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-rw-r--r--Documentation/kernel-parameters.txt5
-rw-r--r--drivers/pci/dmar.c7
-rw-r--r--drivers/pci/intel-iommu.c240
-rw-r--r--drivers/pci/iova.c12
-rw-r--r--include/linux/dma_remapping.h4
5 files changed, 220 insertions, 48 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 5438a2d7907..d9a203b058f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -999,7 +999,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
With this option on every unmap_single operation will
result in a hardware IOTLB flush operation as opposed
to batching them for performance.
-
+ sp_off [Default Off]
+ By default, super page will be supported if Intel IOMMU
+ has the capability. With this option, super page will
+ not be supported.
intremap= [X86-64, Intel-IOMMU]
Format: { on (default) | off | nosid }
on enable Interrupt Remapping (default)
diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c
index 12e02bf92c4..3dc9befa5ae 100644
--- a/drivers/pci/dmar.c
+++ b/drivers/pci/dmar.c
@@ -698,12 +698,7 @@ int __init detect_intel_iommu(void)
{
#ifdef CONFIG_INTR_REMAP
struct acpi_table_dmar *dmar;
- /*
- * for now we will disable dma-remapping when interrupt
- * remapping is enabled.
- * When support for queued invalidation for IOTLB invalidation
- * is added, we will not need this any more.
- */
+
dmar = (struct acpi_table_dmar *) dmar_tbl;
if (ret && cpu_has_x2apic && dmar->flags & 0x1)
printk(KERN_INFO
diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 6af6b628175..59f17acf7f6 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -47,6 +47,8 @@
#define ROOT_SIZE VTD_PAGE_SIZE
#define CONTEXT_SIZE VTD_PAGE_SIZE
+#define IS_BRIDGE_HOST_DEVICE(pdev) \
+ ((pdev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
#define IS_GFX_DEVICE(pdev) ((pdev->class >> 16) == PCI_BASE_CLASS_DISPLAY)
#define IS_ISA_DEVICE(pdev) ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
#define IS_AZALIA(pdev) ((pdev)->vendor == 0x8086 && (pdev)->device == 0x3a3e)
@@ -116,6 +118,11 @@ static inline unsigned long align_to_level(unsigned long pfn, int level)
return (pfn + level_size(level) - 1) & level_mask(level);
}
+static inline unsigned long lvl_to_nr_pages(unsigned int lvl)
+{
+ return 1 << ((lvl - 1) * LEVEL_STRIDE);
+}
+
/* VT-d pages must always be _smaller_ than MM pages. Otherwise things
are never going to work. */
static inline unsigned long dma_to_mm_pfn(unsigned long dma_pfn)
@@ -143,6 +150,12 @@ static void __init check_tylersburg_isoch(void);
static int rwbf_quirk;
/*
+ * set to 1 to panic kernel if can't successfully enable VT-d
+ * (used when kernel is launched w/ TXT)
+ */
+static int force_on = 0;
+
+/*
* 0: Present
* 1-11: Reserved
* 12-63: Context Ptr (12 - (haw-1))
@@ -338,6 +351,9 @@ struct dmar_domain {
int iommu_coherency;/* indicate coherency of iommu access */
int iommu_snooping; /* indicate snooping control feature*/
int iommu_count; /* reference count of iommu */
+ int iommu_superpage;/* Level of superpages supported:
+ 0 == 4KiB (no superpages), 1 == 2MiB,
+ 2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
spinlock_t iommu_lock; /* protect iommu set in domain */
u64 max_addr; /* maximum mapped address */
};
@@ -387,6 +403,7 @@ int dmar_disabled = 1;
static int dmar_map_gfx = 1;
static int dmar_forcedac;
static int intel_iommu_strict;
+static int intel_iommu_superpage = 1;
#define DUMMY_DEVICE_DOMAIN_INFO ((struct device_domain_info *)(-1))
static DEFINE_SPINLOCK(device_domain_lock);
@@ -417,6 +434,10 @@ static int __init intel_iommu_setup(char *str)
printk(KERN_INFO
"Intel-IOMMU: disable batched IOTLB flush\n");
intel_iommu_strict = 1;
+ } else if (!strncmp(str, "sp_off", 6)) {
+ printk(KERN_INFO
+ "Intel-IOMMU: disable supported super page\n");
+ intel_iommu_superpage = 0;
}
str += strcspn(str, ",");
@@ -555,11 +576,32 @@ static void domain_update_iommu_snooping(struct dmar_domain *domain)
}
}
+static void domain_update_iommu_superpage(struct dmar_domain *domain)
+{
+ int i, mask = 0xf;
+
+ if (!intel_iommu_superpage) {
+ domain->iommu_superpage = 0;
+ return;
+ }
+
+ domain->iommu_superpage = 4; /* 1TiB */
+
+ for_each_set_bit(i, &domain->iommu_bmp, g_num_of_iommus) {
+ mask |= cap_super_page_val(g_iommus[i]->cap);
+ if (!mask) {
+ break;
+ }
+ }
+ domain->iommu_superpage = fls(mask);
+}
+
/* Some capabilities may be different across iommus */
static void domain_update_iommu_cap(struct dmar_domain *domain)
{
domain_update_iommu_coherency(domain);
domain_update_iommu_snooping(domain);
+ domain_update_iommu_superpage(domain);
}
static struct intel_iommu *device_to_iommu(int segment, u8 bus, u8 devfn)
@@ -689,23 +731,31 @@ out:
}
static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
- unsigned long pfn)
+ unsigned long pfn, int large_level)
{
int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
struct dma_pte *parent, *pte = NULL;
int level = agaw_to_level(domain->agaw);
- int offset;
+ int offset, target_level;
BUG_ON(!domain->pgd);
BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width);
parent = domain->pgd;
+ /* Search pte */
+ if (!large_level)
+ target_level = 1;
+ else
+ target_level = large_level;
+
while (level > 0) {
void *tmp_page;
offset = pfn_level_offset(pfn, level);
pte = &parent[offset];
- if (level == 1)
+ if (!large_level && (pte->val & DMA_PTE_LARGE_PAGE))
+ break;
+ if (level == target_level)
break;
if (!dma_pte_present(pte)) {
@@ -733,10 +783,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
return pte;
}
+
/* return address's pte at specific level */
static struct dma_pte *dma_pfn_level_pte(struct dmar_domain *domain,
unsigned long pfn,
- int level)
+ int level, int *large_page)
{
struct dma_pte *parent, *pte = NULL;
int total = agaw_to_level(domain->agaw);
@@ -749,8 +800,16 @@ static struct dma_pte *dma_pfn_level_pte(struct dmar_domain *domain,
if (level == total)
return pte;
- if (!dma_pte_present(pte))
+ if (!dma_pte_present(pte)) {
+ *large_page = total;
break;
+ }
+
+ if (pte->val & DMA_PTE_LARGE_PAGE) {
+ *large_page = total;
+ return pte;
+ }
+
parent = phys_to_virt(dma_pte_addr(pte));
total--;
}
@@ -763,6 +822,7 @@ static void dma_pte_clear_range(struct dmar_domain *domain,
unsigned long last_pfn)
{
int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
+ unsigned int large_page = 1;
struct dma_pte *first_pte, *pte;
BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
@@ -771,14 +831,15 @@ static void dma_pte_clear_range(struct dmar_domain *domain,
/* we don't need lock here; nobody else touches the iova range */
do {
- first_pte = pte = dma_pfn_level_pte(domain, start_pfn, 1);
+ large_page = 1;
+ first_pte = pte = dma_pfn_level_pte(domain, start_pfn, 1, &large_page);
if (!pte) {
- start_pfn = align_to_level(start_pfn + 1, 2);
+ start_pfn = align_to_level(start_pfn + 1, large_page + 1);
continue;
}
- do {
+ do {
dma_clear_pte(pte);
- start_pfn++;
+ start_pfn += lvl_to_nr_pages(large_page);
pte++;
} while (start_pfn <= last_pfn && !first_pte_in_page(pte));
@@ -798,6 +859,7 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain,
int total = agaw_to_level(domain->agaw);
int level;
unsigned long tmp;
+ int large_page = 2;
BUG_ON(addr_width < BITS_PER_LONG && start_pfn >> addr_width);
BUG_ON(addr_width < BITS_PER_LONG && last_pfn >> addr_width);
@@ -813,7 +875,10 @@ static void dma_pte_free_pagetable(struct dmar_domain *domain,
return;
do {
- first_pte = pte = dma_pfn_level_pte(domain, tmp, level);
+ large_page = level;
+ first_pte = pte = dma_pfn_level_pte(domain, tmp, level, &large_page);
+ if (large_page > level)
+ level = large_page + 1;
if (!pte) {
tmp = align_to_level(tmp + 1, level + 1);
continue;
@@ -1397,6 +1462,7 @@ static int domain_init(struct dmar_domain *domain, int guest_width)
else
domain->iommu_snooping = 0;
+ domain->iommu_superpage = fls(cap_super_page_val(iommu->cap));
domain->iommu_count = 1;
domain->nid = iommu->node;
@@ -1417,6 +1483,10 @@ static void domain_exit(struct dmar_domain *domain)
if (!domain)
return;
+ /* Flush any lazy unmaps that may reference this domain */
+ if (!intel_iommu_strict)
+ flush_unmaps_timeout(0);
+
domain_remove_dev_info(domain);
/* destroy iovas */
put_iova_domain(&domain->iovad);
@@ -1648,6 +1718,34 @@ static inline unsigned long aligned_nrpages(unsigned long host_addr,
return PAGE_ALIGN(host_addr + size) >> VTD_PAGE_SHIFT;
}
+/* Return largest possible superpage level for a given mapping */
+static inline int hardware_largepage_caps(struct dmar_domain *domain,
+ unsigned long iov_pfn,
+ unsigned long phy_pfn,
+ unsigned long pages)
+{
+ int support, level = 1;
+ unsigned long pfnmerge;
+
+ support = domain->iommu_superpage;
+
+ /* To use a large page, the virtual *and* physical addresses
+ must be aligned to 2MiB/1GiB/etc. Lower bits set in either
+ of them will mean we have to use smaller pages. So just
+ merge them and check both at once. */
+ pfnmerge = iov_pfn | phy_pfn;
+
+ while (support && !(pfnmerge & ~VTD_STRIDE_MASK)) {
+ pages >>= VTD_STRIDE_SHIFT;
+ if (!pages)
+ break;
+ pfnmerge >>= VTD_STRIDE_SHIFT;
+ level++;
+ support--;
+ }
+ return level;
+}
+
static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
struct scatterlist *sg, unsigned long phys_pfn,
unsigned long nr_pages, int prot)
@@ -1656,6 +1754,8 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
phys_addr_t uninitialized_var(pteval);
int addr_width = agaw_to_width(domain->agaw) - VTD_PAGE_SHIFT;
unsigned long sg_res;
+ unsigned int largepage_lvl = 0;
+ unsigned long lvl_pages = 0;
BUG_ON(addr_width < BITS_PER_LONG && (iov_pfn + nr_pages - 1) >> addr_width);
@@ -1671,7 +1771,7 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
pteval = ((phys_addr_t)phys_pfn << VTD_PAGE_SHIFT) | prot;
}
- while (nr_pages--) {
+ while (nr_pages > 0) {
uint64_t tmp;
if (!sg_res) {
@@ -1679,11 +1779,21 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
sg->dma_address = ((dma_addr_t)iov_pfn << VTD_PAGE_SHIFT) + sg->offset;
sg->dma_length = sg->length;
pteval = page_to_phys(sg_page(sg)) | prot;
+ phys_pfn = pteval >> VTD_PAGE_SHIFT;
}
+
if (!pte) {
- first_pte = pte = pfn_to_dma_pte(domain, iov_pfn);
+ largepage_lvl = hardware_largepage_caps(domain, iov_pfn, phys_pfn, sg_res);
+
+ first_pte = pte = pfn_to_dma_pte(domain, iov_pfn, largepage_lvl);
if (!pte)
return -ENOMEM;
+ /* It is large page*/
+ if (largepage_lvl > 1)
+ pteval |= DMA_PTE_LARGE_PAGE;
+ else
+ pteval &= ~(uint64_t)DMA_PTE_LARGE_PAGE;
+
}
/* We don't need lock here, nobody else
* touches the iova range
@@ -1699,16 +1809,38 @@ static int __domain_mapping(struct dmar_domain *domain, unsigned long iov_pfn,
}
WARN_ON(1);
}
+
+ lvl_pages = lvl_to_nr_pages(largepage_lvl);
+
+ BUG_ON(nr_pages < lvl_pages);
+ BUG_ON(sg_res < lvl_pages);
+
+ nr_pages -= lvl_pages;
+ iov_pfn += lvl_pages;
+ phys_pfn += lvl_pages;
+ pteval += lvl_pages * VTD_PAGE_SIZE;
+ sg_res -= lvl_pages;
+
+ /* If the next PTE would be the first in a new page, then we
+ need to flush the cache on the entries we've just written.
+ And then we'll need to recalculate 'pte', so clear it and
+ let it get set again in the if (!pte) block above.
+
+ If we're done (!nr_pages) we need to flush the cache too.
+
+ Also if we've been setting superpages, we may need to
+ recalculate 'pte' and switch back to smaller pages for the
+ end of the mapping, if the trailing size is not enough to
+ use another superpage (i.e. sg_res < lvl_pages). */
pte++;
- if (!nr_pages || first_pte_in_page(pte)) {
+ if (!nr_pages || first_pte_in_page(pte) ||
+ (largepage_lvl > 1 && sg_res < lvl_pages)) {
domain_flush_cache(domain, first_pte,
(void *)pte - (void *)first_pte);
pte = NULL;
}
- iov_pfn++;
- pteval += VTD_PAGE_SIZE;
- sg_res--;
- if (!sg_res)
+
+ if (!sg_res && nr_pages)
sg = sg_next(sg);
}
return 0;
@@ -2016,7 +2148,7 @@ static inline int iommu_prepare_rmrr_dev(struct dmar_rmrr_unit *rmrr,
if (pdev->dev.archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO)
return 0;
return iommu_prepare_identity_map(pdev, rmrr->base_address,
- rmrr->end_address + 1);
+ rmrr->end_address);
}
#ifdef CONFIG_DMAR_FLOPPY_WA
@@ -2030,7 +2162,7 @@ static inline void iommu_prepare_isa(void)
return;
printk(KERN_INFO "IOMMU: Prepare 0-16MiB unity mapping for LPC\n");
- ret = iommu_prepare_identity_map(pdev, 0, 16*1024*1024);
+ ret = iommu_prepare_identity_map(pdev, 0, 16*1024*1024 - 1);
if (ret)
printk(KERN_ERR "IOMMU: Failed to create 0-16MiB identity map; "
@@ -2106,10 +2238,10 @@ static int identity_mapping(struct pci_dev *pdev)
if (likely(!iommu_identity_mapping))
return 0;
+ info = pdev->dev.archdata.iommu;
+ if (info && info != DUMMY_DEVICE_DOMAIN_INFO)
+ return (info->domain == si_domain);
- list_for_each_entry(info, &si_domain->devices, link)
- if (info->dev == pdev)
- return 1;
return 0;
}
@@ -2187,8 +2319,19 @@ static int iommu_should_identity_map(struct pci_dev *pdev, int startup)
* Assume that they will -- if they turn out not to be, then we can
* take them out of the 1:1 domain later.
*/
- if (!startup)
- return pdev->dma_mask > DMA_BIT_MASK(32);
+ if (!startup) {
+ /*
+ * If the device's dma_mask is less than the system's memory
+ * size then this is not a candidate for identity mapping.
+ */
+ u64 dma_mask = pdev->dma_mask;
+
+ if (pdev->dev.coherent_dma_mask &&
+ pdev->dev.coherent_dma_mask < dma_mask)
+ dma_mask = pdev->dev.coherent_dma_mask;
+
+ return dma_mask >= dma_get_required_mask(&pdev->dev);
+ }
return 1;
}
@@ -2203,6 +2346,9 @@ static int __init iommu_prepare_static_identity_mapping(int hw)
return -EFAULT;
for_each_pci_dev(pdev) {
+ /* Skip Host/PCI Bridge devices */
+ if (IS_BRIDGE_HOST_DEVICE(pdev))
+ continue;
if (iommu_should_identity_map(pdev, 1)) {
printk(KERN_INFO "IOMMU: %s identity mapping for device %s\n",
hw ? "hardware" : "software", pci_name(pdev));
@@ -2218,7 +2364,7 @@ static int __init iommu_prepare_static_identity_mapping(int hw)
return 0;
}
-static int __init init_dmars(int force_on)
+static int __init init_dmars(void)
{
struct dmar_drhd_unit *drhd;
struct dmar_rmrr_unit *rmrr;
@@ -2592,8 +2738,7 @@ static dma_addr_t __intel_map_single(struct device *hwdev, phys_addr_t paddr,
iommu = domain_get_iommu(domain);
size = aligned_nrpages(paddr, size);
- iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size),
- pdev->dma_mask);
+ iova = intel_alloc_iova(hwdev, domain, dma_to_mm_pfn(size), dma_mask);
if (!iova)
goto error;
@@ -3118,7 +3263,17 @@ static int init_iommu_hw(void)
if (iommu->qi)
dmar_reenable_qi(iommu);
- for_each_active_iommu(iommu, drhd) {
+ for_each_iommu(iommu, drhd) {
+ if (drhd->ignored) {
+ /*
+ * we always have to disable PMRs or DMA may fail on
+ * this device
+ */
+ if (force_on)
+ iommu_disable_protect_mem_regions(iommu);
+ continue;
+ }
+
iommu_flush_write_buffer(iommu);
iommu_set_root_entry(iommu);
@@ -3127,7 +3282,8 @@ static int init_iommu_hw(void)
DMA_CCMD_GLOBAL_INVL);
iommu->flush.flush_iotlb(iommu, 0, 0, 0,
DMA_TLB_GLOBAL_FLUSH);
- iommu_enable_translation(iommu);
+ if (iommu_enable_translation(iommu))
+ return 1;
iommu_disable_protect_mem_regions(iommu);
}
@@ -3194,7 +3350,10 @@ static void iommu_resume(void)
unsigned long flag;
if (init_iommu_hw()) {
- WARN(1, "IOMMU setup failed, DMAR can not resume!\n");
+ if (force_on)
+ panic("tboot: IOMMU setup failed, DMAR can not resume!\n");
+ else
+ WARN(1, "IOMMU setup failed, DMAR can not resume!\n");
return;
}
@@ -3271,7 +3430,6 @@ static struct notifier_block device_nb = {
int __init intel_iommu_init(void)
{
int ret = 0;
- int force_on = 0;
/* VT-d is required for a TXT/tboot launch, so enforce that */
force_on = tboot_force_iommu();
@@ -3309,7 +3467,7 @@ int __init intel_iommu_init(void)
init_no_remapping_devices();
- ret = init_dmars(force_on);
+ ret = init_dmars();
if (ret) {
if (force_on)
panic("tboot: Failed to initialize DMARs\n");
@@ -3380,8 +3538,8 @@ static void domain_remove_one_dev_info(struct dmar_domain *domain,
spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_safe(entry, tmp, &domain->devices) {
info = list_entry(entry, struct device_domain_info, link);
- /* No need to compare PCI domain; it has to be the same */
- if (info->bus == pdev->bus->number &&
+ if (info->segment == pci_domain_nr(pdev->bus) &&
+ info->bus == pdev->bus->number &&
info->devfn == pdev->devfn) {
list_del(&info->link);
list_del(&info->global);
@@ -3419,10 +3577,13 @@ static void domain_remove_one_dev_info(struct dmar_domain *domain,
domain_update_iommu_cap(domain);
spin_unlock_irqrestore(&domain->iommu_lock, tmp_flags);
- spin_lock_irqsave(&iommu->lock, tmp_flags);
- clear_bit(domain->id, iommu->domain_ids);
- iommu->domains[domain->id] = NULL;
- spin_unlock_irqrestore(&iommu->lock, tmp_flags);
+ if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) &&
+ !(domain->flags & DOMAIN_FLAG_STATIC_IDENTITY)) {
+ spin_lock_irqsave(&iommu->lock, tmp_flags);
+ clear_bit(domain->id, iommu->domain_ids);
+ iommu->domains[domain->id] = NULL;
+ spin_unlock_irqrestore(&iommu->lock, tmp_flags);
+ }
}
spin_unlock_irqrestore(&device_domain_lock, flags);
@@ -3505,6 +3666,7 @@ static int md_domain_init(struct dmar_domain *domain, int guest_width)
domain->iommu_count = 0;
domain->iommu_coherency = 0;
domain->iommu_snooping = 0;
+ domain->iommu_superpage = 0;
domain->max_addr = 0;
domain->nid = -1;
@@ -3720,7 +3882,7 @@ static phys_addr_t intel_iommu_iova_to_phys(struct iommu_domain *domain,
struct dma_pte *pte;
u64 phys = 0;
- pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT);
+ pte = pfn_to_dma_pte(dmar_domain, iova >> VTD_PAGE_SHIFT, 0);
if (pte)
phys = dma_pte_addr(pte);
diff --git a/drivers/pci/iova.c b/drivers/pci/iova.c
index 9606e599a47..c5c274ab5c5 100644
--- a/drivers/pci/iova.c
+++ b/drivers/pci/iova.c
@@ -63,8 +63,16 @@ __cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
curr = iovad->cached32_node;
cached_iova = container_of(curr, struct iova, node);
- if (free->pfn_lo >= cached_iova->pfn_lo)
- iovad->cached32_node = rb_next(&free->node);
+ if (free->pfn_lo >= cached_iova->pfn_lo) {
+ struct rb_node *node = rb_next(&free->node);
+ struct iova *iova = container_of(node, struct iova, node);
+
+ /* only cache if it's below 32bit pfn */
+ if (node && iova->pfn_lo < iovad->dma_32bit_pfn)
+ iovad->cached32_node = node;
+ else
+ iovad->cached32_node = NULL;
+ }
}
/* Computes the padding size required, to make the
diff --git a/include/linux/dma_remapping.h b/include/linux/dma_remapping.h
index 5619f852273..bbd8661b347 100644
--- a/include/linux/dma_remapping.h
+++ b/include/linux/dma_remapping.h
@@ -9,8 +9,12 @@
#define VTD_PAGE_MASK (((u64)-1) << VTD_PAGE_SHIFT)
#define VTD_PAGE_ALIGN(addr) (((addr) + VTD_PAGE_SIZE - 1) & VTD_PAGE_MASK)
+#define VTD_STRIDE_SHIFT (9)
+#define VTD_STRIDE_MASK (((u64)-1) << VTD_STRIDE_SHIFT)
+
#define DMA_PTE_READ (1)
#define DMA_PTE_WRITE (2)
+#define DMA_PTE_LARGE_PAGE (1 << 7)
#define DMA_PTE_SNP (1 << 11)
#define CONTEXT_TT_MULTI_LEVEL 0