linux/virt/kvm/vfio.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * VFIO-KVM bridge pseudo device
 *
 * Copyright (C) 2013 Red Hat, Inc.  All rights reserved.
 *     Author: Alex Williamson <[email protected]>
 */

#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"

#ifdef CONFIG_SPAPR_TCE_IOMMU
#include <asm/kvm_ppc.h>
#endif

struct kvm_vfio_file { … };

struct kvm_vfio { … };

static void kvm_vfio_file_set_kvm(struct file *file, struct kvm *kvm)
{ … }

static bool kvm_vfio_file_enforced_coherent(struct file *file)
{ … }

static bool kvm_vfio_file_is_valid(struct file *file)
{ … }

#ifdef CONFIG_SPAPR_TCE_IOMMU
static struct iommu_group *kvm_vfio_file_iommu_group(struct file *file)
{
	struct iommu_group *(*fn)(struct file *file);
	struct iommu_group *ret;

	fn = symbol_get(vfio_file_iommu_group);
	if (!fn)
		return NULL;

	ret = fn(file);

	symbol_put(vfio_file_iommu_group);

	return ret;
}

static void kvm_spapr_tce_release_vfio_group(struct kvm *kvm,
					     struct kvm_vfio_file *kvf)
{
	if (WARN_ON_ONCE(!kvf->iommu_group))
		return;

	kvm_spapr_tce_release_iommu_group(kvm, kvf->iommu_group);
	iommu_group_put(kvf->iommu_group);
	kvf->iommu_group = NULL;
}
#endif

/*
 * Groups/devices can use the same or different IOMMU domains. If the same
 * then adding a new group/device may change the coherency of groups/devices
 * we've previously been told about. We don't want to care about any of
 * that so we retest each group/device 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)
{ … }

static int kvm_vfio_file_add(struct kvm_device *dev, unsigned int fd)
{ … }

static int kvm_vfio_file_del(struct kvm_device *dev, unsigned int fd)
{ … }

#ifdef CONFIG_SPAPR_TCE_IOMMU
static int kvm_vfio_file_set_spapr_tce(struct kvm_device *dev,
				       void __user *arg)
{
	struct kvm_vfio_spapr_tce param;
	struct kvm_vfio *kv = dev->private;
	struct kvm_vfio_file *kvf;
	struct fd f;
	int ret;

	if (copy_from_user(&param, arg, sizeof(struct kvm_vfio_spapr_tce)))
		return -EFAULT;

	f = fdget(param.groupfd);
	if (!f.file)
		return -EBADF;

	ret = -ENOENT;

	mutex_lock(&kv->lock);

	list_for_each_entry(kvf, &kv->file_list, node) {
		if (kvf->file != f.file)
			continue;

		if (!kvf->iommu_group) {
			kvf->iommu_group = kvm_vfio_file_iommu_group(kvf->file);
			if (WARN_ON_ONCE(!kvf->iommu_group)) {
				ret = -EIO;
				goto err_fdput;
			}
		}

		ret = kvm_spapr_tce_attach_iommu_group(dev->kvm, param.tablefd,
						       kvf->iommu_group);
		break;
	}

err_fdput:
	mutex_unlock(&kv->lock);
	fdput(f);
	return ret;
}
#endif

static int kvm_vfio_set_file(struct kvm_device *dev, long attr,
			     void __user *arg)
{ … }

static int kvm_vfio_set_attr(struct kvm_device *dev,
			     struct kvm_device_attr *attr)
{ … }

static int kvm_vfio_has_attr(struct kvm_device *dev,
			     struct kvm_device_attr *attr)
{ … }

static void kvm_vfio_release(struct kvm_device *dev)
{ … }

static int kvm_vfio_create(struct kvm_device *dev, u32 type);

static struct kvm_device_ops kvm_vfio_ops = …;

static int kvm_vfio_create(struct kvm_device *dev, u32 type)
{ … }

int kvm_vfio_ops_init(void)
{ … }

void kvm_vfio_ops_exit(void)
{ … }