +
> + ret = vgic_lazy_init(kvm);
> + if (ret)
> + return ret;
>
> vcpu = kvm_get_vcpu(kvm, cpuid);
> vgic_update_irq_pending(kvm, vcpu, intid, level);
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 31c9299a..4b2e1b0 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -38,6 +38,7 @@ int vgic_v2_dist_access(struct kvm_vcpu *vcpu, bool is_write,
> int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr);
> void vgic_v2_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
> void vgic_v2_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
> +void vgic_v2_enable(struct kvm_vcpu *vcpu);
> int vgic_v2_probe(struct device_node *vgic_node);
>
> #ifdef CONFIG_KVM_ARM_VGIC_V3
> @@ -52,6 +53,7 @@ int vgic_v3_redist_access(struct kvm_vcpu *vcpu, bool is_write,
> int offset, int len, void *val);
> void vgic_v3_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
> void vgic_v3_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
> +void vgic_v3_enable(struct kvm_vcpu *vcpu);
> int vgic_v3_probe(struct device_node *vgic_node);
> #else
> static inline void vgic_v3_irq_change_affinity(struct kvm *kvm, u32 intid,
> @@ -98,6 +100,10 @@ void vgic_v3_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
> {
> }
>
> +static inline void vgic_v3_enable(struct kvm_vcpu *vcpu)
> +{
> +}
> +
> static inline int vgic_v3_probe(struct device_node *vgic_node)
> {
> return -ENODEV;
> @@ -107,6 +113,8 @@ static inline int vgic_v3_probe(struct device_node *vgic_node)
> void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
> void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
>
> +int vgic_lazy_init(struct kvm *kvm);
> +int vgic_init(struct kvm *kvm);
> void kvm_register_vgic_device(unsigned long type);
>
> #endif
> diff --git a/virt/kvm/arm/vgic/vgic_init.c b/virt/kvm/arm/vgic/vgic_init.c
> index 80bf283..f7a6a11 100644
> --- a/virt/kvm/arm/vgic/vgic_init.c
> +++ b/virt/kvm/arm/vgic/vgic_init.c
> @@ -24,6 +24,42 @@
> #include <asm/kvm_mmu.h>
> #include "vgic.h"
>
> +/*
> + * Initialization rules: there are multiple stages to the vgic
> + * initialization, both for the distributor and the CPU interfaces.
> + *
> + * Distributor:
> + *
> + * - kvm_vgic_early_init(): initialization of static data that doesn't
> + * depend on any sizing information or emulation type. No allocation
> + * is allowed there.
> + *
> + * - vgic_init(): allocation and initialization of the generic data
> + * structures that depend on sizing information (number of CPUs,
> + * number of interrupts). Also initializes the vcpu specific data
> + * structures. Can be executed lazily for GICv2.
> + *
> + * CPU Interface:
> + *
> + * - kvm_vgic_cpu_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
> + */
> +void kvm_vgic_early_init(struct kvm *kvm)
> +{
> +}
> +
> +void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu)
> +{
> +}
> +
> /* CREATION */
>
> /**
> @@ -108,6 +144,184 @@ out:
> return ret;
> }
>
> +/* INIT/DESTROY */
> +
> +/**
> + * kvm_vgic_dist_init: initialize the dist data structures
> + * @kvm: kvm struct pointer
> + * @nr_spis: number of spis, frozen by caller
> + */
> +int kvm_vgic_dist_init(struct kvm *kvm, unsigned int nr_spis)
> +{
> + struct vgic_dist *dist = &kvm->arch.vgic;
> + int i;
> +
> + dist->spis = kcalloc(nr_spis, sizeof(struct vgic_irq), GFP_KERNEL);
> + if (!dist->spis)
> + return -ENOMEM;
> +
> + /*
> + * In following code we do not take the irq struct lock since
> + * no other action on irq structs can happen while the VGIC is
> + * not initialized yet:
> + * injection requires (VGICV3) or does (VGIC2) initialization.
> + * MMIO access triggers init.
> + */
> + for (i = 0; i < nr_spis; i++) {
> + struct vgic_irq *irq = &dist->spis[i];
> +
> + irq->intid = i + VGIC_NR_PRIVATE_IRQS;
> + INIT_LIST_HEAD(&irq->ap_list);
> + spin_lock_init(&irq->irq_lock);
> + irq->vcpu = NULL;
> + if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
> + vgic_v2_irq_change_affinity(kvm, irq->intid, 0);
> + else
> + vgic_v3_irq_change_affinity(kvm, irq->intid, 0);
> + }
> + return 0;
> +}
> +
> +/**
> + * kvm_vgic_vcpu_init: initialize the vcpu data structures and
> + * enable the VCPU interface
> + * @kvm: kvm struct pointer
> + */
> +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);
> + vgic_cpu->nr_lr = kvm_vgic_global_state.nr_lr;
> +
> + /*
> + * 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);

I don't think this is strictly required, but ok.

> + spin_lock_init(&irq->irq_lock);
> + irq->intid = i;
> + irq->vcpu = NULL;
> + irq->target_vcpu = vcpu;
> + irq->targets = 1U << vcpu->vcpu_id;
> + if (i < VGIC_NR_SGIS) {
> + /* 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
> + vgic_v3_enable(vcpu);
> +}
> +
> +/*
> + * vgic_init: allocates and initializes dist and vcpu data structures
> + * depending on two dimensioning parameters:
> + * - the number of spis
> + * - the number of vcpus
> + * The function is generally called when nr_spis has been explicitly set
> + * by the guest through the KVM DEVICE API. If not nr_spis is set to 256.
> + * Completion can be tested by vgic_initialized
> + * Must be called with kvm->lock held!
> + */
> +int vgic_init(struct kvm *kvm)
> +{
> + struct vgic_dist *dist = &kvm->arch.vgic;
> + struct kvm_vcpu *vcpu;
> + int ret = 0, i;
> +
> + if (vgic_initialized(kvm))
> + return 0;
> +
> + /* freeze the number of spis */
> + if (!dist->nr_spis)
> + dist->nr_spis = VGIC_NR_IRQS_LEGACY - VGIC_NR_PRIVATE_IRQS;
> +
> + ret = kvm_vgic_dist_init(kvm, dist->nr_spis);
> + if (ret)
> + goto out;
> +
> + kvm_for_each_vcpu(i, vcpu, kvm)
> + kvm_vgic_vcpu_init(vcpu);
> +
> + dist->initialized = true;
> +out:
> + return ret;
> +}
> +
> +static void kvm_vgic_dist_destroy(struct kvm *kvm)
> +{
> + struct vgic_dist *dist = &kvm->arch.vgic;
> +
> + mutex_lock(&kvm->lock);
> +
> + dist->ready = false;
> + dist->initialized = false;
> +
> + kfree(dist->spis);
> + kfree(dist->dist_iodevs);
> + kfree(dist->redist_iodevs);
> + dist->nr_spis = 0;
> +
> + mutex_unlock(&kvm->lock);
> +}
> +
> +void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
> +{
> + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
> +
> + INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
> + vgic_cpu->nr_lr = 0;
> +}
> +
> +void kvm_vgic_destroy(struct kvm *kvm)
> +{
> + struct kvm_vcpu *vcpu;
> + int i;
> +
> + kvm_vgic_dist_destroy(kvm);
> +
> + kvm_for_each_vcpu(i, vcpu, kvm)
> + kvm_vgic_vcpu_destroy(vcpu);
> +}
> +
> +/**
> + * Lazy init only is allowed if the GIC exposed to the guest is a GICV2.
> + * GICV3 must be explicitly initialized by the guest using the
> + * KVM_DEV_ARM_VGIC_GRP_CTRL KVM_DEVICE group
> + */
> +int vgic_lazy_init(struct kvm *kvm)
> +{
> + int ret = 0;
> +
> + if (unlikely(!vgic_initialized(kvm))) {
> + /*
> + * We only provide the automatic initialization of the VGIC
> + * for the legacy case of a GICv2. Any other type must
> + * be explicitly initialized once setup with the respective
> + * KVM device call.
> + */
> + if (kvm->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V2)
> + return -EBUSY;
> +
> + mutex_lock(&kvm->lock);
> + ret = vgic_init(kvm);
> + mutex_unlock(&kvm->lock);
> + }
> +
> + return ret;
> +}
> +
> /* GENERIC PROBE */
>
> static void vgic_init_maintenance_interrupt(void *info)
> --
> 2.7.3
>