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Commit 841b91c5 authored by Cornelia Huck's avatar Cornelia Huck
Browse files

KVM: s390: adapter interrupt sources 



Add a new interface to register/deregister sources of adapter interrupts
identified by an unique id via the flic. Adapters may also be maskable
and carry a list of pinned pages.

These adapters will be used by irq routing later.

Acked-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
parent d938dc55

Documentation/virtual/kvm/devices/s390_flic.txt

+45 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ FLIC provides support to 
- inspect currently pending interrupts (KVM_FLIC_GET_ALL_IRQS)

- purge all pending floating interrupts (KVM_DEV_FLIC_CLEAR_IRQS)

- enable/disable for the guest transparent async page faults

- register and modify adapter interrupt sources (KVM_DEV_FLIC_ADAPTER_*)



Groups:

  KVM_DEV_FLIC_ENQUEUE
@@ -44,3 +45,47 @@ Groups: 
    Disables async page faults for the guest and waits until already pending

    async page faults are done. This is necessary to trigger a completion interrupt

    for every init interrupt before migrating the interrupt list.



  KVM_DEV_FLIC_ADAPTER_REGISTER

    Register an I/O adapter interrupt source. Takes a kvm_s390_io_adapter

    describing the adapter to register:



struct kvm_s390_io_adapter {

	__u32 id;

	__u8 isc;

	__u8 maskable;

	__u8 swap;

	__u8 pad;

};



   id contains the unique id for the adapter, isc the I/O interruption subclass

   to use, maskable whether this adapter may be masked (interrupts turned off)

   and swap whether the indicators need to be byte swapped.





  KVM_DEV_FLIC_ADAPTER_MODIFY

    Modifies attributes of an existing I/O adapter interrupt source. Takes

    a kvm_s390_io_adapter_req specifiying the adapter and the operation:



struct kvm_s390_io_adapter_req {

	__u32 id;

	__u8 type;

	__u8 mask;

	__u16 pad0;

	__u64 addr;

};



    id specifies the adapter and type the operation. The supported operations

    are:



    KVM_S390_IO_ADAPTER_MASK

      mask or unmask the adapter, as specified in mask



    KVM_S390_IO_ADAPTER_MAP

      perform a gmap translation for the guest address provided in addr,

      pin a userspace page for the translated address and add it to the

      list of mappings



    KVM_S390_IO_ADAPTER_UNMAP

      release a userspace page for the translated address specified in addr

      from the list of mappings

arch/s390/include/asm/kvm_host.h

+23 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/kvm.h>

#include <asm/debug.h>

#include <asm/cpu.h>

#include <asm/isc.h>



#define KVM_MAX_VCPUS 64

#define KVM_USER_MEM_SLOTS 32
@@ -245,6 +246,27 @@ struct kvm_vm_stat { 
struct kvm_arch_memory_slot {

};



struct s390_map_info {

	struct list_head list;

	__u64 guest_addr;

	__u64 addr;

	struct page *page;

};



struct s390_io_adapter {

	unsigned int id;

	int isc;

	bool maskable;

	bool masked;

	bool swap;

	struct rw_semaphore maps_lock;

	struct list_head maps;

	atomic_t nr_maps;

};



#define MAX_S390_IO_ADAPTERS ((MAX_ISC + 1) * 8)

#define MAX_S390_ADAPTER_MAPS 256



struct kvm_arch{

	struct sca_block *sca;

	debug_info_t *dbf;
@@ -252,6 +274,7 @@ struct kvm_arch{ 
	struct kvm_device *flic;

	struct gmap *gmap;

	int css_support;

	struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS];

};



#define KVM_HVA_ERR_BAD		(-1UL)

arch/s390/include/uapi/asm/kvm.h

+22 −0
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ 
#define KVM_DEV_FLIC_CLEAR_IRQS		3

#define KVM_DEV_FLIC_APF_ENABLE		4

#define KVM_DEV_FLIC_APF_DISABLE_WAIT	5

#define KVM_DEV_FLIC_ADAPTER_REGISTER	6

#define KVM_DEV_FLIC_ADAPTER_MODIFY	7

/*

 * We can have up to 4*64k pending subchannels + 8 adapter interrupts,

 * as well as up  to ASYNC_PF_PER_VCPU*KVM_MAX_VCPUS pfault done interrupts.
@@ -32,6 +34,26 @@ 
#define KVM_S390_MAX_FLOAT_IRQS	266250

#define KVM_S390_FLIC_MAX_BUFFER	0x2000000



struct kvm_s390_io_adapter {

	__u32 id;

	__u8 isc;

	__u8 maskable;

	__u8 swap;

	__u8 pad;

};



#define KVM_S390_IO_ADAPTER_MASK 1

#define KVM_S390_IO_ADAPTER_MAP 2

#define KVM_S390_IO_ADAPTER_UNMAP 3



struct kvm_s390_io_adapter_req {

	__u32 id;

	__u8 type;

	__u8 mask;

	__u16 pad0;

	__u64 addr;

};



/* for KVM_GET_REGS and KVM_SET_REGS */

struct kvm_regs {

	/* general purpose regs for s390 */

arch/s390/kvm/interrupt.c

+172 −1
Original line number Diff line number Diff line 
/*

 * handling kvm guest interrupts

 *

 * Copyright IBM Corp. 2008

 * Copyright IBM Corp. 2008,2014

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License (version 2 only)
@@ -1054,6 +1054,171 @@ static int enqueue_floating_irq(struct kvm_device *dev, 
	return r;

}



static struct s390_io_adapter *get_io_adapter(struct kvm *kvm, unsigned int id)

{

	if (id >= MAX_S390_IO_ADAPTERS)

		return NULL;

	return kvm->arch.adapters[id];

}



static int register_io_adapter(struct kvm_device *dev,

			       struct kvm_device_attr *attr)

{

	struct s390_io_adapter *adapter;

	struct kvm_s390_io_adapter adapter_info;



	if (copy_from_user(&adapter_info,

			   (void __user *)attr->addr, sizeof(adapter_info)))

		return -EFAULT;



	if ((adapter_info.id >= MAX_S390_IO_ADAPTERS) ||

	    (dev->kvm->arch.adapters[adapter_info.id] != NULL))

		return -EINVAL;



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

	if (!adapter)

		return -ENOMEM;



	INIT_LIST_HEAD(&adapter->maps);

	init_rwsem(&adapter->maps_lock);

	atomic_set(&adapter->nr_maps, 0);

	adapter->id = adapter_info.id;

	adapter->isc = adapter_info.isc;

	adapter->maskable = adapter_info.maskable;

	adapter->masked = false;

	adapter->swap = adapter_info.swap;

	dev->kvm->arch.adapters[adapter->id] = adapter;



	return 0;

}



int kvm_s390_mask_adapter(struct kvm *kvm, unsigned int id, bool masked)

{

	int ret;

	struct s390_io_adapter *adapter = get_io_adapter(kvm, id);



	if (!adapter || !adapter->maskable)

		return -EINVAL;

	ret = adapter->masked;

	adapter->masked = masked;

	return ret;

}



static int kvm_s390_adapter_map(struct kvm *kvm, unsigned int id, __u64 addr)

{

	struct s390_io_adapter *adapter = get_io_adapter(kvm, id);

	struct s390_map_info *map;

	int ret;



	if (!adapter || !addr)

		return -EINVAL;



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

	if (!map) {

		ret = -ENOMEM;

		goto out;

	}

	INIT_LIST_HEAD(&map->list);

	map->guest_addr = addr;

	map->addr = gmap_translate(addr, kvm->arch.gmap);

	if (map->addr == -EFAULT) {

		ret = -EFAULT;

		goto out;

	}

	ret = get_user_pages_fast(map->addr, 1, 1, &map->page);

	if (ret < 0)

		goto out;

	BUG_ON(ret != 1);

	down_write(&adapter->maps_lock);

	if (atomic_inc_return(&adapter->nr_maps) < MAX_S390_ADAPTER_MAPS) {

		list_add_tail(&map->list, &adapter->maps);

		ret = 0;

	} else {

		put_page(map->page);

		ret = -EINVAL;

	}

	up_write(&adapter->maps_lock);

out:

	if (ret)

		kfree(map);

	return ret;

}



static int kvm_s390_adapter_unmap(struct kvm *kvm, unsigned int id, __u64 addr)

{

	struct s390_io_adapter *adapter = get_io_adapter(kvm, id);

	struct s390_map_info *map, *tmp;

	int found = 0;



	if (!adapter || !addr)

		return -EINVAL;



	down_write(&adapter->maps_lock);

	list_for_each_entry_safe(map, tmp, &adapter->maps, list) {

		if (map->guest_addr == addr) {

			found = 1;

			atomic_dec(&adapter->nr_maps);

			list_del(&map->list);

			put_page(map->page);

			kfree(map);

			break;

		}

	}

	up_write(&adapter->maps_lock);



	return found ? 0 : -EINVAL;

}



void kvm_s390_destroy_adapters(struct kvm *kvm)

{

	int i;

	struct s390_map_info *map, *tmp;



	for (i = 0; i < MAX_S390_IO_ADAPTERS; i++) {

		if (!kvm->arch.adapters[i])

			continue;

		list_for_each_entry_safe(map, tmp,

					 &kvm->arch.adapters[i]->maps, list) {

			list_del(&map->list);

			put_page(map->page);

			kfree(map);

		}

		kfree(kvm->arch.adapters[i]);

	}

}



static int modify_io_adapter(struct kvm_device *dev,

			     struct kvm_device_attr *attr)

{

	struct kvm_s390_io_adapter_req req;

	struct s390_io_adapter *adapter;

	int ret;



	if (copy_from_user(&req, (void __user *)attr->addr, sizeof(req)))

		return -EFAULT;



	adapter = get_io_adapter(dev->kvm, req.id);

	if (!adapter)

		return -EINVAL;

	switch (req.type) {

	case KVM_S390_IO_ADAPTER_MASK:

		ret = kvm_s390_mask_adapter(dev->kvm, req.id, req.mask);

		if (ret > 0)

			ret = 0;

		break;

	case KVM_S390_IO_ADAPTER_MAP:

		ret = kvm_s390_adapter_map(dev->kvm, req.id, req.addr);

		break;

	case KVM_S390_IO_ADAPTER_UNMAP:

		ret = kvm_s390_adapter_unmap(dev->kvm, req.id, req.addr);

		break;

	default:

		ret = -EINVAL;

	}



	return ret;

}



static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)

{

	int r = 0;
@@ -1082,6 +1247,12 @@ static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) 
		kvm_for_each_vcpu(i, vcpu, dev->kvm)

			kvm_clear_async_pf_completion_queue(vcpu);

		break;

	case KVM_DEV_FLIC_ADAPTER_REGISTER:

		r = register_io_adapter(dev, attr);

		break;

	case KVM_DEV_FLIC_ADAPTER_MODIFY:

		r = modify_io_adapter(dev, attr);

		break;

	default:

		r = -EINVAL;

	}

arch/s390/kvm/kvm-s390.c

+1 −0
Original line number Diff line number Diff line
@@ -343,6 +343,7 @@ void kvm_arch_destroy_vm(struct kvm *kvm) 
	debug_unregister(kvm->arch.dbf);

	if (!kvm_is_ucontrol(kvm))

		gmap_free(kvm->arch.gmap);

	kvm_s390_destroy_adapters(kvm);

}



/* Section: vcpu related */