Commit fb5ef351 authored by Wei Liu's avatar Wei Liu
Browse files

iommu/hyperv: setup an IO-APIC IRQ remapping domain for root partition 



Just like MSI/MSI-X, IO-APIC interrupts are remapped by Microsoft
Hypervisor when Linux runs as the root partition. Implement an IRQ
domain to handle mapping and unmapping of IO-APIC interrupts.

Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
Acked-by: default avatarJoerg Roedel <joro@8bytes.org>
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20210203150435.27941-17-wei.liu@kernel.org
parent e39397d1

arch/x86/hyperv/irqdomain.c

+25 −0
Original line number Diff line number Diff line
@@ -358,3 +358,28 @@ struct irq_domain * __init hv_create_pci_msi_domain(void) 
}



#endif /* CONFIG_PCI_MSI */



int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry)

{

	union hv_device_id device_id;



	device_id.as_uint64 = 0;

	device_id.device_type = HV_DEVICE_TYPE_IOAPIC;

	device_id.ioapic.ioapic_id = (u8)ioapic_id;



	return hv_unmap_interrupt(device_id.as_uint64, entry);

}

EXPORT_SYMBOL_GPL(hv_unmap_ioapic_interrupt);



int hv_map_ioapic_interrupt(int ioapic_id, bool level, int cpu, int vector,

		struct hv_interrupt_entry *entry)

{

	union hv_device_id device_id;



	device_id.as_uint64 = 0;

	device_id.device_type = HV_DEVICE_TYPE_IOAPIC;

	device_id.ioapic.ioapic_id = (u8)ioapic_id;



	return hv_map_interrupt(device_id, level, cpu, vector, entry);

}

EXPORT_SYMBOL_GPL(hv_map_ioapic_interrupt);

arch/x86/include/asm/mshyperv.h

+4 −0
Original line number Diff line number Diff line
@@ -265,6 +265,10 @@ static inline void hv_set_msi_entry_from_desc(union hv_msi_entry *msi_entry, 


struct irq_domain *hv_create_pci_msi_domain(void);



int hv_map_ioapic_interrupt(int ioapic_id, bool level, int vcpu, int vector,

		struct hv_interrupt_entry *entry);

int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry);



#else /* CONFIG_HYPERV */

static inline void hyperv_init(void) {}

static inline void hyperv_setup_mmu_ops(void) {}

drivers/iommu/hyperv-iommu.c

+174 −3
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <asm/io_apic.h>

#include <asm/irq_remapping.h>

#include <asm/hypervisor.h>

#include <asm/mshyperv.h>



#include "irq_remapping.h"
@@ -115,30 +116,43 @@ static const struct irq_domain_ops hyperv_ir_domain_ops = { 
	.free = hyperv_irq_remapping_free,

};



static const struct irq_domain_ops hyperv_root_ir_domain_ops;

static int __init hyperv_prepare_irq_remapping(void)

{

	struct fwnode_handle *fn;

	int i;

	const char *name;

	const struct irq_domain_ops *ops;



	if (!hypervisor_is_type(X86_HYPER_MS_HYPERV) ||

	    x86_init.hyper.msi_ext_dest_id() ||

	    !x2apic_supported())

		return -ENODEV;



	fn = irq_domain_alloc_named_id_fwnode("HYPERV-IR", 0);

	if (hv_root_partition) {

		name = "HYPERV-ROOT-IR";

		ops = &hyperv_root_ir_domain_ops;

	} else {

		name = "HYPERV-IR";

		ops = &hyperv_ir_domain_ops;

	}



	fn = irq_domain_alloc_named_id_fwnode(name, 0);

	if (!fn)

		return -ENOMEM;



	ioapic_ir_domain =

		irq_domain_create_hierarchy(arch_get_ir_parent_domain(),

				0, IOAPIC_REMAPPING_ENTRY, fn,

				&hyperv_ir_domain_ops, NULL);

				0, IOAPIC_REMAPPING_ENTRY, fn, ops, NULL);



	if (!ioapic_ir_domain) {

		irq_domain_free_fwnode(fn);

		return -ENOMEM;

	}



	if (hv_root_partition)

		return 0; /* The rest is only relevant to guests */



	/*

	 * Hyper-V doesn't provide irq remapping function for

	 * IO-APIC and so IO-APIC only accepts 8-bit APIC ID.
@@ -166,4 +180,161 @@ struct irq_remap_ops hyperv_irq_remap_ops = { 
	.enable			= hyperv_enable_irq_remapping,

};



/* IRQ remapping domain when Linux runs as the root partition */

struct hyperv_root_ir_data {

	u8 ioapic_id;

	bool is_level;

	struct hv_interrupt_entry entry;

};



static void

hyperv_root_ir_compose_msi_msg(struct irq_data *irq_data, struct msi_msg *msg)

{

	u64 status;

	u32 vector;

	struct irq_cfg *cfg;

	int ioapic_id;

	struct cpumask *affinity;

	int cpu;

	struct hv_interrupt_entry entry;

	struct hyperv_root_ir_data *data = irq_data->chip_data;

	struct IO_APIC_route_entry e;



	cfg = irqd_cfg(irq_data);

	affinity = irq_data_get_effective_affinity_mask(irq_data);

	cpu = cpumask_first_and(affinity, cpu_online_mask);



	vector = cfg->vector;

	ioapic_id = data->ioapic_id;



	if (data->entry.source == HV_DEVICE_TYPE_IOAPIC

	    && data->entry.ioapic_rte.as_uint64) {

		entry = data->entry;



		status = hv_unmap_ioapic_interrupt(ioapic_id, &entry);



		if (status != HV_STATUS_SUCCESS)

			pr_debug("%s: unexpected unmap status %lld\n", __func__, status);



		data->entry.ioapic_rte.as_uint64 = 0;

		data->entry.source = 0; /* Invalid source */

	}





	status = hv_map_ioapic_interrupt(ioapic_id, data->is_level, cpu,

					vector, &entry);



	if (status != HV_STATUS_SUCCESS) {

		pr_err("%s: map hypercall failed, status %lld\n", __func__, status);

		return;

	}



	data->entry = entry;



	/* Turn it into an IO_APIC_route_entry, and generate MSI MSG. */

	e.w1 = entry.ioapic_rte.low_uint32;

	e.w2 = entry.ioapic_rte.high_uint32;



	memset(msg, 0, sizeof(*msg));

	msg->arch_data.vector = e.vector;

	msg->arch_data.delivery_mode = e.delivery_mode;

	msg->arch_addr_lo.dest_mode_logical = e.dest_mode_logical;

	msg->arch_addr_lo.dmar_format = e.ir_format;

	msg->arch_addr_lo.dmar_index_0_14 = e.ir_index_0_14;

}



static int hyperv_root_ir_set_affinity(struct irq_data *data,

		const struct cpumask *mask, bool force)

{

	struct irq_data *parent = data->parent_data;

	struct irq_cfg *cfg = irqd_cfg(data);

	int ret;



	ret = parent->chip->irq_set_affinity(parent, mask, force);

	if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)

		return ret;



	send_cleanup_vector(cfg);



	return 0;

}



static struct irq_chip hyperv_root_ir_chip = {

	.name			= "HYPERV-ROOT-IR",

	.irq_ack		= apic_ack_irq,

	.irq_set_affinity	= hyperv_root_ir_set_affinity,

	.irq_compose_msi_msg	= hyperv_root_ir_compose_msi_msg,

};



static int hyperv_root_irq_remapping_alloc(struct irq_domain *domain,

				     unsigned int virq, unsigned int nr_irqs,

				     void *arg)

{

	struct irq_alloc_info *info = arg;

	struct irq_data *irq_data;

	struct hyperv_root_ir_data *data;

	int ret = 0;



	if (!info || info->type != X86_IRQ_ALLOC_TYPE_IOAPIC || nr_irqs > 1)

		return -EINVAL;



	ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, arg);

	if (ret < 0)

		return ret;



	data = kzalloc(sizeof(*data), GFP_KERNEL);

	if (!data) {

		irq_domain_free_irqs_common(domain, virq, nr_irqs);

		return -ENOMEM;

	}



	irq_data = irq_domain_get_irq_data(domain, virq);

	if (!irq_data) {

		kfree(data);

		irq_domain_free_irqs_common(domain, virq, nr_irqs);

		return -EINVAL;

	}



	data->ioapic_id = info->devid;

	data->is_level = info->ioapic.is_level;



	irq_data->chip = &hyperv_root_ir_chip;

	irq_data->chip_data = data;



	return 0;

}



static void hyperv_root_irq_remapping_free(struct irq_domain *domain,

				 unsigned int virq, unsigned int nr_irqs)

{

	struct irq_data *irq_data;

	struct hyperv_root_ir_data *data;

	struct hv_interrupt_entry *e;

	int i;



	for (i = 0; i < nr_irqs; i++) {

		irq_data = irq_domain_get_irq_data(domain, virq + i);



		if (irq_data && irq_data->chip_data) {

			data = irq_data->chip_data;

			e = &data->entry;



			if (e->source == HV_DEVICE_TYPE_IOAPIC

			      && e->ioapic_rte.as_uint64)

				hv_unmap_ioapic_interrupt(data->ioapic_id,

							&data->entry);



			kfree(data);

		}

	}



	irq_domain_free_irqs_common(domain, virq, nr_irqs);

}



static const struct irq_domain_ops hyperv_root_ir_domain_ops = {

	.select = hyperv_irq_remapping_select,

	.alloc = hyperv_root_irq_remapping_alloc,

	.free = hyperv_root_irq_remapping_free,

};



#endif