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diff --git a/include/virtio_loopback.h b/include/virtio_loopback.h
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+/*
+ * Based on:
+ * 1) virtio.h of QEMU project
+ *
+ * Copyright IBM, Corp. 2007
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ *
+ * 2) virtio-mmio.h of QEMU project
+ *
+ * Copyright (c) 2011 Linaro Limited
+ *
+ * Author:
+ * Peter Maydell <peter.maydell@linaro.org>
+ *
+ * 3) vhost.h of QEMU project
+ *
+ * Copyright 2022-2023 Virtual Open Systems SAS.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2. See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+/*
+ * Control registers
+ */
+#ifndef VIRTIO_LOOPBACK
+#define VIRTIO_LOOPBACK
+
+#include "event_notifier.h"
+
+#define sizeof_field(type, field) sizeof(((type *)0)->field)
+
+/* Magic value ("virt" string) - Read Only */
+#define VIRTIO_MMIO_MAGIC_VALUE 0x000
+
+/* Virtio device version - Read Only */
+#define VIRTIO_MMIO_VERSION 0x004
+
+/* Virtio device ID - Read Only */
+#define VIRTIO_MMIO_DEVICE_ID 0x008
+
+/* Virtio vendor ID - Read Only */
+#define VIRTIO_MMIO_VENDOR_ID 0x00c
+
+/*
+ * Bitmask of the features supported by the device (host)
+ * (32 bits per set) - Read Only
+ */
+#define VIRTIO_MMIO_DEVICE_FEATURES 0x010
+
+/* Device (host) features set selector - Write Only */
+#define VIRTIO_MMIO_DEVICE_FEATURES_SEL 0x014
+
+/*
+ * Bitmask of features activated by the driver (guest)
+ * (32 bits per set) - Write Only
+ */
+#define VIRTIO_MMIO_DRIVER_FEATURES 0x020
+
+/* Activated features set selector - Write Only */
+#define VIRTIO_MMIO_DRIVER_FEATURES_SEL 0x024
+
+/* Guest's memory page size in bytes - Write Only */
+#define VIRTIO_MMIO_GUEST_PAGE_SIZE 0x028
+
+/* Queue selector - Write Only */
+#define VIRTIO_MMIO_QUEUE_SEL 0x030
+
+/* Maximum size of the currently selected queue - Read Only */
+#define VIRTIO_MMIO_QUEUE_NUM_MAX 0x034
+
+/* Queue size for the currently selected queue - Write Only */
+#define VIRTIO_MMIO_QUEUE_NUM 0x038
+
+
+/* Used Ring alignment for the currently selected queue - Write Only */
+#define VIRTIO_MMIO_QUEUE_ALIGN 0x03c
+
+/* Guest's PFN for the currently selected queue - Read Write */
+#define VIRTIO_MMIO_QUEUE_PFN 0x040
+
+/* Ready bit for the currently selected queue - Read Write */
+#define VIRTIO_MMIO_QUEUE_READY 0x044
+
+/* Queue notifier - Write Only */
+#define VIRTIO_MMIO_QUEUE_NOTIFY 0x050
+
+/* Interrupt status - Read Only */
+#define VIRTIO_MMIO_INTERRUPT_STATUS 0x060
+
+/* Interrupt acknowledge - Write Only */
+#define VIRTIO_MMIO_INTERRUPT_ACK 0x064
+
+/* Device status register - Read Write */
+#define VIRTIO_MMIO_STATUS 0x070
+
+/* Selected queue's Descriptor Table address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_DESC_LOW 0x080
+#define VIRTIO_MMIO_QUEUE_DESC_HIGH 0x084
+
+/* Selected queue's Available Ring address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_AVAIL_LOW 0x090
+#define VIRTIO_MMIO_QUEUE_AVAIL_HIGH 0x094
+
+/* Selected queue's Used Ring address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_USED_LOW 0x0a0
+#define VIRTIO_MMIO_QUEUE_USED_HIGH 0x0a4
+
+/* Shared memory region id */
+#define VIRTIO_MMIO_SHM_SEL 0x0ac
+
+/* Shared memory region length, 64 bits in two halves */
+#define VIRTIO_MMIO_SHM_LEN_LOW 0x0b0
+#define VIRTIO_MMIO_SHM_LEN_HIGH 0x0b4
+
+/* Shared memory region base address, 64 bits in two halves */
+#define VIRTIO_MMIO_SHM_BASE_LOW 0x0b8
+#define VIRTIO_MMIO_SHM_BASE_HIGH 0x0bc
+
+/* Configuration atomicity value */
+#define VIRTIO_MMIO_CONFIG_GENERATION 0x0fc
+
+/*
+ * The config space is defined by each driver as
+ * the per-driver configuration space - Read Write
+ */
+#define VIRTIO_MMIO_CONFIG 0x100
+
+/*
+ * Interrupt flags (re: interrupt status & acknowledge registers)
+ */
+#define VIRTIO_MMIO_INT_VRING (1 << 0)
+#define VIRTIO_MMIO_INT_CONFIG (1 << 1)
+
+#define VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD_BIT 1
+#define VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD \
+ (1 << VIRTIO_IOMMIO_FLAG_USE_IOEVENTFD_BIT)
+
+
+/* Virtio loopback driver related */
+
+/* QEMU defines */
+#define VIRT_MAGIC 0x74726976 /* 'virt' */
+#define VIRT_VERSION 2
+#define VIRT_VERSION_LEGACY 1
+#define VIRT_VENDOR 0x554D4551 /* 'QEMU' */
+
+#define VIRTQUEUE_MAX_SIZE 1024
+#define VIRTIO_QUEUE_MAX VIRTQUEUE_MAX_SIZE
+
+#define VIRTIO_NO_VECTOR 0xffff
+#define TYPE_VIRTIO_DEVICE "virtio-device"
+
+/* Loopback negotiation code */
+
+#define PAGE_SHIFT 12
+#define PAGE_SIZE 4096
+
+#define EFD_INIT _IOC(_IOC_WRITE, 'k', 1, sizeof(efd_data_t))
+#define WAKEUP _IOC(_IOC_WRITE, 'k', 2, 0)
+#define START_LOOPBACK _IOC(_IOC_WRITE, 'k', 3, \
+ sizeof(virtio_device_info_struct_t))
+#define IRQ _IOC(_IOC_WRITE, 'k', 4, sizeof(int))
+#define SHARE_VQS _IOC(_IOC_WRITE, 'k', 5, sizeof(uint32_t))
+#define SHARE_COM_STRUCT _IOC(_IOC_WRITE, 'k', 6, 0)
+
+#define VIRTIO_PCI_VRING_ALIGN 4096
+
+typedef struct VirtIOMMIOProxy {
+ /* Generic */
+ bool legacy;
+ uint32_t flags;
+ /* Guest accessible state needing migration and reset */
+ uint32_t host_features_sel;
+ uint32_t guest_features_sel;
+ uint32_t guest_page_shift;
+ /* virtio-bus */
+ bool format_transport_address;
+ /* Fields only used for non-legacy (v2) devices */
+ uint32_t guest_features[2];
+} VirtIOMMIOProxy;
+
+
+/* Vring specific */
+/* This marks a buffer as continuing via the next field. */
+#define VRING_DESC_F_NEXT 1
+/* This marks a buffer as write-only (otherwise read-only). */
+#define VRING_DESC_F_WRITE 2
+/* This means the buffer contains a list of buffer descriptors. */
+#define VRING_DESC_F_INDIRECT 4
+/* Reset vrings value */
+#define VIRTIO_F_RING_RESET 40
+
+
+/*
+ * Mark a descriptor as available or used in packed ring.
+ * Notice: they are defined as shifts instead of shifted values.
+ */
+#define VRING_PACKED_DESC_F_AVAIL 7
+#define VRING_PACKED_DESC_F_USED 15
+
+/*
+ * The Host uses this in used->flags to advise the Guest: don't kick me when
+ * you add a buffer. It's unreliable, so it's simply an optimization. Guest
+ * will still kick if it's out of buffers.
+ */
+#define VRING_USED_F_NO_NOTIFY 1
+/*
+ * The Guest uses this in avail->flags to advise the Host: don't interrupt me
+ * when you consume a buffer. It's unreliable, so it's simply an
+ * optimization.
+ */
+#define VRING_AVAIL_F_NO_INTERRUPT 1
+
+/* Enable events in packed ring. */
+#define VRING_PACKED_EVENT_FLAG_ENABLE 0x0
+/* Disable events in packed ring. */
+#define VRING_PACKED_EVENT_FLAG_DISABLE 0x1
+/*
+ * Enable events for a specific descriptor in packed ring.
+ * (as specified by Descriptor Ring Change Event Offset/Wrap Counter).
+ * Only valid if VIRTIO_RING_F_EVENT_IDX has been negotiated.
+ */
+#define VRING_PACKED_EVENT_FLAG_DESC 0x2
+
+/*
+ * Wrap counter bit shift in event suppression structure
+ * of packed ring.
+ */
+#define VRING_PACKED_EVENT_F_WRAP_CTR 15
+
+/* We support indirect buffer descriptors */
+#define VIRTIO_RING_F_INDIRECT_DESC 28
+
+/*
+ * The Guest publishes the used index for which it expects an interrupt
+ * at the end of the avail ring. Host should ignore the avail->flags field.
+ */
+/*
+ * The Host publishes the avail index for which it expects a kick
+ * at the end of the used ring. Guest should ignore the used->flags field.
+ */
+#define VIRTIO_RING_F_EVENT_IDX 29
+
+/*
+ * Alignment requirements for vring elements.
+ * When using pre-virtio 1.0 layout, these fall out naturally.
+ */
+#define VRING_AVAIL_ALIGN_SIZE 2
+#define VRING_USED_ALIGN_SIZE 4
+#define VRING_DESC_ALIGN_SIZE 16
+/******************/
+
+#define container_of(ptr, type, member) ({ \
+ const typeof(((type *) 0)->member) *__mptr = (ptr); \
+ (type *) ((char *) __mptr - offsetof(type, member));})
+
+typedef struct VRing {
+ unsigned int num;
+ unsigned int num_default;
+ unsigned int align;
+ uint64_t desc;
+ uint64_t avail;
+ uint64_t used;
+} VRing;
+
+typedef struct VRingDesc {
+ uint64_t addr;
+ uint32_t len;
+ uint16_t flags;
+ uint16_t next;
+} VRingDesc;
+
+typedef struct VRingPackedDesc {
+ uint64_t addr;
+ uint32_t len;
+ uint16_t id;
+ uint16_t flags;
+} VRingPackedDesc;
+
+typedef struct VRingAvail {
+ uint16_t flags;
+ uint16_t idx;
+ uint16_t ring[];
+} VRingAvail;
+
+typedef struct VRingUsedElem {
+ uint32_t id;
+ uint32_t len;
+} VRingUsedElem;
+
+typedef struct VRingUsed {
+ uint16_t flags;
+ uint16_t idx;
+ VRingUsedElem ring[];
+} VRingUsed;
+
+typedef struct VirtQueueElement {
+ unsigned int index;
+ unsigned int len;
+ unsigned int ndescs;
+ unsigned int out_num;
+ unsigned int in_num;
+ uint64_t *in_addr;
+ uint64_t *out_addr;
+ struct iovec *in_sg;
+ struct iovec *out_sg;
+} VirtQueueElement;
+
+typedef struct VirtIODevice VirtIODevice;
+typedef struct VirtQueue VirtQueue;
+typedef void (*VirtIOHandleOutput)(VirtIODevice *, VirtQueue *);
+
+typedef struct VirtQueue {
+ VRing vring;
+ VirtQueueElement *used_elems;
+
+ /* Next head to pop */
+ uint16_t last_avail_idx;
+ bool last_avail_wrap_counter;
+
+ /* Last avail_idx read from VQ. */
+ uint16_t shadow_avail_idx;
+ bool shadow_avail_wrap_counter;
+
+ uint16_t used_idx;
+ bool used_wrap_counter;
+
+ /* Last used index value we have signalled on */
+ uint16_t signalled_used;
+
+ /* Last used index value we have signalled on */
+ bool signalled_used_valid;
+
+ /* Notification enabled? */
+ bool notification;
+
+ uint16_t queue_index;
+
+ unsigned int inuse;
+
+ uint16_t vector;
+ VirtIOHandleOutput handle_output;
+ VirtIODevice *vdev;
+
+ EventNotifier guest_notifier;
+ EventNotifier host_notifier;
+ bool host_notifier_enabled;
+} VirtQueue;
+
+typedef struct VirtIORNG VirtIORNG;
+typedef struct VHostUserRNG VHostUserRNG;
+typedef struct VirtioDeviceClass VirtioDeviceClass;
+typedef struct VHostUserBlk VHostUserBlk;
+typedef struct VhostUserInput VhostUserInput;
+typedef struct VHostUserGPIO VHostUserGPIO;
+typedef struct VHostUserSound VHostUserSound;
+typedef struct VHostUserCan VHostUserCan;
+typedef struct VHostUserConsole VHostUserConsole;
+typedef struct VirtioBus VirtioBus;
+
+typedef struct VirtIODevice {
+ VirtioBus *vbus;
+ VirtioDeviceClass *vdev_class;
+ struct vhost_dev *vhdev;
+ const char *name;
+ uint8_t status;
+ uint8_t isr;
+ uint16_t queue_sel;
+ uint64_t guest_features;
+ uint64_t host_features;
+ uint64_t backend_features;
+ size_t config_len;
+ void *config;
+ uint16_t config_vector;
+ uint32_t generation;
+ int last_avail;
+ int prev_level;
+ int int_count;
+ int eventfd_count;
+ int notify_cnt;
+ bool enable_virtio_interrupt;
+ pthread_mutex_t interrupt_lock;
+ int nvectors;
+ VirtQueue *vq;
+ VirtQueue **vqs;
+ int *nvqs;
+ /* TODO: Put a defined value for vq num */
+ uint64_t vring_phys_addrs[12];
+ uint32_t vring_phys_addrs_idx;
+ uint16_t device_id;
+ bool vm_running;
+ bool broken; /* device in invalid state, needs reset */
+ bool use_disabled_flag; /* allow use of 'disable' flag when needed */
+ bool disabled; /* device in temporarily disabled state */
+ bool use_started;
+ bool started;
+ bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
+ bool disable_legacy_check;
+ char *bus_name;
+ uint8_t device_endian;
+ bool use_guest_notifier_mask;
+ union {
+ VirtIORNG *vrng;
+ VHostUserRNG *vhrng;
+ VHostUserBlk *vhublk;
+ VhostUserInput *vhuinput;
+ VHostUserSound *vhusnd;
+ VHostUserGPIO *vhugpio;
+ VHostUserCan *vhucan;
+ VHostUserConsole *vhuconsole;
+ };
+ const int *user_feature_bits;
+} VirtIODevice;
+
+typedef struct efd_data {
+ int efd[2];
+ int pid;
+} efd_data_t;
+
+typedef struct virtio_device_info_struct {
+ unsigned long magic;
+ unsigned long version;
+ unsigned long device_id;
+ unsigned long vendor;
+
+} virtio_device_info_struct_t;
+
+
+/* Negotiation structs */
+
+typedef struct { int counter; } atomic_t;
+
+typedef struct virtio_neg {
+ uint64_t notification;
+ uint64_t data;
+ uint64_t size;
+ bool read;
+ atomic_t done;
+} virtio_neg_t;
+
+
+/* This is left here as a reference, might be useful in the future */
+/*
+ * static void virtio_mmio_bus_class_init(ObjectClass *klass, void *data)
+ * {
+ * BusClass *bus_class = BUS_CLASS(klass);
+ * VirtioBusClass *k = VIRTIO_BUS_CLASS(klass);
+ *
+ * k->notify = virtio_mmio_update_irq;
+ * k->save_config = virtio_mmio_save_config;
+ * k->load_config = virtio_mmio_load_config;
+ * k->save_extra_state = virtio_mmio_save_extra_state;
+ * k->load_extra_state = virtio_mmio_load_extra_state;
+ * k->has_extra_state = virtio_mmio_has_extra_state;
+ * k->set_guest_notifiers = virtio_mmio_set_guest_notifiers;
+ * k->ioeventfd_enabled = virtio_mmio_ioeventfd_enabled;
+ * k->ioeventfd_assign = virtio_mmio_ioeventfd_assign;
+ * k->pre_plugged = virtio_mmio_pre_plugged;
+ * k->vmstate_change = virtio_mmio_vmstate_change;
+ * k->has_variable_vring_alignment = true;
+ * bus_class->max_dev = 1;
+ * bus_class->get_dev_path = virtio_mmio_bus_get_dev_path;
+ * }
+ *
+ */
+
+
+typedef struct VirtioBus {
+
+ VirtIODevice *vdev;
+ void (*notify)(VirtIODevice *d, uint16_t vector);
+ bool (*has_extra_state)(VirtIODevice *d);
+ bool (*query_guest_notifiers)(VirtIODevice *d);
+ int (*set_guest_notifiers)(VirtIODevice *d, int nvqs, bool assign);
+ void (*vmstate_change)(VirtIODevice *d, bool running);
+ void (*pre_plugged)(VirtIODevice *d);
+ void (*device_plugged)(VirtIODevice *d);
+ /*
+ * transport independent exit function.
+ * This is called by virtio-bus just before the device is unplugged.
+ */
+ void (*device_unplugged)(VirtIODevice *d);
+ int (*query_nvectors)(VirtIODevice *d);
+ /*
+ * ioeventfd handling: if the transport implements ioeventfd_assign,
+ * it must implement ioeventfd_enabled as well.
+ */
+ /* Returns true if the ioeventfd is enabled for the device. */
+ bool (*ioeventfd_enabled)(VirtIODevice *d);
+ /*
+ * Assigns/deassigns the ioeventfd backing for the transport on
+ * the device for queue number n. Returns an error value on
+ * failure.
+ */
+ int (*ioeventfd_assign)(VirtIOMMIOProxy *d, EventNotifier *notifier,
+ int n, bool assign);
+ /*
+ * Whether queue number n is enabled.
+ */
+ bool (*queue_enabled)(VirtIODevice *d, int n);
+ /*
+ * Does the transport have variable vring alignment?
+ * (ie can it ever call virtio_queue_set_align()?)
+ * Note that changing this will break migration for this transport.
+ */
+ bool has_variable_vring_alignment;
+ bool (*iommu_enabled)(VirtIODevice *d);
+
+ /*
+ * Set if ioeventfd has been started.
+ */
+ bool ioeventfd_started;
+
+ /*
+ * Set if ioeventfd has been grabbed by vhost. When ioeventfd
+ * is grabbed by vhost, we track its started/stopped state (which
+ * depends in turn on the virtio status register), but do not
+ * register a handler for the ioeventfd. When ioeventfd is
+ * released, if ioeventfd_started is true we finally register
+ * the handler so that QEMU's device model can use ioeventfd.
+ */
+ int ioeventfd_grabbed;
+} VirtioBus;
+
+struct adapter_dev;
+
+typedef struct VirtioDeviceClass {
+ /*< private >*/
+ VirtIODevice *parent;
+ /*< public >*/
+ /* This is what a VirtioDevice must implement */
+ uint64_t (*get_features)(VirtIODevice *vdev,
+ uint64_t requested_features);
+ uint64_t (*bad_features)(VirtIODevice *vdev);
+ void (*set_features)(VirtIODevice *vdev, uint64_t val);
+ int (*validate_features)(VirtIODevice *vdev);
+ void (*get_config)(VirtIODevice *vdev, uint8_t *config);
+ void (*set_config)(VirtIODevice *vdev, const uint8_t *config);
+ void (*reset)(VirtIODevice *vdev);
+ void (*set_status)(VirtIODevice *vdev, uint8_t val);
+ void (*realize)(struct adapter_dev *adev);
+ void (*unrealize)(VirtIODevice *vdev);
+ void (*start)(VirtIODevice *vdev);
+ void (*stop)(VirtIODevice *vdev);
+ /*
+ * For transitional devices, this is a bitmap of features
+ * that are only exposed on the legacy interface but not
+ * the modern one.
+ */
+ uint64_t legacy_features;
+ /*
+ * Test and clear event pending status.
+ * Should be called after unmask to avoid losing events.
+ * If backend does not support masking,
+ * must check in frontend instead.
+ */
+ bool (*guest_notifier_pending)(VirtIODevice *vdev, int n);
+ /*
+ * Mask/unmask events from this vq. Any events reported
+ * while masked will become pending.
+ * If backend does not support masking,
+ * must mask in frontend instead.
+ */
+ void (*guest_notifier_mask)(VirtIODevice *vdev, int n, bool mask);
+ int (*start_ioeventfd)(VirtIODevice *vdev);
+ void (*stop_ioeventfd)(VirtIODevice *vdev);
+ /*
+ * Saving and loading of a device; trying to deprecate save/load
+ * use vmsd for new devices.
+ */
+ /*
+ * Post load hook in vmsd is called early while device is processed, and
+ * when VirtIODevice isn't fully initialized. Devices should use this
+ * instead, unless they specifically want to verify the migration stream
+ * as it's processed, e.g. for bounds checking.
+ */
+ int (*post_load)(VirtIODevice *vdev);
+ bool (*primary_unplug_pending)(void *opaque);
+
+ void (*update_mem_table)(VirtIODevice *vdev);
+ void (*print_config)(uint8_t *config_data);
+
+ struct vhost_dev *(*get_vhost)(VirtIODevice *vdev);
+} VirtioDeviceClass;
+
+void handle_input(VirtIODevice *vdev, VirtQueue *vq);
+void *my_select(void *data);
+void *wait_read_write(void *data);
+void virtio_notify_config(VirtIODevice *vdev);
+void print_neg_flag(uint64_t neg_flag, bool read);
+
+void adapter_read_write_cb(struct adapter_dev *adev);
+int virtio_loopback_start(struct adapter_dev *adev, pthread_t *thread_id);
+void virtio_loopback_stop(struct adapter_dev *adev);
+int virtio_queue_ready(VirtQueue *vq);
+void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
+ unsigned int *out_bytes,
+ unsigned max_in_bytes, unsigned max_out_bytes);
+void virtio_add_feature(uint64_t *features, unsigned int fbit);
+bool virtio_has_feature(uint64_t features, unsigned int fbit);
+bool virtio_device_started(VirtIODevice *vdev, uint8_t status);
+bool virtio_device_should_start(VirtIODevice *vdev, uint8_t status);
+
+int virtio_queue_empty(VirtQueue *vq);
+void *virtqueue_pop(VirtQueue *vq, size_t sz);
+void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,
+ unsigned int len);
+size_t iov_from_buf(const struct iovec *iov, unsigned int iov_cnt,
+ size_t offset, const void *buf, size_t bytes);
+bool virtqueue_get_head(VirtQueue *vq, unsigned int idx,
+ unsigned int *head);
+void virtio_notify_vector(VirtIODevice *vdev);
+
+enum {
+ VIRTQUEUE_READ_DESC_ERROR = -1,
+ VIRTQUEUE_READ_DESC_DONE = 0, /* end of chain */
+ VIRTQUEUE_READ_DESC_MORE = 1, /* more buffers in chain */
+};
+
+size_t qemu_iov_from_buf(const struct iovec *iov, unsigned int iov_cnt,
+ size_t offset, const void *buf, size_t bytes);
+VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
+ VirtIOHandleOutput handle_output);
+VirtQueue *virtio_get_queue(VirtIODevice *vdev, int n);
+void virtio_dev_init(VirtIODevice *vdev, const char *name,
+ uint16_t device_id, size_t config_size);
+void virtio_loopback_bus_init(VirtioBus *k);
+int virtio_bus_set_host_notifier(VirtioBus *vbus, int n, bool assign);
+EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
+EventNotifier *virtio_queue_get_guest_notifier(VirtQueue *vq);
+uint64_t virtio_queue_get_desc_addr(VirtIODevice *vdev, int n);
+uint64_t virtio_queue_get_avail_addr(VirtIODevice *vdev, int n);
+uint64_t virtio_queue_get_used_addr(VirtIODevice *vdev, int n);
+int virtio_queue_get_num(VirtIODevice *vdev, int n);
+unsigned int virtio_queue_get_last_avail_idx(VirtIODevice *vdev, int n);
+uint64_t virtio_queue_get_desc_size(VirtIODevice *vdev, int n);
+uint64_t virtio_queue_get_avail_size(VirtIODevice *vdev, int n);
+uint64_t virtio_queue_get_used_size(VirtIODevice *vdev, int n);
+void virtio_set_isr(VirtIODevice *vdev, int value);
+int virtio_device_grab_ioeventfd(VirtIODevice *vdev);
+bool virtio_bus_device_iommu_enabled(VirtIODevice *vdev);
+size_t iov_from_buf_full(const struct iovec *iov, unsigned int iov_cnt,
+ size_t offset, const void *buf, size_t bytes);
+void event_notifier_set_handler(EventNotifier *e,
+ void *handler);
+void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
+int virtqueue_split_read_next_desc(VirtIODevice *vdev, VRingDesc *desc,
+ unsigned int max, unsigned int *next);
+void print_config(uint8_t *config);
+uint32_t get_vqs_max_size(VirtIODevice *vdev);
+
+/*
+ * Do we get callbacks when the ring is completely used, even if we've
+ * suppressed them?
+ */
+#define VIRTIO_F_NOTIFY_ON_EMPTY 24
+#define VIRTIO_CONFIG_S_FEATURES_OK 8
+#define VIRTIO_CONFIG_S_DRIVER_OK 4
+#define VIRTIO_F_VERSION_1 32
+#define VIRTIO_F_ACCESS_PLATFORM 33
+#define VIRTIO_F_IN_ORDER 35
+#define VIRTIO_F_NOTIFICATION_DATA 38
+
+/*
+ * Legacy name for VIRTIO_F_ACCESS_PLATFORM
+ * (for compatibility with old userspace)
+ */
+#ifndef VIRTIO_F_IOMMU_PLATFORM
+#define VIRTIO_F_IOMMU_PLATFORM 33
+#endif
+
+/* QEMU Aligned functions */
+/*
+ * Round number down to multiple. Safe when m is not a power of 2 (see
+ * ROUND_DOWN for a faster version when a power of 2 is guaranteed).
+ */
+#define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
+
+/*
+ * Round number up to multiple. Safe when m is not a power of 2 (see
+ * ROUND_UP for a faster version when a power of 2 is guaranteed).
+ */
+#define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
+
+/* Check if n is a multiple of m */
+#define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
+
+/* n-byte align pointer down */
+#define QEMU_ALIGN_PTR_DOWN(p, n) \
+ ((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
+
+/* n-byte align pointer up */
+#define QEMU_ALIGN_PTR_UP(p, n) \
+ ((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
+
+/* Check if pointer p is n-bytes aligned */
+#define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
+
+/*
+ * Define 1 GB offset in order to request big enough
+ * memory blocks from the kernel:
+ * 0x40000000 = 1024 * 1024 * 1024 = 64 * 4096 * 4096 = 1G
+ */
+#define OFFSET_1GB (64ULL * PAGE_SIZE * PAGE_SIZE)
+
+/*
+ * Define starting physical address of host memory address space
+ */
+#define INIT_PA 0
+
+#endif /* VIRTIO_LOOPBACK */