From 871480933a1c28f8a9fed4c4d34d06c439a7a422 Mon Sep 17 00:00:00 2001 From: Srikant Patnaik Date: Sun, 11 Jan 2015 12:28:04 +0530 Subject: Moved, renamed, and deleted files The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure. --- drivers/s390/kvm/Makefile | 9 + drivers/s390/kvm/kvm_virtio.c | 481 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 490 insertions(+) create mode 100644 drivers/s390/kvm/Makefile create mode 100644 drivers/s390/kvm/kvm_virtio.c (limited to 'drivers/s390/kvm') diff --git a/drivers/s390/kvm/Makefile b/drivers/s390/kvm/Makefile new file mode 100644 index 00000000..0815690a --- /dev/null +++ b/drivers/s390/kvm/Makefile @@ -0,0 +1,9 @@ +# Makefile for kvm guest drivers on s390 +# +# Copyright IBM Corp. 2008 +# +# 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) +# as published by the Free Software Foundation. + +obj-$(CONFIG_S390_GUEST) += kvm_virtio.o diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c new file mode 100644 index 00000000..d74e9ae6 --- /dev/null +++ b/drivers/s390/kvm/kvm_virtio.c @@ -0,0 +1,481 @@ +/* + * kvm_virtio.c - virtio for kvm on s390 + * + * Copyright IBM Corp. 2008 + * + * 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) + * as published by the Free Software Foundation. + * + * Author(s): Christian Borntraeger + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define VIRTIO_SUBCODE_64 0x0D00 + +/* + * The pointer to our (page) of device descriptions. + */ +static void *kvm_devices; +static struct work_struct hotplug_work; + +struct kvm_device { + struct virtio_device vdev; + struct kvm_device_desc *desc; +}; + +#define to_kvmdev(vd) container_of(vd, struct kvm_device, vdev) + +/* + * memory layout: + * - kvm_device_descriptor + * struct kvm_device_desc + * - configuration + * struct kvm_vqconfig + * - feature bits + * - config space + */ +static struct kvm_vqconfig *kvm_vq_config(const struct kvm_device_desc *desc) +{ + return (struct kvm_vqconfig *)(desc + 1); +} + +static u8 *kvm_vq_features(const struct kvm_device_desc *desc) +{ + return (u8 *)(kvm_vq_config(desc) + desc->num_vq); +} + +static u8 *kvm_vq_configspace(const struct kvm_device_desc *desc) +{ + return kvm_vq_features(desc) + desc->feature_len * 2; +} + +/* + * The total size of the config page used by this device (incl. desc) + */ +static unsigned desc_size(const struct kvm_device_desc *desc) +{ + return sizeof(*desc) + + desc->num_vq * sizeof(struct kvm_vqconfig) + + desc->feature_len * 2 + + desc->config_len; +} + +/* This gets the device's feature bits. */ +static u32 kvm_get_features(struct virtio_device *vdev) +{ + unsigned int i; + u32 features = 0; + struct kvm_device_desc *desc = to_kvmdev(vdev)->desc; + u8 *in_features = kvm_vq_features(desc); + + for (i = 0; i < min(desc->feature_len * 8, 32); i++) + if (in_features[i / 8] & (1 << (i % 8))) + features |= (1 << i); + return features; +} + +static void kvm_finalize_features(struct virtio_device *vdev) +{ + unsigned int i, bits; + struct kvm_device_desc *desc = to_kvmdev(vdev)->desc; + /* Second half of bitmap is features we accept. */ + u8 *out_features = kvm_vq_features(desc) + desc->feature_len; + + /* Give virtio_ring a chance to accept features. */ + vring_transport_features(vdev); + + memset(out_features, 0, desc->feature_len); + bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8; + for (i = 0; i < bits; i++) { + if (test_bit(i, vdev->features)) + out_features[i / 8] |= (1 << (i % 8)); + } +} + +/* + * Reading and writing elements in config space + */ +static void kvm_get(struct virtio_device *vdev, unsigned int offset, + void *buf, unsigned len) +{ + struct kvm_device_desc *desc = to_kvmdev(vdev)->desc; + + BUG_ON(offset + len > desc->config_len); + memcpy(buf, kvm_vq_configspace(desc) + offset, len); +} + +static void kvm_set(struct virtio_device *vdev, unsigned int offset, + const void *buf, unsigned len) +{ + struct kvm_device_desc *desc = to_kvmdev(vdev)->desc; + + BUG_ON(offset + len > desc->config_len); + memcpy(kvm_vq_configspace(desc) + offset, buf, len); +} + +/* + * The operations to get and set the status word just access + * the status field of the device descriptor. set_status will also + * make a hypercall to the host, to tell about status changes + */ +static u8 kvm_get_status(struct virtio_device *vdev) +{ + return to_kvmdev(vdev)->desc->status; +} + +static void kvm_set_status(struct virtio_device *vdev, u8 status) +{ + BUG_ON(!status); + to_kvmdev(vdev)->desc->status = status; + kvm_hypercall1(KVM_S390_VIRTIO_SET_STATUS, + (unsigned long) to_kvmdev(vdev)->desc); +} + +/* + * To reset the device, we use the KVM_VIRTIO_RESET hypercall, using the + * descriptor address. The Host will zero the status and all the + * features. + */ +static void kvm_reset(struct virtio_device *vdev) +{ + kvm_hypercall1(KVM_S390_VIRTIO_RESET, + (unsigned long) to_kvmdev(vdev)->desc); +} + +/* + * When the virtio_ring code wants to notify the Host, it calls us here and we + * make a hypercall. We hand the address of the virtqueue so the Host + * knows which virtqueue we're talking about. + */ +static void kvm_notify(struct virtqueue *vq) +{ + struct kvm_vqconfig *config = vq->priv; + + kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, config->address); +} + +/* + * This routine finds the first virtqueue described in the configuration of + * this device and sets it up. + */ +static struct virtqueue *kvm_find_vq(struct virtio_device *vdev, + unsigned index, + void (*callback)(struct virtqueue *vq), + const char *name) +{ + struct kvm_device *kdev = to_kvmdev(vdev); + struct kvm_vqconfig *config; + struct virtqueue *vq; + int err; + + if (index >= kdev->desc->num_vq) + return ERR_PTR(-ENOENT); + + config = kvm_vq_config(kdev->desc)+index; + + err = vmem_add_mapping(config->address, + vring_size(config->num, + KVM_S390_VIRTIO_RING_ALIGN)); + if (err) + goto out; + + vq = vring_new_virtqueue(config->num, KVM_S390_VIRTIO_RING_ALIGN, + vdev, true, (void *) config->address, + kvm_notify, callback, name); + if (!vq) { + err = -ENOMEM; + goto unmap; + } + + /* + * register a callback token + * The host will sent this via the external interrupt parameter + */ + config->token = (u64) vq; + + vq->priv = config; + return vq; +unmap: + vmem_remove_mapping(config->address, + vring_size(config->num, + KVM_S390_VIRTIO_RING_ALIGN)); +out: + return ERR_PTR(err); +} + +static void kvm_del_vq(struct virtqueue *vq) +{ + struct kvm_vqconfig *config = vq->priv; + + vring_del_virtqueue(vq); + vmem_remove_mapping(config->address, + vring_size(config->num, + KVM_S390_VIRTIO_RING_ALIGN)); +} + +static void kvm_del_vqs(struct virtio_device *vdev) +{ + struct virtqueue *vq, *n; + + list_for_each_entry_safe(vq, n, &vdev->vqs, list) + kvm_del_vq(vq); +} + +static int kvm_find_vqs(struct virtio_device *vdev, unsigned nvqs, + struct virtqueue *vqs[], + vq_callback_t *callbacks[], + const char *names[]) +{ + struct kvm_device *kdev = to_kvmdev(vdev); + int i; + + /* We must have this many virtqueues. */ + if (nvqs > kdev->desc->num_vq) + return -ENOENT; + + for (i = 0; i < nvqs; ++i) { + vqs[i] = kvm_find_vq(vdev, i, callbacks[i], names[i]); + if (IS_ERR(vqs[i])) + goto error; + } + return 0; + +error: + kvm_del_vqs(vdev); + return PTR_ERR(vqs[i]); +} + +static const char *kvm_bus_name(struct virtio_device *vdev) +{ + return ""; +} + +/* + * The config ops structure as defined by virtio config + */ +static struct virtio_config_ops kvm_vq_configspace_ops = { + .get_features = kvm_get_features, + .finalize_features = kvm_finalize_features, + .get = kvm_get, + .set = kvm_set, + .get_status = kvm_get_status, + .set_status = kvm_set_status, + .reset = kvm_reset, + .find_vqs = kvm_find_vqs, + .del_vqs = kvm_del_vqs, + .bus_name = kvm_bus_name, +}; + +/* + * The root device for the kvm virtio devices. + * This makes them appear as /sys/devices/kvm_s390/0,1,2 not /sys/devices/0,1,2. + */ +static struct device *kvm_root; + +/* + * adds a new device and register it with virtio + * appropriate drivers are loaded by the device model + */ +static void add_kvm_device(struct kvm_device_desc *d, unsigned int offset) +{ + struct kvm_device *kdev; + + kdev = kzalloc(sizeof(*kdev), GFP_KERNEL); + if (!kdev) { + printk(KERN_EMERG "Cannot allocate kvm dev %u type %u\n", + offset, d->type); + return; + } + + kdev->vdev.dev.parent = kvm_root; + kdev->vdev.id.device = d->type; + kdev->vdev.config = &kvm_vq_configspace_ops; + kdev->desc = d; + + if (register_virtio_device(&kdev->vdev) != 0) { + printk(KERN_ERR "Failed to register kvm device %u type %u\n", + offset, d->type); + kfree(kdev); + } +} + +/* + * scan_devices() simply iterates through the device page. + * The type 0 is reserved to mean "end of devices". + */ +static void scan_devices(void) +{ + unsigned int i; + struct kvm_device_desc *d; + + for (i = 0; i < PAGE_SIZE; i += desc_size(d)) { + d = kvm_devices + i; + + if (d->type == 0) + break; + + add_kvm_device(d, i); + } +} + +/* + * match for a kvm device with a specific desc pointer + */ +static int match_desc(struct device *dev, void *data) +{ + struct virtio_device *vdev = dev_to_virtio(dev); + struct kvm_device *kdev = to_kvmdev(vdev); + + return kdev->desc == data; +} + +/* + * hotplug_device tries to find changes in the device page. + */ +static void hotplug_devices(struct work_struct *dummy) +{ + unsigned int i; + struct kvm_device_desc *d; + struct device *dev; + + for (i = 0; i < PAGE_SIZE; i += desc_size(d)) { + d = kvm_devices + i; + + /* end of list */ + if (d->type == 0) + break; + + /* device already exists */ + dev = device_find_child(kvm_root, d, match_desc); + if (dev) { + /* XXX check for hotplug remove */ + put_device(dev); + continue; + } + + /* new device */ + printk(KERN_INFO "Adding new virtio device %p\n", d); + add_kvm_device(d, i); + } +} + +/* + * we emulate the request_irq behaviour on top of s390 extints + */ +static void kvm_extint_handler(struct ext_code ext_code, + unsigned int param32, unsigned long param64) +{ + struct virtqueue *vq; + u32 param; + + if ((ext_code.subcode & 0xff00) != VIRTIO_SUBCODE_64) + return; + kstat_cpu(smp_processor_id()).irqs[EXTINT_VRT]++; + + /* The LSB might be overloaded, we have to mask it */ + vq = (struct virtqueue *)(param64 & ~1UL); + + /* We use ext_params to decide what this interrupt means */ + param = param32 & VIRTIO_PARAM_MASK; + + switch (param) { + case VIRTIO_PARAM_CONFIG_CHANGED: + { + struct virtio_driver *drv; + drv = container_of(vq->vdev->dev.driver, + struct virtio_driver, driver); + if (drv->config_changed) + drv->config_changed(vq->vdev); + + break; + } + case VIRTIO_PARAM_DEV_ADD: + schedule_work(&hotplug_work); + break; + case VIRTIO_PARAM_VRING_INTERRUPT: + default: + vring_interrupt(0, vq); + break; + } +} + +/* + * Init function for virtio + * devices are in a single page above top of "normal" mem + */ +static int __init kvm_devices_init(void) +{ + int rc; + + if (!MACHINE_IS_KVM) + return -ENODEV; + + kvm_root = root_device_register("kvm_s390"); + if (IS_ERR(kvm_root)) { + rc = PTR_ERR(kvm_root); + printk(KERN_ERR "Could not register kvm_s390 root device"); + return rc; + } + + rc = vmem_add_mapping(real_memory_size, PAGE_SIZE); + if (rc) { + root_device_unregister(kvm_root); + return rc; + } + + kvm_devices = (void *) real_memory_size; + + INIT_WORK(&hotplug_work, hotplug_devices); + + service_subclass_irq_register(); + register_external_interrupt(0x2603, kvm_extint_handler); + + scan_devices(); + return 0; +} + +/* code for early console output with virtio_console */ +static __init int early_put_chars(u32 vtermno, const char *buf, int count) +{ + char scratch[17]; + unsigned int len = count; + + if (len > sizeof(scratch) - 1) + len = sizeof(scratch) - 1; + scratch[len] = '\0'; + memcpy(scratch, buf, len); + kvm_hypercall1(KVM_S390_VIRTIO_NOTIFY, __pa(scratch)); + return len; +} + +static int __init s390_virtio_console_init(void) +{ + if (!MACHINE_IS_KVM) + return -ENODEV; + return virtio_cons_early_init(early_put_chars); +} +console_initcall(s390_virtio_console_init); + + +/* + * We do this after core stuff, but before the drivers. + */ +postcore_initcall(kvm_devices_init); -- cgit