/*
* 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 <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
typedef struct KVMS390FLICState {
S390FLICState parent_obj;
uint32_t fd;
} 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;
}
/**
* __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_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)
