hw: move VFIO and ivshmem to hw/misc/

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 826 insertions, 0 deletions

diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
new file mode 100644
index 0000000000..f92ce19dde
--- /dev/null
+++ b/hw/misc/ivshmem.c
@@ -0,0 +1,826 @@
+/*
+ * Inter-VM Shared Memory PCI device.
+ *
+ * Author:
+ *      Cam Macdonell <cam@cs.ualberta.ca>
+ *
+ * Based On: cirrus_vga.c
+ *          Copyright (c) 2004 Fabrice Bellard
+ *          Copyright (c) 2004 Makoto Suzuki (suzu)
+ *
+ *      and rtl8139.c
+ *          Copyright (c) 2006 Igor Kovalenko
+ *
+ * This code is licensed under the GNU GPL v2.
+ *
+ * Contributions after 2012-01-13 are licensed under the terms of the
+ * GNU GPL, version 2 or (at your option) any later version.
+ */
+#include "hw/hw.h"
+#include "hw/i386/pc.h"
+#include "hw/pci/pci.h"
+#include "hw/pci/msix.h"
+#include "sysemu/kvm.h"
+#include "migration/migration.h"
+#include "qapi/qmp/qerror.h"
+#include "qemu/event_notifier.h"
+#include "char/char.h"
+
+#include <sys/mman.h>
+#include <sys/types.h>
+
+#define PCI_VENDOR_ID_IVSHMEM   PCI_VENDOR_ID_REDHAT_QUMRANET
+#define PCI_DEVICE_ID_IVSHMEM   0x1110
+
+#define IVSHMEM_IOEVENTFD   0
+#define IVSHMEM_MSI     1
+
+#define IVSHMEM_PEER    0
+#define IVSHMEM_MASTER  1
+
+#define IVSHMEM_REG_BAR_SIZE 0x100
+
+//#define DEBUG_IVSHMEM
+#ifdef DEBUG_IVSHMEM
+#define IVSHMEM_DPRINTF(fmt, ...)        \
+    do {printf("IVSHMEM: " fmt, ## __VA_ARGS__); } while (0)
+#else
+#define IVSHMEM_DPRINTF(fmt, ...)
+#endif
+
+typedef struct Peer {
+    int nb_eventfds;
+    EventNotifier *eventfds;
+} Peer;
+
+typedef struct EventfdEntry {
+    PCIDevice *pdev;
+    int vector;
+} EventfdEntry;
+
+typedef struct IVShmemState {
+    PCIDevice dev;
+    uint32_t intrmask;
+    uint32_t intrstatus;
+    uint32_t doorbell;
+
+    CharDriverState **eventfd_chr;
+    CharDriverState *server_chr;
+    MemoryRegion ivshmem_mmio;
+
+    /* We might need to register the BAR before we actually have the memory.
+     * So prepare a container MemoryRegion for the BAR immediately and
+     * add a subregion when we have the memory.
+     */
+    MemoryRegion bar;
+    MemoryRegion ivshmem;
+    uint64_t ivshmem_size; /* size of shared memory region */
+    uint32_t ivshmem_attr;
+    uint32_t ivshmem_64bit;
+    int shm_fd; /* shared memory file descriptor */
+
+    Peer *peers;
+    int nb_peers; /* how many guests we have space for */
+    int max_peer; /* maximum numbered peer */
+
+    int vm_id;
+    uint32_t vectors;
+    uint32_t features;
+    EventfdEntry *eventfd_table;
+
+    Error *migration_blocker;
+
+    char * shmobj;
+    char * sizearg;
+    char * role;
+    int role_val;   /* scalar to avoid multiple string comparisons */
+} IVShmemState;
+
+/* registers for the Inter-VM shared memory device */
+enum ivshmem_registers {
+    INTRMASK = 0,
+    INTRSTATUS = 4,
+    IVPOSITION = 8,
+    DOORBELL = 12,
+};
+
+static inline uint32_t ivshmem_has_feature(IVShmemState *ivs,
+                                                    unsigned int feature) {
+    return (ivs->features & (1 << feature));
+}
+
+static inline bool is_power_of_two(uint64_t x) {
+    return (x & (x - 1)) == 0;
+}
+
+/* accessing registers - based on rtl8139 */
+static void ivshmem_update_irq(IVShmemState *s, int val)
+{
+    int isr;
+    isr = (s->intrstatus & s->intrmask) & 0xffffffff;
+
+    /* don't print ISR resets */
+    if (isr) {
+        IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
+           isr ? 1 : 0, s->intrstatus, s->intrmask);
+    }
+
+    qemu_set_irq(s->dev.irq[0], (isr != 0));
+}
+
+static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
+{
+    IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
+
+    s->intrmask = val;
+
+    ivshmem_update_irq(s, val);
+}
+
+static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
+{
+    uint32_t ret = s->intrmask;
+
+    IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
+
+    return ret;
+}
+
+static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
+{
+    IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
+
+    s->intrstatus = val;
+
+    ivshmem_update_irq(s, val);
+}
+
+static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
+{
+    uint32_t ret = s->intrstatus;
+
+    /* reading ISR clears all interrupts */
+    s->intrstatus = 0;
+
+    ivshmem_update_irq(s, 0);
+
+    return ret;
+}
+
+static void ivshmem_io_write(void *opaque, hwaddr addr,
+                             uint64_t val, unsigned size)
+{
+    IVShmemState *s = opaque;
+
+    uint16_t dest = val >> 16;
+    uint16_t vector = val & 0xff;
+
+    addr &= 0xfc;
+
+    IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr);
+    switch (addr)
+    {
+        case INTRMASK:
+            ivshmem_IntrMask_write(s, val);
+            break;
+
+        case INTRSTATUS:
+            ivshmem_IntrStatus_write(s, val);
+            break;
+
+        case DOORBELL:
+            /* check that dest VM ID is reasonable */
+            if (dest > s->max_peer) {
+                IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
+                break;
+            }
+
+            /* check doorbell range */
+            if (vector < s->peers[dest].nb_eventfds) {
+                IVSHMEM_DPRINTF("Notifying VM %d on vector %d\n", dest, vector);
+                event_notifier_set(&s->peers[dest].eventfds[vector]);
+            }
+            break;
+        default:
+            IVSHMEM_DPRINTF("Invalid VM Doorbell VM %d\n", dest);
+    }
+}
+
+static uint64_t ivshmem_io_read(void *opaque, hwaddr addr,
+                                unsigned size)
+{
+
+    IVShmemState *s = opaque;
+    uint32_t ret;
+
+    switch (addr)
+    {
+        case INTRMASK:
+            ret = ivshmem_IntrMask_read(s);
+            break;
+
+        case INTRSTATUS:
+            ret = ivshmem_IntrStatus_read(s);
+            break;
+
+        case IVPOSITION:
+            /* return my VM ID if the memory is mapped */
+            if (s->shm_fd > 0) {
+                ret = s->vm_id;
+            } else {
+                ret = -1;
+            }
+            break;
+
+        default:
+            IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr);
+            ret = 0;
+    }
+
+    return ret;
+}
+
+static const MemoryRegionOps ivshmem_mmio_ops = {
+    .read = ivshmem_io_read,
+    .write = ivshmem_io_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .impl = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+};
+
+static void ivshmem_receive(void *opaque, const uint8_t *buf, int size)
+{
+    IVShmemState *s = opaque;
+
+    ivshmem_IntrStatus_write(s, *buf);
+
+    IVSHMEM_DPRINTF("ivshmem_receive 0x%02x\n", *buf);
+}
+
+static int ivshmem_can_receive(void * opaque)
+{
+    return 8;
+}
+
+static void ivshmem_event(void *opaque, int event)
+{
+    IVSHMEM_DPRINTF("ivshmem_event %d\n", event);
+}
+
+static void fake_irqfd(void *opaque, const uint8_t *buf, int size) {
+
+    EventfdEntry *entry = opaque;
+    PCIDevice *pdev = entry->pdev;
+
+    IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, entry->vector);
+    msix_notify(pdev, entry->vector);
+}
+
+static CharDriverState* create_eventfd_chr_device(void * opaque, EventNotifier *n,
+                                                  int vector)
+{
+    /* create a event character device based on the passed eventfd */
+    IVShmemState *s = opaque;
+    CharDriverState * chr;
+    int eventfd = event_notifier_get_fd(n);
+
+    chr = qemu_chr_open_eventfd(eventfd);
+
+    if (chr == NULL) {
+        fprintf(stderr, "creating eventfd for eventfd %d failed\n", eventfd);
+        exit(-1);
+    }
+    qemu_chr_fe_claim_no_fail(chr);
+
+    /* if MSI is supported we need multiple interrupts */
+    if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
+        s->eventfd_table[vector].pdev = &s->dev;
+        s->eventfd_table[vector].vector = vector;
+
+        qemu_chr_add_handlers(chr, ivshmem_can_receive, fake_irqfd,
+                      ivshmem_event, &s->eventfd_table[vector]);
+    } else {
+        qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive,
+                      ivshmem_event, s);
+    }
+
+    return chr;
+
+}
+
+static int check_shm_size(IVShmemState *s, int fd) {
+    /* check that the guest isn't going to try and map more memory than the
+     * the object has allocated return -1 to indicate error */
+
+    struct stat buf;
+
+    fstat(fd, &buf);
+
+    if (s->ivshmem_size > buf.st_size) {
+        fprintf(stderr,
+                "IVSHMEM ERROR: Requested memory size greater"
+                " than shared object size (%" PRIu64 " > %" PRIu64")\n",
+                s->ivshmem_size, (uint64_t)buf.st_size);
+        return -1;
+    } else {
+        return 0;
+    }
+}
+
+/* create the shared memory BAR when we are not using the server, so we can
+ * create the BAR and map the memory immediately */
+static void create_shared_memory_BAR(IVShmemState *s, int fd) {
+
+    void * ptr;
+
+    s->shm_fd = fd;
+
+    ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+
+    memory_region_init_ram_ptr(&s->ivshmem, "ivshmem.bar2",
+                               s->ivshmem_size, ptr);
+    vmstate_register_ram(&s->ivshmem, &s->dev.qdev);
+    memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
+
+    /* region for shared memory */
+    pci_register_bar(&s->dev, 2, s->ivshmem_attr, &s->bar);
+}
+
+static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i)
+{
+    memory_region_add_eventfd(&s->ivshmem_mmio,
+                              DOORBELL,
+                              4,
+                              true,
+                              (posn << 16) | i,
+                              &s->peers[posn].eventfds[i]);
+}
+
+static void ivshmem_del_eventfd(IVShmemState *s, int posn, int i)
+{
+    memory_region_del_eventfd(&s->ivshmem_mmio,
+                              DOORBELL,
+                              4,
+                              true,
+                              (posn << 16) | i,
+                              &s->peers[posn].eventfds[i]);
+}
+
+static void close_guest_eventfds(IVShmemState *s, int posn)
+{
+    int i, guest_curr_max;
+
+    if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
+        return;
+    }
+
+    guest_curr_max = s->peers[posn].nb_eventfds;
+
+    memory_region_transaction_begin();
+    for (i = 0; i < guest_curr_max; i++) {
+        ivshmem_del_eventfd(s, posn, i);
+    }
+    memory_region_transaction_commit();
+    for (i = 0; i < guest_curr_max; i++) {
+        event_notifier_cleanup(&s->peers[posn].eventfds[i]);
+    }
+
+    g_free(s->peers[posn].eventfds);
+    s->peers[posn].nb_eventfds = 0;
+}
+
+/* this function increase the dynamic storage need to store data about other
+ * guests */
+static void increase_dynamic_storage(IVShmemState *s, int new_min_size) {
+
+    int j, old_nb_alloc;
+
+    old_nb_alloc = s->nb_peers;
+
+    while (new_min_size >= s->nb_peers)
+        s->nb_peers = s->nb_peers * 2;
+
+    IVSHMEM_DPRINTF("bumping storage to %d guests\n", s->nb_peers);
+    s->peers = g_realloc(s->peers, s->nb_peers * sizeof(Peer));
+
+    /* zero out new pointers */
+    for (j = old_nb_alloc; j < s->nb_peers; j++) {
+        s->peers[j].eventfds = NULL;
+        s->peers[j].nb_eventfds = 0;
+    }
+}
+
+static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
+{
+    IVShmemState *s = opaque;
+    int incoming_fd, tmp_fd;
+    int guest_max_eventfd;
+    long incoming_posn;
+
+    memcpy(&incoming_posn, buf, sizeof(long));
+    /* pick off s->server_chr->msgfd and store it, posn should accompany msg */
+    tmp_fd = qemu_chr_fe_get_msgfd(s->server_chr);
+    IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd);
+
+    /* make sure we have enough space for this guest */
+    if (incoming_posn >= s->nb_peers) {
+        increase_dynamic_storage(s, incoming_posn);
+    }
+
+    if (tmp_fd == -1) {
+        /* if posn is positive and unseen before then this is our posn*/
+        if ((incoming_posn >= 0) &&
+                            (s->peers[incoming_posn].eventfds == NULL)) {
+            /* receive our posn */
+            s->vm_id = incoming_posn;
+            return;
+        } else {
+            /* otherwise an fd == -1 means an existing guest has gone away */
+            IVSHMEM_DPRINTF("posn %ld has gone away\n", incoming_posn);
+            close_guest_eventfds(s, incoming_posn);
+            return;
+        }
+    }
+
+    /* because of the implementation of get_msgfd, we need a dup */
+    incoming_fd = dup(tmp_fd);
+
+    if (incoming_fd == -1) {
+        fprintf(stderr, "could not allocate file descriptor %s\n",
+                                                            strerror(errno));
+        return;
+    }
+
+    /* if the position is -1, then it's shared memory region fd */
+    if (incoming_posn == -1) {
+
+        void * map_ptr;
+
+        s->max_peer = 0;
+
+        if (check_shm_size(s, incoming_fd) == -1) {
+            exit(-1);
+        }
+
+        /* mmap the region and map into the BAR2 */
+        map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
+                                                            incoming_fd, 0);
+        memory_region_init_ram_ptr(&s->ivshmem,
+                                   "ivshmem.bar2", s->ivshmem_size, map_ptr);
+        vmstate_register_ram(&s->ivshmem, &s->dev.qdev);
+
+        IVSHMEM_DPRINTF("guest h/w addr = %" PRIu64 ", size = %" PRIu64 "\n",
+                         s->ivshmem_offset, s->ivshmem_size);
+
+        memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
+
+        /* only store the fd if it is successfully mapped */
+        s->shm_fd = incoming_fd;
+
+        return;
+    }
+
+    /* each guest has an array of eventfds, and we keep track of how many
+     * guests for each VM */
+    guest_max_eventfd = s->peers[incoming_posn].nb_eventfds;
+
+    if (guest_max_eventfd == 0) {
+        /* one eventfd per MSI vector */
+        s->peers[incoming_posn].eventfds = g_new(EventNotifier, s->vectors);
+    }
+
+    /* this is an eventfd for a particular guest VM */
+    IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn,
+                                            guest_max_eventfd, incoming_fd);
+    event_notifier_init_fd(&s->peers[incoming_posn].eventfds[guest_max_eventfd],
+                           incoming_fd);
+
+    /* increment count for particular guest */
+    s->peers[incoming_posn].nb_eventfds++;
+
+    /* keep track of the maximum VM ID */
+    if (incoming_posn > s->max_peer) {
+        s->max_peer = incoming_posn;
+    }
+
+    if (incoming_posn == s->vm_id) {
+        s->eventfd_chr[guest_max_eventfd] = create_eventfd_chr_device(s,
+                   &s->peers[s->vm_id].eventfds[guest_max_eventfd],
+                   guest_max_eventfd);
+    }
+
+    if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
+        ivshmem_add_eventfd(s, incoming_posn, guest_max_eventfd);
+    }
+}
+
+/* Select the MSI-X vectors used by device.
+ * ivshmem maps events to vectors statically, so
+ * we just enable all vectors on init and after reset. */
+static void ivshmem_use_msix(IVShmemState * s)
+{
+    int i;
+
+    if (!msix_present(&s->dev)) {
+        return;
+    }
+
+    for (i = 0; i < s->vectors; i++) {
+        msix_vector_use(&s->dev, i);
+    }
+}
+
+static void ivshmem_reset(DeviceState *d)
+{
+    IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
+
+    s->intrstatus = 0;
+    ivshmem_use_msix(s);
+}
+
+static uint64_t ivshmem_get_size(IVShmemState * s) {
+
+    uint64_t value;
+    char *ptr;
+
+    value = strtoull(s->sizearg, &ptr, 10);
+    switch (*ptr) {
+        case 0: case 'M': case 'm':
+            value <<= 20;
+            break;
+        case 'G': case 'g':
+            value <<= 30;
+            break;
+        default:
+            fprintf(stderr, "qemu: invalid ram size: %s\n", s->sizearg);
+            exit(1);
+    }
+
+    /* BARs must be a power of 2 */
+    if (!is_power_of_two(value)) {
+        fprintf(stderr, "ivshmem: size must be power of 2\n");
+        exit(1);
+    }
+
+    return value;
+}
+
+static void ivshmem_setup_msi(IVShmemState * s)
+{
+    if (msix_init_exclusive_bar(&s->dev, s->vectors, 1)) {
+        IVSHMEM_DPRINTF("msix initialization failed\n");
+        exit(1);
+    }
+
+    IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
+
+    /* allocate QEMU char devices for receiving interrupts */
+    s->eventfd_table = g_malloc0(s->vectors * sizeof(EventfdEntry));
+
+    ivshmem_use_msix(s);
+}
+
+static void ivshmem_save(QEMUFile* f, void *opaque)
+{
+    IVShmemState *proxy = opaque;
+
+    IVSHMEM_DPRINTF("ivshmem_save\n");
+    pci_device_save(&proxy->dev, f);
+
+    if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) {
+        msix_save(&proxy->dev, f);
+    } else {
+        qemu_put_be32(f, proxy->intrstatus);
+        qemu_put_be32(f, proxy->intrmask);
+    }
+
+}
+
+static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
+{
+    IVSHMEM_DPRINTF("ivshmem_load\n");
+
+    IVShmemState *proxy = opaque;
+    int ret;
+
+    if (version_id > 0) {
+        return -EINVAL;
+    }
+
+    if (proxy->role_val == IVSHMEM_PEER) {
+        fprintf(stderr, "ivshmem: 'peer' devices are not migratable\n");
+        return -EINVAL;
+    }
+
+    ret = pci_device_load(&proxy->dev, f);
+    if (ret) {
+        return ret;
+    }
+
+    if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) {
+        msix_load(&proxy->dev, f);
+	ivshmem_use_msix(proxy);
+    } else {
+        proxy->intrstatus = qemu_get_be32(f);
+        proxy->intrmask = qemu_get_be32(f);
+    }
+
+    return 0;
+}
+
+static void ivshmem_write_config(PCIDevice *pci_dev, uint32_t address,
+				 uint32_t val, int len)
+{
+    pci_default_write_config(pci_dev, address, val, len);
+    msix_write_config(pci_dev, address, val, len);
+}
+
+static int pci_ivshmem_init(PCIDevice *dev)
+{
+    IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
+    uint8_t *pci_conf;
+
+    if (s->sizearg == NULL)
+        s->ivshmem_size = 4 << 20; /* 4 MB default */
+    else {
+        s->ivshmem_size = ivshmem_get_size(s);
+    }
+
+    register_savevm(&s->dev.qdev, "ivshmem", 0, 0, ivshmem_save, ivshmem_load,
+                                                                        dev);
+
+    /* IRQFD requires MSI */
+    if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
+        !ivshmem_has_feature(s, IVSHMEM_MSI)) {
+        fprintf(stderr, "ivshmem: ioeventfd/irqfd requires MSI\n");
+        exit(1);
+    }
+
+    /* check that role is reasonable */
+    if (s->role) {
+        if (strncmp(s->role, "peer", 5) == 0) {
+            s->role_val = IVSHMEM_PEER;
+        } else if (strncmp(s->role, "master", 7) == 0) {
+            s->role_val = IVSHMEM_MASTER;
+        } else {
+            fprintf(stderr, "ivshmem: 'role' must be 'peer' or 'master'\n");
+            exit(1);
+        }
+    } else {
+        s->role_val = IVSHMEM_MASTER; /* default */
+    }
+
+    if (s->role_val == IVSHMEM_PEER) {
+        error_set(&s->migration_blocker, QERR_DEVICE_FEATURE_BLOCKS_MIGRATION,
+                  "peer mode", "ivshmem");
+        migrate_add_blocker(s->migration_blocker);
+    }
+
+    pci_conf = s->dev.config;
+    pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
+
+    pci_config_set_interrupt_pin(pci_conf, 1);
+
+    s->shm_fd = 0;
+
+    memory_region_init_io(&s->ivshmem_mmio, &ivshmem_mmio_ops, s,
+                          "ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
+
+    /* region for registers*/
+    pci_register_bar(&s->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
+                     &s->ivshmem_mmio);
+
+    memory_region_init(&s->bar, "ivshmem-bar2-container", s->ivshmem_size);
+    s->ivshmem_attr = PCI_BASE_ADDRESS_SPACE_MEMORY |
+        PCI_BASE_ADDRESS_MEM_PREFETCH;
+    if (s->ivshmem_64bit) {
+        s->ivshmem_attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;
+    }
+
+    if ((s->server_chr != NULL) &&
+                        (strncmp(s->server_chr->filename, "unix:", 5) == 0)) {
+        /* if we get a UNIX socket as the parameter we will talk
+         * to the ivshmem server to receive the memory region */
+
+        if (s->shmobj != NULL) {
+            fprintf(stderr, "WARNING: do not specify both 'chardev' "
+                                                "and 'shm' with ivshmem\n");
+        }
+
+        IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
+                                                    s->server_chr->filename);
+
+        if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
+            ivshmem_setup_msi(s);
+        }
+
+        /* we allocate enough space for 16 guests and grow as needed */
+        s->nb_peers = 16;
+        s->vm_id = -1;
+
+        /* allocate/initialize space for interrupt handling */
+        s->peers = g_malloc0(s->nb_peers * sizeof(Peer));
+
+        pci_register_bar(&s->dev, 2, s->ivshmem_attr, &s->bar);
+
+        s->eventfd_chr = g_malloc0(s->vectors * sizeof(CharDriverState *));
+
+        qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read,
+                     ivshmem_event, s);
+    } else {
+        /* just map the file immediately, we're not using a server */
+        int fd;
+
+        if (s->shmobj == NULL) {
+            fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
+        }
+
+        IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);
+
+        /* try opening with O_EXCL and if it succeeds zero the memory
+         * by truncating to 0 */
+        if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL,
+                        S_IRWXU|S_IRWXG|S_IRWXO)) > 0) {
+           /* truncate file to length PCI device's memory */
+            if (ftruncate(fd, s->ivshmem_size) != 0) {
+                fprintf(stderr, "ivshmem: could not truncate shared file\n");
+            }
+
+        } else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR,
+                        S_IRWXU|S_IRWXG|S_IRWXO)) < 0) {
+            fprintf(stderr, "ivshmem: could not open shared file\n");
+            exit(-1);
+
+        }
+
+        if (check_shm_size(s, fd) == -1) {
+            exit(-1);
+        }
+
+        create_shared_memory_BAR(s, fd);
+
+    }
+
+    s->dev.config_write = ivshmem_write_config;
+
+    return 0;
+}
+
+static void pci_ivshmem_uninit(PCIDevice *dev)
+{
+    IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
+
+    if (s->migration_blocker) {
+        migrate_del_blocker(s->migration_blocker);
+        error_free(s->migration_blocker);
+    }
+
+    memory_region_destroy(&s->ivshmem_mmio);
+    memory_region_del_subregion(&s->bar, &s->ivshmem);
+    vmstate_unregister_ram(&s->ivshmem, &s->dev.qdev);
+    memory_region_destroy(&s->ivshmem);
+    memory_region_destroy(&s->bar);
+    unregister_savevm(&dev->qdev, "ivshmem", s);
+}
+
+static Property ivshmem_properties[] = {
+    DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
+    DEFINE_PROP_STRING("size", IVShmemState, sizearg),
+    DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
+    DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD, false),
+    DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true),
+    DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
+    DEFINE_PROP_STRING("role", IVShmemState, role),
+    DEFINE_PROP_UINT32("use64", IVShmemState, ivshmem_64bit, 1),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void ivshmem_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
+
+    k->init = pci_ivshmem_init;
+    k->exit = pci_ivshmem_uninit;
+    k->vendor_id = PCI_VENDOR_ID_IVSHMEM;
+    k->device_id = PCI_DEVICE_ID_IVSHMEM;
+    k->class_id = PCI_CLASS_MEMORY_RAM;
+    dc->reset = ivshmem_reset;
+    dc->props = ivshmem_properties;
+}
+
+static const TypeInfo ivshmem_info = {
+    .name          = "ivshmem",
+    .parent        = TYPE_PCI_DEVICE,
+    .instance_size = sizeof(IVShmemState),
+    .class_init    = ivshmem_class_init,
+};
+
+static void ivshmem_register_types(void)
+{
+    type_register_static(&ivshmem_info);
+}
+
+type_init(ivshmem_register_types)