intel-iommu: introduce Intel IOMMU (VT-d) emulation

Add support for emulating Intel IOMMU according to the VT-d specification for
the q35 chipset machine. Implement the logics for DMAR (DMA remapping) without
PASID support. The emulation supports register-based invalidation and primary
fault logging.

Signed-off-by: Le Tan <tamlokveer@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 1257 insertions, 0 deletions

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
new file mode 100644
index 0000000..8e67e04
--- /dev/null
+++ b/hw/i386/intel_iommu.c
@@ -0,0 +1,1257 @@
+/*
+ * QEMU emulation of an Intel IOMMU (VT-d)
+ *   (DMA Remapping device)
+ *
+ * Copyright (C) 2013 Knut Omang, Oracle <knut.omang@oracle.com>
+ * Copyright (C) 2014 Le Tan, <tamlokveer@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+
+ * This program is distributed in the hope that 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hw/sysbus.h"
+#include "exec/address-spaces.h"
+#include "intel_iommu_internal.h"
+
+/*#define DEBUG_INTEL_IOMMU*/
+#ifdef DEBUG_INTEL_IOMMU
+enum {
+    DEBUG_GENERAL, DEBUG_CSR, DEBUG_INV, DEBUG_MMU, DEBUG_FLOG,
+};
+#define VTD_DBGBIT(x)   (1 << DEBUG_##x)
+static int vtd_dbgflags = VTD_DBGBIT(GENERAL) | VTD_DBGBIT(CSR);
+
+#define VTD_DPRINTF(what, fmt, ...) do { \
+    if (vtd_dbgflags & VTD_DBGBIT(what)) { \
+        fprintf(stderr, "(vtd)%s: " fmt "\n", __func__, \
+                ## __VA_ARGS__); } \
+    } while (0)
+#else
+#define VTD_DPRINTF(what, fmt, ...) do {} while (0)
+#endif
+
+static void vtd_define_quad(IntelIOMMUState *s, hwaddr addr, uint64_t val,
+                            uint64_t wmask, uint64_t w1cmask)
+{
+    stq_le_p(&s->csr[addr], val);
+    stq_le_p(&s->wmask[addr], wmask);
+    stq_le_p(&s->w1cmask[addr], w1cmask);
+}
+
+static void vtd_define_quad_wo(IntelIOMMUState *s, hwaddr addr, uint64_t mask)
+{
+    stq_le_p(&s->womask[addr], mask);
+}
+
+static void vtd_define_long(IntelIOMMUState *s, hwaddr addr, uint32_t val,
+                            uint32_t wmask, uint32_t w1cmask)
+{
+    stl_le_p(&s->csr[addr], val);
+    stl_le_p(&s->wmask[addr], wmask);
+    stl_le_p(&s->w1cmask[addr], w1cmask);
+}
+
+static void vtd_define_long_wo(IntelIOMMUState *s, hwaddr addr, uint32_t mask)
+{
+    stl_le_p(&s->womask[addr], mask);
+}
+
+/* "External" get/set operations */
+static void vtd_set_quad(IntelIOMMUState *s, hwaddr addr, uint64_t val)
+{
+    uint64_t oldval = ldq_le_p(&s->csr[addr]);
+    uint64_t wmask = ldq_le_p(&s->wmask[addr]);
+    uint64_t w1cmask = ldq_le_p(&s->w1cmask[addr]);
+    stq_le_p(&s->csr[addr],
+             ((oldval & ~wmask) | (val & wmask)) & ~(w1cmask & val));
+}
+
+static void vtd_set_long(IntelIOMMUState *s, hwaddr addr, uint32_t val)
+{
+    uint32_t oldval = ldl_le_p(&s->csr[addr]);
+    uint32_t wmask = ldl_le_p(&s->wmask[addr]);
+    uint32_t w1cmask = ldl_le_p(&s->w1cmask[addr]);
+    stl_le_p(&s->csr[addr],
+             ((oldval & ~wmask) | (val & wmask)) & ~(w1cmask & val));
+}
+
+static uint64_t vtd_get_quad(IntelIOMMUState *s, hwaddr addr)
+{
+    uint64_t val = ldq_le_p(&s->csr[addr]);
+    uint64_t womask = ldq_le_p(&s->womask[addr]);
+    return val & ~womask;
+}
+
+static uint32_t vtd_get_long(IntelIOMMUState *s, hwaddr addr)
+{
+    uint32_t val = ldl_le_p(&s->csr[addr]);
+    uint32_t womask = ldl_le_p(&s->womask[addr]);
+    return val & ~womask;
+}
+
+/* "Internal" get/set operations */
+static uint64_t vtd_get_quad_raw(IntelIOMMUState *s, hwaddr addr)
+{
+    return ldq_le_p(&s->csr[addr]);
+}
+
+static uint32_t vtd_get_long_raw(IntelIOMMUState *s, hwaddr addr)
+{
+    return ldl_le_p(&s->csr[addr]);
+}
+
+static void vtd_set_quad_raw(IntelIOMMUState *s, hwaddr addr, uint64_t val)
+{
+    stq_le_p(&s->csr[addr], val);
+}
+
+static uint32_t vtd_set_clear_mask_long(IntelIOMMUState *s, hwaddr addr,
+                                        uint32_t clear, uint32_t mask)
+{
+    uint32_t new_val = (ldl_le_p(&s->csr[addr]) & ~clear) | mask;
+    stl_le_p(&s->csr[addr], new_val);
+    return new_val;
+}
+
+static uint64_t vtd_set_clear_mask_quad(IntelIOMMUState *s, hwaddr addr,
+                                        uint64_t clear, uint64_t mask)
+{
+    uint64_t new_val = (ldq_le_p(&s->csr[addr]) & ~clear) | mask;
+    stq_le_p(&s->csr[addr], new_val);
+    return new_val;
+}
+
+/* Given the reg addr of both the message data and address, generate an
+ * interrupt via MSI.
+ */
+static void vtd_generate_interrupt(IntelIOMMUState *s, hwaddr mesg_addr_reg,
+                                   hwaddr mesg_data_reg)
+{
+    hwaddr addr;
+    uint32_t data;
+
+    assert(mesg_data_reg < DMAR_REG_SIZE);
+    assert(mesg_addr_reg < DMAR_REG_SIZE);
+
+    addr = vtd_get_long_raw(s, mesg_addr_reg);
+    data = vtd_get_long_raw(s, mesg_data_reg);
+
+    VTD_DPRINTF(FLOG, "msi: addr 0x%"PRIx64 " data 0x%"PRIx32, addr, data);
+    stl_le_phys(&address_space_memory, addr, data);
+}
+
+/* Generate a fault event to software via MSI if conditions are met.
+ * Notice that the value of FSTS_REG being passed to it should be the one
+ * before any update.
+ */
+static void vtd_generate_fault_event(IntelIOMMUState *s, uint32_t pre_fsts)
+{
+    if (pre_fsts & VTD_FSTS_PPF || pre_fsts & VTD_FSTS_PFO ||
+        pre_fsts & VTD_FSTS_IQE) {
+        VTD_DPRINTF(FLOG, "there are previous interrupt conditions "
+                    "to be serviced by software, fault event is not generated "
+                    "(FSTS_REG 0x%"PRIx32 ")", pre_fsts);
+        return;
+    }
+    vtd_set_clear_mask_long(s, DMAR_FECTL_REG, 0, VTD_FECTL_IP);
+    if (vtd_get_long_raw(s, DMAR_FECTL_REG) & VTD_FECTL_IM) {
+        VTD_DPRINTF(FLOG, "Interrupt Mask set, fault event is not generated");
+    } else {
+        vtd_generate_interrupt(s, DMAR_FEADDR_REG, DMAR_FEDATA_REG);
+        vtd_set_clear_mask_long(s, DMAR_FECTL_REG, VTD_FECTL_IP, 0);
+    }
+}
+
+/* Check if the Fault (F) field of the Fault Recording Register referenced by
+ * @index is Set.
+ */
+static bool vtd_is_frcd_set(IntelIOMMUState *s, uint16_t index)
+{
+    /* Each reg is 128-bit */
+    hwaddr addr = DMAR_FRCD_REG_OFFSET + (((uint64_t)index) << 4);
+    addr += 8; /* Access the high 64-bit half */
+
+    assert(index < DMAR_FRCD_REG_NR);
+
+    return vtd_get_quad_raw(s, addr) & VTD_FRCD_F;
+}
+
+/* Update the PPF field of Fault Status Register.
+ * Should be called whenever change the F field of any fault recording
+ * registers.
+ */
+static void vtd_update_fsts_ppf(IntelIOMMUState *s)
+{
+    uint32_t i;
+    uint32_t ppf_mask = 0;
+
+    for (i = 0; i < DMAR_FRCD_REG_NR; i++) {
+        if (vtd_is_frcd_set(s, i)) {
+            ppf_mask = VTD_FSTS_PPF;
+            break;
+        }
+    }
+    vtd_set_clear_mask_long(s, DMAR_FSTS_REG, VTD_FSTS_PPF, ppf_mask);
+    VTD_DPRINTF(FLOG, "set PPF of FSTS_REG to %d", ppf_mask ? 1 : 0);
+}
+
+static void vtd_set_frcd_and_update_ppf(IntelIOMMUState *s, uint16_t index)
+{
+    /* Each reg is 128-bit */
+    hwaddr addr = DMAR_FRCD_REG_OFFSET + (((uint64_t)index) << 4);
+    addr += 8; /* Access the high 64-bit half */
+
+    assert(index < DMAR_FRCD_REG_NR);
+
+    vtd_set_clear_mask_quad(s, addr, 0, VTD_FRCD_F);
+    vtd_update_fsts_ppf(s);
+}
+
+/* Must not update F field now, should be done later */
+static void vtd_record_frcd(IntelIOMMUState *s, uint16_t index,
+                            uint16_t source_id, hwaddr addr,
+                            VTDFaultReason fault, bool is_write)
+{
+    uint64_t hi = 0, lo;
+    hwaddr frcd_reg_addr = DMAR_FRCD_REG_OFFSET + (((uint64_t)index) << 4);
+
+    assert(index < DMAR_FRCD_REG_NR);
+
+    lo = VTD_FRCD_FI(addr);
+    hi = VTD_FRCD_SID(source_id) | VTD_FRCD_FR(fault);
+    if (!is_write) {
+        hi |= VTD_FRCD_T;
+    }
+    vtd_set_quad_raw(s, frcd_reg_addr, lo);
+    vtd_set_quad_raw(s, frcd_reg_addr + 8, hi);
+    VTD_DPRINTF(FLOG, "record to FRCD_REG #%"PRIu16 ": hi 0x%"PRIx64
+                ", lo 0x%"PRIx64, index, hi, lo);
+}
+
+/* Try to collapse multiple pending faults from the same requester */
+static bool vtd_try_collapse_fault(IntelIOMMUState *s, uint16_t source_id)
+{
+    uint32_t i;
+    uint64_t frcd_reg;
+    hwaddr addr = DMAR_FRCD_REG_OFFSET + 8; /* The high 64-bit half */
+
+    for (i = 0; i < DMAR_FRCD_REG_NR; i++) {
+        frcd_reg = vtd_get_quad_raw(s, addr);
+        VTD_DPRINTF(FLOG, "frcd_reg #%d 0x%"PRIx64, i, frcd_reg);
+        if ((frcd_reg & VTD_FRCD_F) &&
+            ((frcd_reg & VTD_FRCD_SID_MASK) == source_id)) {
+            return true;
+        }
+        addr += 16; /* 128-bit for each */
+    }
+    return false;
+}
+
+/* Log and report an DMAR (address translation) fault to software */
+static void vtd_report_dmar_fault(IntelIOMMUState *s, uint16_t source_id,
+                                  hwaddr addr, VTDFaultReason fault,
+                                  bool is_write)
+{
+    uint32_t fsts_reg = vtd_get_long_raw(s, DMAR_FSTS_REG);
+
+    assert(fault < VTD_FR_MAX);
+
+    if (fault == VTD_FR_RESERVED_ERR) {
+        /* This is not a normal fault reason case. Drop it. */
+        return;
+    }
+    VTD_DPRINTF(FLOG, "sid 0x%"PRIx16 ", fault %d, addr 0x%"PRIx64
+                ", is_write %d", source_id, fault, addr, is_write);
+    if (fsts_reg & VTD_FSTS_PFO) {
+        VTD_DPRINTF(FLOG, "new fault is not recorded due to "
+                    "Primary Fault Overflow");
+        return;
+    }
+    if (vtd_try_collapse_fault(s, source_id)) {
+        VTD_DPRINTF(FLOG, "new fault is not recorded due to "
+                    "compression of faults");
+        return;
+    }
+    if (vtd_is_frcd_set(s, s->next_frcd_reg)) {
+        VTD_DPRINTF(FLOG, "Primary Fault Overflow and "
+                    "new fault is not recorded, set PFO field");
+        vtd_set_clear_mask_long(s, DMAR_FSTS_REG, 0, VTD_FSTS_PFO);
+        return;
+    }
+
+    vtd_record_frcd(s, s->next_frcd_reg, source_id, addr, fault, is_write);
+
+    if (fsts_reg & VTD_FSTS_PPF) {
+        VTD_DPRINTF(FLOG, "there are pending faults already, "
+                    "fault event is not generated");
+        vtd_set_frcd_and_update_ppf(s, s->next_frcd_reg);
+        s->next_frcd_reg++;
+        if (s->next_frcd_reg == DMAR_FRCD_REG_NR) {
+            s->next_frcd_reg = 0;
+        }
+    } else {
+        vtd_set_clear_mask_long(s, DMAR_FSTS_REG, VTD_FSTS_FRI_MASK,
+                                VTD_FSTS_FRI(s->next_frcd_reg));
+        vtd_set_frcd_and_update_ppf(s, s->next_frcd_reg); /* Will set PPF */
+        s->next_frcd_reg++;
+        if (s->next_frcd_reg == DMAR_FRCD_REG_NR) {
+            s->next_frcd_reg = 0;
+        }
+        /* This case actually cause the PPF to be Set.
+         * So generate fault event (interrupt).
+         */
+         vtd_generate_fault_event(s, fsts_reg);
+    }
+}
+
+static inline bool vtd_root_entry_present(VTDRootEntry *root)
+{
+    return root->val & VTD_ROOT_ENTRY_P;
+}
+
+static int vtd_get_root_entry(IntelIOMMUState *s, uint8_t index,
+                              VTDRootEntry *re)
+{
+    dma_addr_t addr;
+
+    addr = s->root + index * sizeof(*re);
+    if (dma_memory_read(&address_space_memory, addr, re, sizeof(*re))) {
+        VTD_DPRINTF(GENERAL, "error: fail to access root-entry at 0x%"PRIx64
+                    " + %"PRIu8, s->root, index);
+        re->val = 0;
+        return -VTD_FR_ROOT_TABLE_INV;
+    }
+    re->val = le64_to_cpu(re->val);
+    return 0;
+}
+
+static inline bool vtd_context_entry_present(VTDContextEntry *context)
+{
+    return context->lo & VTD_CONTEXT_ENTRY_P;
+}
+
+static int vtd_get_context_entry_from_root(VTDRootEntry *root, uint8_t index,
+                                           VTDContextEntry *ce)
+{
+    dma_addr_t addr;
+
+    if (!vtd_root_entry_present(root)) {
+        VTD_DPRINTF(GENERAL, "error: root-entry is not present");
+        return -VTD_FR_ROOT_ENTRY_P;
+    }
+    addr = (root->val & VTD_ROOT_ENTRY_CTP) + index * sizeof(*ce);
+    if (dma_memory_read(&address_space_memory, addr, ce, sizeof(*ce))) {
+        VTD_DPRINTF(GENERAL, "error: fail to access context-entry at 0x%"PRIx64
+                    " + %"PRIu8,
+                    (uint64_t)(root->val & VTD_ROOT_ENTRY_CTP), index);
+        return -VTD_FR_CONTEXT_TABLE_INV;
+    }
+    ce->lo = le64_to_cpu(ce->lo);
+    ce->hi = le64_to_cpu(ce->hi);
+    return 0;
+}
+
+static inline dma_addr_t vtd_get_slpt_base_from_context(VTDContextEntry *ce)
+{
+    return ce->lo & VTD_CONTEXT_ENTRY_SLPTPTR;
+}
+
+/* The shift of an addr for a certain level of paging structure */
+static inline uint32_t vtd_slpt_level_shift(uint32_t level)
+{
+    return VTD_PAGE_SHIFT_4K + (level - 1) * VTD_SL_LEVEL_BITS;
+}
+
+static inline uint64_t vtd_get_slpte_addr(uint64_t slpte)
+{
+    return slpte & VTD_SL_PT_BASE_ADDR_MASK;
+}
+
+/* Whether the pte indicates the address of the page frame */
+static inline bool vtd_is_last_slpte(uint64_t slpte, uint32_t level)
+{
+    return level == VTD_SL_PT_LEVEL || (slpte & VTD_SL_PT_PAGE_SIZE_MASK);
+}
+
+/* Get the content of a spte located in @base_addr[@index] */
+static uint64_t vtd_get_slpte(dma_addr_t base_addr, uint32_t index)
+{
+    uint64_t slpte;
+
+    assert(index < VTD_SL_PT_ENTRY_NR);
+
+    if (dma_memory_read(&address_space_memory,
+                        base_addr + index * sizeof(slpte), &slpte,
+                        sizeof(slpte))) {
+        slpte = (uint64_t)-1;
+        return slpte;
+    }
+    slpte = le64_to_cpu(slpte);
+    return slpte;
+}
+
+/* Given a gpa and the level of paging structure, return the offset of current
+ * level.
+ */
+static inline uint32_t vtd_gpa_level_offset(uint64_t gpa, uint32_t level)
+{
+    return (gpa >> vtd_slpt_level_shift(level)) &
+            ((1ULL << VTD_SL_LEVEL_BITS) - 1);
+}
+
+/* Check Capability Register to see if the @level of page-table is supported */
+static inline bool vtd_is_level_supported(IntelIOMMUState *s, uint32_t level)
+{
+    return VTD_CAP_SAGAW_MASK & s->cap &
+           (1ULL << (level - 2 + VTD_CAP_SAGAW_SHIFT));
+}
+
+/* Get the page-table level that hardware should use for the second-level
+ * page-table walk from the Address Width field of context-entry.
+ */
+static inline uint32_t vtd_get_level_from_context_entry(VTDContextEntry *ce)
+{
+    return 2 + (ce->hi & VTD_CONTEXT_ENTRY_AW);
+}
+
+static inline uint32_t vtd_get_agaw_from_context_entry(VTDContextEntry *ce)
+{
+    return 30 + (ce->hi & VTD_CONTEXT_ENTRY_AW) * 9;
+}
+
+static const uint64_t vtd_paging_entry_rsvd_field[] = {
+    [0] = ~0ULL,
+    /* For not large page */
+    [1] = 0x800ULL | ~(VTD_HAW_MASK | VTD_SL_IGN_COM),
+    [2] = 0x800ULL | ~(VTD_HAW_MASK | VTD_SL_IGN_COM),
+    [3] = 0x800ULL | ~(VTD_HAW_MASK | VTD_SL_IGN_COM),
+    [4] = 0x880ULL | ~(VTD_HAW_MASK | VTD_SL_IGN_COM),
+    /* For large page */
+    [5] = 0x800ULL | ~(VTD_HAW_MASK | VTD_SL_IGN_COM),
+    [6] = 0x1ff800ULL | ~(VTD_HAW_MASK | VTD_SL_IGN_COM),
+    [7] = 0x3ffff800ULL | ~(VTD_HAW_MASK | VTD_SL_IGN_COM),
+    [8] = 0x880ULL | ~(VTD_HAW_MASK | VTD_SL_IGN_COM),
+};
+
+static bool vtd_slpte_nonzero_rsvd(uint64_t slpte, uint32_t level)
+{
+    if (slpte & VTD_SL_PT_PAGE_SIZE_MASK) {
+        /* Maybe large page */
+        return slpte & vtd_paging_entry_rsvd_field[level + 4];
+    } else {
+        return slpte & vtd_paging_entry_rsvd_field[level];
+    }
+}
+
+/* Given the @gpa, get relevant @slptep. @slpte_level will be the last level
+ * of the translation, can be used for deciding the size of large page.
+ */
+static int vtd_gpa_to_slpte(VTDContextEntry *ce, uint64_t gpa, bool is_write,
+                            uint64_t *slptep, uint32_t *slpte_level,
+                            bool *reads, bool *writes)
+{
+    dma_addr_t addr = vtd_get_slpt_base_from_context(ce);
+    uint32_t level = vtd_get_level_from_context_entry(ce);
+    uint32_t offset;
+    uint64_t slpte;
+    uint32_t ce_agaw = vtd_get_agaw_from_context_entry(ce);
+    uint64_t access_right_check;
+
+    /* Check if @gpa is above 2^X-1, where X is the minimum of MGAW in CAP_REG
+     * and AW in context-entry.
+     */
+    if (gpa & ~((1ULL << MIN(ce_agaw, VTD_MGAW)) - 1)) {
+        VTD_DPRINTF(GENERAL, "error: gpa 0x%"PRIx64 " exceeds limits", gpa);
+        return -VTD_FR_ADDR_BEYOND_MGAW;
+    }
+
+    /* FIXME: what is the Atomics request here? */
+    access_right_check = is_write ? VTD_SL_W : VTD_SL_R;
+
+    while (true) {
+        offset = vtd_gpa_level_offset(gpa, level);
+        slpte = vtd_get_slpte(addr, offset);
+
+        if (slpte == (uint64_t)-1) {
+            VTD_DPRINTF(GENERAL, "error: fail to access second-level paging "
+                        "entry at level %"PRIu32 " for gpa 0x%"PRIx64,
+                        level, gpa);
+            if (level == vtd_get_level_from_context_entry(ce)) {
+                /* Invalid programming of context-entry */
+                return -VTD_FR_CONTEXT_ENTRY_INV;
+            } else {
+                return -VTD_FR_PAGING_ENTRY_INV;
+            }
+        }
+        *reads = (*reads) && (slpte & VTD_SL_R);
+        *writes = (*writes) && (slpte & VTD_SL_W);
+        if (!(slpte & access_right_check)) {
+            VTD_DPRINTF(GENERAL, "error: lack of %s permission for "
+                        "gpa 0x%"PRIx64 " slpte 0x%"PRIx64,
+                        (is_write ? "write" : "read"), gpa, slpte);
+            return is_write ? -VTD_FR_WRITE : -VTD_FR_READ;
+        }
+        if (vtd_slpte_nonzero_rsvd(slpte, level)) {
+            VTD_DPRINTF(GENERAL, "error: non-zero reserved field in second "
+                        "level paging entry level %"PRIu32 " slpte 0x%"PRIx64,
+                        level, slpte);
+            return -VTD_FR_PAGING_ENTRY_RSVD;
+        }
+
+        if (vtd_is_last_slpte(slpte, level)) {
+            *slptep = slpte;
+            *slpte_level = level;
+            return 0;
+        }
+        addr = vtd_get_slpte_addr(slpte);
+        level--;
+    }
+}
+
+/* Map a device to its corresponding domain (context-entry) */
+static int vtd_dev_to_context_entry(IntelIOMMUState *s, uint8_t bus_num,
+                                    uint8_t devfn, VTDContextEntry *ce)
+{
+    VTDRootEntry re;
+    int ret_fr;
+
+    ret_fr = vtd_get_root_entry(s, bus_num, &re);
+    if (ret_fr) {
+        return ret_fr;
+    }
+
+    if (!vtd_root_entry_present(&re)) {
+        VTD_DPRINTF(GENERAL, "error: root-entry #%"PRIu8 " is not present",
+                    bus_num);
+        return -VTD_FR_ROOT_ENTRY_P;
+    } else if (re.rsvd || (re.val & VTD_ROOT_ENTRY_RSVD)) {
+        VTD_DPRINTF(GENERAL, "error: non-zero reserved field in root-entry "
+                    "hi 0x%"PRIx64 " lo 0x%"PRIx64, re.rsvd, re.val);
+        return -VTD_FR_ROOT_ENTRY_RSVD;
+    }
+
+    ret_fr = vtd_get_context_entry_from_root(&re, devfn, ce);
+    if (ret_fr) {
+        return ret_fr;
+    }
+
+    if (!vtd_context_entry_present(ce)) {
+        VTD_DPRINTF(GENERAL,
+                    "error: context-entry #%"PRIu8 "(bus #%"PRIu8 ") "
+                    "is not present", devfn, bus_num);
+        return -VTD_FR_CONTEXT_ENTRY_P;
+    } else if ((ce->hi & VTD_CONTEXT_ENTRY_RSVD_HI) ||
+               (ce->lo & VTD_CONTEXT_ENTRY_RSVD_LO)) {
+        VTD_DPRINTF(GENERAL,
+                    "error: non-zero reserved field in context-entry "
+                    "hi 0x%"PRIx64 " lo 0x%"PRIx64, ce->hi, ce->lo);
+        return -VTD_FR_CONTEXT_ENTRY_RSVD;
+    }
+    /* Check if the programming of context-entry is valid */
+    if (!vtd_is_level_supported(s, vtd_get_level_from_context_entry(ce))) {
+        VTD_DPRINTF(GENERAL, "error: unsupported Address Width value in "
+                    "context-entry hi 0x%"PRIx64 " lo 0x%"PRIx64,
+                    ce->hi, ce->lo);
+        return -VTD_FR_CONTEXT_ENTRY_INV;
+    } else if (ce->lo & VTD_CONTEXT_ENTRY_TT) {
+        VTD_DPRINTF(GENERAL, "error: unsupported Translation Type in "
+                    "context-entry hi 0x%"PRIx64 " lo 0x%"PRIx64,
+                    ce->hi, ce->lo);
+        return -VTD_FR_CONTEXT_ENTRY_INV;
+    }
+    return 0;
+}
+
+static inline uint16_t vtd_make_source_id(uint8_t bus_num, uint8_t devfn)
+{
+    return ((bus_num & 0xffUL) << 8) | (devfn & 0xffUL);
+}
+
+static const bool vtd_qualified_faults[] = {
+    [VTD_FR_RESERVED] = false,
+    [VTD_FR_ROOT_ENTRY_P] = false,
+    [VTD_FR_CONTEXT_ENTRY_P] = true,
+    [VTD_FR_CONTEXT_ENTRY_INV] = true,
+    [VTD_FR_ADDR_BEYOND_MGAW] = true,
+    [VTD_FR_WRITE] = true,
+    [VTD_FR_READ] = true,
+    [VTD_FR_PAGING_ENTRY_INV] = true,
+    [VTD_FR_ROOT_TABLE_INV] = false,
+    [VTD_FR_CONTEXT_TABLE_INV] = false,
+    [VTD_FR_ROOT_ENTRY_RSVD] = false,
+    [VTD_FR_PAGING_ENTRY_RSVD] = true,
+    [VTD_FR_CONTEXT_ENTRY_TT] = true,
+    [VTD_FR_RESERVED_ERR] = false,
+    [VTD_FR_MAX] = false,
+};
+
+/* To see if a fault condition is "qualified", which is reported to software
+ * only if the FPD field in the context-entry used to process the faulting
+ * request is 0.
+ */
+static inline bool vtd_is_qualified_fault(VTDFaultReason fault)
+{
+    return vtd_qualified_faults[fault];
+}
+
+static inline bool vtd_is_interrupt_addr(hwaddr addr)
+{
+    return VTD_INTERRUPT_ADDR_FIRST <= addr && addr <= VTD_INTERRUPT_ADDR_LAST;
+}
+
+/* Map dev to context-entry then do a paging-structures walk to do a iommu
+ * translation.
+ * @bus_num: The bus number
+ * @devfn: The devfn, which is the  combined of device and function number
+ * @is_write: The access is a write operation
+ * @entry: IOMMUTLBEntry that contain the addr to be translated and result
+ */
+static void vtd_do_iommu_translate(IntelIOMMUState *s, uint8_t bus_num,
+                                   uint8_t devfn, hwaddr addr, bool is_write,
+                                   IOMMUTLBEntry *entry)
+{
+    VTDContextEntry ce;
+    uint64_t slpte;
+    uint32_t level;
+    uint16_t source_id = vtd_make_source_id(bus_num, devfn);
+    int ret_fr;
+    bool is_fpd_set = false;
+    bool reads = true;
+    bool writes = true;
+
+    /* Check if the request is in interrupt address range */
+    if (vtd_is_interrupt_addr(addr)) {
+        if (is_write) {
+            /* FIXME: since we don't know the length of the access here, we
+             * treat Non-DWORD length write requests without PASID as
+             * interrupt requests, too. Withoud interrupt remapping support,
+             * we just use 1:1 mapping.
+             */
+            VTD_DPRINTF(MMU, "write request to interrupt address "
+                        "gpa 0x%"PRIx64, addr);
+            entry->iova = addr & VTD_PAGE_MASK_4K;
+            entry->translated_addr = addr & VTD_PAGE_MASK_4K;
+            entry->addr_mask = ~VTD_PAGE_MASK_4K;
+            entry->perm = IOMMU_WO;
+            return;
+        } else {
+            VTD_DPRINTF(GENERAL, "error: read request from interrupt address "
+                        "gpa 0x%"PRIx64, addr);
+            vtd_report_dmar_fault(s, source_id, addr, VTD_FR_READ, is_write);
+            return;
+        }
+    }
+
+    ret_fr = vtd_dev_to_context_entry(s, bus_num, devfn, &ce);
+    is_fpd_set = ce.lo & VTD_CONTEXT_ENTRY_FPD;
+    if (ret_fr) {
+        ret_fr = -ret_fr;
+        if (is_fpd_set && vtd_is_qualified_fault(ret_fr)) {
+            VTD_DPRINTF(FLOG, "fault processing is disabled for DMA requests "
+                        "through this context-entry (with FPD Set)");
+        } else {
+            vtd_report_dmar_fault(s, source_id, addr, ret_fr, is_write);
+        }
+        return;
+    }
+
+    ret_fr = vtd_gpa_to_slpte(&ce, addr, is_write, &slpte, &level,
+                              &reads, &writes);
+    if (ret_fr) {
+        ret_fr = -ret_fr;
+        if (is_fpd_set && vtd_is_qualified_fault(ret_fr)) {
+            VTD_DPRINTF(FLOG, "fault processing is disabled for DMA requests "
+                        "through this context-entry (with FPD Set)");
+        } else {
+            vtd_report_dmar_fault(s, source_id, addr, ret_fr, is_write);
+        }
+        return;
+    }
+
+    entry->iova = addr & VTD_PAGE_MASK_4K;
+    entry->translated_addr = vtd_get_slpte_addr(slpte) & VTD_PAGE_MASK_4K;
+    entry->addr_mask = ~VTD_PAGE_MASK_4K;
+    entry->perm = (writes ? 2 : 0) + (reads ? 1 : 0);
+}
+
+static void vtd_root_table_setup(IntelIOMMUState *s)
+{
+    s->root = vtd_get_quad_raw(s, DMAR_RTADDR_REG);
+    s->root_extended = s->root & VTD_RTADDR_RTT;
+    s->root &= VTD_RTADDR_ADDR_MASK;
+
+    VTD_DPRINTF(CSR, "root_table addr 0x%"PRIx64 " %s", s->root,
+                (s->root_extended ? "(extended)" : ""));
+}
+
+/* Context-cache invalidation
+ * Returns the Context Actual Invalidation Granularity.
+ * @val: the content of the CCMD_REG
+ */
+static uint64_t vtd_context_cache_invalidate(IntelIOMMUState *s, uint64_t val)
+{
+    uint64_t caig;
+    uint64_t type = val & VTD_CCMD_CIRG_MASK;
+
+    switch (type) {
+    case VTD_CCMD_GLOBAL_INVL:
+        VTD_DPRINTF(INV, "Global invalidation request");
+        caig = VTD_CCMD_GLOBAL_INVL_A;
+        break;
+
+    case VTD_CCMD_DOMAIN_INVL:
+        VTD_DPRINTF(INV, "Domain-selective invalidation request");
+        caig = VTD_CCMD_DOMAIN_INVL_A;
+        break;
+
+    case VTD_CCMD_DEVICE_INVL:
+        VTD_DPRINTF(INV, "Domain-selective invalidation request");
+        caig = VTD_CCMD_DEVICE_INVL_A;
+        break;
+
+    default:
+        VTD_DPRINTF(GENERAL,
+                    "error: wrong context-cache invalidation granularity");
+        caig = 0;
+    }
+    return caig;
+}
+
+/* Flush IOTLB
+ * Returns the IOTLB Actual Invalidation Granularity.
+ * @val: the content of the IOTLB_REG
+ */
+static uint64_t vtd_iotlb_flush(IntelIOMMUState *s, uint64_t val)
+{
+    uint64_t iaig;
+    uint64_t type = val & VTD_TLB_FLUSH_GRANU_MASK;
+
+    switch (type) {
+    case VTD_TLB_GLOBAL_FLUSH:
+        VTD_DPRINTF(INV, "Global IOTLB flush");
+        iaig = VTD_TLB_GLOBAL_FLUSH_A;
+        break;
+
+    case VTD_TLB_DSI_FLUSH:
+        VTD_DPRINTF(INV, "Domain-selective IOTLB flush");
+        iaig = VTD_TLB_DSI_FLUSH_A;
+        break;
+
+    case VTD_TLB_PSI_FLUSH:
+        VTD_DPRINTF(INV, "Page-selective-within-domain IOTLB flush");
+        iaig = VTD_TLB_PSI_FLUSH_A;
+        break;
+
+    default:
+        VTD_DPRINTF(GENERAL, "error: wrong iotlb flush granularity");
+        iaig = 0;
+    }
+    return iaig;
+}
+
+/* Set Root Table Pointer */
+static void vtd_handle_gcmd_srtp(IntelIOMMUState *s)
+{
+    VTD_DPRINTF(CSR, "set Root Table Pointer");
+
+    vtd_root_table_setup(s);
+    /* Ok - report back to driver */
+    vtd_set_clear_mask_long(s, DMAR_GSTS_REG, 0, VTD_GSTS_RTPS);
+}
+
+/* Handle Translation Enable/Disable */
+static void vtd_handle_gcmd_te(IntelIOMMUState *s, bool en)
+{
+    VTD_DPRINTF(CSR, "Translation Enable %s", (en ? "on" : "off"));
+
+    if (en) {
+        s->dmar_enabled = true;
+        /* Ok - report back to driver */
+        vtd_set_clear_mask_long(s, DMAR_GSTS_REG, 0, VTD_GSTS_TES);
+    } else {
+        s->dmar_enabled = false;
+
+        /* Clear the index of Fault Recording Register */
+        s->next_frcd_reg = 0;
+        /* Ok - report back to driver */
+        vtd_set_clear_mask_long(s, DMAR_GSTS_REG, VTD_GSTS_TES, 0);
+    }
+}
+
+/* Handle write to Global Command Register */
+static void vtd_handle_gcmd_write(IntelIOMMUState *s)
+{
+    uint32_t status = vtd_get_long_raw(s, DMAR_GSTS_REG);
+    uint32_t val = vtd_get_long_raw(s, DMAR_GCMD_REG);
+    uint32_t changed = status ^ val;
+
+    VTD_DPRINTF(CSR, "value 0x%"PRIx32 " status 0x%"PRIx32, val, status);
+    if (changed & VTD_GCMD_TE) {
+        /* Translation enable/disable */
+        vtd_handle_gcmd_te(s, val & VTD_GCMD_TE);
+    }
+    if (val & VTD_GCMD_SRTP) {
+        /* Set/update the root-table pointer */
+        vtd_handle_gcmd_srtp(s);
+    }
+}
+
+/* Handle write to Context Command Register */
+static void vtd_handle_ccmd_write(IntelIOMMUState *s)
+{
+    uint64_t ret;
+    uint64_t val = vtd_get_quad_raw(s, DMAR_CCMD_REG);
+
+    /* Context-cache invalidation request */
+    if (val & VTD_CCMD_ICC) {
+        ret = vtd_context_cache_invalidate(s, val);
+        /* Invalidation completed. Change something to show */
+        vtd_set_clear_mask_quad(s, DMAR_CCMD_REG, VTD_CCMD_ICC, 0ULL);
+        ret = vtd_set_clear_mask_quad(s, DMAR_CCMD_REG, VTD_CCMD_CAIG_MASK,
+                                      ret);
+        VTD_DPRINTF(INV, "CCMD_REG write-back val: 0x%"PRIx64, ret);
+    }
+}
+
+/* Handle write to IOTLB Invalidation Register */
+static void vtd_handle_iotlb_write(IntelIOMMUState *s)
+{
+    uint64_t ret;
+    uint64_t val = vtd_get_quad_raw(s, DMAR_IOTLB_REG);
+
+    /* IOTLB invalidation request */
+    if (val & VTD_TLB_IVT) {
+        ret = vtd_iotlb_flush(s, val);
+        /* Invalidation completed. Change something to show */
+        vtd_set_clear_mask_quad(s, DMAR_IOTLB_REG, VTD_TLB_IVT, 0ULL);
+        ret = vtd_set_clear_mask_quad(s, DMAR_IOTLB_REG,
+                                      VTD_TLB_FLUSH_GRANU_MASK_A, ret);
+        VTD_DPRINTF(INV, "IOTLB_REG write-back val: 0x%"PRIx64, ret);
+    }
+}
+
+static void vtd_handle_fsts_write(IntelIOMMUState *s)
+{
+    uint32_t fsts_reg = vtd_get_long_raw(s, DMAR_FSTS_REG);
+    uint32_t fectl_reg = vtd_get_long_raw(s, DMAR_FECTL_REG);
+    uint32_t status_fields = VTD_FSTS_PFO | VTD_FSTS_PPF | VTD_FSTS_IQE;
+
+    if ((fectl_reg & VTD_FECTL_IP) && !(fsts_reg & status_fields)) {
+        vtd_set_clear_mask_long(s, DMAR_FECTL_REG, VTD_FECTL_IP, 0);
+        VTD_DPRINTF(FLOG, "all pending interrupt conditions serviced, clear "
+                    "IP field of FECTL_REG");
+    }
+}
+
+static void vtd_handle_fectl_write(IntelIOMMUState *s)
+{
+    uint32_t fectl_reg;
+    /* FIXME: when software clears the IM field, check the IP field. But do we
+     * need to compare the old value and the new value to conclude that
+     * software clears the IM field? Or just check if the IM field is zero?
+     */
+    fectl_reg = vtd_get_long_raw(s, DMAR_FECTL_REG);
+    if ((fectl_reg & VTD_FECTL_IP) && !(fectl_reg & VTD_FECTL_IM)) {
+        vtd_generate_interrupt(s, DMAR_FEADDR_REG, DMAR_FEDATA_REG);
+        vtd_set_clear_mask_long(s, DMAR_FECTL_REG, VTD_FECTL_IP, 0);
+        VTD_DPRINTF(FLOG, "IM field is cleared, generate "
+                    "fault event interrupt");
+    }
+}
+
+static uint64_t vtd_mem_read(void *opaque, hwaddr addr, unsigned size)
+{
+    IntelIOMMUState *s = opaque;
+    uint64_t val;
+
+    if (addr + size > DMAR_REG_SIZE) {
+        VTD_DPRINTF(GENERAL, "error: addr outside region: max 0x%"PRIx64
+                    ", got 0x%"PRIx64 " %d",
+                    (uint64_t)DMAR_REG_SIZE, addr, size);
+        return (uint64_t)-1;
+    }
+
+    switch (addr) {
+    /* Root Table Address Register, 64-bit */
+    case DMAR_RTADDR_REG:
+        if (size == 4) {
+            val = s->root & ((1ULL << 32) - 1);
+        } else {
+            val = s->root;
+        }
+        break;
+
+    case DMAR_RTADDR_REG_HI:
+        assert(size == 4);
+        val = s->root >> 32;
+        break;
+
+    default:
+        if (size == 4) {
+            val = vtd_get_long(s, addr);
+        } else {
+            val = vtd_get_quad(s, addr);
+        }
+    }
+    VTD_DPRINTF(CSR, "addr 0x%"PRIx64 " size %d val 0x%"PRIx64,
+                addr, size, val);
+    return val;
+}
+
+static void vtd_mem_write(void *opaque, hwaddr addr,
+                          uint64_t val, unsigned size)
+{
+    IntelIOMMUState *s = opaque;
+
+    if (addr + size > DMAR_REG_SIZE) {
+        VTD_DPRINTF(GENERAL, "error: addr outside region: max 0x%"PRIx64
+                    ", got 0x%"PRIx64 " %d",
+                    (uint64_t)DMAR_REG_SIZE, addr, size);
+        return;
+    }
+
+    switch (addr) {
+    /* Global Command Register, 32-bit */
+    case DMAR_GCMD_REG:
+        VTD_DPRINTF(CSR, "DMAR_GCMD_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        vtd_set_long(s, addr, val);
+        vtd_handle_gcmd_write(s);
+        break;
+
+    /* Context Command Register, 64-bit */
+    case DMAR_CCMD_REG:
+        VTD_DPRINTF(CSR, "DMAR_CCMD_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        if (size == 4) {
+            vtd_set_long(s, addr, val);
+        } else {
+            vtd_set_quad(s, addr, val);
+            vtd_handle_ccmd_write(s);
+        }
+        break;
+
+    case DMAR_CCMD_REG_HI:
+        VTD_DPRINTF(CSR, "DMAR_CCMD_REG_HI write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        vtd_handle_ccmd_write(s);
+        break;
+
+    /* IOTLB Invalidation Register, 64-bit */
+    case DMAR_IOTLB_REG:
+        VTD_DPRINTF(INV, "DMAR_IOTLB_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        if (size == 4) {
+            vtd_set_long(s, addr, val);
+        } else {
+            vtd_set_quad(s, addr, val);
+            vtd_handle_iotlb_write(s);
+        }
+        break;
+
+    case DMAR_IOTLB_REG_HI:
+        VTD_DPRINTF(INV, "DMAR_IOTLB_REG_HI write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        vtd_handle_iotlb_write(s);
+        break;
+
+    /* Fault Status Register, 32-bit */
+    case DMAR_FSTS_REG:
+        VTD_DPRINTF(FLOG, "DMAR_FSTS_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        vtd_handle_fsts_write(s);
+        break;
+
+    /* Fault Event Control Register, 32-bit */
+    case DMAR_FECTL_REG:
+        VTD_DPRINTF(FLOG, "DMAR_FECTL_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        vtd_handle_fectl_write(s);
+        break;
+
+    /* Fault Event Data Register, 32-bit */
+    case DMAR_FEDATA_REG:
+        VTD_DPRINTF(FLOG, "DMAR_FEDATA_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        break;
+
+    /* Fault Event Address Register, 32-bit */
+    case DMAR_FEADDR_REG:
+        VTD_DPRINTF(FLOG, "DMAR_FEADDR_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        break;
+
+    /* Fault Event Upper Address Register, 32-bit */
+    case DMAR_FEUADDR_REG:
+        VTD_DPRINTF(FLOG, "DMAR_FEUADDR_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        break;
+
+    /* Protected Memory Enable Register, 32-bit */
+    case DMAR_PMEN_REG:
+        VTD_DPRINTF(CSR, "DMAR_PMEN_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        break;
+
+    /* Root Table Address Register, 64-bit */
+    case DMAR_RTADDR_REG:
+        VTD_DPRINTF(CSR, "DMAR_RTADDR_REG write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        if (size == 4) {
+            vtd_set_long(s, addr, val);
+        } else {
+            vtd_set_quad(s, addr, val);
+        }
+        break;
+
+    case DMAR_RTADDR_REG_HI:
+        VTD_DPRINTF(CSR, "DMAR_RTADDR_REG_HI write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        break;
+
+    /* Fault Recording Registers, 128-bit */
+    case DMAR_FRCD_REG_0_0:
+        VTD_DPRINTF(FLOG, "DMAR_FRCD_REG_0_0 write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        if (size == 4) {
+            vtd_set_long(s, addr, val);
+        } else {
+            vtd_set_quad(s, addr, val);
+        }
+        break;
+
+    case DMAR_FRCD_REG_0_1:
+        VTD_DPRINTF(FLOG, "DMAR_FRCD_REG_0_1 write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        break;
+
+    case DMAR_FRCD_REG_0_2:
+        VTD_DPRINTF(FLOG, "DMAR_FRCD_REG_0_2 write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        if (size == 4) {
+            vtd_set_long(s, addr, val);
+        } else {
+            vtd_set_quad(s, addr, val);
+            /* May clear bit 127 (Fault), update PPF */
+            vtd_update_fsts_ppf(s);
+        }
+        break;
+
+    case DMAR_FRCD_REG_0_3:
+        VTD_DPRINTF(FLOG, "DMAR_FRCD_REG_0_3 write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        assert(size == 4);
+        vtd_set_long(s, addr, val);
+        /* May clear bit 127 (Fault), update PPF */
+        vtd_update_fsts_ppf(s);
+        break;
+
+    default:
+        VTD_DPRINTF(GENERAL, "error: unhandled reg write addr 0x%"PRIx64
+                    ", size %d, val 0x%"PRIx64, addr, size, val);
+        if (size == 4) {
+            vtd_set_long(s, addr, val);
+        } else {
+            vtd_set_quad(s, addr, val);
+        }
+    }
+}
+
+static IOMMUTLBEntry vtd_iommu_translate(MemoryRegion *iommu, hwaddr addr,
+                                         bool is_write)
+{
+    VTDAddressSpace *vtd_as = container_of(iommu, VTDAddressSpace, iommu);
+    IntelIOMMUState *s = vtd_as->iommu_state;
+    uint8_t bus_num = vtd_as->bus_num;
+    uint8_t devfn = vtd_as->devfn;
+    IOMMUTLBEntry ret = {
+        .target_as = &address_space_memory,
+        .iova = addr,
+        .translated_addr = 0,
+        .addr_mask = ~(hwaddr)0,
+        .perm = IOMMU_NONE,
+    };
+
+    if (!s->dmar_enabled) {
+        /* DMAR disabled, passthrough, use 4k-page*/
+        ret.iova = addr & VTD_PAGE_MASK_4K;
+        ret.translated_addr = addr & VTD_PAGE_MASK_4K;
+        ret.addr_mask = ~VTD_PAGE_MASK_4K;
+        ret.perm = IOMMU_RW;
+        return ret;
+    }
+
+    vtd_do_iommu_translate(s, bus_num, devfn, addr, is_write, &ret);
+
+    VTD_DPRINTF(MMU,
+                "bus %"PRIu8 " slot %"PRIu8 " func %"PRIu8 " devfn %"PRIu8
+                " gpa 0x%"PRIx64 " hpa 0x%"PRIx64, bus_num,
+                VTD_PCI_SLOT(devfn), VTD_PCI_FUNC(devfn), devfn, addr,
+                ret.translated_addr);
+    return ret;
+}
+
+static const VMStateDescription vtd_vmstate = {
+    .name = "iommu-intel",
+    .unmigratable = 1,
+};
+
+static const MemoryRegionOps vtd_mem_ops = {
+    .read = vtd_mem_read,
+    .write = vtd_mem_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 8,
+    },
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 8,
+    },
+};
+
+static Property vtd_properties[] = {
+    DEFINE_PROP_UINT32("version", IntelIOMMUState, version, 0),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+/* Do the initialization. It will also be called when reset, so pay
+ * attention when adding new initialization stuff.
+ */
+static void vtd_init(IntelIOMMUState *s)
+{
+    memset(s->csr, 0, DMAR_REG_SIZE);
+    memset(s->wmask, 0, DMAR_REG_SIZE);
+    memset(s->w1cmask, 0, DMAR_REG_SIZE);
+    memset(s->womask, 0, DMAR_REG_SIZE);
+
+    s->iommu_ops.translate = vtd_iommu_translate;
+    s->root = 0;
+    s->root_extended = false;
+    s->dmar_enabled = false;
+    s->iq_head = 0;
+    s->iq_tail = 0;
+    s->iq = 0;
+    s->iq_size = 0;
+    s->qi_enabled = false;
+    s->iq_last_desc_type = VTD_INV_DESC_NONE;
+    s->next_frcd_reg = 0;
+    s->cap = VTD_CAP_FRO | VTD_CAP_NFR | VTD_CAP_ND | VTD_CAP_MGAW |
+             VTD_CAP_SAGAW;
+    s->ecap = VTD_ECAP_IRO;
+
+    /* Define registers with default values and bit semantics */
+    vtd_define_long(s, DMAR_VER_REG, 0x10UL, 0, 0);
+    vtd_define_quad(s, DMAR_CAP_REG, s->cap, 0, 0);
+    vtd_define_quad(s, DMAR_ECAP_REG, s->ecap, 0, 0);
+    vtd_define_long(s, DMAR_GCMD_REG, 0, 0xff800000UL, 0);
+    vtd_define_long_wo(s, DMAR_GCMD_REG, 0xff800000UL);
+    vtd_define_long(s, DMAR_GSTS_REG, 0, 0, 0);
+    vtd_define_quad(s, DMAR_RTADDR_REG, 0, 0xfffffffffffff000ULL, 0);
+    vtd_define_quad(s, DMAR_CCMD_REG, 0, 0xe0000003ffffffffULL, 0);
+    vtd_define_quad_wo(s, DMAR_CCMD_REG, 0x3ffff0000ULL);
+
+    /* Advanced Fault Logging not supported */
+    vtd_define_long(s, DMAR_FSTS_REG, 0, 0, 0x11UL);
+    vtd_define_long(s, DMAR_FECTL_REG, 0x80000000UL, 0x80000000UL, 0);
+    vtd_define_long(s, DMAR_FEDATA_REG, 0, 0x0000ffffUL, 0);
+    vtd_define_long(s, DMAR_FEADDR_REG, 0, 0xfffffffcUL, 0);
+
+    /* Treated as RsvdZ when EIM in ECAP_REG is not supported
+     * vtd_define_long(s, DMAR_FEUADDR_REG, 0, 0xffffffffUL, 0);
+     */
+    vtd_define_long(s, DMAR_FEUADDR_REG, 0, 0, 0);
+
+    /* Treated as RO for implementations that PLMR and PHMR fields reported
+     * as Clear in the CAP_REG.
+     * vtd_define_long(s, DMAR_PMEN_REG, 0, 0x80000000UL, 0);
+     */
+    vtd_define_long(s, DMAR_PMEN_REG, 0, 0, 0);
+
+    /* IOTLB registers */
+    vtd_define_quad(s, DMAR_IOTLB_REG, 0, 0Xb003ffff00000000ULL, 0);
+    vtd_define_quad(s, DMAR_IVA_REG, 0, 0xfffffffffffff07fULL, 0);
+    vtd_define_quad_wo(s, DMAR_IVA_REG, 0xfffffffffffff07fULL);
+
+    /* Fault Recording Registers, 128-bit */
+    vtd_define_quad(s, DMAR_FRCD_REG_0_0, 0, 0, 0);
+    vtd_define_quad(s, DMAR_FRCD_REG_0_2, 0, 0, 0x8000000000000000ULL);
+}
+
+/* Should not reset address_spaces when reset because devices will still use
+ * the address space they got at first (won't ask the bus again).
+ */
+static void vtd_reset(DeviceState *dev)
+{
+    IntelIOMMUState *s = INTEL_IOMMU_DEVICE(dev);
+
+    VTD_DPRINTF(GENERAL, "");
+    vtd_init(s);
+}
+
+static void vtd_realize(DeviceState *dev, Error **errp)
+{
+    IntelIOMMUState *s = INTEL_IOMMU_DEVICE(dev);
+
+    VTD_DPRINTF(GENERAL, "");
+    memset(s->address_spaces, 0, sizeof(s->address_spaces));
+    memory_region_init_io(&s->csrmem, OBJECT(s), &vtd_mem_ops, s,
+                          "intel_iommu", DMAR_REG_SIZE);
+    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->csrmem);
+    vtd_init(s);
+}
+
+static void vtd_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->reset = vtd_reset;
+    dc->realize = vtd_realize;
+    dc->vmsd = &vtd_vmstate;
+    dc->props = vtd_properties;
+}
+
+static const TypeInfo vtd_info = {
+    .name          = TYPE_INTEL_IOMMU_DEVICE,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(IntelIOMMUState),
+    .class_init    = vtd_class_init,
+};
+
+static void vtd_register_types(void)
+{
+    VTD_DPRINTF(GENERAL, "");
+    type_register_static(&vtd_info);
+}
+
+type_init(vtd_register_types)