hw/intc/s390_flic_kvm.c - chromiumos/third_party/qemu - Git at Google

 /*
  * QEMU S390x KVM floating interrupt controller (flic)
  *
  * Copyright 2014 IBM Corp.
  * Author(s): Jens Freimann <jfrei@linux.vnet.ibm.com>
  *            Cornelia Huck <cornelia.huck@de.ibm.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or (at
  * your option) any later version. See the COPYING file in the top-level
  * directory.
  */

 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "cpu.h"
 #include <sys/ioctl.h>
 #include "qemu/error-report.h"
 #include "hw/sysbus.h"
 #include "sysemu/kvm.h"
 #include "migration/qemu-file.h"
 #include "hw/s390x/s390_flic.h"
 #include "hw/s390x/adapter.h"
 #include "trace.h"

 #define FLIC_SAVE_INITIAL_SIZE getpagesize()
 #define FLIC_FAILED (-1UL)
 #define FLIC_SAVEVM_VERSION 1

 typedef struct KVMS390FLICState {
     S390FLICState parent_obj;

     uint32_t fd;
     bool clear_io_supported;
 } KVMS390FLICState;

 DeviceState *s390_flic_kvm_create(void)
 {
     DeviceState *dev = NULL;

     if (kvm_enabled()) {
         dev = qdev_create(NULL, TYPE_KVM_S390_FLIC);
         object_property_add_child(qdev_get_machine(), TYPE_KVM_S390_FLIC,
                                   OBJECT(dev), NULL);
     }
     return dev;
 }

 /**
  * flic_get_all_irqs - store all pending irqs in buffer
  * @buf: pointer to buffer which is passed to kernel
  * @len: length of buffer
  * @flic: pointer to flic device state
  *
  * Returns: -ENOMEM if buffer is too small,
  * -EINVAL if attr.group is invalid,
  * -EFAULT if copying to userspace failed,
  * on success return number of stored interrupts
  */
 static int flic_get_all_irqs(KVMS390FLICState *flic,
                              void *buf, int len)
 {
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_GET_ALL_IRQS,
         .addr = (uint64_t) buf,
         .attr = len,
     };
     int rc;

     rc = ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr);

     return rc == -1 ? -errno : rc;
 }

 static void flic_enable_pfault(KVMS390FLICState *flic)
 {
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_APF_ENABLE,
     };
     int rc;

     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);

     if (rc) {
         fprintf(stderr, "flic: couldn't enable pfault\n");
     }
 }

 static void flic_disable_wait_pfault(KVMS390FLICState *flic)
 {
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_APF_DISABLE_WAIT,
     };
     int rc;

     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);

     if (rc) {
         fprintf(stderr, "flic: couldn't disable pfault\n");
     }
 }

 /** flic_enqueue_irqs - returns 0 on success
  * @buf: pointer to buffer which is passed to kernel
  * @len: length of buffer
  * @flic: pointer to flic device state
  *
  * Returns: -EINVAL if attr.group is unknown
  */
 static int flic_enqueue_irqs(void *buf, uint64_t len,
                             KVMS390FLICState *flic)
 {
     int rc;
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_ENQUEUE,
         .addr = (uint64_t) buf,
         .attr = len,
     };

     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);

     return rc ? -errno : 0;
 }

 int kvm_s390_inject_flic(struct kvm_s390_irq *irq)
 {
     static KVMS390FLICState *flic;

     if (unlikely(!flic)) {
         flic = KVM_S390_FLIC(s390_get_flic());
     }
     return flic_enqueue_irqs(irq, sizeof(*irq), flic);
 }

 static int kvm_s390_clear_io_flic(S390FLICState *fs, uint16_t subchannel_id,
                            uint16_t subchannel_nr)
 {
     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
     int rc;
     uint32_t sid = subchannel_id << 16 | subchannel_nr;
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_CLEAR_IO_IRQ,
         .addr = (uint64_t) &sid,
         .attr = sizeof(sid),
     };
     if (unlikely(!flic->clear_io_supported)) {
         return -ENOSYS;
     }
     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
     return rc ? -errno : 0;
 }

 /**
  * __get_all_irqs - store all pending irqs in buffer
  * @flic: pointer to flic device state
  * @buf: pointer to pointer to a buffer
  * @len: length of buffer
  *
  * Returns: return value of flic_get_all_irqs
  * Note: Retry and increase buffer size until flic_get_all_irqs
  * either returns a value >= 0 or a negative error code.
  * -ENOMEM is an exception, which means the buffer is too small
  * and we should try again. Other negative error codes can be
  * -EFAULT and -EINVAL which we ignore at this point
  */
 static int __get_all_irqs(KVMS390FLICState *flic,
                           void **buf, int len)
 {
     int r;

     do {
         /* returns -ENOMEM if buffer is too small and number
          * of queued interrupts on success */
         r = flic_get_all_irqs(flic, *buf, len);
         if (r >= 0) {
             break;
         }
         len *= 2;
         *buf = g_try_realloc(*buf, len);
         if (!buf) {
             return -ENOMEM;
         }
     } while (r == -ENOMEM && len <= KVM_S390_FLIC_MAX_BUFFER);

     return r;
 }

 static int kvm_s390_register_io_adapter(S390FLICState *fs, uint32_t id,
                                         uint8_t isc, bool swap,
                                         bool is_maskable)
 {
     struct kvm_s390_io_adapter adapter = {
         .id = id,
         .isc = isc,
         .maskable = is_maskable,
         .swap = swap,
     };
     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
     int r;
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_ADAPTER_REGISTER,
         .addr = (uint64_t)&adapter,
     };

     if (!kvm_check_extension(kvm_state, KVM_CAP_IRQ_ROUTING)) {
         /* nothing to do */
         return 0;
     }

     r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);

     return r ? -errno : 0;
 }

 static int kvm_s390_io_adapter_map(S390FLICState *fs, uint32_t id,
                                    uint64_t map_addr, bool do_map)
 {
     struct kvm_s390_io_adapter_req req = {
         .id = id,
         .type = do_map ? KVM_S390_IO_ADAPTER_MAP : KVM_S390_IO_ADAPTER_UNMAP,
         .addr = map_addr,
     };
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_ADAPTER_MODIFY,
         .addr = (uint64_t)&req,
     };
     KVMS390FLICState *flic = KVM_S390_FLIC(fs);
     int r;

     if (!kvm_check_extension(kvm_state, KVM_CAP_IRQ_ROUTING)) {
         /* nothing to do */
         return 0;
     }

     r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
     return r ? -errno : 0;
 }

 static int kvm_s390_add_adapter_routes(S390FLICState *fs,
                                        AdapterRoutes *routes)
 {
     int ret, i;
     uint64_t ind_offset = routes->adapter.ind_offset;

     for (i = 0; i < routes->num_routes; i++) {
         ret = kvm_irqchip_add_adapter_route(kvm_state, &routes->adapter);
         if (ret < 0) {
             goto out_undo;
         }
         routes->gsi[i] = ret;
         routes->adapter.ind_offset++;
     }
     kvm_irqchip_commit_routes(kvm_state);

     /* Restore passed-in structure to original state. */
     routes->adapter.ind_offset = ind_offset;
     return 0;
 out_undo:
     while (--i >= 0) {
         kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
         routes->gsi[i] = -1;
     }
     routes->adapter.ind_offset = ind_offset;
     return ret;
 }

 static void kvm_s390_release_adapter_routes(S390FLICState *fs,
                                             AdapterRoutes *routes)
 {
     int i;

     for (i = 0; i < routes->num_routes; i++) {
         if (routes->gsi[i] >= 0) {
             kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
             routes->gsi[i] = -1;
         }
     }
 }

 /**
  * kvm_flic_save - Save pending floating interrupts
  * @f: QEMUFile containing migration state
  * @opaque: pointer to flic device state
  * @size: ignored
  *
  * Note: Pass buf and len to kernel. Start with one page and
  * increase until buffer is sufficient or maxium size is
  * reached
  */
 static void kvm_flic_save(QEMUFile *f, void *opaque, size_t size)
 {
     KVMS390FLICState *flic = opaque;
     int len = FLIC_SAVE_INITIAL_SIZE;
     void *buf;
     int count;

     flic_disable_wait_pfault((struct KVMS390FLICState *) opaque);

     buf = g_try_malloc0(len);
     if (!buf) {
         /* Storing FLIC_FAILED into the count field here will cause the
          * target system to fail when attempting to load irqs from the
          * migration state */
         error_report("flic: couldn't allocate memory");
         qemu_put_be64(f, FLIC_FAILED);
         return;
     }

     count = __get_all_irqs(flic, &buf, len);
     if (count < 0) {
         error_report("flic: couldn't retrieve irqs from kernel, rc %d",
                      count);
         /* Storing FLIC_FAILED into the count field here will cause the
          * target system to fail when attempting to load irqs from the
          * migration state */
         qemu_put_be64(f, FLIC_FAILED);
     } else {
         qemu_put_be64(f, count);
         qemu_put_buffer(f, (uint8_t *) buf,
                         count * sizeof(struct kvm_s390_irq));
     }
     g_free(buf);
 }

 /**
  * kvm_flic_load - Load pending floating interrupts
  * @f: QEMUFile containing migration state
  * @opaque: pointer to flic device state
  * @size: ignored
  *
  * Returns: value of flic_enqueue_irqs, -EINVAL on error
  * Note: Do nothing when no interrupts where stored
  * in QEMUFile
  */
 static int kvm_flic_load(QEMUFile *f, void *opaque, size_t size)
 {
     uint64_t len = 0;
     uint64_t count = 0;
     void *buf = NULL;
     int r = 0;

     flic_enable_pfault((struct KVMS390FLICState *) opaque);

     count = qemu_get_be64(f);
     len = count * sizeof(struct kvm_s390_irq);
     if (count == FLIC_FAILED) {
         r = -EINVAL;
         goto out;
     }
     if (count == 0) {
         r = 0;
         goto out;
     }
     buf = g_try_malloc0(len);
     if (!buf) {
         r = -ENOMEM;
         goto out;
     }

     if (qemu_get_buffer(f, (uint8_t *) buf, len) != len) {
         r = -EINVAL;
         goto out_free;
     }
     r = flic_enqueue_irqs(buf, len, (struct KVMS390FLICState *) opaque);

 out_free:
     g_free(buf);
 out:
     return r;
 }

 static const VMStateDescription kvm_s390_flic_vmstate = {
     .name = "s390-flic",
     .version_id = FLIC_SAVEVM_VERSION,
     .minimum_version_id = FLIC_SAVEVM_VERSION,
     .fields = (VMStateField[]) {
         {
             .name = "irqs",
             .info = &(const VMStateInfo) {
                 .name = "irqs",
                 .get = kvm_flic_load,
                 .put = kvm_flic_save,
             },
             .flags = VMS_SINGLE,
         },
         VMSTATE_END_OF_LIST()
     }
 };

 static void kvm_s390_flic_realize(DeviceState *dev, Error **errp)
 {
     KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
     struct kvm_create_device cd = {0};
     struct kvm_device_attr test_attr = {0};
     int ret;

     flic_state->fd = -1;
     if (!kvm_check_extension(kvm_state, KVM_CAP_DEVICE_CTRL)) {
         trace_flic_no_device_api(errno);
         return;
     }

     cd.type = KVM_DEV_TYPE_FLIC;
     ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
     if (ret < 0) {
         trace_flic_create_device(errno);
         return;
     }
     flic_state->fd = cd.fd;

     /* Check clear_io_irq support */
     test_attr.group = KVM_DEV_FLIC_CLEAR_IO_IRQ;
     flic_state->clear_io_supported = !ioctl(flic_state->fd,
                                             KVM_HAS_DEVICE_ATTR, test_attr);

 }

 static void kvm_s390_flic_reset(DeviceState *dev)
 {
     KVMS390FLICState *flic = KVM_S390_FLIC(dev);
     struct kvm_device_attr attr = {
         .group = KVM_DEV_FLIC_CLEAR_IRQS,
     };
     int rc = 0;

     if (flic->fd == -1) {
         return;
     }

     flic_disable_wait_pfault(flic);

     rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
     if (rc) {
         trace_flic_reset_failed(errno);
     }

     flic_enable_pfault(flic);
 }

 static void kvm_s390_flic_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
     S390FLICStateClass *fsc = S390_FLIC_COMMON_CLASS(oc);

     dc->realize = kvm_s390_flic_realize;
     dc->vmsd = &kvm_s390_flic_vmstate;
     dc->reset = kvm_s390_flic_reset;
     fsc->register_io_adapter = kvm_s390_register_io_adapter;
     fsc->io_adapter_map = kvm_s390_io_adapter_map;
     fsc->add_adapter_routes = kvm_s390_add_adapter_routes;
     fsc->release_adapter_routes = kvm_s390_release_adapter_routes;
     fsc->clear_io_irq = kvm_s390_clear_io_flic;
 }

 static const TypeInfo kvm_s390_flic_info = {
     .name          = TYPE_KVM_S390_FLIC,
     .parent        = TYPE_S390_FLIC_COMMON,
     .instance_size = sizeof(KVMS390FLICState),
     .class_init    = kvm_s390_flic_class_init,
 };

 static void kvm_s390_flic_register_types(void)
 {
     type_register_static(&kvm_s390_flic_info);
 }

 type_init(kvm_s390_flic_register_types)
	/*
	* QEMU S390x KVM floating interrupt controller (flic)
	*
	* Copyright 2014 IBM Corp.
	* Author(s): Jens Freimann <jfrei@linux.vnet.ibm.com>
	* Cornelia Huck <cornelia.huck@de.ibm.com>
	*
	* This work is licensed under the terms of the GNU GPL, version 2 or (at
	* your option) any later version. See the COPYING file in the top-level
	* directory.
	*/

	#include "qemu/osdep.h"
	#include "qemu-common.h"
	#include "cpu.h"
	#include <sys/ioctl.h>
	#include "qemu/error-report.h"
	#include "hw/sysbus.h"
	#include "sysemu/kvm.h"
	#include "migration/qemu-file.h"
	#include "hw/s390x/s390_flic.h"
	#include "hw/s390x/adapter.h"
	#include "trace.h"

	#define FLIC_SAVE_INITIAL_SIZE getpagesize()
	#define FLIC_FAILED (-1UL)
	#define FLIC_SAVEVM_VERSION 1

	typedef struct KVMS390FLICState {
	S390FLICState parent_obj;

	uint32_t fd;
	bool clear_io_supported;
	} KVMS390FLICState;

	DeviceState *s390_flic_kvm_create(void)
	{
	DeviceState *dev = NULL;

	if (kvm_enabled()) {
	dev = qdev_create(NULL, TYPE_KVM_S390_FLIC);
	object_property_add_child(qdev_get_machine(), TYPE_KVM_S390_FLIC,
	OBJECT(dev), NULL);
	}
	return dev;
	}

	/**
	* flic_get_all_irqs - store all pending irqs in buffer
	* @buf: pointer to buffer which is passed to kernel
	* @len: length of buffer
	* @flic: pointer to flic device state
	*
	* Returns: -ENOMEM if buffer is too small,
	* -EINVAL if attr.group is invalid,
	* -EFAULT if copying to userspace failed,
	* on success return number of stored interrupts
	*/
	static int flic_get_all_irqs(KVMS390FLICState *flic,
	void *buf, int len)
	{
	struct kvm_device_attr attr = {
	.group = KVM_DEV_FLIC_GET_ALL_IRQS,
	.addr = (uint64_t) buf,
	.attr = len,
	};
	int rc;

	rc = ioctl(flic->fd, KVM_GET_DEVICE_ATTR, &attr);

	return rc == -1 ? -errno : rc;
	}

	static void flic_enable_pfault(KVMS390FLICState *flic)
	{
	struct kvm_device_attr attr = {
	.group = KVM_DEV_FLIC_APF_ENABLE,
	};
	int rc;

	rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);

	if (rc) {
	fprintf(stderr, "flic: couldn't enable pfault\n");
	}
	}

	static void flic_disable_wait_pfault(KVMS390FLICState *flic)
	{
	struct kvm_device_attr attr = {
	.group = KVM_DEV_FLIC_APF_DISABLE_WAIT,
	};
	int rc;

	rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);

	if (rc) {
	fprintf(stderr, "flic: couldn't disable pfault\n");
	}
	}

	/** flic_enqueue_irqs - returns 0 on success
	* @buf: pointer to buffer which is passed to kernel
	* @len: length of buffer
	* @flic: pointer to flic device state
	*
	* Returns: -EINVAL if attr.group is unknown
	*/
	static int flic_enqueue_irqs(void *buf, uint64_t len,
	KVMS390FLICState *flic)
	{
	int rc;
	struct kvm_device_attr attr = {
	.group = KVM_DEV_FLIC_ENQUEUE,
	.addr = (uint64_t) buf,
	.attr = len,
	};

	rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);

	return rc ? -errno : 0;
	}

	int kvm_s390_inject_flic(struct kvm_s390_irq *irq)
	{
	static KVMS390FLICState *flic;

	if (unlikely(!flic)) {
	flic = KVM_S390_FLIC(s390_get_flic());
	}
	return flic_enqueue_irqs(irq, sizeof(*irq), flic);
	}

	static int kvm_s390_clear_io_flic(S390FLICState *fs, uint16_t subchannel_id,
	uint16_t subchannel_nr)
	{
	KVMS390FLICState *flic = KVM_S390_FLIC(fs);
	int rc;
	uint32_t sid = subchannel_id << 16 \| subchannel_nr;
	struct kvm_device_attr attr = {
	.group = KVM_DEV_FLIC_CLEAR_IO_IRQ,
	.addr = (uint64_t) &sid,
	.attr = sizeof(sid),
	};
	if (unlikely(!flic->clear_io_supported)) {
	return -ENOSYS;
	}
	rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
	return rc ? -errno : 0;
	}

	/**
	* __get_all_irqs - store all pending irqs in buffer
	* @flic: pointer to flic device state
	* @buf: pointer to pointer to a buffer
	* @len: length of buffer
	*
	* Returns: return value of flic_get_all_irqs
	* Note: Retry and increase buffer size until flic_get_all_irqs
	* either returns a value >= 0 or a negative error code.
	* -ENOMEM is an exception, which means the buffer is too small
	* and we should try again. Other negative error codes can be
	* -EFAULT and -EINVAL which we ignore at this point
	*/
	static int __get_all_irqs(KVMS390FLICState *flic,
	void **buf, int len)
	{
	int r;

	do {
	/* returns -ENOMEM if buffer is too small and number
	* of queued interrupts on success */
	r = flic_get_all_irqs(flic, *buf, len);
	if (r >= 0) {
	break;
	}
	len *= 2;
	buf = g_try_realloc(buf, len);
	if (!buf) {
	return -ENOMEM;
	}
	} while (r == -ENOMEM && len <= KVM_S390_FLIC_MAX_BUFFER);

	return r;
	}

	static int kvm_s390_register_io_adapter(S390FLICState *fs, uint32_t id,
	uint8_t isc, bool swap,
	bool is_maskable)
	{
	struct kvm_s390_io_adapter adapter = {
	.id = id,
	.isc = isc,
	.maskable = is_maskable,
	.swap = swap,
	};
	KVMS390FLICState *flic = KVM_S390_FLIC(fs);
	int r;
	struct kvm_device_attr attr = {
	.group = KVM_DEV_FLIC_ADAPTER_REGISTER,
	.addr = (uint64_t)&adapter,
	};

	if (!kvm_check_extension(kvm_state, KVM_CAP_IRQ_ROUTING)) {
	/* nothing to do */
	return 0;
	}

	r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);

	return r ? -errno : 0;
	}

	static int kvm_s390_io_adapter_map(S390FLICState *fs, uint32_t id,
	uint64_t map_addr, bool do_map)
	{
	struct kvm_s390_io_adapter_req req = {
	.id = id,
	.type = do_map ? KVM_S390_IO_ADAPTER_MAP : KVM_S390_IO_ADAPTER_UNMAP,
	.addr = map_addr,
	};
	struct kvm_device_attr attr = {
	.group = KVM_DEV_FLIC_ADAPTER_MODIFY,
	.addr = (uint64_t)&req,
	};
	KVMS390FLICState *flic = KVM_S390_FLIC(fs);
	int r;

	if (!kvm_check_extension(kvm_state, KVM_CAP_IRQ_ROUTING)) {
	/* nothing to do */
	return 0;
	}

	r = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
	return r ? -errno : 0;
	}

	static int kvm_s390_add_adapter_routes(S390FLICState *fs,
	AdapterRoutes *routes)
	{
	int ret, i;
	uint64_t ind_offset = routes->adapter.ind_offset;

	for (i = 0; i < routes->num_routes; i++) {
	ret = kvm_irqchip_add_adapter_route(kvm_state, &routes->adapter);
	if (ret < 0) {
	goto out_undo;
	}
	routes->gsi[i] = ret;
	routes->adapter.ind_offset++;
	}
	kvm_irqchip_commit_routes(kvm_state);

	/* Restore passed-in structure to original state. */
	routes->adapter.ind_offset = ind_offset;
	return 0;
	out_undo:
	while (--i >= 0) {
	kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
	routes->gsi[i] = -1;
	}
	routes->adapter.ind_offset = ind_offset;
	return ret;
	}

	static void kvm_s390_release_adapter_routes(S390FLICState *fs,
	AdapterRoutes *routes)
	{
	int i;

	for (i = 0; i < routes->num_routes; i++) {
	if (routes->gsi[i] >= 0) {
	kvm_irqchip_release_virq(kvm_state, routes->gsi[i]);
	routes->gsi[i] = -1;
	}
	}
	}

	/**
	* kvm_flic_save - Save pending floating interrupts
	* @f: QEMUFile containing migration state
	* @opaque: pointer to flic device state
	* @size: ignored
	*
	* Note: Pass buf and len to kernel. Start with one page and
	* increase until buffer is sufficient or maxium size is
	* reached
	*/
	static void kvm_flic_save(QEMUFile f, void opaque, size_t size)
	{
	KVMS390FLICState *flic = opaque;
	int len = FLIC_SAVE_INITIAL_SIZE;
	void *buf;
	int count;

	flic_disable_wait_pfault((struct KVMS390FLICState *) opaque);

	buf = g_try_malloc0(len);
	if (!buf) {
	/* Storing FLIC_FAILED into the count field here will cause the
	* target system to fail when attempting to load irqs from the
	* migration state */
	error_report("flic: couldn't allocate memory");
	qemu_put_be64(f, FLIC_FAILED);
	return;
	}

	count = __get_all_irqs(flic, &buf, len);
	if (count < 0) {
	error_report("flic: couldn't retrieve irqs from kernel, rc %d",
	count);
	/* Storing FLIC_FAILED into the count field here will cause the
	* target system to fail when attempting to load irqs from the
	* migration state */
	qemu_put_be64(f, FLIC_FAILED);
	} else {
	qemu_put_be64(f, count);
	qemu_put_buffer(f, (uint8_t *) buf,
	count * sizeof(struct kvm_s390_irq));
	}
	g_free(buf);
	}

	/**
	* kvm_flic_load - Load pending floating interrupts
	* @f: QEMUFile containing migration state
	* @opaque: pointer to flic device state
	* @size: ignored
	*
	* Returns: value of flic_enqueue_irqs, -EINVAL on error
	* Note: Do nothing when no interrupts where stored
	* in QEMUFile
	*/
	static int kvm_flic_load(QEMUFile f, void opaque, size_t size)
	{
	uint64_t len = 0;
	uint64_t count = 0;
	void *buf = NULL;
	int r = 0;

	flic_enable_pfault((struct KVMS390FLICState *) opaque);

	count = qemu_get_be64(f);
	len = count * sizeof(struct kvm_s390_irq);
	if (count == FLIC_FAILED) {
	r = -EINVAL;
	goto out;
	}
	if (count == 0) {
	r = 0;
	goto out;
	}
	buf = g_try_malloc0(len);
	if (!buf) {
	r = -ENOMEM;
	goto out;
	}

	if (qemu_get_buffer(f, (uint8_t *) buf, len) != len) {
	r = -EINVAL;
	goto out_free;
	}
	r = flic_enqueue_irqs(buf, len, (struct KVMS390FLICState *) opaque);

	out_free:
	g_free(buf);
	out:
	return r;
	}

	static const VMStateDescription kvm_s390_flic_vmstate = {
	.name = "s390-flic",
	.version_id = FLIC_SAVEVM_VERSION,
	.minimum_version_id = FLIC_SAVEVM_VERSION,
	.fields = (VMStateField[]) {
	{
	.name = "irqs",
	.info = &(const VMStateInfo) {
	.name = "irqs",
	.get = kvm_flic_load,
	.put = kvm_flic_save,
	},
	.flags = VMS_SINGLE,
	},
	VMSTATE_END_OF_LIST()
	}
	};

	static void kvm_s390_flic_realize(DeviceState dev, Error *errp)
	{
	KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
	struct kvm_create_device cd = {0};
	struct kvm_device_attr test_attr = {0};
	int ret;

	flic_state->fd = -1;
	if (!kvm_check_extension(kvm_state, KVM_CAP_DEVICE_CTRL)) {
	trace_flic_no_device_api(errno);
	return;
	}

	cd.type = KVM_DEV_TYPE_FLIC;
	ret = kvm_vm_ioctl(kvm_state, KVM_CREATE_DEVICE, &cd);
	if (ret < 0) {
	trace_flic_create_device(errno);
	return;
	}
	flic_state->fd = cd.fd;

	/* Check clear_io_irq support */
	test_attr.group = KVM_DEV_FLIC_CLEAR_IO_IRQ;
	flic_state->clear_io_supported = !ioctl(flic_state->fd,
	KVM_HAS_DEVICE_ATTR, test_attr);

	}

	static void kvm_s390_flic_reset(DeviceState *dev)
	{
	KVMS390FLICState *flic = KVM_S390_FLIC(dev);
	struct kvm_device_attr attr = {
	.group = KVM_DEV_FLIC_CLEAR_IRQS,
	};
	int rc = 0;

	if (flic->fd == -1) {
	return;
	}

	flic_disable_wait_pfault(flic);

	rc = ioctl(flic->fd, KVM_SET_DEVICE_ATTR, &attr);
	if (rc) {
	trace_flic_reset_failed(errno);
	}

	flic_enable_pfault(flic);
	}

	static void kvm_s390_flic_class_init(ObjectClass oc, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(oc);
	S390FLICStateClass *fsc = S390_FLIC_COMMON_CLASS(oc);

	dc->realize = kvm_s390_flic_realize;
	dc->vmsd = &kvm_s390_flic_vmstate;
	dc->reset = kvm_s390_flic_reset;
	fsc->register_io_adapter = kvm_s390_register_io_adapter;
	fsc->io_adapter_map = kvm_s390_io_adapter_map;
	fsc->add_adapter_routes = kvm_s390_add_adapter_routes;
	fsc->release_adapter_routes = kvm_s390_release_adapter_routes;
	fsc->clear_io_irq = kvm_s390_clear_io_flic;
	}

	static const TypeInfo kvm_s390_flic_info = {
	.name = TYPE_KVM_S390_FLIC,
	.parent = TYPE_S390_FLIC_COMMON,
	.instance_size = sizeof(KVMS390FLICState),
	.class_init = kvm_s390_flic_class_init,
	};

	static void kvm_s390_flic_register_types(void)
	{
	type_register_static(&kvm_s390_flic_info);
	}

	type_init(kvm_s390_flic_register_types)