hw/i386: Introduce AMD IOMMU

Add AMD IOMMU emulaton to Qemu in addition to Intel IOMMU.
The IOMMU does basic translation, error checking and has a
minimal IOTLB implementation. This IOMMU bypassed the need
for target aborts by responding with IOMMU_NONE access rights
and exempts the region 0xfee00000-0xfeefffff from translation
as it is the q35 interrupt region.

We advertise features that are not yet implemented to please
the Linux IOMMU driver.

IOTLB aims at implementing commands on real IOMMUs which is
essential for debugging and may not offer any performance
benefits

Signed-off-by: David Kiarie <davidkiarie4@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

3 files changed, 1490 insertions, 0 deletions

diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
index 90e94ffefd..909ead6a77 100644
--- a/hw/i386/Makefile.objs
+++ b/hw/i386/Makefile.objs
@@ -3,6 +3,7 @@ obj-y += multiboot.o
 obj-y += pc.o pc_piix.o pc_q35.o
 obj-y += pc_sysfw.o
 obj-y += x86-iommu.o intel_iommu.o
+obj-y += amd_iommu.o
 obj-$(CONFIG_XEN) += ../xenpv/ xen/
 
 obj-y += kvmvapic.o
diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
new file mode 100644
index 0000000000..4eec9b80ed
--- /dev/null
+++ b/hw/i386/amd_iommu.c
@@ -0,0 +1,1200 @@
+/*
+ * QEMU emulation of AMD IOMMU (AMD-Vi)
+ *
+ * Copyright (C) 2011 Eduard - Gabriel Munteanu
+ * Copyright (C) 2015 David Kiarie, <davidkiarie4@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/>.
+ *
+ * Cache implementation inspired by hw/i386/intel_iommu.c
+ */
+#include "qemu/osdep.h"
+#include "hw/i386/amd_iommu.h"
+#include "trace.h"
+
+/* used AMD-Vi MMIO registers */
+const char *amdvi_mmio_low[] = {
+    "AMDVI_MMIO_DEVTAB_BASE",
+    "AMDVI_MMIO_CMDBUF_BASE",
+    "AMDVI_MMIO_EVTLOG_BASE",
+    "AMDVI_MMIO_CONTROL",
+    "AMDVI_MMIO_EXCL_BASE",
+    "AMDVI_MMIO_EXCL_LIMIT",
+    "AMDVI_MMIO_EXT_FEATURES",
+    "AMDVI_MMIO_PPR_BASE",
+    "UNHANDLED"
+};
+const char *amdvi_mmio_high[] = {
+    "AMDVI_MMIO_COMMAND_HEAD",
+    "AMDVI_MMIO_COMMAND_TAIL",
+    "AMDVI_MMIO_EVTLOG_HEAD",
+    "AMDVI_MMIO_EVTLOG_TAIL",
+    "AMDVI_MMIO_STATUS",
+    "AMDVI_MMIO_PPR_HEAD",
+    "AMDVI_MMIO_PPR_TAIL",
+    "UNHANDLED"
+};
+
+struct AMDVIAddressSpace {
+    uint8_t bus_num;            /* bus number                           */
+    uint8_t devfn;              /* device function                      */
+    AMDVIState *iommu_state;    /* AMDVI - one per machine              */
+    MemoryRegion iommu;         /* Device's address translation region  */
+    MemoryRegion iommu_ir;      /* Device's interrupt remapping region  */
+    AddressSpace as;            /* device's corresponding address space */
+};
+
+/* AMDVI cache entry */
+typedef struct AMDVIIOTLBEntry {
+    uint16_t domid;             /* assigned domain id  */
+    uint16_t devid;             /* device owning entry */
+    uint64_t perms;             /* access permissions  */
+    uint64_t translated_addr;   /* translated address  */
+    uint64_t page_mask;         /* physical page size  */
+} AMDVIIOTLBEntry;
+
+/* configure MMIO registers at startup/reset */
+static void amdvi_set_quad(AMDVIState *s, hwaddr addr, uint64_t val,
+                           uint64_t romask, uint64_t w1cmask)
+{
+    stq_le_p(&s->mmior[addr], val);
+    stq_le_p(&s->romask[addr], romask);
+    stq_le_p(&s->w1cmask[addr], w1cmask);
+}
+
+static uint16_t amdvi_readw(AMDVIState *s, hwaddr addr)
+{
+    return lduw_le_p(&s->mmior[addr]);
+}
+
+static uint32_t amdvi_readl(AMDVIState *s, hwaddr addr)
+{
+    return ldl_le_p(&s->mmior[addr]);
+}
+
+static uint64_t amdvi_readq(AMDVIState *s, hwaddr addr)
+{
+    return ldq_le_p(&s->mmior[addr]);
+}
+
+/* internal write */
+static void amdvi_writeq_raw(AMDVIState *s, uint64_t val, hwaddr addr)
+{
+    stq_le_p(&s->mmior[addr], val);
+}
+
+/* external write */
+static void amdvi_writew(AMDVIState *s, hwaddr addr, uint16_t val)
+{
+    uint16_t romask = lduw_le_p(&s->romask[addr]);
+    uint16_t w1cmask = lduw_le_p(&s->w1cmask[addr]);
+    uint16_t oldval = lduw_le_p(&s->mmior[addr]);
+    stw_le_p(&s->mmior[addr],
+            ((oldval & romask) | (val & ~romask)) & ~(val & w1cmask));
+}
+
+static void amdvi_writel(AMDVIState *s, hwaddr addr, uint32_t val)
+{
+    uint32_t romask = ldl_le_p(&s->romask[addr]);
+    uint32_t w1cmask = ldl_le_p(&s->w1cmask[addr]);
+    uint32_t oldval = ldl_le_p(&s->mmior[addr]);
+    stl_le_p(&s->mmior[addr],
+            ((oldval & romask) | (val & ~romask)) & ~(val & w1cmask));
+}
+
+static void amdvi_writeq(AMDVIState *s, hwaddr addr, uint64_t val)
+{
+    uint64_t romask = ldq_le_p(&s->romask[addr]);
+    uint64_t w1cmask = ldq_le_p(&s->w1cmask[addr]);
+    uint32_t oldval = ldq_le_p(&s->mmior[addr]);
+    stq_le_p(&s->mmior[addr],
+            ((oldval & romask) | (val & ~romask)) & ~(val & w1cmask));
+}
+
+/* OR a 64-bit register with a 64-bit value */
+static bool amdvi_test_mask(AMDVIState *s, hwaddr addr, uint64_t val)
+{
+    return amdvi_readq(s, addr) | val;
+}
+
+/* OR a 64-bit register with a 64-bit value storing result in the register */
+static void amdvi_assign_orq(AMDVIState *s, hwaddr addr, uint64_t val)
+{
+    amdvi_writeq_raw(s, addr, amdvi_readq(s, addr) | val);
+}
+
+/* AND a 64-bit register with a 64-bit value storing result in the register */
+static void amdvi_assign_andq(AMDVIState *s, hwaddr addr, uint64_t val)
+{
+   amdvi_writeq_raw(s, addr, amdvi_readq(s, addr) & val);
+}
+
+static void amdvi_generate_msi_interrupt(AMDVIState *s)
+{
+    MSIMessage msg;
+    MemTxAttrs attrs;
+
+    attrs.requester_id = pci_requester_id(&s->pci.dev);
+
+    if (msi_enabled(&s->pci.dev)) {
+        msg = msi_get_message(&s->pci.dev, 0);
+        address_space_stl_le(&address_space_memory, msg.address, msg.data,
+                             attrs, NULL);
+    }
+}
+
+static void amdvi_log_event(AMDVIState *s, uint64_t *evt)
+{
+    /* event logging not enabled */
+    if (!s->evtlog_enabled || amdvi_test_mask(s, AMDVI_MMIO_STATUS,
+        AMDVI_MMIO_STATUS_EVT_OVF)) {
+        return;
+    }
+
+    /* event log buffer full */
+    if (s->evtlog_tail >= s->evtlog_len) {
+        amdvi_assign_orq(s, AMDVI_MMIO_STATUS, AMDVI_MMIO_STATUS_EVT_OVF);
+        /* generate interrupt */
+        amdvi_generate_msi_interrupt(s);
+        return;
+    }
+
+    if (dma_memory_write(&address_space_memory, s->evtlog + s->evtlog_tail,
+        &evt, AMDVI_EVENT_LEN)) {
+        trace_amdvi_evntlog_fail(s->evtlog, s->evtlog_tail);
+    }
+
+    s->evtlog_tail += AMDVI_EVENT_LEN;
+    amdvi_assign_orq(s, AMDVI_MMIO_STATUS, AMDVI_MMIO_STATUS_COMP_INT);
+    amdvi_generate_msi_interrupt(s);
+}
+
+static void amdvi_setevent_bits(uint64_t *buffer, uint64_t value, int start,
+                                int length)
+{
+    int index = start / 64, bitpos = start % 64;
+    uint64_t mask = ((1 << length) - 1) << bitpos;
+    buffer[index] &= ~mask;
+    buffer[index] |= (value << bitpos) & mask;
+}
+/*
+ * AMDVi event structure
+ *    0:15   -> DeviceID
+ *    55:63  -> event type + miscellaneous info
+ *    63:127 -> related address
+ */
+static void amdvi_encode_event(uint64_t *evt, uint16_t devid, uint64_t addr,
+                               uint16_t info)
+{
+    amdvi_setevent_bits(evt, devid, 0, 16);
+    amdvi_setevent_bits(evt, info, 55, 8);
+    amdvi_setevent_bits(evt, addr, 63, 64);
+}
+/* log an error encountered during a page walk
+ *
+ * @addr: virtual address in translation request
+ */
+static void amdvi_page_fault(AMDVIState *s, uint16_t devid,
+                             hwaddr addr, uint16_t info)
+{
+    uint64_t evt[4];
+
+    info |= AMDVI_EVENT_IOPF_I | AMDVI_EVENT_IOPF;
+    amdvi_encode_event(evt, devid, addr, info);
+    amdvi_log_event(s, evt);
+    pci_word_test_and_set_mask(s->pci.dev.config + PCI_STATUS,
+            PCI_STATUS_SIG_TARGET_ABORT);
+}
+/*
+ * log a master abort accessing device table
+ *  @devtab : address of device table entry
+ *  @info : error flags
+ */
+static void amdvi_log_devtab_error(AMDVIState *s, uint16_t devid,
+                                   hwaddr devtab, uint16_t info)
+{
+    uint64_t evt[4];
+
+    info |= AMDVI_EVENT_DEV_TAB_HW_ERROR;
+
+    amdvi_encode_event(evt, devid, devtab, info);
+    amdvi_log_event(s, evt);
+    pci_word_test_and_set_mask(s->pci.dev.config + PCI_STATUS,
+            PCI_STATUS_SIG_TARGET_ABORT);
+}
+/* log an event trying to access command buffer
+ *   @addr : address that couldn't be accessed
+ */
+static void amdvi_log_command_error(AMDVIState *s, hwaddr addr)
+{
+    uint64_t evt[4], info = AMDVI_EVENT_COMMAND_HW_ERROR;
+
+    amdvi_encode_event(evt, 0, addr, info);
+    amdvi_log_event(s, evt);
+    pci_word_test_and_set_mask(s->pci.dev.config + PCI_STATUS,
+            PCI_STATUS_SIG_TARGET_ABORT);
+}
+/* log an illegal comand event
+ *   @addr : address of illegal command
+ */
+static void amdvi_log_illegalcom_error(AMDVIState *s, uint16_t info,
+                                       hwaddr addr)
+{
+    uint64_t evt[4];
+
+    info |= AMDVI_EVENT_ILLEGAL_COMMAND_ERROR;
+    amdvi_encode_event(evt, 0, addr, info);
+    amdvi_log_event(s, evt);
+}
+/* log an error accessing device table
+ *
+ *  @devid : device owning the table entry
+ *  @devtab : address of device table entry
+ *  @info : error flags
+ */
+static void amdvi_log_illegaldevtab_error(AMDVIState *s, uint16_t devid,
+                                          hwaddr addr, uint16_t info)
+{
+    uint64_t evt[4];
+
+    info |= AMDVI_EVENT_ILLEGAL_DEVTAB_ENTRY;
+    amdvi_encode_event(evt, devid, addr, info);
+    amdvi_log_event(s, evt);
+}
+/* log an error accessing a PTE entry
+ * @addr : address that couldn't be accessed
+ */
+static void amdvi_log_pagetab_error(AMDVIState *s, uint16_t devid,
+                                    hwaddr addr, uint16_t info)
+{
+    uint64_t evt[4];
+
+    info |= AMDVI_EVENT_PAGE_TAB_HW_ERROR;
+    amdvi_encode_event(evt, devid, addr, info);
+    amdvi_log_event(s, evt);
+    pci_word_test_and_set_mask(s->pci.dev.config + PCI_STATUS,
+             PCI_STATUS_SIG_TARGET_ABORT);
+}
+
+static gboolean amdvi_uint64_equal(gconstpointer v1, gconstpointer v2)
+{
+    return *((const uint64_t *)v1) == *((const uint64_t *)v2);
+}
+
+static guint amdvi_uint64_hash(gconstpointer v)
+{
+    return (guint)*(const uint64_t *)v;
+}
+
+static AMDVIIOTLBEntry *amdvi_iotlb_lookup(AMDVIState *s, hwaddr addr,
+                                           uint64_t devid)
+{
+    uint64_t key = (addr >> AMDVI_PAGE_SHIFT_4K) |
+                   ((uint64_t)(devid) << AMDVI_DEVID_SHIFT);
+    return g_hash_table_lookup(s->iotlb, &key);
+}
+
+static void amdvi_iotlb_reset(AMDVIState *s)
+{
+    assert(s->iotlb);
+    trace_amdvi_iotlb_reset();
+    g_hash_table_remove_all(s->iotlb);
+}
+
+static gboolean amdvi_iotlb_remove_by_devid(gpointer key, gpointer value,
+                                            gpointer user_data)
+{
+    AMDVIIOTLBEntry *entry = (AMDVIIOTLBEntry *)value;
+    uint16_t devid = *(uint16_t *)user_data;
+    return entry->devid == devid;
+}
+
+static void amdvi_iotlb_remove_page(AMDVIState *s, hwaddr addr,
+                                    uint64_t devid)
+{
+    uint64_t key = (addr >> AMDVI_PAGE_SHIFT_4K) |
+                   ((uint64_t)(devid) << AMDVI_DEVID_SHIFT);
+    g_hash_table_remove(s->iotlb, &key);
+}
+
+static void amdvi_update_iotlb(AMDVIState *s, uint16_t devid,
+                               uint64_t gpa, IOMMUTLBEntry to_cache,
+                               uint16_t domid)
+{
+    AMDVIIOTLBEntry *entry = g_malloc(sizeof(*entry));
+    uint64_t *key = g_malloc(sizeof(key));
+    uint64_t gfn = gpa >> AMDVI_PAGE_SHIFT_4K;
+
+    /* don't cache erroneous translations */
+    if (to_cache.perm != IOMMU_NONE) {
+        trace_amdvi_cache_update(domid, PCI_BUS_NUM(devid), PCI_SLOT(devid),
+                PCI_FUNC(devid), gpa, to_cache.translated_addr);
+
+        if (g_hash_table_size(s->iotlb) >= AMDVI_IOTLB_MAX_SIZE) {
+            amdvi_iotlb_reset(s);
+        }
+
+        entry->domid = domid;
+        entry->perms = to_cache.perm;
+        entry->translated_addr = to_cache.translated_addr;
+        entry->page_mask = to_cache.addr_mask;
+        *key = gfn | ((uint64_t)(devid) << AMDVI_DEVID_SHIFT);
+        g_hash_table_replace(s->iotlb, key, entry);
+    }
+}
+
+static void amdvi_completion_wait(AMDVIState *s, uint64_t *cmd)
+{
+    /* pad the last 3 bits */
+    hwaddr addr = cpu_to_le64(extract64(cmd[0], 3, 49)) << 3;
+    uint64_t data = cpu_to_le64(cmd[1]);
+
+    if (extract64(cmd[0], 51, 8)) {
+        amdvi_log_illegalcom_error(s, extract64(cmd[0], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+    }
+    if (extract64(cmd[0], 0, 1)) {
+        if (dma_memory_write(&address_space_memory, addr, &data,
+            AMDVI_COMPLETION_DATA_SIZE)) {
+            trace_amdvi_completion_wait_fail(addr);
+        }
+    }
+    /* set completion interrupt */
+    if (extract64(cmd[0], 1, 1)) {
+        amdvi_test_mask(s, AMDVI_MMIO_STATUS, AMDVI_MMIO_STATUS_COMP_INT);
+        /* generate interrupt */
+        amdvi_generate_msi_interrupt(s);
+    }
+    trace_amdvi_completion_wait(addr, data);
+}
+
+/* log error without aborting since linux seems to be using reserved bits */
+static void amdvi_inval_devtab_entry(AMDVIState *s, uint64_t *cmd)
+{
+    uint16_t devid = cpu_to_le16((uint16_t)extract64(cmd[0], 0, 16));
+
+    /* This command should invalidate internal caches of which there isn't */
+    if (extract64(cmd[0], 15, 16) || cmd[1]) {
+        amdvi_log_illegalcom_error(s, extract64(cmd[0], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+    }
+    trace_amdvi_devtab_inval(PCI_BUS_NUM(devid), PCI_SLOT(devid),
+                             PCI_FUNC(devid));
+}
+
+static void amdvi_complete_ppr(AMDVIState *s, uint64_t *cmd)
+{
+    if (extract64(cmd[0], 15, 16) ||  extract64(cmd[0], 19, 8) ||
+        extract64(cmd[1], 0, 2) || extract64(cmd[1], 3, 29)
+        || extract64(cmd[1], 47, 16)) {
+        amdvi_log_illegalcom_error(s, extract64(cmd[0], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+    }
+    trace_amdvi_ppr_exec();
+}
+
+static void amdvi_inval_all(AMDVIState *s, uint64_t *cmd)
+{
+    if (extract64(cmd[0], 0, 60) || cmd[1]) {
+        amdvi_log_illegalcom_error(s, extract64(cmd[0], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+    }
+
+    amdvi_iotlb_reset(s);
+    trace_amdvi_all_inval();
+}
+
+static gboolean amdvi_iotlb_remove_by_domid(gpointer key, gpointer value,
+                                            gpointer user_data)
+{
+    AMDVIIOTLBEntry *entry = (AMDVIIOTLBEntry *)value;
+    uint16_t domid = *(uint16_t *)user_data;
+    return entry->domid == domid;
+}
+
+/* we don't have devid - we can't remove pages by address */
+static void amdvi_inval_pages(AMDVIState *s, uint64_t *cmd)
+{
+    uint16_t domid = cpu_to_le16((uint16_t)extract64(cmd[0], 32, 16));
+
+    if (extract64(cmd[0], 20, 12) || extract64(cmd[0], 16, 12) ||
+        extract64(cmd[0], 3, 10)) {
+        amdvi_log_illegalcom_error(s, extract64(cmd[0], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+    }
+
+    g_hash_table_foreach_remove(s->iotlb, amdvi_iotlb_remove_by_domid,
+                                &domid);
+    trace_amdvi_pages_inval(domid);
+}
+
+static void amdvi_prefetch_pages(AMDVIState *s, uint64_t *cmd)
+{
+    if (extract64(cmd[0], 16, 8) || extract64(cmd[0], 20, 8) ||
+        extract64(cmd[1], 1, 1) || extract64(cmd[1], 3, 1) ||
+        extract64(cmd[1], 5, 7)) {
+        amdvi_log_illegalcom_error(s, extract64(cmd[0], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+    }
+
+    trace_amdvi_prefetch_pages();
+}
+
+static void amdvi_inval_inttable(AMDVIState *s, uint64_t *cmd)
+{
+    if (extract64(cmd[0], 16, 16) || cmd[1]) {
+        amdvi_log_illegalcom_error(s, extract64(cmd[0], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+        return;
+    }
+
+    trace_amdvi_intr_inval();
+}
+
+/* FIXME: Try to work with the specified size instead of all the pages
+ * when the S bit is on
+ */
+static void iommu_inval_iotlb(AMDVIState *s, uint64_t *cmd)
+{
+
+    uint16_t devid = extract64(cmd[0], 0, 16);
+    if (extract64(cmd[1], 1, 1) || extract64(cmd[1], 3, 9)) {
+        amdvi_log_illegalcom_error(s, extract64(cmd[0], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+        return;
+    }
+
+    if (extract64(cmd[1], 0, 1)) {
+        g_hash_table_foreach_remove(s->iotlb, amdvi_iotlb_remove_by_devid,
+                                    &devid);
+    } else {
+        amdvi_iotlb_remove_page(s, cpu_to_le64(extract64(cmd[1], 12, 52)) << 12,
+                                cpu_to_le16(extract64(cmd[1], 0, 16)));
+    }
+    trace_amdvi_iotlb_inval();
+}
+
+/* not honouring reserved bits is regarded as an illegal command */
+static void amdvi_cmdbuf_exec(AMDVIState *s)
+{
+    uint64_t cmd[2];
+
+    if (dma_memory_read(&address_space_memory, s->cmdbuf + s->cmdbuf_head,
+        cmd, AMDVI_COMMAND_SIZE)) {
+        trace_amdvi_command_read_fail(s->cmdbuf, s->cmdbuf_head);
+        amdvi_log_command_error(s, s->cmdbuf + s->cmdbuf_head);
+        return;
+    }
+
+    switch (extract64(cmd[0], 60, 4)) {
+    case AMDVI_CMD_COMPLETION_WAIT:
+        amdvi_completion_wait(s, cmd);
+        break;
+    case AMDVI_CMD_INVAL_DEVTAB_ENTRY:
+        amdvi_inval_devtab_entry(s, cmd);
+        break;
+    case AMDVI_CMD_INVAL_AMDVI_PAGES:
+        amdvi_inval_pages(s, cmd);
+        break;
+    case AMDVI_CMD_INVAL_IOTLB_PAGES:
+        iommu_inval_iotlb(s, cmd);
+        break;
+    case AMDVI_CMD_INVAL_INTR_TABLE:
+        amdvi_inval_inttable(s, cmd);
+        break;
+    case AMDVI_CMD_PREFETCH_AMDVI_PAGES:
+        amdvi_prefetch_pages(s, cmd);
+        break;
+    case AMDVI_CMD_COMPLETE_PPR_REQUEST:
+        amdvi_complete_ppr(s, cmd);
+        break;
+    case AMDVI_CMD_INVAL_AMDVI_ALL:
+        amdvi_inval_all(s, cmd);
+        break;
+    default:
+        trace_amdvi_unhandled_command(extract64(cmd[1], 60, 4));
+        /* log illegal command */
+        amdvi_log_illegalcom_error(s, extract64(cmd[1], 60, 4),
+                                   s->cmdbuf + s->cmdbuf_head);
+    }
+}
+
+static void amdvi_cmdbuf_run(AMDVIState *s)
+{
+    if (!s->cmdbuf_enabled) {
+        trace_amdvi_command_error(amdvi_readq(s, AMDVI_MMIO_CONTROL));
+        return;
+    }
+
+    /* check if there is work to do. */
+    while (s->cmdbuf_head != s->cmdbuf_tail) {
+        trace_amdvi_command_exec(s->cmdbuf_head, s->cmdbuf_tail, s->cmdbuf);
+        amdvi_cmdbuf_exec(s);
+        s->cmdbuf_head += AMDVI_COMMAND_SIZE;
+        amdvi_writeq_raw(s, s->cmdbuf_head, AMDVI_MMIO_COMMAND_HEAD);
+
+        /* wrap head pointer */
+        if (s->cmdbuf_head >= s->cmdbuf_len * AMDVI_COMMAND_SIZE) {
+            s->cmdbuf_head = 0;
+        }
+    }
+}
+
+static void amdvi_mmio_trace(hwaddr addr, unsigned size)
+{
+    uint8_t index = (addr & ~0x2000) / 8;
+
+    if ((addr & 0x2000)) {
+        /* high table */
+        index = index >= AMDVI_MMIO_REGS_HIGH ? AMDVI_MMIO_REGS_HIGH : index;
+        trace_amdvi_mmio_read(amdvi_mmio_high[index], addr, size, addr & ~0x07);
+    } else {
+        index = index >= AMDVI_MMIO_REGS_LOW ? AMDVI_MMIO_REGS_LOW : index;
+        trace_amdvi_mmio_read(amdvi_mmio_high[index], addr, size, addr & ~0x07);
+    }
+}
+
+static uint64_t amdvi_mmio_read(void *opaque, hwaddr addr, unsigned size)
+{
+    AMDVIState *s = opaque;
+
+    uint64_t val = -1;
+    if (addr + size > AMDVI_MMIO_SIZE) {
+        trace_amdvi_mmio_read("error: addr outside region: max ",
+                (uint64_t)AMDVI_MMIO_SIZE, addr, size);
+        return (uint64_t)-1;
+    }
+
+    if (size == 2) {
+        val = amdvi_readw(s, addr);
+    } else if (size == 4) {
+        val = amdvi_readl(s, addr);
+    } else if (size == 8) {
+        val = amdvi_readq(s, addr);
+    }
+    amdvi_mmio_trace(addr, size);
+
+    return val;
+}
+
+static void amdvi_handle_control_write(AMDVIState *s)
+{
+    unsigned long control = amdvi_readq(s, AMDVI_MMIO_CONTROL);
+    s->enabled = !!(control & AMDVI_MMIO_CONTROL_AMDVIEN);
+
+    s->ats_enabled = !!(control & AMDVI_MMIO_CONTROL_HTTUNEN);
+    s->evtlog_enabled = s->enabled && !!(control &
+                        AMDVI_MMIO_CONTROL_EVENTLOGEN);
+
+    s->evtlog_intr = !!(control & AMDVI_MMIO_CONTROL_EVENTINTEN);
+    s->completion_wait_intr = !!(control & AMDVI_MMIO_CONTROL_COMWAITINTEN);
+    s->cmdbuf_enabled = s->enabled && !!(control &
+                        AMDVI_MMIO_CONTROL_CMDBUFLEN);
+
+    /* update the flags depending on the control register */
+    if (s->cmdbuf_enabled) {
+        amdvi_assign_orq(s, AMDVI_MMIO_STATUS, AMDVI_MMIO_STATUS_CMDBUF_RUN);
+    } else {
+        amdvi_assign_andq(s, AMDVI_MMIO_STATUS, ~AMDVI_MMIO_STATUS_CMDBUF_RUN);
+    }
+    if (s->evtlog_enabled) {
+        amdvi_assign_orq(s, AMDVI_MMIO_STATUS, AMDVI_MMIO_STATUS_EVT_RUN);
+    } else {
+        amdvi_assign_andq(s, AMDVI_MMIO_STATUS, ~AMDVI_MMIO_STATUS_EVT_RUN);
+    }
+
+    trace_amdvi_control_status(control);
+    amdvi_cmdbuf_run(s);
+}
+
+static inline void amdvi_handle_devtab_write(AMDVIState *s)
+
+{
+    uint64_t val = amdvi_readq(s, AMDVI_MMIO_DEVICE_TABLE);
+    s->devtab = (val & AMDVI_MMIO_DEVTAB_BASE_MASK);
+
+    /* set device table length */
+    s->devtab_len = ((val & AMDVI_MMIO_DEVTAB_SIZE_MASK) + 1 *
+                    (AMDVI_MMIO_DEVTAB_SIZE_UNIT /
+                     AMDVI_MMIO_DEVTAB_ENTRY_SIZE));
+}
+
+static inline void amdvi_handle_cmdhead_write(AMDVIState *s)
+{
+    s->cmdbuf_head = amdvi_readq(s, AMDVI_MMIO_COMMAND_HEAD)
+                     & AMDVI_MMIO_CMDBUF_HEAD_MASK;
+    amdvi_cmdbuf_run(s);
+}
+
+static inline void amdvi_handle_cmdbase_write(AMDVIState *s)
+{
+    s->cmdbuf = amdvi_readq(s, AMDVI_MMIO_COMMAND_BASE)
+                & AMDVI_MMIO_CMDBUF_BASE_MASK;
+    s->cmdbuf_len = 1UL << (amdvi_readq(s, AMDVI_MMIO_CMDBUF_SIZE_BYTE)
+                    & AMDVI_MMIO_CMDBUF_SIZE_MASK);
+    s->cmdbuf_head = s->cmdbuf_tail = 0;
+}
+
+static inline void amdvi_handle_cmdtail_write(AMDVIState *s)
+{
+    s->cmdbuf_tail = amdvi_readq(s, AMDVI_MMIO_COMMAND_TAIL)
+                     & AMDVI_MMIO_CMDBUF_TAIL_MASK;
+    amdvi_cmdbuf_run(s);
+}
+
+static inline void amdvi_handle_excllim_write(AMDVIState *s)
+{
+    uint64_t val = amdvi_readq(s, AMDVI_MMIO_EXCL_LIMIT);
+    s->excl_limit = (val & AMDVI_MMIO_EXCL_LIMIT_MASK) |
+                    AMDVI_MMIO_EXCL_LIMIT_LOW;
+}
+
+static inline void amdvi_handle_evtbase_write(AMDVIState *s)
+{
+    uint64_t val = amdvi_readq(s, AMDVI_MMIO_EVENT_BASE);
+    s->evtlog = val & AMDVI_MMIO_EVTLOG_BASE_MASK;
+    s->evtlog_len = 1UL << (amdvi_readq(s, AMDVI_MMIO_EVTLOG_SIZE_BYTE)
+                    & AMDVI_MMIO_EVTLOG_SIZE_MASK);
+}
+
+static inline void amdvi_handle_evttail_write(AMDVIState *s)
+{
+    uint64_t val = amdvi_readq(s, AMDVI_MMIO_EVENT_TAIL);
+    s->evtlog_tail = val & AMDVI_MMIO_EVTLOG_TAIL_MASK;
+}
+
+static inline void amdvi_handle_evthead_write(AMDVIState *s)
+{
+    uint64_t val = amdvi_readq(s, AMDVI_MMIO_EVENT_HEAD);
+    s->evtlog_head = val & AMDVI_MMIO_EVTLOG_HEAD_MASK;
+}
+
+static inline void amdvi_handle_pprbase_write(AMDVIState *s)
+{
+    uint64_t val = amdvi_readq(s, AMDVI_MMIO_PPR_BASE);
+    s->ppr_log = val & AMDVI_MMIO_PPRLOG_BASE_MASK;
+    s->pprlog_len = 1UL << (amdvi_readq(s, AMDVI_MMIO_PPRLOG_SIZE_BYTE)
+                    & AMDVI_MMIO_PPRLOG_SIZE_MASK);
+}
+
+static inline void amdvi_handle_pprhead_write(AMDVIState *s)
+{
+    uint64_t val = amdvi_readq(s, AMDVI_MMIO_PPR_HEAD);
+    s->pprlog_head = val & AMDVI_MMIO_PPRLOG_HEAD_MASK;
+}
+
+static inline void amdvi_handle_pprtail_write(AMDVIState *s)
+{
+    uint64_t val = amdvi_readq(s, AMDVI_MMIO_PPR_TAIL);
+    s->pprlog_tail = val & AMDVI_MMIO_PPRLOG_TAIL_MASK;
+}
+
+/* FIXME: something might go wrong if System Software writes in chunks
+ * of one byte but linux writes in chunks of 4 bytes so currently it
+ * works correctly with linux but will definitely be busted if software
+ * reads/writes 8 bytes
+ */
+static void amdvi_mmio_reg_write(AMDVIState *s, unsigned size, uint64_t val,
+                                 hwaddr addr)
+{
+    if (size == 2) {
+        amdvi_writew(s, addr, val);
+    } else if (size == 4) {
+        amdvi_writel(s, addr, val);
+    } else if (size == 8) {
+        amdvi_writeq(s, addr, val);
+    }
+}
+
+static void amdvi_mmio_write(void *opaque, hwaddr addr, uint64_t val,
+                             unsigned size)
+{
+    AMDVIState *s = opaque;
+    unsigned long offset = addr & 0x07;
+
+    if (addr + size > AMDVI_MMIO_SIZE) {
+        trace_amdvi_mmio_write("error: addr outside region: max ",
+                (uint64_t)AMDVI_MMIO_SIZE, size, val, offset);
+        return;
+    }
+
+    amdvi_mmio_trace(addr, size);
+    switch (addr & ~0x07) {
+    case AMDVI_MMIO_CONTROL:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_control_write(s);
+        break;
+    case AMDVI_MMIO_DEVICE_TABLE:
+        amdvi_mmio_reg_write(s, size, val, addr);
+       /*  set device table address
+        *   This also suffers from inability to tell whether software
+        *   is done writing
+        */
+        if (offset || (size == 8)) {
+            amdvi_handle_devtab_write(s);
+        }
+        break;
+    case AMDVI_MMIO_COMMAND_HEAD:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_cmdhead_write(s);
+        break;
+    case AMDVI_MMIO_COMMAND_BASE:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        /* FIXME - make sure System Software has finished writing incase
+         * it writes in chucks less than 8 bytes in a robust way.As for
+         * now, this hacks works for the linux driver
+         */
+        if (offset || (size == 8)) {
+            amdvi_handle_cmdbase_write(s);
+        }
+        break;
+    case AMDVI_MMIO_COMMAND_TAIL:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_cmdtail_write(s);
+        break;
+    case AMDVI_MMIO_EVENT_BASE:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_evtbase_write(s);
+        break;
+    case AMDVI_MMIO_EVENT_HEAD:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_evthead_write(s);
+        break;
+    case AMDVI_MMIO_EVENT_TAIL:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_evttail_write(s);
+        break;
+    case AMDVI_MMIO_EXCL_LIMIT:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_excllim_write(s);
+        break;
+        /* PPR log base - unused for now */
+    case AMDVI_MMIO_PPR_BASE:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_pprbase_write(s);
+        break;
+        /* PPR log head - also unused for now */
+    case AMDVI_MMIO_PPR_HEAD:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_pprhead_write(s);
+        break;
+        /* PPR log tail - unused for now */
+    case AMDVI_MMIO_PPR_TAIL:
+        amdvi_mmio_reg_write(s, size, val, addr);
+        amdvi_handle_pprtail_write(s);
+        break;
+    }
+}
+
+static inline uint64_t amdvi_get_perms(uint64_t entry)
+{
+    return (entry & (AMDVI_DEV_PERM_READ | AMDVI_DEV_PERM_WRITE)) >>
+           AMDVI_DEV_PERM_SHIFT;
+}
+
+/* a valid entry should have V = 1 and reserved bits honoured */
+static bool amdvi_validate_dte(AMDVIState *s, uint16_t devid,
+                               uint64_t *dte)
+{
+    if ((dte[0] & AMDVI_DTE_LOWER_QUAD_RESERVED)
+        || (dte[1] & AMDVI_DTE_MIDDLE_QUAD_RESERVED)
+        || (dte[2] & AMDVI_DTE_UPPER_QUAD_RESERVED) || dte[3]) {
+        amdvi_log_illegaldevtab_error(s, devid,
+                                      s->devtab +
+                                      devid * AMDVI_DEVTAB_ENTRY_SIZE, 0);
+        return false;
+    }
+
+    return dte[0] & AMDVI_DEV_VALID;
+}
+
+/* get a device table entry given the devid */
+static bool amdvi_get_dte(AMDVIState *s, int devid, uint64_t *entry)
+{
+    uint32_t offset = devid * AMDVI_DEVTAB_ENTRY_SIZE;
+
+    if (dma_memory_read(&address_space_memory, s->devtab + offset, entry,
+        AMDVI_DEVTAB_ENTRY_SIZE)) {
+        trace_amdvi_dte_get_fail(s->devtab, offset);
+        /* log error accessing dte */
+        amdvi_log_devtab_error(s, devid, s->devtab + offset, 0);
+        return false;
+    }
+
+    *entry = le64_to_cpu(*entry);
+    if (!amdvi_validate_dte(s, devid, entry)) {
+        trace_amdvi_invalid_dte(entry[0]);
+        return false;
+    }
+
+    return true;
+}
+
+/* get pte translation mode */
+static inline uint8_t get_pte_translation_mode(uint64_t pte)
+{
+    return (pte >> AMDVI_DEV_MODE_RSHIFT) & AMDVI_DEV_MODE_MASK;
+}
+
+static inline uint64_t pte_override_page_mask(uint64_t pte)
+{
+    uint8_t page_mask = 12;
+    uint64_t addr = (pte & AMDVI_DEV_PT_ROOT_MASK) ^ AMDVI_DEV_PT_ROOT_MASK;
+    /* find the first zero bit */
+    while (addr & 1) {
+        page_mask++;
+        addr = addr >> 1;
+    }
+
+    return ~((1ULL << page_mask) - 1);
+}
+
+static inline uint64_t pte_get_page_mask(uint64_t oldlevel)
+{
+    return ~((1UL << ((oldlevel * 9) + 3)) - 1);
+}
+
+static inline uint64_t amdvi_get_pte_entry(AMDVIState *s, uint64_t pte_addr,
+                                          uint16_t devid)
+{
+    uint64_t pte;
+
+    if (dma_memory_read(&address_space_memory, pte_addr, &pte, sizeof(pte))) {
+        trace_amdvi_get_pte_hwerror(pte_addr);
+        amdvi_log_pagetab_error(s, devid, pte_addr, 0);
+        pte = 0;
+        return pte;
+    }
+
+    pte = le64_to_cpu(pte);
+    return pte;
+}
+
+static void amdvi_page_walk(AMDVIAddressSpace *as, uint64_t *dte,
+                            IOMMUTLBEntry *ret, unsigned perms,
+                            hwaddr addr)
+{
+    unsigned level, present, pte_perms, oldlevel;
+    uint64_t pte = dte[0], pte_addr, page_mask;
+
+    /* make sure the DTE has TV = 1 */
+    if (pte & AMDVI_DEV_TRANSLATION_VALID) {
+        level = get_pte_translation_mode(pte);
+        if (level >= 7) {
+            trace_amdvi_mode_invalid(level, addr);
+            return;
+        }
+        if (level == 0) {
+            goto no_remap;
+        }
+
+        /* we are at the leaf page table or page table encodes a huge page */
+        while (level > 0) {
+            pte_perms = amdvi_get_perms(pte);
+            present = pte & 1;
+            if (!present || perms != (perms & pte_perms)) {
+                amdvi_page_fault(as->iommu_state, as->devfn, addr, perms);
+                trace_amdvi_page_fault(addr);
+                return;
+            }
+
+            /* go to the next lower level */
+            pte_addr = pte & AMDVI_DEV_PT_ROOT_MASK;
+            /* add offset and load pte */
+            pte_addr += ((addr >> (3 + 9 * level)) & 0x1FF) << 3;
+            pte = amdvi_get_pte_entry(as->iommu_state, pte_addr, as->devfn);
+            if (!pte) {
+                return;
+            }
+            oldlevel = level;
+            level = get_pte_translation_mode(pte);
+            if (level == 0x7) {
+                break;
+            }
+        }
+
+        if (level == 0x7) {
+            page_mask = pte_override_page_mask(pte);
+        } else {
+            page_mask = pte_get_page_mask(oldlevel);
+        }
+
+        /* get access permissions from pte */
+        ret->iova = addr & page_mask;
+        ret->translated_addr = (pte & AMDVI_DEV_PT_ROOT_MASK) & page_mask;
+        ret->addr_mask = ~page_mask;
+        ret->perm = amdvi_get_perms(pte);
+        return;
+    }
+no_remap:
+    ret->iova = addr & AMDVI_PAGE_MASK_4K;
+    ret->translated_addr = addr & AMDVI_PAGE_MASK_4K;
+    ret->addr_mask = ~AMDVI_PAGE_MASK_4K;
+    ret->perm = amdvi_get_perms(pte);
+}
+
+static void amdvi_do_translate(AMDVIAddressSpace *as, hwaddr addr,
+                               bool is_write, IOMMUTLBEntry *ret)
+{
+    AMDVIState *s = as->iommu_state;
+    uint16_t devid = PCI_BUILD_BDF(as->bus_num, as->devfn);
+    AMDVIIOTLBEntry *iotlb_entry = amdvi_iotlb_lookup(s, addr, devid);
+    uint64_t entry[4];
+
+    if (iotlb_entry) {
+        trace_amdvi_iotlb_hit(PCI_BUS_NUM(devid), PCI_SLOT(devid),
+                PCI_FUNC(devid), addr, iotlb_entry->translated_addr);
+        ret->iova = addr & ~iotlb_entry->page_mask;
+        ret->translated_addr = iotlb_entry->translated_addr;
+        ret->addr_mask = iotlb_entry->page_mask;
+        ret->perm = iotlb_entry->perms;
+        return;
+    }
+
+    /* devices with V = 0 are not translated */
+    if (!amdvi_get_dte(s, devid, entry)) {
+        goto out;
+    }
+
+    amdvi_page_walk(as, entry, ret,
+                    is_write ? AMDVI_PERM_WRITE : AMDVI_PERM_READ, addr);
+
+    amdvi_update_iotlb(s, devid, addr, *ret,
+                       entry[1] & AMDVI_DEV_DOMID_ID_MASK);
+    return;
+
+out:
+    ret->iova = addr & AMDVI_PAGE_MASK_4K;
+    ret->translated_addr = addr & AMDVI_PAGE_MASK_4K;
+    ret->addr_mask = ~AMDVI_PAGE_MASK_4K;
+    ret->perm = IOMMU_RW;
+}
+
+static inline bool amdvi_is_interrupt_addr(hwaddr addr)
+{
+    return addr >= AMDVI_INT_ADDR_FIRST && addr <= AMDVI_INT_ADDR_LAST;
+}
+
+static IOMMUTLBEntry amdvi_translate(MemoryRegion *iommu, hwaddr addr,
+                                     bool is_write)
+{
+    AMDVIAddressSpace *as = container_of(iommu, AMDVIAddressSpace, iommu);
+    AMDVIState *s = as->iommu_state;
+    IOMMUTLBEntry ret = {
+        .target_as = &address_space_memory,
+        .iova = addr,
+        .translated_addr = 0,
+        .addr_mask = ~(hwaddr)0,
+        .perm = IOMMU_NONE
+    };
+
+    if (!s->enabled) {
+        /* AMDVI disabled - corresponds to iommu=off not
+         * failure to provide any parameter
+         */
+        ret.iova = addr & AMDVI_PAGE_MASK_4K;
+        ret.translated_addr = addr & AMDVI_PAGE_MASK_4K;
+        ret.addr_mask = ~AMDVI_PAGE_MASK_4K;
+        ret.perm = IOMMU_RW;
+        return ret;
+    } else if (amdvi_is_interrupt_addr(addr)) {
+        ret.iova = addr & AMDVI_PAGE_MASK_4K;
+        ret.translated_addr = addr & AMDVI_PAGE_MASK_4K;
+        ret.addr_mask = ~AMDVI_PAGE_MASK_4K;
+        ret.perm = IOMMU_WO;
+        return ret;
+    }
+
+    amdvi_do_translate(as, addr, is_write, &ret);
+    trace_amdvi_translation_result(as->bus_num, PCI_SLOT(as->devfn),
+            PCI_FUNC(as->devfn), addr, ret.translated_addr);
+    return ret;
+}
+
+static AddressSpace *amdvi_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
+{
+    AMDVIState *s = opaque;
+    AMDVIAddressSpace **iommu_as;
+    int bus_num = pci_bus_num(bus);
+
+    iommu_as = s->address_spaces[bus_num];
+
+    /* allocate memory during the first run */
+    if (!iommu_as) {
+        iommu_as = g_malloc0(sizeof(AMDVIAddressSpace *) * PCI_DEVFN_MAX);
+        s->address_spaces[bus_num] = iommu_as;
+    }
+
+    /* set up AMD-Vi region */
+    if (!iommu_as[devfn]) {
+        iommu_as[devfn] = g_malloc0(sizeof(AMDVIAddressSpace));
+        iommu_as[devfn]->bus_num = (uint8_t)bus_num;
+        iommu_as[devfn]->devfn = (uint8_t)devfn;
+        iommu_as[devfn]->iommu_state = s;
+
+        memory_region_init_iommu(&iommu_as[devfn]->iommu, OBJECT(s),
+                                 &s->iommu_ops, "amd-iommu", UINT64_MAX);
+        address_space_init(&iommu_as[devfn]->as, &iommu_as[devfn]->iommu,
+                           "amd-iommu");
+    }
+    return &iommu_as[devfn]->as;
+}
+
+static const MemoryRegionOps mmio_mem_ops = {
+    .read = amdvi_mmio_read,
+    .write = amdvi_mmio_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .impl = {
+        .min_access_size = 1,
+        .max_access_size = 8,
+        .unaligned = false,
+    },
+    .valid = {
+        .min_access_size = 1,
+        .max_access_size = 8,
+    }
+};
+
+static void amdvi_iommu_notify_started(MemoryRegion *iommu)
+{
+    AMDVIAddressSpace *as = container_of(iommu, AMDVIAddressSpace, iommu);
+
+    hw_error("device %02x.%02x.%x requires iommu notifier which is not "
+             "currently supported", as->bus_num, PCI_SLOT(as->devfn),
+             PCI_FUNC(as->devfn));
+}
+
+static void amdvi_init(AMDVIState *s)
+{
+    amdvi_iotlb_reset(s);
+
+    s->iommu_ops.translate = amdvi_translate;
+    s->iommu_ops.notify_started = amdvi_iommu_notify_started;
+    s->devtab_len = 0;
+    s->cmdbuf_len = 0;
+    s->cmdbuf_head = 0;
+    s->cmdbuf_tail = 0;
+    s->evtlog_head = 0;
+    s->evtlog_tail = 0;
+    s->excl_enabled = false;
+    s->excl_allow = false;
+    s->mmio_enabled = false;
+    s->enabled = false;
+    s->ats_enabled = false;
+    s->cmdbuf_enabled = false;
+
+    /* reset MMIO */
+    memset(s->mmior, 0, AMDVI_MMIO_SIZE);
+    amdvi_set_quad(s, AMDVI_MMIO_EXT_FEATURES, AMDVI_EXT_FEATURES,
+            0xffffffffffffffef, 0);
+    amdvi_set_quad(s, AMDVI_MMIO_STATUS, 0, 0x98, 0x67);
+
+    /* reset device ident */
+    pci_config_set_vendor_id(s->pci.dev.config, PCI_VENDOR_ID_AMD);
+    pci_config_set_prog_interface(s->pci.dev.config, 00);
+    pci_config_set_device_id(s->pci.dev.config, s->devid);
+    pci_config_set_class(s->pci.dev.config, 0x0806);
+
+    /* reset AMDVI specific capabilities, all r/o */
+    pci_set_long(s->pci.dev.config + s->capab_offset, AMDVI_CAPAB_FEATURES);
+    pci_set_long(s->pci.dev.config + s->capab_offset + AMDVI_CAPAB_BAR_LOW,
+                 s->mmio.addr & ~(0xffff0000));
+    pci_set_long(s->pci.dev.config + s->capab_offset + AMDVI_CAPAB_BAR_HIGH,
+                (s->mmio.addr & ~(0xffff)) >> 16);
+    pci_set_long(s->pci.dev.config + s->capab_offset + AMDVI_CAPAB_RANGE,
+                 0xff000000);
+    pci_set_long(s->pci.dev.config + s->capab_offset + AMDVI_CAPAB_MISC, 0);
+    pci_set_long(s->pci.dev.config + s->capab_offset + AMDVI_CAPAB_MISC,
+            AMDVI_MAX_PH_ADDR | AMDVI_MAX_GVA_ADDR | AMDVI_MAX_VA_ADDR);
+}
+
+static void amdvi_reset(DeviceState *dev)
+{
+    AMDVIState *s = AMD_IOMMU_DEVICE(dev);
+
+    msi_reset(&s->pci.dev);
+    amdvi_init(s);
+}
+
+static void amdvi_realize(DeviceState *dev, Error **err)
+{
+    AMDVIState *s = AMD_IOMMU_DEVICE(dev);
+    PCIBus *bus = PC_MACHINE(qdev_get_machine())->bus;
+    s->iotlb = g_hash_table_new_full(amdvi_uint64_hash,
+                                     amdvi_uint64_equal, g_free, g_free);
+
+    /* This device should take care of IOMMU PCI properties */
+    qdev_set_parent_bus(DEVICE(&s->pci), &bus->qbus);
+    object_property_set_bool(OBJECT(&s->pci), true, "realized", err);
+    s->capab_offset = pci_add_capability(&s->pci.dev, AMDVI_CAPAB_ID_SEC, 0,
+                                         AMDVI_CAPAB_SIZE);
+    pci_add_capability(&s->pci.dev, PCI_CAP_ID_MSI, 0, AMDVI_CAPAB_REG_SIZE);
+    pci_add_capability(&s->pci.dev, PCI_CAP_ID_HT, 0, AMDVI_CAPAB_REG_SIZE);
+
+    /* set up MMIO */
+    memory_region_init_io(&s->mmio, OBJECT(s), &mmio_mem_ops, s, "amdvi-mmio",
+                          AMDVI_MMIO_SIZE);
+
+    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->mmio);
+    sysbus_mmio_map(SYS_BUS_DEVICE(s), 0, AMDVI_BASE_ADDR);
+    pci_setup_iommu(bus, amdvi_host_dma_iommu, s);
+    s->devid = object_property_get_int(OBJECT(&s->pci), "addr", err);
+    msi_init(&s->pci.dev, 0, 1, true, false, err);
+    amdvi_init(s);
+}
+
+static const VMStateDescription vmstate_amdvi = {
+    .name = "amd-iommu",
+    .unmigratable = 1
+};
+
+static void amdvi_instance_init(Object *klass)
+{
+    AMDVIState *s = AMD_IOMMU_DEVICE(klass);
+
+    object_initialize(&s->pci, sizeof(s->pci), TYPE_AMD_IOMMU_PCI);
+}
+
+static void amdvi_class_init(ObjectClass *klass, void* data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    X86IOMMUClass *dc_class = X86_IOMMU_CLASS(klass);
+
+    dc->reset = amdvi_reset;
+    dc->vmsd = &vmstate_amdvi;
+    dc->hotpluggable = false;
+    dc_class->realize = amdvi_realize;
+}
+
+static const TypeInfo amdvi = {
+    .name = TYPE_AMD_IOMMU_DEVICE,
+    .parent = TYPE_X86_IOMMU_DEVICE,
+    .instance_size = sizeof(AMDVIState),
+    .instance_init = amdvi_instance_init,
+    .class_init = amdvi_class_init
+};
+
+static const TypeInfo amdviPCI = {
+    .name = "AMDVI-PCI",
+    .parent = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(AMDVIPCIState),
+};
+
+static void amdviPCI_register_types(void)
+{
+    type_register_static(&amdviPCI);
+    type_register_static(&amdvi);
+}
+
+type_init(amdviPCI_register_types);
diff --git a/hw/i386/amd_iommu.h b/hw/i386/amd_iommu.h
new file mode 100644
index 0000000000..884926e9e7
--- /dev/null
+++ b/hw/i386/amd_iommu.h
@@ -0,0 +1,289 @@
+/*
+ * QEMU emulation of an AMD IOMMU (AMD-Vi)
+ *
+ * Copyright (C) 2011 Eduard - Gabriel Munteanu
+ * Copyright (C) 2015 David Kiarie, <davidkiarie4@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/>.
+ */
+
+#ifndef AMD_IOMMU_H_
+#define AMD_IOMMU_H_
+
+#include "hw/hw.h"
+#include "hw/pci/pci.h"
+#include "hw/pci/msi.h"
+#include "hw/sysbus.h"
+#include "sysemu/dma.h"
+#include "hw/i386/pc.h"
+#include "hw/pci/pci_bus.h"
+#include "hw/i386/x86-iommu.h"
+
+/* Capability registers */
+#define AMDVI_CAPAB_BAR_LOW           0x04
+#define AMDVI_CAPAB_BAR_HIGH          0x08
+#define AMDVI_CAPAB_RANGE             0x0C
+#define AMDVI_CAPAB_MISC              0x10
+
+#define AMDVI_CAPAB_SIZE              0x18
+#define AMDVI_CAPAB_REG_SIZE          0x04
+
+/* Capability header data */
+#define AMDVI_CAPAB_ID_SEC            0xf
+#define AMDVI_CAPAB_FLAT_EXT          (1 << 28)
+#define AMDVI_CAPAB_EFR_SUP           (1 << 27)
+#define AMDVI_CAPAB_FLAG_NPCACHE      (1 << 26)
+#define AMDVI_CAPAB_FLAG_HTTUNNEL     (1 << 25)
+#define AMDVI_CAPAB_FLAG_IOTLBSUP     (1 << 24)
+#define AMDVI_CAPAB_INIT_TYPE         (3 << 16)
+
+/* No. of used MMIO registers */
+#define AMDVI_MMIO_REGS_HIGH  8
+#define AMDVI_MMIO_REGS_LOW   7
+
+/* MMIO registers */
+#define AMDVI_MMIO_DEVICE_TABLE       0x0000
+#define AMDVI_MMIO_COMMAND_BASE       0x0008
+#define AMDVI_MMIO_EVENT_BASE         0x0010
+#define AMDVI_MMIO_CONTROL            0x0018
+#define AMDVI_MMIO_EXCL_BASE          0x0020
+#define AMDVI_MMIO_EXCL_LIMIT         0x0028
+#define AMDVI_MMIO_EXT_FEATURES       0x0030
+#define AMDVI_MMIO_COMMAND_HEAD       0x2000
+#define AMDVI_MMIO_COMMAND_TAIL       0x2008
+#define AMDVI_MMIO_EVENT_HEAD         0x2010
+#define AMDVI_MMIO_EVENT_TAIL         0x2018
+#define AMDVI_MMIO_STATUS             0x2020
+#define AMDVI_MMIO_PPR_BASE           0x0038
+#define AMDVI_MMIO_PPR_HEAD           0x2030
+#define AMDVI_MMIO_PPR_TAIL           0x2038
+
+#define AMDVI_MMIO_SIZE               0x4000
+
+#define AMDVI_MMIO_DEVTAB_SIZE_MASK   ((1ULL << 12) - 1)
+#define AMDVI_MMIO_DEVTAB_BASE_MASK   (((1ULL << 52) - 1) & ~ \
+                                       AMDVI_MMIO_DEVTAB_SIZE_MASK)
+#define AMDVI_MMIO_DEVTAB_ENTRY_SIZE  32
+#define AMDVI_MMIO_DEVTAB_SIZE_UNIT   4096
+
+/* some of this are similar but just for readability */
+#define AMDVI_MMIO_CMDBUF_SIZE_BYTE       (AMDVI_MMIO_COMMAND_BASE + 7)
+#define AMDVI_MMIO_CMDBUF_SIZE_MASK       0x0f
+#define AMDVI_MMIO_CMDBUF_BASE_MASK       AMDVI_MMIO_DEVTAB_BASE_MASK
+#define AMDVI_MMIO_CMDBUF_HEAD_MASK       (((1ULL << 19) - 1) & ~0x0f)
+#define AMDVI_MMIO_CMDBUF_TAIL_MASK       AMDVI_MMIO_EVTLOG_HEAD_MASK
+
+#define AMDVI_MMIO_EVTLOG_SIZE_BYTE       (AMDVI_MMIO_EVENT_BASE + 7)
+#define AMDVI_MMIO_EVTLOG_SIZE_MASK       AMDVI_MMIO_CMDBUF_SIZE_MASK
+#define AMDVI_MMIO_EVTLOG_BASE_MASK       AMDVI_MMIO_CMDBUF_BASE_MASK
+#define AMDVI_MMIO_EVTLOG_HEAD_MASK       (((1ULL << 19) - 1) & ~0x0f)
+#define AMDVI_MMIO_EVTLOG_TAIL_MASK       AMDVI_MMIO_EVTLOG_HEAD_MASK
+
+#define AMDVI_MMIO_PPRLOG_SIZE_BYTE       (AMDVI_MMIO_EVENT_BASE + 7)
+#define AMDVI_MMIO_PPRLOG_HEAD_MASK       AMDVI_MMIO_EVTLOG_HEAD_MASK
+#define AMDVI_MMIO_PPRLOG_TAIL_MASK       AMDVI_MMIO_EVTLOG_HEAD_MASK
+#define AMDVI_MMIO_PPRLOG_BASE_MASK       AMDVI_MMIO_EVTLOG_BASE_MASK
+#define AMDVI_MMIO_PPRLOG_SIZE_MASK       AMDVI_MMIO_EVTLOG_SIZE_MASK
+
+#define AMDVI_MMIO_EXCL_ENABLED_MASK      (1ULL << 0)
+#define AMDVI_MMIO_EXCL_ALLOW_MASK        (1ULL << 1)
+#define AMDVI_MMIO_EXCL_LIMIT_MASK        AMDVI_MMIO_DEVTAB_BASE_MASK
+#define AMDVI_MMIO_EXCL_LIMIT_LOW         0xfff
+
+/* mmio control register flags */
+#define AMDVI_MMIO_CONTROL_AMDVIEN        (1ULL << 0)
+#define AMDVI_MMIO_CONTROL_HTTUNEN        (1ULL << 1)
+#define AMDVI_MMIO_CONTROL_EVENTLOGEN     (1ULL << 2)
+#define AMDVI_MMIO_CONTROL_EVENTINTEN     (1ULL << 3)
+#define AMDVI_MMIO_CONTROL_COMWAITINTEN   (1ULL << 4)
+#define AMDVI_MMIO_CONTROL_CMDBUFLEN      (1ULL << 12)
+
+/* MMIO status register bits */
+#define AMDVI_MMIO_STATUS_CMDBUF_RUN  (1 << 4)
+#define AMDVI_MMIO_STATUS_EVT_RUN     (1 << 3)
+#define AMDVI_MMIO_STATUS_COMP_INT    (1 << 2)
+#define AMDVI_MMIO_STATUS_EVT_OVF     (1 << 0)
+
+#define AMDVI_CMDBUF_ID_BYTE              0x07
+#define AMDVI_CMDBUF_ID_RSHIFT            4
+
+#define AMDVI_CMD_COMPLETION_WAIT         0x01
+#define AMDVI_CMD_INVAL_DEVTAB_ENTRY      0x02
+#define AMDVI_CMD_INVAL_AMDVI_PAGES       0x03
+#define AMDVI_CMD_INVAL_IOTLB_PAGES       0x04
+#define AMDVI_CMD_INVAL_INTR_TABLE        0x05
+#define AMDVI_CMD_PREFETCH_AMDVI_PAGES    0x06
+#define AMDVI_CMD_COMPLETE_PPR_REQUEST    0x07
+#define AMDVI_CMD_INVAL_AMDVI_ALL         0x08
+
+#define AMDVI_DEVTAB_ENTRY_SIZE           32
+
+/* Device table entry bits 0:63 */
+#define AMDVI_DEV_VALID                   (1ULL << 0)
+#define AMDVI_DEV_TRANSLATION_VALID       (1ULL << 1)
+#define AMDVI_DEV_MODE_MASK               0x7
+#define AMDVI_DEV_MODE_RSHIFT             9
+#define AMDVI_DEV_PT_ROOT_MASK            0xffffffffff000
+#define AMDVI_DEV_PT_ROOT_RSHIFT          12
+#define AMDVI_DEV_PERM_SHIFT              61
+#define AMDVI_DEV_PERM_READ               (1ULL << 61)
+#define AMDVI_DEV_PERM_WRITE              (1ULL << 62)
+
+/* Device table entry bits 64:127 */
+#define AMDVI_DEV_DOMID_ID_MASK          ((1ULL << 16) - 1)
+
+/* Event codes and flags, as stored in the info field */
+#define AMDVI_EVENT_ILLEGAL_DEVTAB_ENTRY  (0x1U << 12)
+#define AMDVI_EVENT_IOPF                  (0x2U << 12)
+#define   AMDVI_EVENT_IOPF_I              (1U << 3)
+#define AMDVI_EVENT_DEV_TAB_HW_ERROR      (0x3U << 12)
+#define AMDVI_EVENT_PAGE_TAB_HW_ERROR     (0x4U << 12)
+#define AMDVI_EVENT_ILLEGAL_COMMAND_ERROR (0x5U << 12)
+#define AMDVI_EVENT_COMMAND_HW_ERROR      (0x6U << 12)
+
+#define AMDVI_EVENT_LEN                  16
+#define AMDVI_PERM_READ             (1 << 0)
+#define AMDVI_PERM_WRITE            (1 << 1)
+
+#define AMDVI_FEATURE_PREFETCH            (1ULL << 0) /* page prefetch       */
+#define AMDVI_FEATURE_PPR                 (1ULL << 1) /* PPR Support         */
+#define AMDVI_FEATURE_GT                  (1ULL << 4) /* Guest Translation   */
+#define AMDVI_FEATURE_IA                  (1ULL << 6) /* inval all support   */
+#define AMDVI_FEATURE_GA                  (1ULL << 7) /* guest VAPIC support */
+#define AMDVI_FEATURE_HE                  (1ULL << 8) /* hardware error regs */
+#define AMDVI_FEATURE_PC                  (1ULL << 9) /* Perf counters       */
+
+/* reserved DTE bits */
+#define AMDVI_DTE_LOWER_QUAD_RESERVED  0x80300000000000fc
+#define AMDVI_DTE_MIDDLE_QUAD_RESERVED 0x0000000000000100
+#define AMDVI_DTE_UPPER_QUAD_RESERVED  0x08f0000000000000
+
+/* AMDVI paging mode */
+#define AMDVI_GATS_MODE                 (6ULL <<  12)
+#define AMDVI_HATS_MODE                 (6ULL <<  10)
+
+/* IOTLB */
+#define AMDVI_IOTLB_MAX_SIZE 1024
+#define AMDVI_DEVID_SHIFT    36
+
+/* extended feature support */
+#define AMDVI_EXT_FEATURES (AMDVI_FEATURE_PREFETCH | AMDVI_FEATURE_PPR | \
+        AMDVI_FEATURE_IA | AMDVI_FEATURE_GT | AMDVI_FEATURE_HE | \
+        AMDVI_GATS_MODE | AMDVI_HATS_MODE)
+
+/* capabilities header */
+#define AMDVI_CAPAB_FEATURES (AMDVI_CAPAB_FLAT_EXT | \
+        AMDVI_CAPAB_FLAG_NPCACHE | AMDVI_CAPAB_FLAG_IOTLBSUP \
+        | AMDVI_CAPAB_ID_SEC | AMDVI_CAPAB_INIT_TYPE | \
+        AMDVI_CAPAB_FLAG_HTTUNNEL |  AMDVI_CAPAB_EFR_SUP)
+
+/* AMDVI default address */
+#define AMDVI_BASE_ADDR 0xfed80000
+
+/* page management constants */
+#define AMDVI_PAGE_SHIFT 12
+#define AMDVI_PAGE_SIZE  (1ULL << AMDVI_PAGE_SHIFT)
+
+#define AMDVI_PAGE_SHIFT_4K 12
+#define AMDVI_PAGE_MASK_4K  (~((1ULL << AMDVI_PAGE_SHIFT_4K) - 1))
+
+#define AMDVI_MAX_VA_ADDR          (48UL << 5)
+#define AMDVI_MAX_PH_ADDR          (40UL << 8)
+#define AMDVI_MAX_GVA_ADDR         (48UL << 15)
+
+/* Completion Wait data size */
+#define AMDVI_COMPLETION_DATA_SIZE    8
+
+#define AMDVI_COMMAND_SIZE   16
+/* Completion Wait data size */
+#define AMDVI_COMPLETION_DATA_SIZE    8
+
+#define AMDVI_COMMAND_SIZE   16
+
+#define AMDVI_INT_ADDR_FIRST 0xfee00000
+#define AMDVI_INT_ADDR_LAST  0xfeefffff
+
+#define TYPE_AMD_IOMMU_DEVICE "amd-iommu"
+#define AMD_IOMMU_DEVICE(obj)\
+    OBJECT_CHECK(AMDVIState, (obj), TYPE_AMD_IOMMU_DEVICE)
+
+#define TYPE_AMD_IOMMU_PCI "AMDVI-PCI"
+
+typedef struct AMDVIAddressSpace AMDVIAddressSpace;
+
+/* functions to steal PCI config space */
+typedef struct AMDVIPCIState {
+    PCIDevice dev;               /* The PCI device itself        */
+} AMDVIPCIState;
+
+typedef struct AMDVIState {
+    X86IOMMUState iommu;        /* IOMMU bus device             */
+    AMDVIPCIState pci;          /* IOMMU PCI device             */
+
+    uint32_t version;
+    uint32_t capab_offset;       /* capability offset pointer    */
+
+    uint64_t mmio_addr;
+
+    uint32_t devid;              /* auto-assigned devid          */
+
+    bool enabled;                /* IOMMU enabled                */
+    bool ats_enabled;            /* address translation enabled  */
+    bool cmdbuf_enabled;         /* command buffer enabled       */
+    bool evtlog_enabled;         /* event log enabled            */
+    bool excl_enabled;
+
+    hwaddr devtab;               /* base address device table    */
+    size_t devtab_len;           /* device table length          */
+
+    hwaddr cmdbuf;               /* command buffer base address  */
+    uint64_t cmdbuf_len;         /* command buffer length        */
+    uint32_t cmdbuf_head;        /* current IOMMU read position  */
+    uint32_t cmdbuf_tail;        /* next Software write position */
+    bool completion_wait_intr;
+
+    hwaddr evtlog;               /* base address event log       */
+    bool evtlog_intr;
+    uint32_t evtlog_len;         /* event log length             */
+    uint32_t evtlog_head;        /* current IOMMU write position */
+    uint32_t evtlog_tail;        /* current Software read position */
+
+    /* unused for now */
+    hwaddr excl_base;            /* base DVA - IOMMU exclusion range */
+    hwaddr excl_limit;           /* limit of IOMMU exclusion range   */
+    bool excl_allow;             /* translate accesses to the exclusion range */
+    bool excl_enable;            /* exclusion range enabled          */
+
+    hwaddr ppr_log;              /* base address ppr log */
+    uint32_t pprlog_len;         /* ppr log len  */
+    uint32_t pprlog_head;        /* ppr log head */
+    uint32_t pprlog_tail;        /* ppr log tail */
+
+    MemoryRegion mmio;                 /* MMIO region                  */
+    uint8_t mmior[AMDVI_MMIO_SIZE];    /* read/write MMIO              */
+    uint8_t w1cmask[AMDVI_MMIO_SIZE];  /* read/write 1 clear mask      */
+    uint8_t romask[AMDVI_MMIO_SIZE];   /* MMIO read/only mask          */
+    bool mmio_enabled;
+
+    /* IOMMU function */
+    MemoryRegionIOMMUOps iommu_ops;
+
+    /* for each served device */
+    AMDVIAddressSpace **address_spaces[PCI_BUS_MAX];
+
+    /* IOTLB */
+    GHashTable *iotlb;
+} AMDVIState;
+
+#endif