hw/intc/s390_flic.c - qemu-android - Git at Google

 /*
  * QEMU S390x KVM floating interrupt controller (flic)
  *
  * Copyright 2014 IBM Corp.
  * Author(s): Jens Freimann <jfrei@linux.vnet.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 <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 "trace.h"

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

 void s390_flic_init(void)
 {
     DeviceState *dev;
     int r;

     if (kvm_enabled()) {
         dev = qdev_create(NULL, "s390-flic");
         object_property_add_child(qdev_get_machine(), "s390-flic",
                                 OBJECT(dev), NULL);
         r = qdev_init(dev);
         if (r) {
             error_report("flic: couldn't create qdev");
         }
     }
 }

 /**
  * 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;
 }

 /**
  * __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;
 }

 /**
  * kvm_flic_save - Save pending floating interrupts
  * @f: QEMUFile containing migration state
  * @opaque: pointer to flic device state
  *
  * 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)
 {
     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
  * @version_id: version id for migration
  *
  * 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, int version_id)
 {
     uint64_t len = 0;
     uint64_t count = 0;
     void *buf = NULL;
     int r = 0;

     if (version_id != FLIC_SAVEVM_VERSION) {
         r = -EINVAL;
         goto out;
     }

     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 void kvm_s390_flic_realize(DeviceState *dev, Error **errp)
 {
     KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
     struct kvm_create_device cd = {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;

     /* Register savevm handler for floating interrupts */
     register_savevm(NULL, "s390-flic", 0, 1, kvm_flic_save,
                     kvm_flic_load, (void *) flic_state);
 }

 static void kvm_s390_flic_unrealize(DeviceState *dev, Error **errp)
 {
     KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);

     unregister_savevm(DEVICE(flic_state), "s390-flic", flic_state);
 }

 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);

     dc->realize = kvm_s390_flic_realize;
     dc->unrealize = kvm_s390_flic_unrealize;
     dc->reset = kvm_s390_flic_reset;
 }

 static const TypeInfo kvm_s390_flic_info = {
     .name          = TYPE_KVM_S390_FLIC,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .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>
	*
	* 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 <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 "trace.h"

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

	void s390_flic_init(void)
	{
	DeviceState *dev;
	int r;

	if (kvm_enabled()) {
	dev = qdev_create(NULL, "s390-flic");
	object_property_add_child(qdev_get_machine(), "s390-flic",
	OBJECT(dev), NULL);
	r = qdev_init(dev);
	if (r) {
	error_report("flic: couldn't create qdev");
	}
	}
	}

	/**
	* 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;
	}

	/**
	* __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;
	}

	/**
	* kvm_flic_save - Save pending floating interrupts
	* @f: QEMUFile containing migration state
	* @opaque: pointer to flic device state
	*
	* 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)
	{
	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
	* @version_id: version id for migration
	*
	* 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, int version_id)
	{
	uint64_t len = 0;
	uint64_t count = 0;
	void *buf = NULL;
	int r = 0;

	if (version_id != FLIC_SAVEVM_VERSION) {
	r = -EINVAL;
	goto out;
	}

	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 void kvm_s390_flic_realize(DeviceState dev, Error *errp)
	{
	KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);
	struct kvm_create_device cd = {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;

	/* Register savevm handler for floating interrupts */
	register_savevm(NULL, "s390-flic", 0, 1, kvm_flic_save,
	kvm_flic_load, (void *) flic_state);
	}

	static void kvm_s390_flic_unrealize(DeviceState dev, Error *errp)
	{
	KVMS390FLICState *flic_state = KVM_S390_FLIC(dev);

	unregister_savevm(DEVICE(flic_state), "s390-flic", flic_state);
	}

	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);

	dc->realize = kvm_s390_flic_realize;
	dc->unrealize = kvm_s390_flic_unrealize;
	dc->reset = kvm_s390_flic_reset;
	}

	static const TypeInfo kvm_s390_flic_info = {
	.name = TYPE_KVM_S390_FLIC,
	.parent = TYPE_SYS_BUS_DEVICE,
	.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)