Subject: [PATCH v3 50/55] KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init

From: [email-masked] (Christoffer Dall)
Date: Thu, 12 May 2016 21:25:50 +0200

On Fri, May 06, 2016 at 11:46:03AM +0100, Andre Przywara wrote:
> From: Eric Auger <[email-masked]>
> 
> 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 early_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.

I suggest deleting the last two paragraphs.

> 
> Signed-off-by: Eric Auger <[email-masked]>
> Signed-off-by: Andre Przywara <[email-masked]>
> ---
> Changelog RFC..v1:
> - initialize v2/v3 default CPU affinities explicitly
> 
> Changelog v1 .. v2:
> - move lazy_init() into vgic_update_irq_pending()
> 
>  include/kvm/vgic/vgic.h       |   7 +-
>  virt/kvm/arm/vgic/vgic-init.c | 213 ++++++++++++++++++++++++++++++++++++++++++
>  virt/kvm/arm/vgic/vgic-v2.c   |   5 +
>  virt/kvm/arm/vgic/vgic-v3.c   |   5 +
>  virt/kvm/arm/vgic/vgic.c      |   4 +
>  virt/kvm/arm/vgic/vgic.h      |   8 ++
>  6 files changed, 241 insertions(+), 1 deletion(-)
> 
> diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
> index 899b7b7..538078a 100644
> --- a/include/kvm/vgic/vgic.h
> +++ b/include/kvm/vgic/vgic.h
> @@ -119,6 +119,7 @@ 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;
> @@ -202,7 +203,11 @@ 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,
> @@ -211,7 +216,7 @@ 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-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index a150363..3f9c137 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 +144,183 @@ 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)

is this ever called from outside this file?

If not, why is it not static?

> +{
> +	struct vgic_dist *dist = &kvm->arch.vgic;
> +	struct kvm_vcpu *vcpu0 = kvm_get_vcpu(kvm, 0);
> +	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.

I don't understand these two last lines of comment?

> +	 */
> +	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;
> +		irq->target_vcpu = vcpu0;
> +		if (dist->vgic_model == KVM_DEV_TYPE_ARM_VGIC_V2)
> +			irq->targets = 0;
> +		else
> +			irq->mpidr = 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)

same here

> +{
> +	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;
> +		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
> +		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

s/Completion can be tested by vgic_initialized/
  vgic_initialized() returns true when this function has succeeded/

> + * 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->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);

this is actually not the state prior to initialization, so is this
really required?

> +}
> +
> +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

nit: period after 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)
> diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
> index 91b69a4..48aa877 100644
> --- a/virt/kvm/arm/vgic/vgic-v2.c
> +++ b/virt/kvm/arm/vgic/vgic-v2.c
> @@ -211,6 +211,11 @@ void vgic_v2_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
>  			GICH_VMCR_PRIMASK_SHIFT;
>  }
>  
> +/* 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 48b0bb7..7cab5b9 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -195,6 +195,11 @@ 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 5355de6..068389a 100644
> --- a/virt/kvm/arm/vgic/vgic.c
> +++ b/virt/kvm/arm/vgic/vgic.c
> @@ -255,6 +255,10 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
>  
>  	trace_vgic_update_irq_pending(cpuid, intid, level);
>  
> +	ret = vgic_lazy_init(kvm);
> +	if (ret)
> +		return ret;
> +
>  	vcpu = kvm_get_vcpu(kvm, cpuid);
>  	if (!vcpu && intid < VGIC_NR_PRIVATE_IRQS)
>  		return -EINVAL;
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index e49b1df..cad04eb 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -43,6 +43,7 @@ int vgic_v2_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
>  			  int offset, u32 *val);
>  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);
>  int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
>  			     enum vgic_type);
> @@ -55,6 +56,7 @@ void vgic_v3_clear_lr(struct kvm_vcpu *vcpu, int lr);
>  void vgic_v3_set_underflow(struct kvm_vcpu *vcpu);
>  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);
>  int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address);
>  #else
> @@ -89,6 +91,10 @@ 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;
> @@ -102,5 +108,7 @@ static inline int vgic_register_redist_iodevs(struct kvm *kvm,
>  #endif
>  
>  void kvm_register_vgic_device(unsigned long type);
> +int vgic_lazy_init(struct kvm *kvm);
> +int vgic_init(struct kvm *kvm);
>  
>  #endif
> -- 
> 2.7.3
> 
> --

The cosmetic comments notwithstanding:

Reviewed-by: Christoffer Dall <[email-masked]>