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Diffstat (limited to 'hw/intc/s390_flic.c')
-rw-r--r--hw/intc/s390_flic.c322
1 files changed, 322 insertions, 0 deletions
diff --git a/hw/intc/s390_flic.c b/hw/intc/s390_flic.c
new file mode 100644
index 0000000000..b2ef3e3f8e
--- /dev/null
+++ b/hw/intc/s390_flic.c
@@ -0,0 +1,322 @@
+/*
+ * 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)
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-22 05:36:12 +0000