mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-24 17:59:32 +00:00
![Alex Williamson](/assets/img/avatar_default.png)
We've been ignoring read-only mappings and programming everything into the iommu as read-write. Fix this to only include the write access flag when read-only is not set. Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
357 lines
8.3 KiB
C
357 lines
8.3 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
|
|
* 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_flags & KVM_IOMMU_CACHE_COHERENCY)
|
|
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;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
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, 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) {
|
|
dev_err(&pdev->dev, "kvm assign device failed ret %d", r);
|
|
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;
|
|
}
|
|
|
|
pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
|
|
|
|
printk(KERN_DEBUG "assign device %x:%x:%x.%x\n",
|
|
assigned_dev->host_segnr,
|
|
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);
|
|
|
|
pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
|
|
|
|
printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n",
|
|
assigned_dev->host_segnr,
|
|
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_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);
|
|
|
|
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;
|
|
mutex_unlock(&kvm->slots_lock);
|
|
|
|
iommu_domain_free(domain);
|
|
return 0;
|
|
}
|