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>
This commit is contained in:
Ben-Ami Yassour 2008-09-14 03:48:28 +03:00 committed by Avi Kivity
parent 3871794642
commit 62c476c7c7
7 changed files with 281 additions and 21 deletions

View file

@ -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

198
arch/x86/kvm/vtd.c Normal file
View file

@ -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;
}

View file

@ -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);

View file

@ -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 {

View file

@ -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

View file

@ -286,6 +286,53 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *v);
int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu);
void kvm_vcpu_kick(struct kvm_vcpu *vcpu);
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;
};
#ifdef CONFIG_DMAR
int kvm_iommu_map_pages(struct kvm *kvm, gfn_t base_gfn,
unsigned long npages);
int kvm_iommu_map_guest(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev);
int kvm_iommu_unmap_guest(struct kvm *kvm);
#else /* CONFIG_DMAR */
static inline int kvm_iommu_map_pages(struct kvm *kvm,
gfn_t base_gfn,
unsigned long npages)
{
return 0;
}
static inline int kvm_iommu_map_guest(struct kvm *kvm,
struct kvm_assigned_dev_kernel
*assigned_dev)
{
return -ENODEV;
}
static inline int kvm_iommu_unmap_guest(struct kvm *kvm)
{
return 0;
}
#endif /* CONFIG_DMAR */
static inline void kvm_guest_enter(void)
{
account_system_vtime(current);
@ -308,6 +355,11 @@ static inline gpa_t gfn_to_gpa(gfn_t gfn)
return (gpa_t)gfn << PAGE_SHIFT;
}
static inline hpa_t pfn_to_hpa(pfn_t pfn)
{
return (hpa_t)pfn << PAGE_SHIFT;
}
static inline void kvm_migrate_timers(struct kvm_vcpu *vcpu)
{
set_bit(KVM_REQ_MIGRATE_TIMER, &vcpu->requests);

View file

@ -41,6 +41,7 @@
#include <linux/pagemap.h>
#include <linux/mman.h>
#include <linux/swap.h>
#include <linux/intel-iommu.h>
#include <asm/processor.h>
#include <asm/io.h>
@ -76,7 +77,7 @@ static inline int valid_vcpu(int n)
return likely(n >= 0 && n < KVM_MAX_VCPUS);
}
static inline int is_mmio_pfn(pfn_t pfn)
inline int is_mmio_pfn(pfn_t pfn)
{
if (pfn_valid(pfn))
return PageReserved(pfn_to_page(pfn));
@ -578,6 +579,12 @@ int __kvm_set_memory_region(struct kvm *kvm,
}
kvm_free_physmem_slot(&old, &new);
/* map the pages in iommu page table */
r = kvm_iommu_map_pages(kvm, base_gfn, npages);
if (r)
goto out;
return 0;
out_free: