[PATCH V2 4/5] kvm: arm64: Implement ACPI probing code for GICv2

[Wei Huang <wei@redhat.com>]

This patches enables ACPI support for KVM virtual GICv2. KVM parses
ACPI table for virt GIC related information and initializes resources.

Signed-off-by: Alexander Spyridaki <a.spyridakis@virtualopensystems.com>
Signed-off-by: Wei Huang <wei@redhat.com>
---
 virt/kvm/arm/vgic-v2.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
index 711de82..f6e56e9 100644
--- a/virt/kvm/arm/vgic-v2.c
+++ b/virt/kvm/arm/vgic-v2.c
@@ -264,6 +264,54 @@ int vgic_v2_acpi_probe(struct acpi_madt_generic_interrupt *vgic_acpi,
 		       const struct vgic_ops **ops,
 		       const struct vgic_params **params)
 {
-	return -EINVAL;
+	struct vgic_params *vgic = &vgic_v2_params;
+	int irq_mode, ret;
+
+	/* IRQ trigger mode */
+	irq_mode = (vgic_acpi->flags & ACPI_MADT_VGIC_IRQ_MODE) ?
+		ACPI_EDGE_SENSITIVE : ACPI_LEVEL_SENSITIVE;
+	vgic->maint_irq = acpi_register_gsi(NULL, vgic_acpi->vgic_interrupt,
+					    irq_mode, ACPI_ACTIVE_HIGH);
+	if (!vgic->maint_irq) {
+		kvm_err("Cannot register VGIC ACPI maintenance irq\n");
+		ret = -ENXIO;
+		goto out;
+	}
+
+	/* GICH resource */
+	vgic->vctrl_base = ioremap(vgic_acpi->gich_base_address, SZ_8K);
+	if (!vgic->vctrl_base) {
+		kvm_err("cannot ioremap GICH memory\n");
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	vgic->nr_lr = readl_relaxed(vgic->vctrl_base + GICH_VTR);
+	vgic->nr_lr = (vgic->nr_lr & 0x3f) + 1;
+
+	ret = create_hyp_io_mappings(vgic->vctrl_base,
+				     vgic->vctrl_base + SZ_8K,
+				     vgic_acpi->gich_base_address);
+	if (ret) {
+		kvm_err("Cannot map GICH into hyp\n");
+		goto out;
+	}
+
+	vgic->vcpu_base = vgic_acpi->gicv_base_address;
+	vgic->can_emulate_gicv2 = true;
+	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
+
+	kvm_info("GICH base=0x%llx, GICV base=0x%llx, IRQ=%d\n",
+		 (unsigned long long)vgic_acpi->gich_base_address,
+		 (unsigned long long)vgic_acpi->gicv_base_address,
+		 vgic->maint_irq);
+
+	vgic->type = VGIC_V2;
+	vgic->max_gic_vcpus = VGIC_V2_MAX_CPUS;
+	*ops = &vgic_v2_ops;
+	*params = vgic;
+
+out:
+	return ret;
 }
 #endif /* CONFIG_ACPI */
-- 
1.8.3.1