cregit-Linux how code gets into the kernel

Release 4.7 virt/kvm/vfio.c

Directory: virt/kvm
/*
 * VFIO-KVM bridge pseudo device
 *
 * Copyright (C) 2013 Red Hat, Inc.  All rights reserved.
 *     Author: Alex Williamson <alex.williamson@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/errno.h>
#include <linux/file.h>
#include <linux/kvm_host.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include "vfio.h"


struct kvm_vfio_group {
	
struct list_head node;
	
struct vfio_group *vfio_group;
};


struct kvm_vfio {
	
struct list_head group_list;
	
struct mutex lock;
	
bool noncoherent;
};


static struct vfio_group *kvm_vfio_group_get_external_user(struct file *filep) { struct vfio_group *vfio_group; struct vfio_group *(*fn)(struct file *); fn = symbol_get(vfio_group_get_external_user); if (!fn) return ERR_PTR(-EINVAL); vfio_group = fn(filep); symbol_put(vfio_group_get_external_user); return vfio_group; }

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alex williamsonalex williamson65100.00%1100.00%
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static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group) { void (*fn)(struct vfio_group *); fn = symbol_get(vfio_group_put_external_user); if (!fn) return; fn(vfio_group); symbol_put(vfio_group_put_external_user); }

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alex williamsonalex williamson45100.00%1100.00%
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static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group) { long (*fn)(struct vfio_group *, unsigned long); long ret; fn = symbol_get(vfio_external_check_extension); if (!fn) return false; ret = fn(vfio_group, VFIO_DMA_CC_IOMMU); symbol_put(vfio_external_check_extension); return ret > 0; }

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alex williamsonalex williamson62100.00%1100.00%
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/* * Groups can use the same or different IOMMU domains. If the same then * adding a new group may change the coherency of groups we've previously * been told about. We don't want to care about any of that so we retest * each group and bail as soon as we find one that's noncoherent. This * means we only ever [un]register_noncoherent_dma once for the whole device. */
static void kvm_vfio_update_coherency(struct kvm_device *dev) { struct kvm_vfio *kv = dev->private; bool noncoherent = false; struct kvm_vfio_group *kvg; mutex_lock(&kv->lock); list_for_each_entry(kvg, &kv->group_list, node) { if (!kvm_vfio_group_is_coherent(kvg->vfio_group)) { noncoherent = true; break; } } if (noncoherent != kv->noncoherent) { kv->noncoherent = noncoherent; if (kv->noncoherent) kvm_arch_register_noncoherent_dma(dev->kvm); else kvm_arch_unregister_noncoherent_dma(dev->kvm); } mutex_unlock(&kv->lock); }

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alex williamsonalex williamson110100.00%2100.00%
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static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg) { struct kvm_vfio *kv = dev->private; struct vfio_group *vfio_group; struct kvm_vfio_group *kvg; int32_t __user *argp = (int32_t __user *)(unsigned long)arg; struct fd f; int32_t fd; int ret; switch (attr) { case KVM_DEV_VFIO_GROUP_ADD: if (get_user(fd, argp)) return -EFAULT; f = fdget(fd); if (!f.file) return -EBADF; vfio_group = kvm_vfio_group_get_external_user(f.file); fdput(f); if (IS_ERR(vfio_group)) return PTR_ERR(vfio_group); mutex_lock(&kv->lock); list_for_each_entry(kvg, &kv->group_list, node) { if (kvg->vfio_group == vfio_group) { mutex_unlock(&kv->lock); kvm_vfio_group_put_external_user(vfio_group); return -EEXIST; } } kvg = kzalloc(sizeof(*kvg), GFP_KERNEL); if (!kvg) { mutex_unlock(&kv->lock); kvm_vfio_group_put_external_user(vfio_group); return -ENOMEM; } list_add_tail(&kvg->node, &kv->group_list); kvg->vfio_group = vfio_group; kvm_arch_start_assignment(dev->kvm); mutex_unlock(&kv->lock); kvm_vfio_update_coherency(dev); return 0; case KVM_DEV_VFIO_GROUP_DEL: if (get_user(fd, argp)) return -EFAULT; f = fdget(fd); if (!f.file) return -EBADF; vfio_group = kvm_vfio_group_get_external_user(f.file); fdput(f); if (IS_ERR(vfio_group)) return PTR_ERR(vfio_group); ret = -ENOENT; mutex_lock(&kv->lock); list_for_each_entry(kvg, &kv->group_list, node) { if (kvg->vfio_group != vfio_group) continue; list_del(&kvg->node); kvm_vfio_group_put_external_user(kvg->vfio_group); kfree(kvg); ret = 0; break; } kvm_arch_end_assignment(dev->kvm); mutex_unlock(&kv->lock); kvm_vfio_group_put_external_user(vfio_group); kvm_vfio_update_coherency(dev); return ret; } return -ENXIO; }

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alex williamsonalex williamson38395.04%250.00%
paolo bonzinipaolo bonzini143.47%125.00%
paul bollepaul bolle61.49%125.00%
Total403100.00%4100.00%


static int kvm_vfio_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { switch (attr->group) { case KVM_DEV_VFIO_GROUP: return kvm_vfio_set_group(dev, attr->attr, attr->addr); } return -ENXIO; }

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alex williamsonalex williamson45100.00%1100.00%
Total45100.00%1100.00%


static int kvm_vfio_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { switch (attr->group) { case KVM_DEV_VFIO_GROUP: switch (attr->attr) { case KVM_DEV_VFIO_GROUP_ADD: case KVM_DEV_VFIO_GROUP_DEL: return 0; } break; } return -ENXIO; }

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alex williamsonalex williamson49100.00%1100.00%
Total49100.00%1100.00%


static void kvm_vfio_destroy(struct kvm_device *dev) { struct kvm_vfio *kv = dev->private; struct kvm_vfio_group *kvg, *tmp; list_for_each_entry_safe(kvg, tmp, &kv->group_list, node) { kvm_vfio_group_put_external_user(kvg->vfio_group); list_del(&kvg->node); kfree(kvg); kvm_arch_end_assignment(dev->kvm); } kvm_vfio_update_coherency(dev); kfree(kv); kfree(dev); /* alloc by kvm_ioctl_create_device, free by .destroy */ }

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alex williamsonalex williamson7691.57%266.67%
paolo bonzinipaolo bonzini78.43%133.33%
Total83100.00%3100.00%

static int kvm_vfio_create(struct kvm_device *dev, u32 type); static struct kvm_device_ops kvm_vfio_ops = { .name = "kvm-vfio", .create = kvm_vfio_create, .destroy = kvm_vfio_destroy, .set_attr = kvm_vfio_set_attr, .has_attr = kvm_vfio_has_attr, };
static int kvm_vfio_create(struct kvm_device *dev, u32 type) { struct kvm_device *tmp; struct kvm_vfio *kv; /* Only one VFIO "device" per VM */ list_for_each_entry(tmp, &dev->kvm->devices, vm_node) if (tmp->ops == &kvm_vfio_ops) return -EBUSY; kv = kzalloc(sizeof(*kv), GFP_KERNEL); if (!kv) return -ENOMEM; INIT_LIST_HEAD(&kv->group_list); mutex_init(&kv->lock); dev->private = kv; return 0; }

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alex williamsonalex williamson93100.00%1100.00%
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int kvm_vfio_ops_init(void) { return kvm_register_device_ops(&kvm_vfio_ops, KVM_DEV_TYPE_VFIO); }

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will deaconwill deacon1593.75%150.00%
alex williamsonalex williamson16.25%150.00%
Total16100.00%2100.00%


void kvm_vfio_ops_exit(void) { kvm_unregister_device_ops(KVM_DEV_TYPE_VFIO); }

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wanpeng liwanpeng li12100.00%1100.00%
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alex williamsonalex williamson98890.64%337.50%
will deaconwill deacon605.50%112.50%
paolo bonzinipaolo bonzini242.20%225.00%
wanpeng liwanpeng li121.10%112.50%
paul bollepaul bolle60.55%112.50%
Total1090100.00%8100.00%
Directory: virt/kvm
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