/*
* 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>
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 size)
{
gfn_t end_gfn;
pfn_t pfn;
pfn = gfn_to_pfn_memslot(slot, gfn);
end_gfn = gfn + (size >> PAGE_SHIFT);
gfn += 1;
if (is_error_noslot_pfn(pfn))
return pfn;
while (gfn < end_gfn)
gfn_to_pfn_memslot(slot, gfn++);
return pfn;
}
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);
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);
goto unmap_pages;
}
gfn += page_size >> PAGE_SHIFT;
}
return 0;
unmap_pages:
kvm_iommu_put_pages(kvm, slot->base_gfn, 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 kvm_assigned_dev_kernel *assigned_dev)
{
struct pci_dev *pdev = NULL;
struct iommu_domain *domain = kvm->arch.iommu_domain;
int r;
bool noncoherent;
/* 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) {
dev_err(&pdev->dev, "kvm assign device failed ret %d", r);
return r;
}
noncoherent = !iommu_domain_has_cap(kvm->arch.iommu_domain,
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;
}
pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
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 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);
pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
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_domain_has_cap(kvm->arch.iommu_domain,
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_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);
}
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;
}
