diff options
Diffstat (limited to 'virt/kvm')
| -rw-r--r-- | virt/kvm/Kconfig | 3 | ||||
| -rw-r--r-- | virt/kvm/iommu.c | 22 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 40 | ||||
| -rw-r--r-- | virt/kvm/vfio.c | 264 |
4 files changed, 304 insertions, 25 deletions
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 779262f..fbe1a48 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -27,3 +27,6 @@ config HAVE_KVM_MSI config HAVE_KVM_CPU_RELAX_INTERCEPT bool + +config KVM_VFIO + bool diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c index a3b1410..c7d9ce1 100644 --- a/virt/kvm/iommu.c +++ b/virt/kvm/iommu.c @@ -79,7 +79,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot) flags = IOMMU_READ; if (!(slot->flags & KVM_MEM_READONLY)) flags |= IOMMU_WRITE; - if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY) + if (!kvm->arch.iommu_noncoherent) flags |= IOMMU_CACHE; @@ -140,6 +140,9 @@ static int kvm_iommu_map_memslots(struct kvm *kvm) struct kvm_memslots *slots; struct kvm_memory_slot *memslot; + if (kvm->arch.iommu_noncoherent) + kvm_arch_register_noncoherent_dma(kvm); + idx = srcu_read_lock(&kvm->srcu); slots = kvm_memslots(kvm); @@ -158,7 +161,8 @@ int kvm_assign_device(struct kvm *kvm, { struct pci_dev *pdev = NULL; struct iommu_domain *domain = kvm->arch.iommu_domain; - int r, last_flags; + int r; + bool noncoherent; /* check if iommu exists and in use */ if (!domain) @@ -174,15 +178,13 @@ int kvm_assign_device(struct kvm *kvm, return r; } - last_flags = kvm->arch.iommu_flags; - if (iommu_domain_has_cap(kvm->arch.iommu_domain, - IOMMU_CAP_CACHE_COHERENCY)) - kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY; + noncoherent = !iommu_domain_has_cap(kvm->arch.iommu_domain, + IOMMU_CAP_CACHE_COHERENCY); /* Check if need to update IOMMU page table for guest memory */ - if ((last_flags ^ kvm->arch.iommu_flags) == - KVM_IOMMU_CACHE_COHERENCY) { + if (noncoherent != kvm->arch.iommu_noncoherent) { kvm_iommu_unmap_memslots(kvm); + kvm->arch.iommu_noncoherent = noncoherent; r = kvm_iommu_map_memslots(kvm); if (r) goto out_unmap; @@ -328,6 +330,9 @@ static int kvm_iommu_unmap_memslots(struct kvm *kvm) srcu_read_unlock(&kvm->srcu, idx); + if (kvm->arch.iommu_noncoherent) + kvm_arch_unregister_noncoherent_dma(kvm); + return 0; } @@ -342,6 +347,7 @@ int kvm_iommu_unmap_guest(struct kvm *kvm) mutex_lock(&kvm->slots_lock); kvm_iommu_unmap_memslots(kvm); kvm->arch.iommu_domain = NULL; + kvm->arch.iommu_noncoherent = false; mutex_unlock(&kvm->slots_lock); iommu_domain_free(domain); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0932c3b..7a317a7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -874,21 +874,6 @@ int __kvm_set_memory_region(struct kvm *kvm, goto out_free; } - /* - * IOMMU mapping: New slots need to be mapped. Old slots need to be - * un-mapped and re-mapped if their base changes. Since base change - * unmapping is handled above with slot deletion, mapping alone is - * needed here. Anything else the iommu might care about for existing - * slots (size changes, userspace addr changes and read-only flag - * changes) is disallowed above, so any other attribute changes getting - * here can be skipped. - */ - if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) { - r = kvm_iommu_map_pages(kvm, &new); - if (r) - goto out_slots; - } - /* actual memory is freed via old in kvm_free_physmem_slot below */ if (change == KVM_MR_DELETE) { new.dirty_bitmap = NULL; @@ -902,6 +887,20 @@ int __kvm_set_memory_region(struct kvm *kvm, kvm_free_physmem_slot(kvm, &old, &new); kfree(old_memslots); + /* + * IOMMU mapping: New slots need to be mapped. Old slots need to be + * un-mapped and re-mapped if their base changes. Since base change + * unmapping is handled above with slot deletion, mapping alone is + * needed here. Anything else the iommu might care about for existing + * slots (size changes, userspace addr changes and read-only flag + * changes) is disallowed above, so any other attribute changes getting + * here can be skipped. + */ + if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) { + r = kvm_iommu_map_pages(kvm, &new); + return r; + } + return 0; out_slots: @@ -1067,10 +1066,12 @@ EXPORT_SYMBOL_GPL(gfn_to_hva); unsigned long gfn_to_hva_prot(struct kvm *kvm, gfn_t gfn, bool *writable) { struct kvm_memory_slot *slot = gfn_to_memslot(kvm, gfn); - if (writable) + unsigned long hva = __gfn_to_hva_many(slot, gfn, NULL, false); + + if (!kvm_is_error_hva(hva) && writable) *writable = !memslot_is_readonly(slot); - return __gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL, false); + return hva; } static int kvm_read_hva(void *data, void __user *hva, int len) @@ -2274,6 +2275,11 @@ static int kvm_ioctl_create_device(struct kvm *kvm, ops = &kvm_xics_ops; break; #endif +#ifdef CONFIG_KVM_VFIO + case KVM_DEV_TYPE_VFIO: + ops = &kvm_vfio_ops; + break; +#endif default: return -ENODEV; } diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c new file mode 100644 index 0000000..ca4260e --- /dev/null +++ b/virt/kvm/vfio.c @@ -0,0 +1,264 @@ +/* + * 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> + +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; +} + +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); +} + +/* + * 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) { + /* + * TODO: We need an interface to check the coherency of + * the IOMMU domain this group is using. For now, assume + * it's always noncoherent. + */ + 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); +} + +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; + void __user *argp = (void __user *)arg; + struct fd f; + int32_t fd; + int ret; + + switch (attr) { + case KVM_DEV_VFIO_GROUP_ADD: + if (get_user(fd, (int32_t __user *)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; + + mutex_unlock(&kv->lock); + + kvm_vfio_update_coherency(dev); + + return 0; + + case KVM_DEV_VFIO_GROUP_DEL: + if (get_user(fd, (int32_t __user *)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; + } + + mutex_unlock(&kv->lock); + + kvm_vfio_group_put_external_user(vfio_group); + + kvm_vfio_update_coherency(dev); + + return ret; + } + + return -ENXIO; +} + +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; +} + +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; +} + +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_vfio_update_coherency(dev); + + kfree(kv); + kfree(dev); /* alloc by kvm_ioctl_create_device, free by .destroy */ +} + +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; +} + +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, +}; |
