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authorBen-Ami Yassour <benami@il.ibm.com>2008-09-14 03:48:28 +0300
committerAvi Kivity <avi@redhat.com>2008-10-15 14:25:04 +0200
commit62c476c7c7f25a5b245b9902a935636e6316e58c (patch)
tree6584591c7c345fcbb3c6d437203dc7f4a628573a /arch/x86
parent387179464257921eb9aa3d15cc3ff194f6945a7c (diff)
KVM: Device Assignment with VT-d
Based on a patch by: Kay, Allen M <allen.m.kay@intel.com> This patch enables PCI device assignment based on VT-d support. When a device is assigned to the guest, the guest memory is pinned and the mapping is updated in the VT-d IOMMU. [Amit: Expose KVM_CAP_IOMMU so we can check if an IOMMU is present and also control enable/disable from userspace] Signed-off-by: Kay, Allen M <allen.m.kay@intel.com> Signed-off-by: Weidong Han <weidong.han@intel.com> Signed-off-by: Ben-Ami Yassour <benami@il.ibm.com> Signed-off-by: Amit Shah <amit.shah@qumranet.com> Acked-by: Mark Gross <mgross@linux.intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/Makefile3
-rw-r--r--arch/x86/kvm/vtd.c198
-rw-r--r--arch/x86/kvm/x86.c14
3 files changed, 215 insertions, 0 deletions
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index d0e940bb6f4..3072b17447a 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -12,6 +12,9 @@ EXTRA_CFLAGS += -Ivirt/kvm -Iarch/x86/kvm
kvm-objs := $(common-objs) x86.o mmu.o x86_emulate.o i8259.o irq.o lapic.o \
i8254.o
+ifeq ($(CONFIG_DMAR),y)
+kvm-objs += vtd.o
+endif
obj-$(CONFIG_KVM) += kvm.o
kvm-intel-objs = vmx.o
obj-$(CONFIG_KVM_INTEL) += kvm-intel.o
diff --git a/arch/x86/kvm/vtd.c b/arch/x86/kvm/vtd.c
new file mode 100644
index 00000000000..667bf3fb64b
--- /dev/null
+++ b/arch/x86/kvm/vtd.c
@@ -0,0 +1,198 @@
+/*
+ * 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
+ * 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/pci.h>
+#include <linux/dmar.h>
+#include <linux/intel-iommu.h>
+
+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);
+
+int kvm_iommu_map_pages(struct kvm *kvm,
+ gfn_t base_gfn, unsigned long npages)
+{
+ gfn_t gfn = base_gfn;
+ pfn_t pfn;
+ int i, r;
+ struct dmar_domain *domain = kvm->arch.intel_iommu_domain;
+
+ /* check if iommu exists and in use */
+ if (!domain)
+ return 0;
+
+ r = -EINVAL;
+ for (i = 0; i < npages; i++) {
+ /* check if already mapped */
+ pfn = (pfn_t)intel_iommu_iova_to_pfn(domain,
+ gfn_to_gpa(gfn));
+ if (pfn && !is_mmio_pfn(pfn))
+ continue;
+
+ pfn = gfn_to_pfn(kvm, gfn);
+ if (!is_mmio_pfn(pfn)) {
+ r = intel_iommu_page_mapping(domain,
+ gfn_to_gpa(gfn),
+ pfn_to_hpa(pfn),
+ PAGE_SIZE,
+ DMA_PTE_READ |
+ DMA_PTE_WRITE);
+ if (r) {
+ printk(KERN_DEBUG "kvm_iommu_map_pages:"
+ "iommu failed to map pfn=%lx\n", pfn);
+ goto unmap_pages;
+ }
+ } else {
+ printk(KERN_DEBUG "kvm_iommu_map_page:"
+ "invalid pfn=%lx\n", pfn);
+ goto unmap_pages;
+ }
+ gfn++;
+ }
+ return 0;
+
+unmap_pages:
+ kvm_iommu_put_pages(kvm, base_gfn, i);
+ return r;
+}
+
+static int kvm_iommu_map_memslots(struct kvm *kvm)
+{
+ int i, r;
+
+ down_read(&kvm->slots_lock);
+ for (i = 0; i < kvm->nmemslots; i++) {
+ r = kvm_iommu_map_pages(kvm, kvm->memslots[i].base_gfn,
+ kvm->memslots[i].npages);
+ if (r)
+ break;
+ }
+ up_read(&kvm->slots_lock);
+ return r;
+}
+
+int kvm_iommu_map_guest(struct kvm *kvm,
+ struct kvm_assigned_dev_kernel *assigned_dev)
+{
+ struct pci_dev *pdev = NULL;
+ int r;
+
+ if (!intel_iommu_found()) {
+ printk(KERN_ERR "%s: intel iommu not found\n", __func__);
+ return -ENODEV;
+ }
+
+ printk(KERN_DEBUG "VT-d direct map: host bdf = %x:%x:%x\n",
+ assigned_dev->host_busnr,
+ PCI_SLOT(assigned_dev->host_devfn),
+ PCI_FUNC(assigned_dev->host_devfn));
+
+ pdev = assigned_dev->dev;
+
+ if (pdev == NULL) {
+ if (kvm->arch.intel_iommu_domain) {
+ intel_iommu_domain_exit(kvm->arch.intel_iommu_domain);
+ kvm->arch.intel_iommu_domain = NULL;
+ }
+ return -ENODEV;
+ }
+
+ kvm->arch.intel_iommu_domain = intel_iommu_domain_alloc(pdev);
+ if (!kvm->arch.intel_iommu_domain)
+ return -ENODEV;
+
+ r = kvm_iommu_map_memslots(kvm);
+ if (r)
+ goto out_unmap;
+
+ intel_iommu_detach_dev(kvm->arch.intel_iommu_domain,
+ pdev->bus->number, pdev->devfn);
+
+ r = intel_iommu_context_mapping(kvm->arch.intel_iommu_domain,
+ pdev);
+ if (r) {
+ printk(KERN_ERR "Domain context map for %s failed",
+ pci_name(pdev));
+ goto out_unmap;
+ }
+ return 0;
+
+out_unmap:
+ kvm_iommu_unmap_memslots(kvm);
+ return r;
+}
+
+static void kvm_iommu_put_pages(struct kvm *kvm,
+ gfn_t base_gfn, unsigned long npages)
+{
+ gfn_t gfn = base_gfn;
+ pfn_t pfn;
+ struct dmar_domain *domain = kvm->arch.intel_iommu_domain;
+ int i;
+
+ for (i = 0; i < npages; i++) {
+ pfn = (pfn_t)intel_iommu_iova_to_pfn(domain,
+ gfn_to_gpa(gfn));
+ kvm_release_pfn_clean(pfn);
+ gfn++;
+ }
+}
+
+static int kvm_iommu_unmap_memslots(struct kvm *kvm)
+{
+ int i;
+ down_read(&kvm->slots_lock);
+ for (i = 0; i < kvm->nmemslots; i++) {
+ kvm_iommu_put_pages(kvm, kvm->memslots[i].base_gfn,
+ kvm->memslots[i].npages);
+ }
+ up_read(&kvm->slots_lock);
+
+ return 0;
+}
+
+int kvm_iommu_unmap_guest(struct kvm *kvm)
+{
+ struct kvm_assigned_dev_kernel *entry;
+ struct dmar_domain *domain = kvm->arch.intel_iommu_domain;
+
+ /* check if iommu exists and in use */
+ if (!domain)
+ return 0;
+
+ list_for_each_entry(entry, &kvm->arch.assigned_dev_head, list) {
+ printk(KERN_DEBUG "VT-d unmap: host bdf = %x:%x:%x\n",
+ entry->host_busnr,
+ PCI_SLOT(entry->host_devfn),
+ PCI_FUNC(entry->host_devfn));
+
+ /* detach kvm dmar domain */
+ intel_iommu_detach_dev(domain, entry->host_busnr,
+ entry->host_devfn);
+ }
+ kvm_iommu_unmap_memslots(kvm);
+ intel_iommu_domain_exit(domain);
+ return 0;
+}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2134f3e0a51..c8a2793626e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -35,6 +35,7 @@
#include <linux/module.h>
#include <linux/mman.h>
#include <linux/highmem.h>
+#include <linux/intel-iommu.h>
#include <asm/uaccess.h>
#include <asm/msr.h>
@@ -277,9 +278,18 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
list_add(&match->list, &kvm->arch.assigned_dev_head);
+ if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) {
+ r = kvm_iommu_map_guest(kvm, match);
+ if (r)
+ goto out_list_del;
+ }
+
out:
mutex_unlock(&kvm->lock);
return r;
+out_list_del:
+ list_del(&match->list);
+ pci_release_regions(dev);
out_disable:
pci_disable_device(dev);
out_put:
@@ -1147,6 +1157,9 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_PV_MMU:
r = !tdp_enabled;
break;
+ case KVM_CAP_IOMMU:
+ r = intel_iommu_found();
+ break;
default:
r = 0;
break;
@@ -4282,6 +4295,7 @@ static void kvm_free_vcpus(struct kvm *kvm)
void kvm_arch_destroy_vm(struct kvm *kvm)
{
+ kvm_iommu_unmap_guest(kvm);
kvm_free_assigned_devices(kvm);
kvm_free_pit(kvm);
kfree(kvm->arch.vpic);