diff options
Diffstat (limited to 'kernel/arch/x86/kvm/iommu.c')
| -rw-r--r-- | kernel/arch/x86/kvm/iommu.c | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/kernel/arch/x86/kvm/iommu.c b/kernel/arch/x86/kvm/iommu.c new file mode 100644 index 000000000..7dbced309 --- /dev/null +++ b/kernel/arch/x86/kvm/iommu.c @@ -0,0 +1,355 @@ +/* + * Copyright (c) 2006, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 59 Temple + * Place - Suite 330, Boston, MA 02111-1307 USA. + * + * Copyright (C) 2006-2008 Intel Corporation + * Copyright IBM Corporation, 2008 + * Copyright 2010 Red Hat, Inc. and/or its affiliates. + * + * Author: Allen M. Kay <allen.m.kay@intel.com> + * Author: Weidong Han <weidong.han@intel.com> + * Author: Ben-Ami Yassour <benami@il.ibm.com> + */ + +#include <linux/list.h> +#include <linux/kvm_host.h> +#include <linux/module.h> +#include <linux/pci.h> +#include <linux/stat.h> +#include <linux/dmar.h> +#include <linux/iommu.h> +#include <linux/intel-iommu.h> +#include "assigned-dev.h" + +static bool allow_unsafe_assigned_interrupts; +module_param_named(allow_unsafe_assigned_interrupts, + allow_unsafe_assigned_interrupts, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(allow_unsafe_assigned_interrupts, + "Enable device assignment on platforms without interrupt remapping support."); + +static int kvm_iommu_unmap_memslots(struct kvm *kvm); +static void kvm_iommu_put_pages(struct kvm *kvm, + gfn_t base_gfn, unsigned long npages); + +static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn, + unsigned long npages) +{ + gfn_t end_gfn; + pfn_t pfn; + + pfn = gfn_to_pfn_memslot(slot, gfn); + end_gfn = gfn + npages; + gfn += 1; + + if (is_error_noslot_pfn(pfn)) + return pfn; + + while (gfn < end_gfn) + gfn_to_pfn_memslot(slot, gfn++); + + return pfn; +} + +static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages) +{ + unsigned long i; + + for (i = 0; i < npages; ++i) + kvm_release_pfn_clean(pfn + i); +} + +int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot) +{ + gfn_t gfn, end_gfn; + pfn_t pfn; + int r = 0; + struct iommu_domain *domain = kvm->arch.iommu_domain; + int flags; + + /* check if iommu exists and in use */ + if (!domain) + return 0; + + gfn = slot->base_gfn; + end_gfn = gfn + slot->npages; + + flags = IOMMU_READ; + if (!(slot->flags & KVM_MEM_READONLY)) + flags |= IOMMU_WRITE; + if (!kvm->arch.iommu_noncoherent) + flags |= IOMMU_CACHE; + + + while (gfn < end_gfn) { + unsigned long page_size; + + /* Check if already mapped */ + if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn))) { + gfn += 1; + continue; + } + + /* Get the page size we could use to map */ + page_size = kvm_host_page_size(kvm, gfn); + + /* Make sure the page_size does not exceed the memslot */ + while ((gfn + (page_size >> PAGE_SHIFT)) > end_gfn) + page_size >>= 1; + + /* Make sure gfn is aligned to the page size we want to map */ + while ((gfn << PAGE_SHIFT) & (page_size - 1)) + page_size >>= 1; + + /* Make sure hva is aligned to the page size we want to map */ + while (__gfn_to_hva_memslot(slot, gfn) & (page_size - 1)) + page_size >>= 1; + + /* + * Pin all pages we are about to map in memory. This is + * important because we unmap and unpin in 4kb steps later. + */ + pfn = kvm_pin_pages(slot, gfn, page_size >> PAGE_SHIFT); + if (is_error_noslot_pfn(pfn)) { + gfn += 1; + continue; + } + + /* Map into IO address space */ + r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn), + page_size, flags); + if (r) { + printk(KERN_ERR "kvm_iommu_map_address:" + "iommu failed to map pfn=%llx\n", pfn); + kvm_unpin_pages(kvm, pfn, page_size >> PAGE_SHIFT); + goto unmap_pages; + } + + gfn += page_size >> PAGE_SHIFT; + + cond_resched(); + } + + return 0; + +unmap_pages: + kvm_iommu_put_pages(kvm, slot->base_gfn, gfn - slot->base_gfn); + return r; +} + +static int kvm_iommu_map_memslots(struct kvm *kvm) +{ + int idx, r = 0; + 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); + + kvm_for_each_memslot(memslot, slots) { + r = kvm_iommu_map_pages(kvm, memslot); + if (r) + break; + } + srcu_read_unlock(&kvm->srcu, idx); + + return r; +} + +int kvm_assign_device(struct kvm *kvm, struct pci_dev *pdev) +{ + struct iommu_domain *domain = kvm->arch.iommu_domain; + int r; + bool noncoherent; + + /* check if iommu exists and in use */ + if (!domain) + return 0; + + if (pdev == NULL) + return -ENODEV; + + r = iommu_attach_device(domain, &pdev->dev); + if (r) { + dev_err(&pdev->dev, "kvm assign device failed ret %d", r); + return r; + } + + noncoherent = !iommu_capable(&pci_bus_type, IOMMU_CAP_CACHE_COHERENCY); + + /* Check if need to update IOMMU page table for guest memory */ + 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; + } + + pci_set_dev_assigned(pdev); + + dev_info(&pdev->dev, "kvm assign device\n"); + + return 0; +out_unmap: + kvm_iommu_unmap_memslots(kvm); + return r; +} + +int kvm_deassign_device(struct kvm *kvm, struct pci_dev *pdev) +{ + struct iommu_domain *domain = kvm->arch.iommu_domain; + + /* check if iommu exists and in use */ + if (!domain) + return 0; + + if (pdev == NULL) + return -ENODEV; + + iommu_detach_device(domain, &pdev->dev); + + pci_clear_dev_assigned(pdev); + + dev_info(&pdev->dev, "kvm deassign device\n"); + + return 0; +} + +int kvm_iommu_map_guest(struct kvm *kvm) +{ + int r; + + if (!iommu_present(&pci_bus_type)) { + printk(KERN_ERR "%s: iommu not found\n", __func__); + return -ENODEV; + } + + mutex_lock(&kvm->slots_lock); + + kvm->arch.iommu_domain = iommu_domain_alloc(&pci_bus_type); + if (!kvm->arch.iommu_domain) { + r = -ENOMEM; + goto out_unlock; + } + + if (!allow_unsafe_assigned_interrupts && + !iommu_capable(&pci_bus_type, IOMMU_CAP_INTR_REMAP)) { + printk(KERN_WARNING "%s: No interrupt remapping support," + " disallowing device assignment." + " Re-enble with \"allow_unsafe_assigned_interrupts=1\"" + " module option.\n", __func__); + iommu_domain_free(kvm->arch.iommu_domain); + kvm->arch.iommu_domain = NULL; + r = -EPERM; + goto out_unlock; + } + + r = kvm_iommu_map_memslots(kvm); + if (r) + kvm_iommu_unmap_memslots(kvm); + +out_unlock: + mutex_unlock(&kvm->slots_lock); + return r; +} + +static void kvm_iommu_put_pages(struct kvm *kvm, + gfn_t base_gfn, unsigned long npages) +{ + struct iommu_domain *domain; + gfn_t end_gfn, gfn; + pfn_t pfn; + u64 phys; + + domain = kvm->arch.iommu_domain; + end_gfn = base_gfn + npages; + gfn = base_gfn; + + /* check if iommu exists and in use */ + if (!domain) + return; + + while (gfn < end_gfn) { + unsigned long unmap_pages; + size_t size; + + /* Get physical address */ + phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn)); + + if (!phys) { + gfn++; + continue; + } + + pfn = phys >> PAGE_SHIFT; + + /* Unmap address from IO address space */ + size = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE); + unmap_pages = 1ULL << get_order(size); + + /* Unpin all pages we just unmapped to not leak any memory */ + kvm_unpin_pages(kvm, pfn, unmap_pages); + + gfn += unmap_pages; + + cond_resched(); + } +} + +void kvm_iommu_unmap_pages(struct kvm *kvm, struct kvm_memory_slot *slot) +{ + kvm_iommu_put_pages(kvm, slot->base_gfn, slot->npages); +} + +static int kvm_iommu_unmap_memslots(struct kvm *kvm) +{ + int idx; + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + + idx = srcu_read_lock(&kvm->srcu); + slots = kvm_memslots(kvm); + + kvm_for_each_memslot(memslot, slots) + kvm_iommu_unmap_pages(kvm, memslot); + + srcu_read_unlock(&kvm->srcu, idx); + + if (kvm->arch.iommu_noncoherent) + kvm_arch_unregister_noncoherent_dma(kvm); + + return 0; +} + +int kvm_iommu_unmap_guest(struct kvm *kvm) +{ + struct iommu_domain *domain = kvm->arch.iommu_domain; + + /* check if iommu exists and in use */ + if (!domain) + return 0; + + 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); + return 0; +} |