vfio: vfio-pci device assignment driver

This adds the core of the QEMU VFIO-based PCI device assignment driver.
To make use of this driver, enable CONFIG_VFIO, CONFIG_VFIO_IOMMU_TYPE1,
and CONFIG_VFIO_PCI in your host Linux kernel config.  Load the vfio-pci
module.  To assign device 0000:05:00.0 to a guest, do the following:

for dev in $(ls /sys/bus/pci/devices/0000:05:00.0/iommu_group/devices); do
    vendor=$(cat /sys/bus/pci/devices/$dev/vendor)
    device=$(cat /sys/bus/pci/devices/$dev/device)
    if [ -e /sys/bus/pci/devices/$dev/driver ]; then
        echo $dev > /sys/bus/pci/devices/$dev/driver/unbind
    fi
    echo $vendor $device > /sys/bus/pci/drivers/vfio-pci/new_id
done

See Documentation/vfio.txt in the Linux kernel tree for further
description of IOMMU groups and VFIO.

Then launch qemu including the option:

-device vfio-pci,host=0000:05:00.0

Legacy PCI interrupts (INTx) currently makes use of a kludge where we
trap BAR accesses and assume the access is in response to an interrupt,
therefore de-asserting and unmasking the interrupt.  It's not quite as
targetted as using the EOI for this, but it's self contained and seems
to work across all architectures.  The side-effect is a significant
performance slow-down for device in INTx mode.  Some devices, like
graphics cards, don't really use their interrupt, so this can be turned
off with the x-intx=off option, which disables INTx alltogether.  This
should be considered an experimental option until we refine this code.
Both MSI and MSI-X are supported and avoid these issues.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

2 files changed, 1978 insertions, 0 deletions

diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
new file mode 100644
index 000000000..a24558aaa
--- /dev/null
+++ b/hw/vfio_pci.c
@@ -0,0 +1,1864 @@
+/*
+ * vfio based device assignment support
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Authors:
+ *  Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ * Based on qemu-kvm device-assignment:
+ *  Adapted for KVM by Qumranet.
+ *  Copyright (c) 2007, Neocleus, Alex Novik (alex@neocleus.com)
+ *  Copyright (c) 2007, Neocleus, Guy Zana (guy@neocleus.com)
+ *  Copyright (C) 2008, Qumranet, Amit Shah (amit.shah@qumranet.com)
+ *  Copyright (C) 2008, Red Hat, Amit Shah (amit.shah@redhat.com)
+ *  Copyright (C) 2008, IBM, Muli Ben-Yehuda (muli@il.ibm.com)
+ */
+
+#include <dirent.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <linux/vfio.h>
+
+#include "config.h"
+#include "event_notifier.h"
+#include "exec-memory.h"
+#include "kvm.h"
+#include "memory.h"
+#include "msi.h"
+#include "msix.h"
+#include "qemu-error.h"
+#include "range.h"
+#include "vfio_pci_int.h"
+
+/* #define DEBUG_VFIO */
+#ifdef DEBUG_VFIO
+#define DPRINTF(fmt, ...) \
+    do { fprintf(stderr, "vfio: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define DPRINTF(fmt, ...) \
+    do { } while (0)
+#endif
+
+#define MSIX_CAP_LENGTH 12
+
+static QLIST_HEAD(, VFIOContainer)
+    container_list = QLIST_HEAD_INITIALIZER(container_list);
+
+static QLIST_HEAD(, VFIOGroup)
+    group_list = QLIST_HEAD_INITIALIZER(group_list);
+
+static void vfio_disable_interrupts(VFIODevice *vdev);
+static uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len);
+static void vfio_mmap_set_enabled(VFIODevice *vdev, bool enabled);
+
+/*
+ * Common VFIO interrupt disable
+ */
+static void vfio_disable_irqindex(VFIODevice *vdev, int index)
+{
+    struct vfio_irq_set irq_set = {
+        .argsz = sizeof(irq_set),
+        .flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_TRIGGER,
+        .index = index,
+        .start = 0,
+        .count = 0,
+    };
+
+    ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
+
+    vdev->interrupt = VFIO_INT_NONE;
+}
+
+/*
+ * INTx
+ */
+static void vfio_unmask_intx(VFIODevice *vdev)
+{
+    struct vfio_irq_set irq_set = {
+        .argsz = sizeof(irq_set),
+        .flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_UNMASK,
+        .index = VFIO_PCI_INTX_IRQ_INDEX,
+        .start = 0,
+        .count = 1,
+    };
+
+    ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set);
+}
+
+static void vfio_intx_interrupt(void *opaque)
+{
+    VFIODevice *vdev = opaque;
+
+    if (!event_notifier_test_and_clear(&vdev->intx.interrupt)) {
+        return;
+    }
+
+    DPRINTF("%s(%04x:%02x:%02x.%x) Pin %c\n", __func__, vdev->host.domain,
+            vdev->host.bus, vdev->host.slot, vdev->host.function,
+            'A' + vdev->intx.pin);
+
+    vdev->intx.pending = true;
+    qemu_set_irq(vdev->pdev.irq[vdev->intx.pin], 1);
+}
+
+static void vfio_eoi(VFIODevice *vdev)
+{
+    if (!vdev->intx.pending) {
+        return;
+    }
+
+    DPRINTF("%s(%04x:%02x:%02x.%x) EOI\n", __func__, vdev->host.domain,
+            vdev->host.bus, vdev->host.slot, vdev->host.function);
+
+    vdev->intx.pending = false;
+    qemu_set_irq(vdev->pdev.irq[vdev->intx.pin], 0);
+    vfio_unmask_intx(vdev);
+}
+
+typedef struct QEMU_PACKED VFIOIRQSetFD {
+    struct vfio_irq_set irq_set;
+    int32_t fd;
+} VFIOIRQSetFD;
+
+static int vfio_enable_intx(VFIODevice *vdev)
+{
+    VFIOIRQSetFD irq_set_fd = {
+        .irq_set = {
+            .argsz = sizeof(irq_set_fd),
+            .flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER,
+            .index = VFIO_PCI_INTX_IRQ_INDEX,
+            .start = 0,
+            .count = 1,
+        },
+    };
+    uint8_t pin = vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1);
+    int ret;
+
+    if (vdev->intx.disabled || !pin) {
+        return 0;
+    }
+
+    vfio_disable_interrupts(vdev);
+
+    vdev->intx.pin = pin - 1; /* Pin A (1) -> irq[0] */
+    ret = event_notifier_init(&vdev->intx.interrupt, 0);
+    if (ret) {
+        error_report("vfio: Error: event_notifier_init failed\n");
+        return ret;
+    }
+
+    irq_set_fd.fd = event_notifier_get_fd(&vdev->intx.interrupt);
+    qemu_set_fd_handler(irq_set_fd.fd, vfio_intx_interrupt, NULL, vdev);
+
+    if (ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd)) {
+        error_report("vfio: Error: Failed to setup INTx fd: %m\n");
+        return -errno;
+    }
+
+    /*
+     * Disable mmaps so we can trap on BAR accesses.  We interpret any
+     * access as a response to an interrupt and unmask the physical
+     * device.  The device will re-assert if the interrupt is still
+     * pending.  We'll likely retrigger on the host multiple times per
+     * guest interrupt, but without EOI notification it's better than
+     * nothing.  Acceleration paths through KVM will avoid this.
+     */
+    vfio_mmap_set_enabled(vdev, false);
+
+    vdev->interrupt = VFIO_INT_INTx;
+
+    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
+            vdev->host.bus, vdev->host.slot, vdev->host.function);
+
+    return 0;
+}
+
+static void vfio_disable_intx(VFIODevice *vdev)
+{
+    int fd;
+
+    vfio_disable_irqindex(vdev, VFIO_PCI_INTX_IRQ_INDEX);
+    vdev->intx.pending = false;
+    qemu_set_irq(vdev->pdev.irq[vdev->intx.pin], 0);
+    vfio_mmap_set_enabled(vdev, true);
+
+    fd = event_notifier_get_fd(&vdev->intx.interrupt);
+    qemu_set_fd_handler(fd, NULL, NULL, vdev);
+    event_notifier_cleanup(&vdev->intx.interrupt);
+
+    vdev->interrupt = VFIO_INT_NONE;
+
+    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
+            vdev->host.bus, vdev->host.slot, vdev->host.function);
+}
+
+/*
+ * MSI/X
+ */
+static void vfio_msi_interrupt(void *opaque)
+{
+    VFIOMSIVector *vector = opaque;
+    VFIODevice *vdev = vector->vdev;
+    int nr = vector - vdev->msi_vectors;
+
+    if (!event_notifier_test_and_clear(&vector->interrupt)) {
+        return;
+    }
+
+    DPRINTF("%s(%04x:%02x:%02x.%x) vector %d\n", __func__,
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function, nr);
+
+    if (vdev->interrupt == VFIO_INT_MSIX) {
+        msix_notify(&vdev->pdev, nr);
+    } else if (vdev->interrupt == VFIO_INT_MSI) {
+        msi_notify(&vdev->pdev, nr);
+    } else {
+        error_report("vfio: MSI interrupt receieved, but not enabled?\n");
+    }
+}
+
+static int vfio_enable_vectors(VFIODevice *vdev, bool msix)
+{
+    struct vfio_irq_set *irq_set;
+    int ret = 0, i, argsz;
+    int32_t *fds;
+
+    argsz = sizeof(*irq_set) + (vdev->nr_vectors * sizeof(*fds));
+
+    irq_set = g_malloc0(argsz);
+    irq_set->argsz = argsz;
+    irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
+    irq_set->index = msix ? VFIO_PCI_MSIX_IRQ_INDEX : VFIO_PCI_MSI_IRQ_INDEX;
+    irq_set->start = 0;
+    irq_set->count = vdev->nr_vectors;
+    fds = (int32_t *)&irq_set->data;
+
+    for (i = 0; i < vdev->nr_vectors; i++) {
+        if (!vdev->msi_vectors[i].use) {
+            fds[i] = -1;
+            continue;
+        }
+
+        fds[i] = event_notifier_get_fd(&vdev->msi_vectors[i].interrupt);
+    }
+
+    ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+    g_free(irq_set);
+
+    if (!ret) {
+        vdev->interrupt = msix ? VFIO_INT_MSIX : VFIO_INT_MSI;
+    }
+
+    return ret;
+}
+
+static int vfio_msix_vector_use(PCIDevice *pdev,
+                                unsigned int nr, MSIMessage msg)
+{
+    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
+    VFIOMSIVector *vector;
+    int ret;
+
+    DPRINTF("%s(%04x:%02x:%02x.%x) vector %d used\n", __func__,
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function, nr);
+
+    if (vdev->interrupt != VFIO_INT_MSIX) {
+        vfio_disable_interrupts(vdev);
+    }
+
+    if (!vdev->msi_vectors) {
+        vdev->msi_vectors = g_malloc0(vdev->msix->entries *
+                                      sizeof(VFIOMSIVector));
+    }
+
+    vector = &vdev->msi_vectors[nr];
+    vector->vdev = vdev;
+    vector->use = true;
+
+    msix_vector_use(pdev, nr);
+
+    if (event_notifier_init(&vector->interrupt, 0)) {
+        error_report("vfio: Error: event_notifier_init failed\n");
+    }
+
+    /*
+     * Attempt to enable route through KVM irqchip,
+     * default to userspace handling if unavailable.
+     */
+    vector->virq = kvm_irqchip_add_msi_route(kvm_state, msg);
+    if (vector->virq < 0 ||
+        kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
+                                       vector->virq) < 0) {
+        if (vector->virq >= 0) {
+            kvm_irqchip_release_virq(kvm_state, vector->virq);
+            vector->virq = -1;
+        }
+        qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
+                            vfio_msi_interrupt, NULL, vector);
+    }
+
+    /*
+     * We don't want to have the host allocate all possible MSI vectors
+     * for a device if they're not in use, so we shutdown and incrementally
+     * increase them as needed.
+     */
+    if (vdev->nr_vectors < nr + 1) {
+        int i;
+
+        vfio_disable_irqindex(vdev, VFIO_PCI_MSIX_IRQ_INDEX);
+        vdev->nr_vectors = nr + 1;
+        ret = vfio_enable_vectors(vdev, true);
+        if (ret) {
+            error_report("vfio: failed to enable vectors, %d\n", ret);
+        }
+
+        /* We don't know if we've missed interrupts in the interim... */
+        for (i = 0; i < vdev->msix->entries; i++) {
+            if (vdev->msi_vectors[i].use) {
+                msix_notify(&vdev->pdev, i);
+            }
+        }
+    } else {
+        VFIOIRQSetFD irq_set_fd = {
+            .irq_set = {
+                .argsz = sizeof(irq_set_fd),
+                .flags = VFIO_IRQ_SET_DATA_EVENTFD |
+                         VFIO_IRQ_SET_ACTION_TRIGGER,
+                .index = VFIO_PCI_MSIX_IRQ_INDEX,
+                .start = nr,
+                .count = 1,
+            },
+            .fd = event_notifier_get_fd(&vector->interrupt),
+        };
+        ret = ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd);
+        if (ret) {
+            error_report("vfio: failed to modify vector, %d\n", ret);
+        }
+
+        /*
+         * If we were connected to the hardware PBA we could skip this,
+         * until then, a spurious interrupt is better than starvation.
+         */
+        msix_notify(&vdev->pdev, nr);
+    }
+
+    return 0;
+}
+
+static void vfio_msix_vector_release(PCIDevice *pdev, unsigned int nr)
+{
+    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
+    VFIOMSIVector *vector = &vdev->msi_vectors[nr];
+    VFIOIRQSetFD irq_set_fd = {
+        .irq_set = {
+            .argsz = sizeof(irq_set_fd),
+            .flags = VFIO_IRQ_SET_DATA_EVENTFD |
+                     VFIO_IRQ_SET_ACTION_TRIGGER,
+            .index = VFIO_PCI_MSIX_IRQ_INDEX,
+            .start = nr,
+            .count = 1,
+        },
+        .fd = -1,
+    };
+
+    DPRINTF("%s(%04x:%02x:%02x.%x) vector %d released\n", __func__,
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function, nr);
+
+    /*
+     * XXX What's the right thing to do here?  This turns off the interrupt
+     * completely, but do we really just want to switch the interrupt to
+     * bouncing through userspace and let msix.c drop it?  Not sure.
+     */
+    msix_vector_unuse(pdev, nr);
+    ioctl(vdev->fd, VFIO_DEVICE_SET_IRQS, &irq_set_fd);
+
+    if (vector->virq < 0) {
+        qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
+                            NULL, NULL, NULL);
+    } else {
+        kvm_irqchip_remove_irqfd_notifier(kvm_state, &vector->interrupt,
+                                          vector->virq);
+        kvm_irqchip_release_virq(kvm_state, vector->virq);
+        vector->virq = -1;
+    }
+
+    event_notifier_cleanup(&vector->interrupt);
+    vector->use = false;
+}
+
+/* TODO This should move to msi.c */
+static MSIMessage msi_get_msg(PCIDevice *pdev, unsigned int vector)
+{
+    uint16_t flags = pci_get_word(pdev->config + pdev->msi_cap + PCI_MSI_FLAGS);
+    bool msi64bit = flags & PCI_MSI_FLAGS_64BIT;
+    MSIMessage msg;
+
+    if (msi64bit) {
+        msg.address = pci_get_quad(pdev->config +
+                                   pdev->msi_cap + PCI_MSI_ADDRESS_LO);
+    } else {
+        msg.address = pci_get_long(pdev->config +
+                                   pdev->msi_cap + PCI_MSI_ADDRESS_LO);
+    }
+
+    msg.data = pci_get_word(pdev->config + pdev->msi_cap +
+                            (msi64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32));
+    msg.data += vector;
+
+    return msg;
+}
+
+/* So should this */
+static void msi_set_qsize(PCIDevice *pdev, uint8_t size)
+{
+    uint8_t *config = pdev->config + pdev->msi_cap;
+    uint16_t flags;
+
+    flags = pci_get_word(config + PCI_MSI_FLAGS);
+    flags = le16_to_cpu(flags);
+    flags &= ~PCI_MSI_FLAGS_QSIZE;
+    flags |= (size & 0x7) << 4;
+    flags = cpu_to_le16(flags);
+    pci_set_word(config + PCI_MSI_FLAGS, flags);
+}
+
+static void vfio_enable_msi(VFIODevice *vdev)
+{
+    int ret, i;
+
+    vfio_disable_interrupts(vdev);
+
+    vdev->nr_vectors = msi_nr_vectors_allocated(&vdev->pdev);
+retry:
+    vdev->msi_vectors = g_malloc0(vdev->nr_vectors * sizeof(VFIOMSIVector));
+
+    for (i = 0; i < vdev->nr_vectors; i++) {
+        MSIMessage msg;
+        VFIOMSIVector *vector = &vdev->msi_vectors[i];
+
+        vector->vdev = vdev;
+        vector->use = true;
+
+        if (event_notifier_init(&vector->interrupt, 0)) {
+            error_report("vfio: Error: event_notifier_init failed\n");
+        }
+
+        msg = msi_get_msg(&vdev->pdev, i);
+
+        /*
+         * Attempt to enable route through KVM irqchip,
+         * default to userspace handling if unavailable.
+         */
+        vector->virq = kvm_irqchip_add_msi_route(kvm_state, msg);
+        if (vector->virq < 0 ||
+            kvm_irqchip_add_irqfd_notifier(kvm_state, &vector->interrupt,
+                                           vector->virq) < 0) {
+            qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
+                                vfio_msi_interrupt, NULL, vector);
+        }
+    }
+
+    ret = vfio_enable_vectors(vdev, false);
+    if (ret) {
+        if (ret < 0) {
+            error_report("vfio: Error: Failed to setup MSI fds: %m\n");
+        } else if (ret != vdev->nr_vectors) {
+            error_report("vfio: Error: Failed to enable %d "
+                         "MSI vectors, retry with %d\n", vdev->nr_vectors, ret);
+        }
+
+        for (i = 0; i < vdev->nr_vectors; i++) {
+            VFIOMSIVector *vector = &vdev->msi_vectors[i];
+            if (vector->virq >= 0) {
+                kvm_irqchip_remove_irqfd_notifier(kvm_state, &vector->interrupt,
+                                                  vector->virq);
+                kvm_irqchip_release_virq(kvm_state, vector->virq);
+                vector->virq = -1;
+            } else {
+                qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
+                                    NULL, NULL, NULL);
+            }
+            event_notifier_cleanup(&vector->interrupt);
+        }
+
+        g_free(vdev->msi_vectors);
+
+        if (ret > 0 && ret != vdev->nr_vectors) {
+            vdev->nr_vectors = ret;
+            goto retry;
+        }
+        vdev->nr_vectors = 0;
+
+        return;
+    }
+
+    msi_set_qsize(&vdev->pdev, vdev->nr_vectors);
+
+    DPRINTF("%s(%04x:%02x:%02x.%x) Enabled %d MSI vectors\n", __func__,
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function, vdev->nr_vectors);
+}
+
+static void vfio_disable_msi_x(VFIODevice *vdev, bool msix)
+{
+    int i;
+
+    vfio_disable_irqindex(vdev, msix ? VFIO_PCI_MSIX_IRQ_INDEX :
+                                       VFIO_PCI_MSI_IRQ_INDEX);
+
+    for (i = 0; i < vdev->nr_vectors; i++) {
+        VFIOMSIVector *vector = &vdev->msi_vectors[i];
+
+        if (!vector->use) {
+            continue;
+        }
+
+        if (vector->virq >= 0) {
+            kvm_irqchip_remove_irqfd_notifier(kvm_state,
+                                              &vector->interrupt, vector->virq);
+            kvm_irqchip_release_virq(kvm_state, vector->virq);
+            vector->virq = -1;
+        } else {
+            qemu_set_fd_handler(event_notifier_get_fd(&vector->interrupt),
+                                NULL, NULL, NULL);
+        }
+
+        if (msix) {
+            msix_vector_unuse(&vdev->pdev, i);
+        }
+
+        event_notifier_cleanup(&vector->interrupt);
+    }
+
+    g_free(vdev->msi_vectors);
+    vdev->msi_vectors = NULL;
+    vdev->nr_vectors = 0;
+
+    if (!msix) {
+        msi_set_qsize(&vdev->pdev, 0); /* Actually still means 1 vector */
+    }
+
+    DPRINTF("%s(%04x:%02x:%02x.%x, msi%s)\n", __func__,
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function, msix ? "x" : "");
+
+    vfio_enable_intx(vdev);
+}
+
+/*
+ * IO Port/MMIO - Beware of the endians, VFIO is always little endian
+ */
+static void vfio_bar_write(void *opaque, target_phys_addr_t addr,
+                           uint64_t data, unsigned size)
+{
+    VFIOBAR *bar = opaque;
+    union {
+        uint8_t byte;
+        uint16_t word;
+        uint32_t dword;
+        uint64_t qword;
+    } buf;
+
+    switch (size) {
+    case 1:
+        buf.byte = data;
+        break;
+    case 2:
+        buf.word = cpu_to_le16(data);
+        break;
+    case 4:
+        buf.dword = cpu_to_le32(data);
+        break;
+    default:
+        hw_error("vfio: unsupported write size, %d bytes\n", size);
+        break;
+    }
+
+    if (pwrite(bar->fd, &buf, size, bar->fd_offset + addr) != size) {
+        error_report("%s(,0x%"TARGET_PRIxPHYS", 0x%"PRIx64", %d) failed: %m\n",
+                     __func__, addr, data, size);
+    }
+
+    DPRINTF("%s(BAR%d+0x%"TARGET_PRIxPHYS", 0x%"PRIx64", %d)\n",
+            __func__, bar->nr, addr, data, size);
+
+    /*
+     * A read or write to a BAR always signals an INTx EOI.  This will
+     * do nothing if not pending (including not in INTx mode).  We assume
+     * that a BAR access is in response to an interrupt and that BAR
+     * accesses will service the interrupt.  Unfortunately, we don't know
+     * which access will service the interrupt, so we're potentially
+     * getting quite a few host interrupts per guest interrupt.
+     */
+    vfio_eoi(DO_UPCAST(VFIODevice, bars[bar->nr], bar));
+}
+
+static uint64_t vfio_bar_read(void *opaque,
+                              target_phys_addr_t addr, unsigned size)
+{
+    VFIOBAR *bar = opaque;
+    union {
+        uint8_t byte;
+        uint16_t word;
+        uint32_t dword;
+        uint64_t qword;
+    } buf;
+    uint64_t data = 0;
+
+    if (pread(bar->fd, &buf, size, bar->fd_offset + addr) != size) {
+        error_report("%s(,0x%"TARGET_PRIxPHYS", %d) failed: %m\n",
+                     __func__, addr, size);
+        return (uint64_t)-1;
+    }
+
+    switch (size) {
+    case 1:
+        data = buf.byte;
+        break;
+    case 2:
+        data = le16_to_cpu(buf.word);
+        break;
+    case 4:
+        data = le32_to_cpu(buf.dword);
+        break;
+    default:
+        hw_error("vfio: unsupported read size, %d bytes\n", size);
+        break;
+    }
+
+    DPRINTF("%s(BAR%d+0x%"TARGET_PRIxPHYS", %d) = 0x%"PRIx64"\n",
+            __func__, bar->nr, addr, size, data);
+
+    /* Same as write above */
+    vfio_eoi(DO_UPCAST(VFIODevice, bars[bar->nr], bar));
+
+    return data;
+}
+
+static const MemoryRegionOps vfio_bar_ops = {
+    .read = vfio_bar_read,
+    .write = vfio_bar_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+/*
+ * PCI config space
+ */
+static uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
+{
+    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
+    uint32_t val = 0;
+
+    /*
+     * We only need QEMU PCI config support for the ROM BAR, the MSI and MSIX
+     * capabilities, and the multifunction bit below.  We let VFIO handle
+     * virtualizing everything else.  Performance is not a concern here.
+     */
+    if (ranges_overlap(addr, len, PCI_ROM_ADDRESS, 4) ||
+        (pdev->cap_present & QEMU_PCI_CAP_MSIX &&
+         ranges_overlap(addr, len, pdev->msix_cap, MSIX_CAP_LENGTH)) ||
+        (pdev->cap_present & QEMU_PCI_CAP_MSI &&
+         ranges_overlap(addr, len, pdev->msi_cap, vdev->msi_cap_size))) {
+
+        val = pci_default_read_config(pdev, addr, len);
+    } else {
+        if (pread(vdev->fd, &val, len, vdev->config_offset + addr) != len) {
+            error_report("%s(%04x:%02x:%02x.%x, 0x%x, 0x%x) failed: %m\n",
+                         __func__, vdev->host.domain, vdev->host.bus,
+                         vdev->host.slot, vdev->host.function, addr, len);
+            return -errno;
+        }
+        val = le32_to_cpu(val);
+    }
+
+    /* Multifunction bit is virualized in QEMU */
+    if (unlikely(ranges_overlap(addr, len, PCI_HEADER_TYPE, 1))) {
+        uint32_t mask = PCI_HEADER_TYPE_MULTI_FUNCTION;
+
+        if (len == 4) {
+            mask <<= 16;
+        }
+
+        if (pdev->cap_present & QEMU_PCI_CAP_MULTIFUNCTION) {
+            val |= mask;
+        } else {
+            val &= ~mask;
+        }
+    }
+
+    DPRINTF("%s(%04x:%02x:%02x.%x, @0x%x, len=0x%x) %x\n", __func__,
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function, addr, len, val);
+
+    return val;
+}
+
+static void vfio_pci_write_config(PCIDevice *pdev, uint32_t addr,
+                                  uint32_t val, int len)
+{
+    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
+    uint32_t val_le = cpu_to_le32(val);
+
+    DPRINTF("%s(%04x:%02x:%02x.%x, @0x%x, 0x%x, len=0x%x)\n", __func__,
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function, addr, val, len);
+
+    /* Write everything to VFIO, let it filter out what we can't write */
+    if (pwrite(vdev->fd, &val_le, len, vdev->config_offset + addr) != len) {
+        error_report("%s(%04x:%02x:%02x.%x, 0x%x, 0x%x, 0x%x) failed: %m\n",
+                     __func__, vdev->host.domain, vdev->host.bus,
+                     vdev->host.slot, vdev->host.function, addr, val, len);
+    }
+
+    /* Write standard header bits to emulation */
+    if (addr < PCI_CONFIG_HEADER_SIZE) {
+        pci_default_write_config(pdev, addr, val, len);
+        return;
+    }
+
+    /* MSI/MSI-X Enabling/Disabling */
+    if (pdev->cap_present & QEMU_PCI_CAP_MSI &&
+        ranges_overlap(addr, len, pdev->msi_cap, vdev->msi_cap_size)) {
+        int is_enabled, was_enabled = msi_enabled(pdev);
+
+        pci_default_write_config(pdev, addr, val, len);
+
+        is_enabled = msi_enabled(pdev);
+
+        if (!was_enabled && is_enabled) {
+            vfio_enable_msi(vdev);
+        } else if (was_enabled && !is_enabled) {
+            vfio_disable_msi_x(vdev, false);
+        }
+    }
+
+    if (pdev->cap_present & QEMU_PCI_CAP_MSIX &&
+        ranges_overlap(addr, len, pdev->msix_cap, MSIX_CAP_LENGTH)) {
+        int is_enabled, was_enabled = msix_enabled(pdev);
+
+        pci_default_write_config(pdev, addr, val, len);
+
+        is_enabled = msix_enabled(pdev);
+
+        if (!was_enabled && is_enabled) {
+            /* vfio_msix_vector_use handles this automatically */
+        } else if (was_enabled && !is_enabled) {
+            vfio_disable_msi_x(vdev, true);
+        }
+    }
+}
+
+/*
+ * DMA - Mapping and unmapping for the "type1" IOMMU interface used on x86
+ */
+static int vfio_dma_map(VFIOContainer *container, target_phys_addr_t iova,
+                        ram_addr_t size, void *vaddr, bool readonly)
+{
+    struct vfio_iommu_type1_dma_map map = {
+        .argsz = sizeof(map),
+        .flags = VFIO_DMA_MAP_FLAG_READ,
+        .vaddr = (__u64)vaddr,
+        .iova = iova,
+        .size = size,
+    };
+
+    if (!readonly) {
+        map.flags |= VFIO_DMA_MAP_FLAG_WRITE;
+    }
+
+    if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map)) {
+        DPRINTF("VFIO_MAP_DMA: %d\n", -errno);
+        return -errno;
+    }
+
+    return 0;
+}
+
+static int vfio_dma_unmap(VFIOContainer *container,
+                          target_phys_addr_t iova, ram_addr_t size)
+{
+    struct vfio_iommu_type1_dma_unmap unmap = {
+        .argsz = sizeof(unmap),
+        .flags = 0,
+        .iova = iova,
+        .size = size,
+    };
+
+    if (ioctl(container->fd, VFIO_IOMMU_UNMAP_DMA, &unmap)) {
+        DPRINTF("VFIO_UNMAP_DMA: %d\n", -errno);
+        return -errno;
+    }
+
+    return 0;
+}
+
+static void vfio_listener_dummy1(MemoryListener *listener)
+{
+    /* We don't do batching (begin/commit) or care about logging */
+}
+
+static void vfio_listener_dummy2(MemoryListener *listener,
+                                 MemoryRegionSection *section)
+{
+    /* We don't do logging or care about nops */
+}
+
+static void vfio_listener_dummy3(MemoryListener *listener,
+                                 MemoryRegionSection *section,
+                                 bool match_data, uint64_t data,
+                                 EventNotifier *e)
+{
+    /* We don't care about eventfds */
+}
+
+static bool vfio_listener_skipped_section(MemoryRegionSection *section)
+{
+    return !memory_region_is_ram(section->mr);
+}
+
+static void vfio_listener_region_add(MemoryListener *listener,
+                                     MemoryRegionSection *section)
+{
+    VFIOContainer *container = container_of(listener, VFIOContainer,
+                                            iommu_data.listener);
+    target_phys_addr_t iova, end;
+    void *vaddr;
+    int ret;
+
+    if (vfio_listener_skipped_section(section)) {
+        DPRINTF("vfio: SKIPPING region_add %"TARGET_PRIxPHYS" - %"PRIx64"\n",
+                section->offset_within_address_space,
+                section->offset_within_address_space + section->size - 1);
+        return;
+    }
+
+    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
+                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
+        error_report("%s received unaligned region\n", __func__);
+        return;
+    }
+
+    iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
+    end = (section->offset_within_address_space + section->size) &
+          TARGET_PAGE_MASK;
+
+    if (iova >= end) {
+        return;
+    }
+
+    vaddr = memory_region_get_ram_ptr(section->mr) +
+            section->offset_within_region +
+            (iova - section->offset_within_address_space);
+
+    DPRINTF("vfio: region_add %"TARGET_PRIxPHYS" - %"TARGET_PRIxPHYS" [%p]\n",
+            iova, end - 1, vaddr);
+
+    ret = vfio_dma_map(container, iova, end - iova, vaddr, section->readonly);
+    if (ret) {
+        error_report("vfio_dma_map(%p, 0x%"TARGET_PRIxPHYS", "
+                     "0x%"TARGET_PRIxPHYS", %p) = %d (%m)\n",
+                     container, iova, end - iova, vaddr, ret);
+    }
+}
+
+static void vfio_listener_region_del(MemoryListener *listener,
+                                     MemoryRegionSection *section)
+{
+    VFIOContainer *container = container_of(listener, VFIOContainer,
+                                            iommu_data.listener);
+    target_phys_addr_t iova, end;
+    int ret;
+
+    if (vfio_listener_skipped_section(section)) {
+        DPRINTF("vfio: SKIPPING region_del %"TARGET_PRIxPHYS" - %"PRIx64"\n",
+                section->offset_within_address_space,
+                section->offset_within_address_space + section->size - 1);
+        return;
+    }
+
+    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
+                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
+        error_report("%s received unaligned region\n", __func__);
+        return;
+    }
+
+    iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
+    end = (section->offset_within_address_space + section->size) &
+          TARGET_PAGE_MASK;
+
+    if (iova >= end) {
+        return;
+    }
+
+    DPRINTF("vfio: region_del %"TARGET_PRIxPHYS" - %"TARGET_PRIxPHYS"\n",
+            iova, end - 1);
+
+    ret = vfio_dma_unmap(container, iova, end - iova);
+    if (ret) {
+        error_report("vfio_dma_unmap(%p, 0x%"TARGET_PRIxPHYS", "
+                     "0x%"TARGET_PRIxPHYS") = %d (%m)\n",
+                     container, iova, end - iova, ret);
+    }
+}
+
+static MemoryListener vfio_memory_listener = {
+    .begin = vfio_listener_dummy1,
+    .commit = vfio_listener_dummy1,
+    .region_add = vfio_listener_region_add,
+    .region_del = vfio_listener_region_del,
+    .region_nop = vfio_listener_dummy2,
+    .log_start = vfio_listener_dummy2,
+    .log_stop = vfio_listener_dummy2,
+    .log_sync = vfio_listener_dummy2,
+    .log_global_start = vfio_listener_dummy1,
+    .log_global_stop = vfio_listener_dummy1,
+    .eventfd_add = vfio_listener_dummy3,
+    .eventfd_del = vfio_listener_dummy3,
+};
+
+static void vfio_listener_release(VFIOContainer *container)
+{
+    memory_listener_unregister(&container->iommu_data.listener);
+}
+
+/*
+ * Interrupt setup
+ */
+static void vfio_disable_interrupts(VFIODevice *vdev)
+{
+    switch (vdev->interrupt) {
+    case VFIO_INT_INTx:
+        vfio_disable_intx(vdev);
+        break;
+    case VFIO_INT_MSI:
+        vfio_disable_msi_x(vdev, false);
+        break;
+    case VFIO_INT_MSIX:
+        vfio_disable_msi_x(vdev, true);
+        break;
+    }
+}
+
+static int vfio_setup_msi(VFIODevice *vdev, int pos)
+{
+    uint16_t ctrl;
+    bool msi_64bit, msi_maskbit;
+    int ret, entries;
+
+    /*
+     * TODO: don't peek into msi_supported, let msi_init fail and
+     * check for ENOTSUP
+     */
+    if (!msi_supported) {
+        return 0;
+    }
+
+    if (pread(vdev->fd, &ctrl, sizeof(ctrl),
+              vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
+        return -errno;
+    }
+    ctrl = le16_to_cpu(ctrl);
+
+    msi_64bit = !!(ctrl & PCI_MSI_FLAGS_64BIT);
+    msi_maskbit = !!(ctrl & PCI_MSI_FLAGS_MASKBIT);
+    entries = 1 << ((ctrl & PCI_MSI_FLAGS_QMASK) >> 1);
+
+    DPRINTF("%04x:%02x:%02x.%x PCI MSI CAP @0x%x\n", vdev->host.domain,
+            vdev->host.bus, vdev->host.slot, vdev->host.function, pos);
+
+    ret = msi_init(&vdev->pdev, pos, entries, msi_64bit, msi_maskbit);
+    if (ret < 0) {
+        error_report("vfio: msi_init failed\n");
+        return ret;
+    }
+    vdev->msi_cap_size = 0xa + (msi_maskbit ? 0xa : 0) + (msi_64bit ? 0x4 : 0);
+
+    return 0;
+}
+
+/*
+ * We don't have any control over how pci_add_capability() inserts
+ * capabilities into the chain.  In order to setup MSI-X we need a
+ * MemoryRegion for the BAR.  In order to setup the BAR and not
+ * attempt to mmap the MSI-X table area, which VFIO won't allow, we
+ * need to first look for where the MSI-X table lives.  So we
+ * unfortunately split MSI-X setup across two functions.
+ */
+static int vfio_early_setup_msix(VFIODevice *vdev)
+{
+    uint8_t pos;
+    uint16_t ctrl;
+    uint32_t table, pba;
+
+    pos = pci_find_capability(&vdev->pdev, PCI_CAP_ID_MSIX);
+    if (!pos) {
+        return 0;
+    }
+
+    if (pread(vdev->fd, &ctrl, sizeof(ctrl),
+              vdev->config_offset + pos + PCI_CAP_FLAGS) != sizeof(ctrl)) {
+        return -errno;
+    }
+
+    if (pread(vdev->fd, &table, sizeof(table),
+              vdev->config_offset + pos + PCI_MSIX_TABLE) != sizeof(table)) {
+        return -errno;
+    }
+
+    if (pread(vdev->fd, &pba, sizeof(pba),
+              vdev->config_offset + pos + PCI_MSIX_PBA) != sizeof(pba)) {
+        return -errno;
+    }
+
+    ctrl = le16_to_cpu(ctrl);
+    table = le32_to_cpu(table);
+    pba = le32_to_cpu(pba);
+
+    vdev->msix = g_malloc0(sizeof(*(vdev->msix)));
+    vdev->msix->table_bar = table & PCI_MSIX_FLAGS_BIRMASK;
+    vdev->msix->table_offset = table & ~PCI_MSIX_FLAGS_BIRMASK;
+    vdev->msix->pba_bar = pba & PCI_MSIX_FLAGS_BIRMASK;
+    vdev->msix->pba_offset = pba & ~PCI_MSIX_FLAGS_BIRMASK;
+    vdev->msix->entries = (ctrl & PCI_MSIX_FLAGS_QSIZE) + 1;
+
+    DPRINTF("%04x:%02x:%02x.%x "
+            "PCI MSI-X CAP @0x%x, BAR %d, offset 0x%x, entries %d\n",
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function, pos, vdev->msix->table_bar,
+            vdev->msix->table_offset, vdev->msix->entries);
+
+    return 0;
+}
+
+static int vfio_setup_msix(VFIODevice *vdev, int pos)
+{
+    int ret;
+
+    /*
+     * TODO: don't peek into msi_supported, let msix_init fail and
+     * check for ENOTSUP
+     */
+    if (!msi_supported) {
+        return 0;
+    }
+
+    ret = msix_init(&vdev->pdev, vdev->msix->entries,
+                    &vdev->bars[vdev->msix->table_bar].mem,
+                    vdev->msix->table_bar, vdev->msix->table_offset,
+                    &vdev->bars[vdev->msix->pba_bar].mem,
+                    vdev->msix->pba_bar, vdev->msix->pba_offset, pos);
+    if (ret < 0) {
+        error_report("vfio: msix_init failed\n");
+        return ret;
+    }
+
+    ret = msix_set_vector_notifiers(&vdev->pdev, vfio_msix_vector_use,
+                                    vfio_msix_vector_release);
+    if (ret) {
+        error_report("vfio: msix_set_vector_notifiers failed %d\n", ret);
+        msix_uninit(&vdev->pdev, &vdev->bars[vdev->msix->table_bar].mem,
+                    &vdev->bars[vdev->msix->pba_bar].mem);
+        return ret;
+    }
+
+    return 0;
+}
+
+static void vfio_teardown_msi(VFIODevice *vdev)
+{
+    msi_uninit(&vdev->pdev);
+
+    if (vdev->msix) {
+        /* FIXME: Why can't unset just silently do nothing?? */
+        if (vdev->pdev.msix_vector_use_notifier &&
+            vdev->pdev.msix_vector_release_notifier) {
+            msix_unset_vector_notifiers(&vdev->pdev);
+        }
+
+        msix_uninit(&vdev->pdev, &vdev->bars[vdev->msix->table_bar].mem,
+                    &vdev->bars[vdev->msix->pba_bar].mem);
+    }
+}
+
+/*
+ * Resource setup
+ */
+static void vfio_mmap_set_enabled(VFIODevice *vdev, bool enabled)
+{
+    int i;
+
+    for (i = 0; i < PCI_ROM_SLOT; i++) {
+        VFIOBAR *bar = &vdev->bars[i];
+
+        if (!bar->size) {
+            continue;
+        }
+
+        memory_region_set_enabled(&bar->mmap_mem, enabled);
+        if (vdev->msix && vdev->msix->table_bar == i) {
+            memory_region_set_enabled(&vdev->msix->mmap_mem, enabled);
+        }
+    }
+}
+
+static void vfio_unmap_bar(VFIODevice *vdev, int nr)
+{
+    VFIOBAR *bar = &vdev->bars[nr];
+
+    if (!bar->size) {
+        return;
+    }
+
+    memory_region_del_subregion(&bar->mem, &bar->mmap_mem);
+    munmap(bar->mmap, memory_region_size(&bar->mmap_mem));
+
+    if (vdev->msix && vdev->msix->table_bar == nr) {
+        memory_region_del_subregion(&bar->mem, &vdev->msix->mmap_mem);
+        munmap(vdev->msix->mmap, memory_region_size(&vdev->msix->mmap_mem));
+    }
+
+    memory_region_destroy(&bar->mem);
+}
+
+static int vfio_mmap_bar(VFIOBAR *bar, MemoryRegion *mem, MemoryRegion *submem,
+                         void **map, size_t size, off_t offset,
+                         const char *name)
+{
+    int ret = 0;
+
+    if (size && bar->flags & VFIO_REGION_INFO_FLAG_MMAP) {
+        int prot = 0;
+
+        if (bar->flags & VFIO_REGION_INFO_FLAG_READ) {
+            prot |= PROT_READ;
+        }
+
+        if (bar->flags & VFIO_REGION_INFO_FLAG_WRITE) {
+            prot |= PROT_WRITE;
+        }
+
+        *map = mmap(NULL, size, prot, MAP_SHARED,
+                    bar->fd, bar->fd_offset + offset);
+        if (*map == MAP_FAILED) {
+            *map = NULL;
+            ret = -errno;
+            goto empty_region;
+        }
+
+        memory_region_init_ram_ptr(submem, name, size, *map);
+    } else {
+empty_region:
+        /* Create a zero sized sub-region to make cleanup easy. */
+        memory_region_init(submem, name, 0);
+    }
+
+    memory_region_add_subregion(mem, offset, submem);
+
+    return ret;
+}
+
+static void vfio_map_bar(VFIODevice *vdev, int nr)
+{
+    VFIOBAR *bar = &vdev->bars[nr];
+    unsigned size = bar->size;
+    char name[64];
+    uint32_t pci_bar;
+    uint8_t type;
+    int ret;
+
+    /* Skip both unimplemented BARs and the upper half of 64bit BARS. */
+    if (!size) {
+        return;
+    }
+
+    snprintf(name, sizeof(name), "VFIO %04x:%02x:%02x.%x BAR %d",
+             vdev->host.domain, vdev->host.bus, vdev->host.slot,
+             vdev->host.function, nr);
+
+    /* Determine what type of BAR this is for registration */
+    ret = pread(vdev->fd, &pci_bar, sizeof(pci_bar),
+                vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr));
+    if (ret != sizeof(pci_bar)) {
+        error_report("vfio: Failed to read BAR %d (%m)\n", nr);
+        return;
+    }
+
+    pci_bar = le32_to_cpu(pci_bar);
+    type = pci_bar & (pci_bar & PCI_BASE_ADDRESS_SPACE_IO ?
+           ~PCI_BASE_ADDRESS_IO_MASK : ~PCI_BASE_ADDRESS_MEM_MASK);
+
+    /* A "slow" read/write mapping underlies all BARs */
+    memory_region_init_io(&bar->mem, &vfio_bar_ops, bar, name, size);
+    pci_register_bar(&vdev->pdev, nr, type, &bar->mem);
+
+    /*
+     * We can't mmap areas overlapping the MSIX vector table, so we
+     * potentially insert a direct-mapped subregion before and after it.
+     */
+    if (vdev->msix && vdev->msix->table_bar == nr) {
+        size = vdev->msix->table_offset & TARGET_PAGE_MASK;
+    }
+
+    strncat(name, " mmap", sizeof(name) - strlen(name) - 1);
+    if (vfio_mmap_bar(bar, &bar->mem,
+                      &bar->mmap_mem, &bar->mmap, size, 0, name)) {
+        error_report("%s unsupported. Performance may be slow\n", name);
+    }
+
+    if (vdev->msix && vdev->msix->table_bar == nr) {
+        unsigned start;
+
+        start = TARGET_PAGE_ALIGN(vdev->msix->table_offset +
+                                  (vdev->msix->entries * PCI_MSIX_ENTRY_SIZE));
+
+        size = start < bar->size ? bar->size - start : 0;
+        strncat(name, " msix-hi", sizeof(name) - strlen(name) - 1);
+        /* VFIOMSIXInfo contains another MemoryRegion for this mapping */
+        if (vfio_mmap_bar(bar, &bar->mem, &vdev->msix->mmap_mem,
+                          &vdev->msix->mmap, size, start, name)) {
+            error_report("%s unsupported. Performance may be slow\n", name);
+        }
+    }
+}
+
+static void vfio_map_bars(VFIODevice *vdev)
+{
+    int i;
+
+    for (i = 0; i < PCI_ROM_SLOT; i++) {
+        vfio_map_bar(vdev, i);
+    }
+}
+
+static void vfio_unmap_bars(VFIODevice *vdev)
+{
+    int i;
+
+    for (i = 0; i < PCI_ROM_SLOT; i++) {
+        vfio_unmap_bar(vdev, i);
+    }
+}
+
+/*
+ * General setup
+ */
+static uint8_t vfio_std_cap_max_size(PCIDevice *pdev, uint8_t pos)
+{
+    uint8_t tmp, next = 0xff;
+
+    for (tmp = pdev->config[PCI_CAPABILITY_LIST]; tmp;
+         tmp = pdev->config[tmp + 1]) {
+        if (tmp > pos && tmp < next) {
+            next = tmp;
+        }
+    }
+
+    return next - pos;
+}
+
+static int vfio_add_std_cap(VFIODevice *vdev, uint8_t pos)
+{
+    PCIDevice *pdev = &vdev->pdev;
+    uint8_t cap_id, next, size;
+    int ret;
+
+    cap_id = pdev->config[pos];
+    next = pdev->config[pos + 1];
+
+    /*
+     * If it becomes important to configure capabilities to their actual
+     * size, use this as the default when it's something we don't recognize.
+     * Since QEMU doesn't actually handle many of the config accesses,
+     * exact size doesn't seem worthwhile.
+     */
+    size = vfio_std_cap_max_size(pdev, pos);
+
+    /*
+     * pci_add_capability always inserts the new capability at the head
+     * of the chain.  Therefore to end up with a chain that matches the
+     * physical device, we insert from the end by making this recursive.
+     * This is also why we pre-caclulate size above as cached config space
+     * will be changed as we unwind the stack.
+     */
+    if (next) {
+        ret = vfio_add_std_cap(vdev, next);
+        if (ret) {
+            return ret;
+        }
+    } else {
+        pdev->config[PCI_CAPABILITY_LIST] = 0; /* Begin the rebuild */
+    }
+
+    switch (cap_id) {
+    case PCI_CAP_ID_MSI:
+        ret = vfio_setup_msi(vdev, pos);
+        break;
+    case PCI_CAP_ID_MSIX:
+        ret = vfio_setup_msix(vdev, pos);
+        break;
+    default:
+        ret = pci_add_capability(pdev, cap_id, pos, size);
+        break;
+    }
+
+    if (ret < 0) {
+        error_report("vfio: %04x:%02x:%02x.%x Error adding PCI capability "
+                     "0x%x[0x%x]@0x%x: %d\n", vdev->host.domain,
+                     vdev->host.bus, vdev->host.slot, vdev->host.function,
+                     cap_id, size, pos, ret);
+        return ret;
+    }
+
+    return 0;
+}
+
+static int vfio_add_capabilities(VFIODevice *vdev)
+{
+    PCIDevice *pdev = &vdev->pdev;
+
+    if (!(pdev->config[PCI_STATUS] & PCI_STATUS_CAP_LIST) ||
+        !pdev->config[PCI_CAPABILITY_LIST]) {
+        return 0; /* Nothing to add */
+    }
+
+    return vfio_add_std_cap(vdev, pdev->config[PCI_CAPABILITY_LIST]);
+}
+
+static int vfio_load_rom(VFIODevice *vdev)
+{
+    uint64_t size = vdev->rom_size;
+    char name[32];
+    off_t off = 0, voff = vdev->rom_offset;
+    ssize_t bytes;
+    void *ptr;
+
+    /* If loading ROM from file, pci handles it */
+    if (vdev->pdev.romfile || !vdev->pdev.rom_bar || !size) {
+        return 0;
+    }
+
+    DPRINTF("%s(%04x:%02x:%02x.%x)\n", __func__, vdev->host.domain,
+            vdev->host.bus, vdev->host.slot, vdev->host.function);
+
+    snprintf(name, sizeof(name), "vfio[%04x:%02x:%02x.%x].rom",
+             vdev->host.domain, vdev->host.bus, vdev->host.slot,
+             vdev->host.function);
+    memory_region_init_ram(&vdev->pdev.rom, name, size);
+    ptr = memory_region_get_ram_ptr(&vdev->pdev.rom);
+    memset(ptr, 0xff, size);
+
+    while (size) {
+        bytes = pread(vdev->fd, ptr + off, size, voff + off);
+        if (bytes == 0) {
+            break; /* expect that we could get back less than the ROM BAR */
+        } else if (bytes > 0) {
+            off += bytes;
+            size -= bytes;
+        } else {
+            if (errno == EINTR || errno == EAGAIN) {
+                continue;
+            }
+            error_report("vfio: Error reading device ROM: %m\n");
+            memory_region_destroy(&vdev->pdev.rom);
+            return -errno;
+        }
+    }
+
+    pci_register_bar(&vdev->pdev, PCI_ROM_SLOT, 0, &vdev->pdev.rom);
+    vdev->pdev.has_rom = true;
+    return 0;
+}
+
+static int vfio_connect_container(VFIOGroup *group)
+{
+    VFIOContainer *container;
+    int ret, fd;
+
+    if (group->container) {
+        return 0;
+    }
+
+    QLIST_FOREACH(container, &container_list, next) {
+        if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
+            group->container = container;
+            QLIST_INSERT_HEAD(&container->group_list, group, container_next);
+            return 0;
+        }
+    }
+
+    fd = qemu_open("/dev/vfio/vfio", O_RDWR);
+    if (fd < 0) {
+        error_report("vfio: failed to open /dev/vfio/vfio: %m\n");
+        return -errno;
+    }
+
+    ret = ioctl(fd, VFIO_GET_API_VERSION);
+    if (ret != VFIO_API_VERSION) {
+        error_report("vfio: supported vfio version: %d, "
+                     "reported version: %d\n", VFIO_API_VERSION, ret);
+        close(fd);
+        return -EINVAL;
+    }
+
+    container = g_malloc0(sizeof(*container));
+    container->fd = fd;
+
+    if (ioctl(fd, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU)) {
+        ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);
+        if (ret) {
+            error_report("vfio: failed to set group container: %m\n");
+            g_free(container);
+            close(fd);
+            return -errno;
+        }
+
+        ret = ioctl(fd, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU);
+        if (ret) {
+            error_report("vfio: failed to set iommu for container: %m\n");
+            g_free(container);
+            close(fd);
+            return -errno;
+        }
+
+        container->iommu_data.listener = vfio_memory_listener;
+        container->iommu_data.release = vfio_listener_release;
+
+        memory_listener_register(&container->iommu_data.listener,
+                                 get_system_memory());
+    } else {
+        error_report("vfio: No available IOMMU models\n");
+        g_free(container);
+        close(fd);
+        return -EINVAL;
+    }
+
+    QLIST_INIT(&container->group_list);
+    QLIST_INSERT_HEAD(&container_list, container, next);
+
+    group->container = container;
+    QLIST_INSERT_HEAD(&container->group_list, group, container_next);
+
+    return 0;
+}
+
+static void vfio_disconnect_container(VFIOGroup *group)
+{
+    VFIOContainer *container = group->container;
+
+    if (ioctl(group->fd, VFIO_GROUP_UNSET_CONTAINER, &container->fd)) {
+        error_report("vfio: error disconnecting group %d from container\n",
+                     group->groupid);
+    }
+
+    QLIST_REMOVE(group, container_next);
+    group->container = NULL;
+
+    if (QLIST_EMPTY(&container->group_list)) {
+        if (container->iommu_data.release) {
+            container->iommu_data.release(container);
+        }
+        QLIST_REMOVE(container, next);
+        DPRINTF("vfio_disconnect_container: close container->fd\n");
+        close(container->fd);
+        g_free(container);
+    }
+}
+
+static VFIOGroup *vfio_get_group(int groupid)
+{
+    VFIOGroup *group;
+    char path[32];
+    struct vfio_group_status status = { .argsz = sizeof(status) };
+
+    QLIST_FOREACH(group, &group_list, next) {
+        if (group->groupid == groupid) {
+            return group;
+        }
+    }
+
+    group = g_malloc0(sizeof(*group));
+
+    snprintf(path, sizeof(path), "/dev/vfio/%d", groupid);
+    group->fd = qemu_open(path, O_RDWR);
+    if (group->fd < 0) {
+        error_report("vfio: error opening %s: %m\n", path);
+        g_free(group);
+        return NULL;
+    }
+
+    if (ioctl(group->fd, VFIO_GROUP_GET_STATUS, &status)) {
+        error_report("vfio: error getting group status: %m\n");
+        close(group->fd);
+        g_free(group);
+        return NULL;
+    }
+
+    if (!(status.flags & VFIO_GROUP_FLAGS_VIABLE)) {
+        error_report("vfio: error, group %d is not viable, please ensure "
+                     "all devices within the iommu_group are bound to their "
+                     "vfio bus driver.\n", groupid);
+        close(group->fd);
+        g_free(group);
+        return NULL;
+    }
+
+    group->groupid = groupid;
+    QLIST_INIT(&group->device_list);
+
+    if (vfio_connect_container(group)) {
+        error_report("vfio: failed to setup container for group %d\n", groupid);
+        close(group->fd);
+        g_free(group);
+        return NULL;
+    }
+
+    QLIST_INSERT_HEAD(&group_list, group, next);
+
+    return group;
+}
+
+static void vfio_put_group(VFIOGroup *group)
+{
+    if (!QLIST_EMPTY(&group->device_list)) {
+        return;
+    }
+
+    vfio_disconnect_container(group);
+    QLIST_REMOVE(group, next);
+    DPRINTF("vfio_put_group: close group->fd\n");
+    close(group->fd);
+    g_free(group);
+}
+
+static int vfio_get_device(VFIOGroup *group, const char *name, VFIODevice *vdev)
+{
+    struct vfio_device_info dev_info = { .argsz = sizeof(dev_info) };
+    struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
+    int ret, i;
+
+    ret = ioctl(group->fd, VFIO_GROUP_GET_DEVICE_FD, name);
+    if (ret < 0) {
+        error_report("vfio: error getting device %s from group %d: %m\n",
+                     name, group->groupid);
+        error_report("Verify all devices in group %d are bound to vfio-pci "
+                     "or pci-stub and not already in use\n", group->groupid);
+        return ret;
+    }
+
+    vdev->fd = ret;
+    vdev->group = group;
+    QLIST_INSERT_HEAD(&group->device_list, vdev, next);
+
+    /* Sanity check device */
+    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_INFO, &dev_info);
+    if (ret) {
+        error_report("vfio: error getting device info: %m\n");
+        goto error;
+    }
+
+    DPRINTF("Device %s flags: %u, regions: %u, irgs: %u\n", name,
+            dev_info.flags, dev_info.num_regions, dev_info.num_irqs);
+
+    if (!(dev_info.flags & VFIO_DEVICE_FLAGS_PCI)) {
+        error_report("vfio: Um, this isn't a PCI device\n");
+        goto error;
+    }
+
+    vdev->reset_works = !!(dev_info.flags & VFIO_DEVICE_FLAGS_RESET);
+    if (!vdev->reset_works) {
+        error_report("Warning, device %s does not support reset\n", name);
+    }
+
+    if (dev_info.num_regions != VFIO_PCI_NUM_REGIONS) {
+        error_report("vfio: unexpected number of io regions %u\n",
+                     dev_info.num_regions);
+        goto error;
+    }
+
+    if (dev_info.num_irqs != VFIO_PCI_NUM_IRQS) {
+        error_report("vfio: unexpected number of irqs %u\n", dev_info.num_irqs);
+        goto error;
+    }
+
+    for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
+        reg_info.index = i;
+
+        ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+        if (ret) {
+            error_report("vfio: Error getting region %d info: %m\n", i);
+            goto error;
+        }
+
+        DPRINTF("Device %s region %d:\n", name, i);
+        DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
+                (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
+                (unsigned long)reg_info.flags);
+
+        vdev->bars[i].flags = reg_info.flags;
+        vdev->bars[i].size = reg_info.size;
+        vdev->bars[i].fd_offset = reg_info.offset;
+        vdev->bars[i].fd = vdev->fd;
+        vdev->bars[i].nr = i;
+    }
+
+    reg_info.index = VFIO_PCI_ROM_REGION_INDEX;
+
+    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+    if (ret) {
+        error_report("vfio: Error getting ROM info: %m\n");
+        goto error;
+    }
+
+    DPRINTF("Device %s ROM:\n", name);
+    DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
+            (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
+            (unsigned long)reg_info.flags);
+
+    vdev->rom_size = reg_info.size;
+    vdev->rom_offset = reg_info.offset;
+
+    reg_info.index = VFIO_PCI_CONFIG_REGION_INDEX;
+
+    ret = ioctl(vdev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+    if (ret) {
+        error_report("vfio: Error getting config info: %m\n");
+        goto error;
+    }
+
+    DPRINTF("Device %s config:\n", name);
+    DPRINTF("  size: 0x%lx, offset: 0x%lx, flags: 0x%lx\n",
+            (unsigned long)reg_info.size, (unsigned long)reg_info.offset,
+            (unsigned long)reg_info.flags);
+
+    vdev->config_size = reg_info.size;
+    vdev->config_offset = reg_info.offset;
+
+error:
+    if (ret) {
+        QLIST_REMOVE(vdev, next);
+        vdev->group = NULL;
+        close(vdev->fd);
+    }
+    return ret;
+}
+
+static void vfio_put_device(VFIODevice *vdev)
+{
+    QLIST_REMOVE(vdev, next);
+    vdev->group = NULL;
+    DPRINTF("vfio_put_device: close vdev->fd\n");
+    close(vdev->fd);
+    if (vdev->msix) {
+        g_free(vdev->msix);
+        vdev->msix = NULL;
+    }
+}
+
+static int vfio_initfn(PCIDevice *pdev)
+{
+    VFIODevice *pvdev, *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
+    VFIOGroup *group;
+    char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
+    ssize_t len;
+    struct stat st;
+    int groupid;
+    int ret;
+
+    /* Check that the host device exists */
+    snprintf(path, sizeof(path),
+             "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/",
+             vdev->host.domain, vdev->host.bus, vdev->host.slot,
+             vdev->host.function);
+    if (stat(path, &st) < 0) {
+        error_report("vfio: error: no such host device: %s\n", path);
+        return -errno;
+    }
+
+    strncat(path, "iommu_group", sizeof(path) - strlen(path) - 1);
+
+    len = readlink(path, iommu_group_path, PATH_MAX);
+    if (len <= 0) {
+        error_report("vfio: error no iommu_group for device\n");
+        return -errno;
+    }
+
+    iommu_group_path[len] = 0;
+    group_name = basename(iommu_group_path);
+
+    if (sscanf(group_name, "%d", &groupid) != 1) {
+        error_report("vfio: error reading %s: %m\n", path);
+        return -errno;
+    }
+
+    DPRINTF("%s(%04x:%02x:%02x.%x) group %d\n", __func__, vdev->host.domain,
+            vdev->host.bus, vdev->host.slot, vdev->host.function, groupid);
+
+    group = vfio_get_group(groupid);
+    if (!group) {
+        error_report("vfio: failed to get group %d\n", groupid);
+        return -ENOENT;
+    }
+
+    snprintf(path, sizeof(path), "%04x:%02x:%02x.%01x",
+            vdev->host.domain, vdev->host.bus, vdev->host.slot,
+            vdev->host.function);
+
+    QLIST_FOREACH(pvdev, &group->device_list, next) {
+        if (pvdev->host.domain == vdev->host.domain &&
+            pvdev->host.bus == vdev->host.bus &&
+            pvdev->host.slot == vdev->host.slot &&
+            pvdev->host.function == vdev->host.function) {
+
+            error_report("vfio: error: device %s is already attached\n", path);
+            vfio_put_group(group);
+            return -EBUSY;
+        }
+    }
+
+    ret = vfio_get_device(group, path, vdev);
+    if (ret) {
+        error_report("vfio: failed to get device %s\n", path);
+        vfio_put_group(group);
+        return ret;
+    }
+
+    /* Get a copy of config space */
+    ret = pread(vdev->fd, vdev->pdev.config,
+                MIN(pci_config_size(&vdev->pdev), vdev->config_size),
+                vdev->config_offset);
+    if (ret < (int)MIN(pci_config_size(&vdev->pdev), vdev->config_size)) {
+        ret = ret < 0 ? -errno : -EFAULT;
+        error_report("vfio: Failed to read device config space\n");
+        goto out_put;
+    }
+
+    /*
+     * Clear host resource mapping info.  If we choose not to register a
+     * BAR, such as might be the case with the option ROM, we can get
+     * confusing, unwritable, residual addresses from the host here.
+     */
+    memset(&vdev->pdev.config[PCI_BASE_ADDRESS_0], 0, 24);
+    memset(&vdev->pdev.config[PCI_ROM_ADDRESS], 0, 4);
+
+    vfio_load_rom(vdev);
+
+    ret = vfio_early_setup_msix(vdev);
+    if (ret) {
+        goto out_put;
+    }
+
+    vfio_map_bars(vdev);
+
+    ret = vfio_add_capabilities(vdev);
+    if (ret) {
+        goto out_teardown;
+    }
+
+    if (vfio_pci_read_config(&vdev->pdev, PCI_INTERRUPT_PIN, 1)) {
+        if (vdev->intx.intx && strcmp(vdev->intx.intx, "off")) {
+            error_report("vfio: Unknown option x-intx=%s, "
+                         "valid options: \"off\".\n", vdev->intx.intx);
+            ret = -EINVAL;
+            goto out_teardown;
+        }
+
+        if (vdev->intx.intx && !strcmp(vdev->intx.intx, "off")) {
+            vdev->intx.disabled = true;
+        }
+
+        ret = vfio_enable_intx(vdev);
+        if (ret) {
+            goto out_teardown;
+        }
+    }
+
+    return 0;
+
+out_teardown:
+    pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
+    vfio_teardown_msi(vdev);
+    vfio_unmap_bars(vdev);
+out_put:
+    vfio_put_device(vdev);
+    vfio_put_group(group);
+    return ret;
+}
+
+static void vfio_exitfn(PCIDevice *pdev)
+{
+    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
+    VFIOGroup *group = vdev->group;
+
+    pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
+    vfio_disable_interrupts(vdev);
+    vfio_teardown_msi(vdev);
+    vfio_unmap_bars(vdev);
+    vfio_put_device(vdev);
+    vfio_put_group(group);
+}
+
+static void vfio_pci_reset(DeviceState *dev)
+{
+    PCIDevice *pdev = DO_UPCAST(PCIDevice, qdev, dev);
+    VFIODevice *vdev = DO_UPCAST(VFIODevice, pdev, pdev);
+
+    if (!vdev->reset_works) {
+        return;
+    }
+
+    if (ioctl(vdev->fd, VFIO_DEVICE_RESET)) {
+        error_report("vfio: Error unable to reset physical device "
+                     "(%04x:%02x:%02x.%x): %m\n", vdev->host.domain,
+                     vdev->host.bus, vdev->host.slot, vdev->host.function);
+    }
+}
+
+static Property vfio_pci_dev_properties[] = {
+    DEFINE_PROP_PCI_HOST_DEVADDR("host", VFIODevice, host),
+    DEFINE_PROP_STRING("x-intx", VFIODevice, intx.intx),
+    /*
+     * TODO - support passed fds... is this necessary?
+     * DEFINE_PROP_STRING("vfiofd", VFIODevice, vfiofd_name),
+     * DEFINE_PROP_STRING("vfiogroupfd, VFIODevice, vfiogroupfd_name),
+     */
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+
+static void vfio_pci_dev_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *pdc = PCI_DEVICE_CLASS(klass);
+
+    dc->reset = vfio_pci_reset;
+    dc->props = vfio_pci_dev_properties;
+    pdc->init = vfio_initfn;
+    pdc->exit = vfio_exitfn;
+    pdc->config_read = vfio_pci_read_config;
+    pdc->config_write = vfio_pci_write_config;
+}
+
+static const TypeInfo vfio_pci_dev_info = {
+    .name = "vfio-pci",
+    .parent = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(VFIODevice),
+    .class_init = vfio_pci_dev_class_init,
+};
+
+static void register_vfio_pci_dev_type(void)
+{
+    type_register_static(&vfio_pci_dev_info);
+}
+
+type_init(register_vfio_pci_dev_type)
diff --git a/hw/vfio_pci_int.h b/hw/vfio_pci_int.h
new file mode 100644
index 000000000..3812d8d7f
--- /dev/null
+++ b/hw/vfio_pci_int.h
@@ -0,0 +1,114 @@
+/*
+ * vfio based device assignment support
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Authors:
+ *  Alex Williamson <alex.williamson@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+
+#ifndef HW_VFIO_PCI_INT_H
+#define HW_VFIO_PCI_INT_H
+
+#include "qemu-common.h"
+#include "qemu-queue.h"
+#include "pci.h"
+#include "event_notifier.h"
+
+typedef struct VFIOBAR {
+    off_t fd_offset; /* offset of BAR within device fd */
+    int fd; /* device fd, allows us to pass VFIOBAR as opaque data */
+    MemoryRegion mem; /* slow, read/write access */
+    MemoryRegion mmap_mem; /* direct mapped access */
+    void *mmap;
+    size_t size;
+    uint32_t flags; /* VFIO region flags (rd/wr/mmap) */
+    uint8_t nr; /* cache the BAR number for debug */
+} VFIOBAR;
+
+typedef struct VFIOINTx {
+    bool pending; /* interrupt pending */
+    bool kvm_accel; /* set when QEMU bypass through KVM enabled */
+    uint8_t pin; /* which pin to pull for qemu_set_irq */
+    EventNotifier interrupt; /* eventfd triggered on interrupt */
+    EventNotifier unmask; /* eventfd for unmask on QEMU bypass */
+    PCIINTxRoute route; /* routing info for QEMU bypass */
+    bool disabled;
+    char *intx;
+} VFIOINTx;
+
+struct VFIODevice;
+
+typedef struct VFIOMSIVector {
+    EventNotifier interrupt; /* eventfd triggered on interrupt */
+    struct VFIODevice *vdev; /* back pointer to device */
+    int virq; /* KVM irqchip route for QEMU bypass */
+    bool use;
+} VFIOMSIVector;
+
+enum {
+    VFIO_INT_NONE = 0,
+    VFIO_INT_INTx = 1,
+    VFIO_INT_MSI  = 2,
+    VFIO_INT_MSIX = 3,
+};
+
+struct VFIOGroup;
+
+typedef struct VFIOContainer {
+    int fd; /* /dev/vfio/vfio, empowered by the attached groups */
+    struct {
+        /* enable abstraction to support various iommu backends */
+        union {
+            MemoryListener listener; /* Used by type1 iommu */
+        };
+        void (*release)(struct VFIOContainer *);
+    } iommu_data;
+    QLIST_HEAD(, VFIOGroup) group_list;
+    QLIST_ENTRY(VFIOContainer) next;
+} VFIOContainer;
+
+/* Cache of MSI-X setup plus extra mmap and memory region for split BAR map */
+typedef struct VFIOMSIXInfo {
+    uint8_t table_bar;
+    uint8_t pba_bar;
+    uint16_t entries;
+    uint32_t table_offset;
+    uint32_t pba_offset;
+    MemoryRegion mmap_mem;
+    void *mmap;
+} VFIOMSIXInfo;
+
+typedef struct VFIODevice {
+    PCIDevice pdev;
+    int fd;
+    VFIOINTx intx;
+    unsigned int config_size;
+    off_t config_offset; /* Offset of config space region within device fd */
+    unsigned int rom_size;
+    off_t rom_offset; /* Offset of ROM region within device fd */
+    int msi_cap_size;
+    VFIOMSIVector *msi_vectors;
+    VFIOMSIXInfo *msix;
+    int nr_vectors; /* Number of MSI/MSIX vectors currently in use */
+    int interrupt; /* Current interrupt type */
+    VFIOBAR bars[PCI_NUM_REGIONS - 1]; /* No ROM */
+    PCIHostDeviceAddress host;
+    QLIST_ENTRY(VFIODevice) next;
+    struct VFIOGroup *group;
+    bool reset_works;
+} VFIODevice;
+
+typedef struct VFIOGroup {
+    int fd;
+    int groupid;
+    VFIOContainer *container;
+    QLIST_HEAD(, VFIODevice) device_list;
+    QLIST_ENTRY(VFIOGroup) next;
+    QLIST_ENTRY(VFIOGroup) container_next;
+} VFIOGroup;
+
+#endif /* HW_VFIO_PCI_INT_H */