Commit 62c476c7 authored by Ben-Ami Yassour's avatar Ben-Ami Yassour Committed by Avi Kivity
Browse files

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: default avatarKay, Allen M <allen.m.kay@intel.com>
Signed-off-by: default avatarWeidong Han <weidong.han@intel.com>
Signed-off-by: default avatarBen-Ami Yassour <benami@il.ibm.com>
Signed-off-by: default avatarAmit Shah <amit.shah@qumranet.com>

Acked-by: default avatarMark Gross <mgross@linux.intel.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 38717946

arch/x86/kvm/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/kvm/vtd.c

0 → 100644
+198 −0
Original line number Diff line number Diff line 
/*

 * 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;

}

arch/x86/kvm/x86.c

+14 −0
Original line number Diff line number Diff line
@@ -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);

include/asm-x86/kvm_host.h

+3 −20
Original line number Diff line number Diff line
@@ -331,26 +331,6 @@ struct kvm_mem_alias { 
	gfn_t target_gfn;

};



struct kvm_irq_ack_notifier {

	struct hlist_node link;

	unsigned gsi;

	void (*irq_acked)(struct kvm_irq_ack_notifier *kian);

};



struct kvm_assigned_dev_kernel {

	struct kvm_irq_ack_notifier ack_notifier;

	struct work_struct interrupt_work;

	struct list_head list;

	int assigned_dev_id;

	int host_busnr;

	int host_devfn;

	int host_irq;

	int guest_irq;

	int irq_requested;

	struct pci_dev *dev;

	struct kvm *kvm;

};



struct kvm_arch{

	int naliases;

	struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS];
@@ -364,6 +344,7 @@ struct kvm_arch{ 
	 */

	struct list_head active_mmu_pages;

	struct list_head assigned_dev_head;

	struct dmar_domain *intel_iommu_domain;

	struct kvm_pic *vpic;

	struct kvm_ioapic *vioapic;

	struct kvm_pit *vpit;
@@ -514,6 +495,8 @@ int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, 
int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,

		  gpa_t addr, unsigned long *ret);



int is_mmio_pfn(pfn_t pfn);



extern bool tdp_enabled;



enum emulation_result {

include/linux/kvm.h

+3 −0
Original line number Diff line number Diff line
@@ -384,6 +384,7 @@ struct kvm_trace_rec { 
#define KVM_CAP_COALESCED_MMIO 15

#define KVM_CAP_SYNC_MMU 16  /* Changes to host mmap are reflected in guest */

#define KVM_CAP_DEVICE_ASSIGNMENT 17

#define KVM_CAP_IOMMU 18



/*

 * ioctls for VM fds
@@ -495,4 +496,6 @@ struct kvm_assigned_irq { 
	__u32 flags;

};



#define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)



#endif

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