Re: [PATCH v2] KVM: arm/arm64: vgic-new: Switch to firmware-independent probing

[Christoffer Dall <christoffer.dall@linaro.org>]

On Tue, May 10, 2016 at 09:46:23AM +0100, Marc Zyngier wrote:
> As we did for the legacy code, switch the new VGIC implementation
> the firmware-independent probing, giving us ACPI support for free.
> 
> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

So just remembered you wrote this after sending my comments to patch 48.

Are we planning to squash this into the series so I can review in
completeness/with context, or?

Thanks,
-Christoffer

> ---
> - From v1: Some additional cleanups, rebased on the lastest drop.
> 
>  virt/kvm/arm/vgic/vgic-init.c | 39 ++++++++++----------
>  virt/kvm/arm/vgic/vgic-v2.c   | 82 +++++++++++++++----------------------------
>  virt/kvm/arm/vgic/vgic-v3.c   | 44 ++++++-----------------
>  virt/kvm/arm/vgic/vgic.h      |  8 +++--
>  4 files changed, 63 insertions(+), 110 deletions(-)
> 
> diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
> index 7fefb12..0c2c504 100644
> --- a/virt/kvm/arm/vgic/vgic-init.c
> +++ b/virt/kvm/arm/vgic/vgic-init.c
> @@ -17,8 +17,6 @@
>  #include <linux/uaccess.h>
>  #include <linux/interrupt.h>
>  #include <linux/cpu.h>
> -#include <linux/of_address.h>
> -#include <linux/of_irq.h>
>  #include <linux/kvm_host.h>
>  #include <kvm/arm_vgic.h>
>  #include <asm/kvm_mmu.h>
> @@ -387,14 +385,6 @@ static irqreturn_t vgic_maintenance_handler(int irq, void *data)
>  	return IRQ_HANDLED;
>  }
>  
> -static const struct of_device_id vgic_ids[] = {
> -	{ .compatible = "arm,cortex-a15-gic",	.data = vgic_v2_probe, },
> -	{ .compatible = "arm,cortex-a7-gic",	.data = vgic_v2_probe, },
> -	{ .compatible = "arm,gic-400",		.data = vgic_v2_probe, },
> -	{ .compatible = "arm,gic-v3",		.data = vgic_v3_probe, },
> -	{},
> -};
> -
>  /**
>   * kvm_vgic_hyp_init: populates the kvm_vgic_global_state variable
>   * according to the host GIC model. Accordingly calls either
> @@ -403,23 +393,33 @@ static const struct of_device_id vgic_ids[] = {
>   */
>  int kvm_vgic_hyp_init(void)
>  {
> -	const struct of_device_id *matched_id;
> -	const int (*vgic_probe)(struct device_node *);
> -	struct device_node *vgic_node;
> +	const struct gic_kvm_info *gic_kvm_info;
>  	int ret;
>  
> -	vgic_node = of_find_matching_node_and_match(NULL,
> -						    vgic_ids, &matched_id);
> -	if (!vgic_node) {
> -		kvm_err("error: no compatible GIC node found\n");
> +	gic_kvm_info = gic_get_kvm_info();
> +	if (!gic_kvm_info)
>  		return -ENODEV;
> +
> +	if (!gic_kvm_info->maint_irq) {
> +		kvm_err("No vgic maintenance irq\n");
> +		return -ENXIO;
>  	}
>  
> -	vgic_probe = matched_id->data;
> -	ret = vgic_probe(vgic_node);
> +	switch (gic_kvm_info->type) {
> +	case GIC_V2:
> +		ret = vgic_v2_probe(gic_kvm_info);
> +		break;
> +	case GIC_V3:
> +		ret = vgic_v3_probe(gic_kvm_info);
> +		break;
> +	default:
> +		ret = -ENODEV;
> +	};
> +
>  	if (ret)
>  		return ret;
>  
> +	kvm_vgic_global_state.maint_irq = gic_kvm_info->maint_irq;
>  	ret = request_percpu_irq(kvm_vgic_global_state.maint_irq,
>  				 vgic_maintenance_handler,
>  				 "vgic", kvm_get_running_vcpus());
> @@ -437,6 +437,7 @@ int kvm_vgic_hyp_init(void)
>  
>  	on_each_cpu(vgic_init_maintenance_interrupt, NULL, 1);
>  
> +	kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
>  	return 0;
>  
>  out_free_irq:
> diff --git a/virt/kvm/arm/vgic/vgic-v2.c b/virt/kvm/arm/vgic/vgic-v2.c
> index 4493593..e88b5aa 100644
> --- a/virt/kvm/arm/vgic/vgic-v2.c
> +++ b/virt/kvm/arm/vgic/vgic-v2.c
> @@ -18,9 +18,6 @@
>  #include <linux/kvm.h>
>  #include <linux/kvm_host.h>
>  #include <kvm/arm_vgic.h>
> -#include <linux/of.h>
> -#include <linux/of_address.h>
> -#include <linux/of_irq.h>
>  #include <asm/kvm_mmu.h>
>  
>  #include "vgic.h"
> @@ -278,81 +275,58 @@ out:
>   *
>   * Returns 0 if a GICv2 has been found, returns an error code otherwise
>   */
> -int vgic_v2_probe(struct device_node *vgic_node)
> +int vgic_v2_probe(const struct gic_kvm_info *info)
>  {
>  	int ret;
> -	struct resource vctrl_res;
> -	struct resource vcpu_res;
>  
> -	kvm_vgic_global_state.maint_irq = irq_of_parse_and_map(vgic_node, 0);
> -	if (!kvm_vgic_global_state.maint_irq) {
> -		kvm_err("error getting vgic maintenance irq from DT\n");
> -		ret = -ENXIO;
> -		goto out;
> +	if (!info->vctrl.start) {
> +		kvm_err("GICH not present in the firmware table\n");
> +		return -ENXIO;
>  	}
>  
> -	ret = of_address_to_resource(vgic_node, 2, &vctrl_res);
> -	if (ret) {
> -		kvm_err("Cannot obtain GICH resource\n");
> -		goto out;
> +	if (!PAGE_ALIGNED(info->vcpu.start)) {
> +		kvm_err("GICV physical address 0x%llx not page aligned\n",
> +			(unsigned long long)info->vcpu.start);
> +		return -ENXIO;
> +	}
> +
> +	if (!PAGE_ALIGNED(resource_size(&info->vcpu))) {
> +		kvm_err("GICV size 0x%llx not a multiple of page size 0x%lx\n",
> +			(unsigned long long)resource_size(&info->vcpu),
> +			PAGE_SIZE);
> +		return -ENXIO;
>  	}
>  
> -	kvm_vgic_global_state.vctrl_base = of_iomap(vgic_node, 2);
> +	kvm_vgic_global_state.vctrl_base = ioremap(info->vctrl.start,
> +						   resource_size(&info->vctrl));
>  	if (!kvm_vgic_global_state.vctrl_base) {
>  		kvm_err("Cannot ioremap GICH\n");
> -		ret = -ENOMEM;
> -		goto out;
> +		return -ENOMEM;
>  	}
>  
>  	kvm_vgic_global_state.nr_lr =
>  		readl_relaxed(kvm_vgic_global_state.vctrl_base + GICH_VTR);
> -	kvm_vgic_global_state.nr_lr = (kvm_vgic_global_state.nr_lr & 0x3f) + 1;
> +	kvm_vgic_global_state.nr_lr &= 0x3f;
> +	kvm_vgic_global_state.nr_lr += 1;
>  
>  	ret = create_hyp_io_mappings(kvm_vgic_global_state.vctrl_base,
>  				     kvm_vgic_global_state.vctrl_base +
> -					 resource_size(&vctrl_res),
> -				     vctrl_res.start);
> +					 resource_size(&info->vctrl),
> +				     info->vctrl.start);
>  	if (ret) {
>  		kvm_err("Cannot map VCTRL into hyp\n");
> -		goto out_unmap;
> -	}
> -
> -	if (of_address_to_resource(vgic_node, 3, &vcpu_res)) {
> -		kvm_err("Cannot obtain GICV resource\n");
> -		ret = -ENXIO;
> -		goto out_unmap;
> -	}
> -
> -	if (!PAGE_ALIGNED(vcpu_res.start)) {
> -		kvm_err("GICV physical address 0x%llx not page aligned\n",
> -			(unsigned long long)vcpu_res.start);
> -		ret = -ENXIO;
> -		goto out_unmap;
> -	}
> -
> -	if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
> -		kvm_err("GICV size 0x%llx not a multiple of page size 0x%lx\n",
> -			(unsigned long long)resource_size(&vcpu_res),
> -			PAGE_SIZE);
> -		ret = -ENXIO;
> -		goto out_unmap;
> +		iounmap(kvm_vgic_global_state.vctrl_base);
> +		return ret;
>  	}
>  
>  	kvm_vgic_global_state.can_emulate_gicv2 = true;
>  	kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
>  
> -	kvm_vgic_global_state.vcpu_base = vcpu_res.start;
> -
> -	kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
> -		 vctrl_res.start, kvm_vgic_global_state.maint_irq);
> -
> +	kvm_vgic_global_state.vcpu_base = info->vcpu.start;
>  	kvm_vgic_global_state.type = VGIC_V2;
>  	kvm_vgic_global_state.max_gic_vcpus = VGIC_V2_MAX_CPUS;
> -	goto out;
>  
> -out_unmap:
> -	iounmap(kvm_vgic_global_state.vctrl_base);
> -out:
> -	of_node_put(vgic_node);
> -	return ret;
> +	kvm_info("vgic-v2@%llx\n", info->vctrl.start);
> +
> +	return 0;
>  }
> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
> index 6d7422f..6073f5d 100644
> --- a/virt/kvm/arm/vgic/vgic-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-v3.c
> @@ -16,9 +16,6 @@
>  #include <linux/kvm.h>
>  #include <linux/kvm_host.h>
>  #include <kvm/arm_vgic.h>
> -#include <linux/of.h>
> -#include <linux/of_address.h>
> -#include <linux/of_irq.h>
>  #include <asm/kvm_mmu.h>
>  #include <asm/kvm_asm.h>
>  
> @@ -271,21 +268,9 @@ out:
>   *
>   * Returns 0 if a GICv3 has been found, returns an error code otherwise
>   */
> -int vgic_v3_probe(struct device_node *vgic_node)
> +int vgic_v3_probe(const struct gic_kvm_info *info)
>  {
> -	u32 ich_vtr_el2;
> -	u32 gicv_idx;
> -	int ret = 0;
> -	struct resource vcpu_res;
> -
> -	kvm_vgic_global_state.maint_irq = irq_of_parse_and_map(vgic_node, 0);
> -	if (!kvm_vgic_global_state.maint_irq) {
> -		kvm_err("error getting vgic maintenance irq from DT\n");
> -		ret = -ENXIO;
> -		goto out;
> -	}
> -
> -	ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
> +	u32 ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
>  
>  	/*
>  	 * The ListRegs field is 5 bits, but there is a architectural
> @@ -294,27 +279,23 @@ int vgic_v3_probe(struct device_node *vgic_node)
>  	kvm_vgic_global_state.nr_lr = (ich_vtr_el2 & 0xf) + 1;
>  	kvm_vgic_global_state.can_emulate_gicv2 = false;
>  
> -	if (of_property_read_u32(vgic_node, "#redistributor-regions",
> -				 &gicv_idx))
> -		gicv_idx = 1;
> -
> -	gicv_idx += 3; /* Also skip GICD, GICC, GICH */
> -	if (of_address_to_resource(vgic_node, gicv_idx, &vcpu_res)) {
> +	if (!info->vcpu.start) {
>  		kvm_info("GICv3: no GICV resource entry\n");
>  		kvm_vgic_global_state.vcpu_base = 0;
> -	} else if (!PAGE_ALIGNED(vcpu_res.start)) {
> +	} else if (!PAGE_ALIGNED(info->vcpu.start)) {
>  		pr_warn("GICV physical address 0x%llx not page aligned\n",
> -			(unsigned long long)vcpu_res.start);
> +			(unsigned long long)info->vcpu.start);
>  		kvm_vgic_global_state.vcpu_base = 0;
> -	} else if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
> +	} else if (!PAGE_ALIGNED(resource_size(&info->vcpu))) {
>  		pr_warn("GICV size 0x%llx not a multiple of page size 0x%lx\n",
> -			(unsigned long long)resource_size(&vcpu_res),
> +			(unsigned long long)resource_size(&info->vcpu),
>  			PAGE_SIZE);
>  		kvm_vgic_global_state.vcpu_base = 0;
>  	} else {
> -		kvm_vgic_global_state.vcpu_base = vcpu_res.start;
> +		kvm_vgic_global_state.vcpu_base = info->vcpu.start;
>  		kvm_vgic_global_state.can_emulate_gicv2 = true;
>  		kvm_register_vgic_device(KVM_DEV_TYPE_ARM_VGIC_V2);
> +		kvm_info("vgic-v2@%llx\n", info->vcpu.start);
>  	}
>  	if (kvm_vgic_global_state.vcpu_base == 0)
>  		kvm_info("disabling GICv2 emulation\n");
> @@ -324,10 +305,5 @@ int vgic_v3_probe(struct device_node *vgic_node)
>  	kvm_vgic_global_state.type = VGIC_V3;
>  	kvm_vgic_global_state.max_gic_vcpus = VGIC_V3_MAX_CPUS;
>  
> -	kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
> -		 vcpu_res.start, kvm_vgic_global_state.maint_irq);
> -
> -out:
> -	of_node_put(vgic_node);
> -	return ret;
> +	return 0;
>  }
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index 5c7dc99..83d3c48 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -16,6 +16,8 @@
>  #ifndef __KVM_ARM_VGIC_NEW_H__
>  #define __KVM_ARM_VGIC_NEW_H__
>  
> +#include <linux/irqchip/arm-gic-common.h>
> +
>  #define PRODUCT_ID_KVM		0x4b	/* ASCII code K */
>  #define IMPLEMENTER_ARM		0x43b
>  
> @@ -44,7 +46,7 @@ int vgic_v2_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
>  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_v2_probe(const struct gic_kvm_info *info);
>  int vgic_v2_map_resources(struct kvm *kvm);
>  int vgic_register_dist_iodev(struct kvm *kvm, gpa_t dist_base_address,
>  			     enum vgic_type);
> @@ -58,7 +60,7 @@ 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_v3_probe(const struct gic_kvm_info *info);
>  int vgic_v3_map_resources(struct kvm *kvm);
>  int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address);
>  #else
> @@ -97,7 +99,7 @@ static inline void vgic_v3_enable(struct kvm_vcpu *vcpu)
>  {
>  }
>  
> -static inline int vgic_v3_probe(struct device_node *vgic_node)
> +static inline int vgic_v3_probe(const struct gic_kvm_info *info)
>  {
>  	return -ENODEV;
>  }
> -- 
> 2.1.4
>