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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /virt/kvm/vfio.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | virt/kvm/vfio.c | 394 |
1 files changed, 394 insertions, 0 deletions
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c new file mode 100644 index 0000000000..ca24ce1209 --- /dev/null +++ b/virt/kvm/vfio.c @@ -0,0 +1,394 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * VFIO-KVM bridge pseudo device + * + * Copyright (C) 2013 Red Hat, Inc. All rights reserved. + * Author: Alex Williamson <alex.williamson@redhat.com> + */ + +#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 list_head node; + struct file *file; +#ifdef CONFIG_SPAPR_TCE_IOMMU + struct iommu_group *iommu_group; +#endif +}; + +struct kvm_vfio { + struct list_head file_list; + struct mutex lock; + bool noncoherent; +}; + +static void kvm_vfio_file_set_kvm(struct file *file, struct kvm *kvm) +{ + void (*fn)(struct file *file, struct kvm *kvm); + + fn = symbol_get(vfio_file_set_kvm); + if (!fn) + return; + + fn(file, kvm); + + symbol_put(vfio_file_set_kvm); +} + +static bool kvm_vfio_file_enforced_coherent(struct file *file) +{ + bool (*fn)(struct file *file); + bool ret; + + fn = symbol_get(vfio_file_enforced_coherent); + if (!fn) + return false; + + ret = fn(file); + + symbol_put(vfio_file_enforced_coherent); + + return ret; +} + +static bool kvm_vfio_file_is_valid(struct file *file) +{ + bool (*fn)(struct file *file); + bool ret; + + fn = symbol_get(vfio_file_is_valid); + if (!fn) + return false; + + ret = fn(file); + + symbol_put(vfio_file_is_valid); + + return ret; +} + +#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) +{ + struct kvm_vfio *kv = dev->private; + bool noncoherent = false; + struct kvm_vfio_file *kvf; + + list_for_each_entry(kvf, &kv->file_list, node) { + if (!kvm_vfio_file_enforced_coherent(kvf->file)) { + 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); + } +} + +static int kvm_vfio_file_add(struct kvm_device *dev, unsigned int fd) +{ + struct kvm_vfio *kv = dev->private; + struct kvm_vfio_file *kvf; + struct file *filp; + int ret = 0; + + filp = fget(fd); + if (!filp) + return -EBADF; + + /* Ensure the FD is a vfio FD. */ + if (!kvm_vfio_file_is_valid(filp)) { + ret = -EINVAL; + goto out_fput; + } + + mutex_lock(&kv->lock); + + list_for_each_entry(kvf, &kv->file_list, node) { + if (kvf->file == filp) { + ret = -EEXIST; + goto out_unlock; + } + } + + kvf = kzalloc(sizeof(*kvf), GFP_KERNEL_ACCOUNT); + if (!kvf) { + ret = -ENOMEM; + goto out_unlock; + } + + kvf->file = get_file(filp); + list_add_tail(&kvf->node, &kv->file_list); + + kvm_arch_start_assignment(dev->kvm); + kvm_vfio_file_set_kvm(kvf->file, dev->kvm); + kvm_vfio_update_coherency(dev); + +out_unlock: + mutex_unlock(&kv->lock); +out_fput: + fput(filp); + return ret; +} + +static int kvm_vfio_file_del(struct kvm_device *dev, unsigned int fd) +{ + struct kvm_vfio *kv = dev->private; + struct kvm_vfio_file *kvf; + struct fd f; + int ret; + + f = fdget(fd); + 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; + + list_del(&kvf->node); + kvm_arch_end_assignment(dev->kvm); +#ifdef CONFIG_SPAPR_TCE_IOMMU + kvm_spapr_tce_release_vfio_group(dev->kvm, kvf); +#endif + kvm_vfio_file_set_kvm(kvf->file, NULL); + fput(kvf->file); + kfree(kvf); + ret = 0; + break; + } + + kvm_vfio_update_coherency(dev); + + mutex_unlock(&kv->lock); + + fdput(f); + + return ret; +} + +#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(¶m, 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) +{ + int32_t __user *argp = arg; + int32_t fd; + + switch (attr) { + case KVM_DEV_VFIO_FILE_ADD: + if (get_user(fd, argp)) + return -EFAULT; + return kvm_vfio_file_add(dev, fd); + + case KVM_DEV_VFIO_FILE_DEL: + if (get_user(fd, argp)) + return -EFAULT; + return kvm_vfio_file_del(dev, fd); + +#ifdef CONFIG_SPAPR_TCE_IOMMU + case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: + return kvm_vfio_file_set_spapr_tce(dev, arg); +#endif + } + + return -ENXIO; +} + +static int kvm_vfio_set_attr(struct kvm_device *dev, + struct kvm_device_attr *attr) +{ + switch (attr->group) { + case KVM_DEV_VFIO_FILE: + return kvm_vfio_set_file(dev, attr->attr, + u64_to_user_ptr(attr->addr)); + } + + return -ENXIO; +} + +static int kvm_vfio_has_attr(struct kvm_device *dev, + struct kvm_device_attr *attr) +{ + switch (attr->group) { + case KVM_DEV_VFIO_FILE: + switch (attr->attr) { + case KVM_DEV_VFIO_FILE_ADD: + case KVM_DEV_VFIO_FILE_DEL: +#ifdef CONFIG_SPAPR_TCE_IOMMU + case KVM_DEV_VFIO_GROUP_SET_SPAPR_TCE: +#endif + return 0; + } + + break; + } + + return -ENXIO; +} + +static void kvm_vfio_release(struct kvm_device *dev) +{ + struct kvm_vfio *kv = dev->private; + struct kvm_vfio_file *kvf, *tmp; + + list_for_each_entry_safe(kvf, tmp, &kv->file_list, node) { +#ifdef CONFIG_SPAPR_TCE_IOMMU + kvm_spapr_tce_release_vfio_group(dev->kvm, kvf); +#endif + kvm_vfio_file_set_kvm(kvf->file, NULL); + fput(kvf->file); + list_del(&kvf->node); + kfree(kvf); + kvm_arch_end_assignment(dev->kvm); + } + + kvm_vfio_update_coherency(dev); + + kfree(kv); + kfree(dev); /* alloc by kvm_ioctl_create_device, free by .release */ +} + +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, + .release = kvm_vfio_release, + .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_ACCOUNT); + if (!kv) + return -ENOMEM; + + INIT_LIST_HEAD(&kv->file_list); + mutex_init(&kv->lock); + + dev->private = kv; + + return 0; +} + +int kvm_vfio_ops_init(void) +{ + return kvm_register_device_ops(&kvm_vfio_ops, KVM_DEV_TYPE_VFIO); +} + +void kvm_vfio_ops_exit(void) +{ + kvm_unregister_device_ops(KVM_DEV_TYPE_VFIO); +} |