Re: [PATCH v4 8/9] KVM: arm/arm64: vgic: Rely on the GIC driver to parse the firmware tables

Christoffer Dall
2016-04-01T10:32:17Z

On Thu, Mar 24, 2016 at 05:53:42PM +0000, Julien Grall wrote:
> Currently, the firmware tables are parsed 2 times: once in the GIC
> drivers, the other time when initializing the vGIC. It means code
> duplication and make more tedious to add the support for another
> firmware table (like ACPI).
>
> Use the recently introduced helper gic_get_kvm_info() to get
> information about the virtual GIC.
>
> With this change, the virtual GIC becomes agnostic to the firmware
> table and KVM will be able to initialize the vGIC on ACPI.
>
> Signed-off-by: Julien Grall <julien.grall@arm.com>
>
> ---
> Cc: Christoffer Dall <christoffer.dall@linaro.org>
> Cc: Marc Zyngier <marc.zyngier@arm.com>
> Cc: Gleb Natapov <gleb@kernel.org>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
>
> Changes in v4:
> - Remove validation check as they are already done during
> parsing.
> - Move the alignement check from the parsing to the vGIC code.
> - Fix typo in the commit message
>
> Changes in v2:
> - Use 0 rather than a negative value to know when the maintenance IRQ
> is not present.
> - Use resource for vcpu and vctrl.
> ---
> include/kvm/arm_vgic.h | 7 +++---
> virt/kvm/arm/vgic-v2.c | 61 +++++++++++++++++++++-----------------------------
> virt/kvm/arm/vgic-v3.c | 47 +++++++++++++-------------------------
> virt/kvm/arm/vgic.c | 50 ++++++++++++++++++++++-------------------
> 4 files changed, 73 insertions(+), 92 deletions(-)
>
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 281caf8..be6037a 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -25,6 +25,7 @@
> #include <linux/spinlock.h>
> #include <linux/types.h>
> #include <kvm/iodev.h>
> +#include <linux/irqchip/arm-gic-common.h>
>
> #define VGIC_NR_IRQS_LEGACY 256
> #define VGIC_NR_SGIS 16
> @@ -353,15 +354,15 @@ bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, struct irq_phys_map *map);
> #define vgic_initialized(k) (!!((k)->arch.vgic.nr_cpus))
> #define vgic_ready(k) ((k)->arch.vgic.ready)
>
> -int vgic_v2_probe(struct device_node *vgic_node,
> +int vgic_v2_probe(const struct gic_kvm_info *gic_kvm_info,
> const struct vgic_ops **ops,
> const struct vgic_params **params);
> #ifdef CONFIG_KVM_ARM_VGIC_V3
> -int vgic_v3_probe(struct device_node *vgic_node,
> +int vgic_v3_probe(const struct gic_kvm_info *gic_kvm_info,
> const struct vgic_ops **ops,
> const struct vgic_params **params);
> #else
> -static inline int vgic_v3_probe(struct device_node *vgic_node,
> +static inline int vgic_v3_probe(const struct gic_kvm_info *gic_kvm_info,
> const struct vgic_ops **ops,
> const struct vgic_params **params)
> {
> diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
> index 67ec334..7e826c9 100644
> --- a/virt/kvm/arm/vgic-v2.c
> +++ b/virt/kvm/arm/vgic-v2.c
> @@ -20,9 +20,6 @@
> #include <linux/kvm_host.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> -#include <linux/of.h>
> -#include <linux/of_address.h>
> -#include <linux/of_irq.h>
>
> #include <linux/irqchip/arm-gic.h>
>
> @@ -186,38 +183,39 @@ static void vgic_cpu_init_lrs(void *params)
> }
>
> /**
> - * vgic_v2_probe - probe for a GICv2 compatible interrupt controller in DT
> - * @node: pointer to the DT node
> - * @ops: address of a pointer to the GICv2 operations
> - * @params: address of a pointer to HW-specific parameters
> + * vgic_v2_probe - probe for a GICv2 compatible interrupt controller
> + * @gic_kvm_info: pointer to the GIC description
> + * @ops: address of a pointer to the GICv2 operations
> + * @params: address of a pointer to HW-specific parameters
> *
> * Returns 0 if a GICv2 has been found, with the low level operations
> * in *ops and the HW parameters in *params. Returns an error code
> * otherwise.
> */
> -int vgic_v2_probe(struct device_node *vgic_node,
> - const struct vgic_ops **ops,
> - const struct vgic_params **params)
> +int vgic_v2_probe(const struct gic_kvm_info *gic_kvm_info,
> + const struct vgic_ops **ops,
> + const struct vgic_params **params)
> {
> int ret;
> - struct resource vctrl_res;
> - struct resource vcpu_res;
> struct vgic_params *vgic = &vgic_v2_params;
> + const struct resource *vctrl_res = &gic_kvm_info->vctrl;
> + const struct resource *vcpu_res = &gic_kvm_info->vcpu;
>
> - vgic->maint_irq = irq_of_parse_and_map(vgic_node, 0);
> - if (!vgic->maint_irq) {
> - kvm_err("error getting vgic maintenance irq from DT\n");
> + if (!gic_kvm_info->maint_irq) {
> + kvm_err("error getting vgic maintenance irq\n");
> ret = -ENXIO;
> goto out;
> }
> + vgic->maint_irq = gic_kvm_info->maint_irq;
>
> - ret = of_address_to_resource(vgic_node, 2, &vctrl_res);
> - if (ret) {
> - kvm_err("Cannot obtain GICH resource\n");
> + if (!gic_kvm_info->vctrl.start) {
> + kvm_err("GICH not present in the firmware table\n");
> + ret = -ENXIO;
> goto out;
> }
>
> - vgic->vctrl_base = of_iomap(vgic_node, 2);
> + vgic->vctrl_base = ioremap(gic_kvm_info->vctrl.start,
> + resource_size(&gic_kvm_info->vctrl));
> if (!vgic->vctrl_base) {
> kvm_err("Cannot ioremap GICH\n");
> ret = -ENOMEM;
> @@ -228,29 +226,23 @@ int vgic_v2_probe(struct device_node *vgic_node,
> vgic->nr_lr = (vgic->nr_lr & 0x3f) + 1;
>
> ret = create_hyp_io_mappings(vgic->vctrl_base,
> - vgic->vctrl_base + resource_size(&vctrl_res),
> - vctrl_res.start);
> + vgic->vctrl_base + resource_size(vctrl_res),
> + vctrl_res->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)) {
> + if (!PAGE_ALIGNED(vcpu_res->start)) {
> kvm_err("GICV physical address 0x%llx not page aligned\n",
> - (unsigned long long)vcpu_res.start);
> + (unsigned long long)vcpu_res->start);
> ret = -ENXIO;
> goto out_unmap;
> }
>
> - if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
> + 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),
> + (unsigned long long)resource_size(vcpu_res),
> PAGE_SIZE);
> ret = -ENXIO;
> goto out_unmap;
> @@ -259,10 +251,10 @@ int vgic_v2_probe(struct device_node *vgic_node,
> vgic->can_emulate_gicv2 = true;
> kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
>
> - vgic->vcpu_base = vcpu_res.start;
> + vgic->vcpu_base = vcpu_res->start;
>
> - kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
> - vctrl_res.start, vgic->maint_irq);
> + kvm_info("GICH base=0x%llx, GICV base=0x%llx, IRQ=%d\n",
> + gic_kvm_info->vctrl.start, vgic->vcpu_base, vgic->maint_irq);
>
> vgic->type = VGIC_V2;
> vgic->max_gic_vcpus = VGIC_V2_MAX_CPUS;
> @@ -276,6 +268,5 @@ int vgic_v2_probe(struct device_node *vgic_node,
> out_unmap:
> iounmap(vgic->vctrl_base);
> out:
> - of_node_put(vgic_node);
> return ret;
> }
> diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c
> index 999bdc6..c02a1b1 100644
> --- a/virt/kvm/arm/vgic-v3.c
> +++ b/virt/kvm/arm/vgic-v3.c
> @@ -20,11 +20,9 @@
> #include <linux/kvm_host.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> -#include <linux/of.h>
> -#include <linux/of_address.h>
> -#include <linux/of_irq.h>
>
> #include <linux/irqchip/arm-gic-v3.h>
> +#include <linux/irqchip/arm-gic-common.h>
>
> #include <asm/kvm_emulate.h>
> #include <asm/kvm_arm.h>
> @@ -222,30 +220,24 @@ static void vgic_cpu_init_lrs(void *params)
> }
>
> /**
> - * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
> - * @node: pointer to the DT node
> - * @ops: address of a pointer to the GICv3 operations
> - * @params: address of a pointer to HW-specific parameters
> + * vgic_v3_probe - probe for a GICv3 compatible interrupt controller
> + * @gic_kvm_info: pointer to the GIC description
> + * @ops: address of a pointer to the GICv3 operations
> + * @params: address of a pointer to HW-specific parameters
> *
> * Returns 0 if a GICv3 has been found, with the low level operations
> * in *ops and the HW parameters in *params. Returns an error code
> * otherwise.
> */
> -int vgic_v3_probe(struct device_node *vgic_node,
> +int vgic_v3_probe(const struct gic_kvm_info *gic_kvm_info,
> const struct vgic_ops **ops,
> const struct vgic_params **params)
> {
> int ret = 0;
> - u32 gicv_idx;
> - struct resource vcpu_res;
> struct vgic_params *vgic = &vgic_v3_params;
> + const struct resource *vcpu_res = &gic_kvm_info->vcpu;
>
> - vgic->maint_irq = irq_of_parse_and_map(vgic_node, 0);
> - if (!vgic->maint_irq) {
> - kvm_err("error getting vgic maintenance irq from DT\n");
> - ret = -ENXIO;
> - goto out;
> - }
> + vgic->maint_irq = gic_kvm_info->maint_irq;
>
> ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
>
> @@ -256,24 +248,19 @@ int vgic_v3_probe(struct device_node *vgic_node,
> vgic->nr_lr = (ich_vtr_el2 & 0xf) + 1;
> vgic->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 (!vcpu_res->start) {
> kvm_info("GICv3: no GICV resource entry\n");
> vgic->vcpu_base = 0;
> - } else if (!PAGE_ALIGNED(vcpu_res.start)) {
> + } else if (!PAGE_ALIGNED(vcpu_res->start)) {
> pr_warn("GICV physical address 0x%llx not page aligned\n",
> - (unsigned long long)vcpu_res.start);
> + (unsigned long long)vcpu_res->start);
> vgic->vcpu_base = 0;
> - } else if (!PAGE_ALIGNED(resource_size(&vcpu_res))) {
> + } else if (!PAGE_ALIGNED(resource_size(vcpu_res))) {
> 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(vcpu_res),
> PAGE_SIZE);
> - vgic->vcpu_base = 0;

See my comments in patch 6. Perhaps I'm missing something, but I still
don't see a clear split between KVM vs. GIC error checking.

> } else {
> - vgic->vcpu_base = vcpu_res.start;
> + vgic->vcpu_base = vcpu_res->start;
> vgic->can_emulate_gicv2 = true;
> kvm_register_device_ops(&kvm_arm_vgic_v2_ops,
> KVM_DEV_TYPE_ARM_VGIC_V2);
> @@ -286,15 +273,13 @@ int vgic_v3_probe(struct device_node *vgic_node,
> vgic->type = VGIC_V3;
> vgic->max_gic_vcpus = VGIC_V3_MAX_CPUS;
>
> - kvm_info("%s@%llx IRQ%d\n", vgic_node->name,
> - vcpu_res.start, vgic->maint_irq);
> + kvm_info("GICV base=0x%llx, IRQ=%d\n",
> + vgic->vcpu_base, vgic->maint_irq);
>
> on_each_cpu(vgic_cpu_init_lrs, vgic, 1);
>
> *ops = &vgic_v3_ops;
> *params = vgic;
>
> -out:
> - of_node_put(vgic_node);
> return ret;
> }
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index 00429b3..60668a7 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -21,9 +21,7 @@
> #include <linux/kvm_host.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> -#include <linux/of.h>
> -#include <linux/of_address.h>
> -#include <linux/of_irq.h>
> +#include <linux/irq.h>
> #include <linux/rculist.h>
> #include <linux/uaccess.h>
>
> @@ -33,6 +31,7 @@
> #include <trace/events/kvm.h>
> #include <asm/kvm.h>
> #include <kvm/iodev.h>
> +#include <linux/irqchip/arm-gic-common.h>
>
> #define CREATE_TRACE_POINTS
> #include "trace.h"
> @@ -2389,33 +2388,38 @@ static struct notifier_block vgic_cpu_nb = {
> .notifier_call = vgic_cpu_notify,
> };
>
> -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, },
> - {},
> -};
> -
> -int kvm_vgic_hyp_init(void)
> +static int kvm_vgic_probe(void)
> {
> - const struct of_device_id *matched_id;
> - const int (*vgic_probe)(struct device_node *,const struct vgic_ops **,
> - const struct vgic_params **);
> - 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;
> +
> + switch (gic_kvm_info->type) {
> + case GIC_V2:
> + ret = vgic_v2_probe(gic_kvm_info, &vgic_ops, &vgic);
> + break;
> + case GIC_V3:
> + ret = vgic_v3_probe(gic_kvm_info, &vgic_ops, &vgic);
> + break;
> + default:
> + ret = -ENODEV;
> }
>
> - vgic_probe = matched_id->data;
> - ret = vgic_probe(vgic_node, &vgic_ops, &vgic);
> - if (ret)
> + return ret;
> +}
> +
> +int kvm_vgic_hyp_init(void)
> +{
> + int ret;
> +
> + ret = kvm_vgic_probe();
> + if (ret) {
> + kvm_err("error: KVM vGIC probing failed\n");
> return ret;
> + }
>
> ret = request_percpu_irq(vgic->maint_irq, vgic_maintenance_handler,
> "vgic", kvm_get_running_vcpus());
> --
> 1.9.1
>