linux/virt/kvm/iommu.c
Sheng Yang 522c68c441 KVM: Enable snooping control for supported hardware
Memory aliases with different memory type is a problem for guest. For the guest
without assigned device, the memory type of guest memory would always been the
same as host(WB); but for the assigned device, some part of memory may be used
as DMA and then set to uncacheable memory type(UC/WC), which would be a conflict of
host memory type then be a potential issue.

Snooping control can guarantee the cache correctness of memory go through the
DMA engine of VT-d.

[avi: fix build on ia64]

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-06-10 11:48:50 +03:00

234 lines
5.3 KiB
C

/*
* 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/iommu.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 = 0;
struct iommu_domain *domain = kvm->arch.iommu_domain;
int flags;
/* check if iommu exists and in use */
if (!domain)
return 0;
flags = IOMMU_READ | IOMMU_WRITE;
if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
flags |= IOMMU_CACHE;
for (i = 0; i < npages; i++) {
/* check if already mapped */
if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn)))
continue;
pfn = gfn_to_pfn(kvm, gfn);
r = iommu_map_range(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=%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 = 0;
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;
}
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 failed",
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;
}
printk(KERN_DEBUG "assign device: host bdf = %x:%x:%x\n",
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);
printk(KERN_DEBUG "deassign device: host bdf = %x:%x:%x\n",
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_found()) {
printk(KERN_ERR "%s: iommu not found\n", __func__);
return -ENODEV;
}
kvm->arch.iommu_domain = iommu_domain_alloc();
if (!kvm->arch.iommu_domain)
return -ENOMEM;
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_iommu_put_pages(struct kvm *kvm,
gfn_t base_gfn, unsigned long npages)
{
gfn_t gfn = base_gfn;
pfn_t pfn;
struct iommu_domain *domain = kvm->arch.iommu_domain;
unsigned long i;
u64 phys;
/* check if iommu exists and in use */
if (!domain)
return;
for (i = 0; i < npages; i++) {
phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
pfn = phys >> PAGE_SHIFT;
kvm_release_pfn_clean(pfn);
gfn++;
}
iommu_unmap_range(domain, gfn_to_gpa(base_gfn), PAGE_SIZE * npages);
}
static int kvm_iommu_unmap_memslots(struct kvm *kvm)
{
int i;
for (i = 0; i < kvm->nmemslots; i++) {
kvm_iommu_put_pages(kvm, kvm->memslots[i].base_gfn,
kvm->memslots[i].npages);
}
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;
}