/* * 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> 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 *kvm, struct kvm_memory_slot *slot, gfn_t gfn, unsigned long size) { gfn_t end_gfn; pfn_t pfn; pfn = gfn_to_pfn_memslot(kvm, slot, gfn); end_gfn = gfn + (size >> PAGE_SHIFT); gfn += 1; if (is_error_pfn(pfn)) return pfn; while (gfn < end_gfn) gfn_to_pfn_memslot(kvm, slot, gfn++); return pfn; } 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 | IOMMU_WRITE; if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY) 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; /* * 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(kvm, slot, gfn, page_size); if (is_error_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); goto unmap_pages; } gfn += page_size >> PAGE_SHIFT; } return 0; unmap_pages: kvm_iommu_put_pages(kvm, slot->base_gfn, 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; 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 kvm_assigned_dev_kernel *assigned_dev) { struct pci_dev *pdev = NULL; struct iommu_domain *domain = kvm->arch.iommu_domain; int r, last_flags; /* check if iommu exists and in use */ if (!domain) return 0; pdev = assigned_dev->dev; if (pdev == NULL) return -ENODEV; r = iommu_attach_device(domain, &pdev->dev); if (r) { printk(KERN_ERR "assign device %x:%x:%x.%x failed", pci_domain_nr(pdev->bus), pdev->bus->number, PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn)); 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; /* Check if need to update IOMMU page table for guest memory */ if ((last_flags ^ kvm->arch.iommu_flags) == KVM_IOMMU_CACHE_COHERENCY) { kvm_iommu_unmap_memslots(kvm); r = kvm_iommu_map_memslots(kvm); if (r) goto out_unmap; } pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED; printk(KERN_DEBUG "assign device %x:%x:%x.%x\n", assigned_dev->host_segnr, assigned_dev->host_busnr, PCI_SLOT(assigned_dev->host_devfn), PCI_FUNC(assigned_dev->host_devfn)); return 0; out_unmap: kvm_iommu_unmap_memslots(kvm); return r; } int kvm_deassign_device(struct kvm *kvm, struct kvm_assigned_dev_kernel *assigned_dev) { struct iommu_domain *domain = kvm->arch.iommu_domain; struct pci_dev *pdev = NULL; /* check if iommu exists and in use */ if (!domain) return 0; pdev = assigned_dev->dev; if (pdev == NULL) return -ENODEV; iommu_detach_device(domain, &pdev->dev); pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED; printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n", assigned_dev->host_segnr, assigned_dev->host_busnr, PCI_SLOT(assigned_dev->host_devfn), PCI_FUNC(assigned_dev->host_devfn)); 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; } kvm->arch.iommu_domain = iommu_domain_alloc(&pci_bus_type); if (!kvm->arch.iommu_domain) return -ENOMEM; if (!allow_unsafe_assigned_interrupts && !iommu_domain_has_cap(kvm->arch.iommu_domain, 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; return -EPERM; } r = kvm_iommu_map_memslots(kvm); if (r) goto out_unmap; return 0; out_unmap: kvm_iommu_unmap_memslots(kvm); return r; } 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); } 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)); 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; } } 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_put_pages(kvm, memslot->base_gfn, memslot->npages); srcu_read_unlock(&kvm->srcu, idx); 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; kvm_iommu_unmap_memslots(kvm); iommu_domain_free(domain); return 0; }