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-rw-r--r--arch/x86/kvm/iommu.c353
1 files changed, 353 insertions, 0 deletions
diff --git a/arch/x86/kvm/iommu.c b/arch/x86/kvm/iommu.c
new file mode 100644
index 000000000000..17b73eeac8a4
--- /dev/null
+++ b/arch/x86/kvm/iommu.c
@@ -0,0 +1,353 @@
+/*
+ * 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;
+
+
+ }
+
+ 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;
+ }
+}
+
+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;
+}
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