--- /dev/null
+/*
+ * VMware VMCI Driver
+ *
+ * Copyright (C) 2012 VMware, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation version 2 and no later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ */
+
+#ifndef _VMW_VMCI_DEF_H_
+#define _VMW_VMCI_DEF_H_
+
+#include <linux/atomic.h>
+
+/* Register offsets. */
+#define VMCI_STATUS_ADDR 0x00
+#define VMCI_CONTROL_ADDR 0x04
+#define VMCI_ICR_ADDR 0x08
+#define VMCI_IMR_ADDR 0x0c
+#define VMCI_DATA_OUT_ADDR 0x10
+#define VMCI_DATA_IN_ADDR 0x14
+#define VMCI_CAPS_ADDR 0x18
+#define VMCI_RESULT_LOW_ADDR 0x1c
+#define VMCI_RESULT_HIGH_ADDR 0x20
+
+/* Max number of devices. */
+#define VMCI_MAX_DEVICES 1
+
+/* Status register bits. */
+#define VMCI_STATUS_INT_ON 0x1
+
+/* Control register bits. */
+#define VMCI_CONTROL_RESET 0x1
+#define VMCI_CONTROL_INT_ENABLE 0x2
+#define VMCI_CONTROL_INT_DISABLE 0x4
+
+/* Capabilities register bits. */
+#define VMCI_CAPS_HYPERCALL 0x1
+#define VMCI_CAPS_GUESTCALL 0x2
+#define VMCI_CAPS_DATAGRAM 0x4
+#define VMCI_CAPS_NOTIFICATIONS 0x8
+
+/* Interrupt Cause register bits. */
+#define VMCI_ICR_DATAGRAM 0x1
+#define VMCI_ICR_NOTIFICATION 0x2
+
+/* Interrupt Mask register bits. */
+#define VMCI_IMR_DATAGRAM 0x1
+#define VMCI_IMR_NOTIFICATION 0x2
+
+/* Interrupt type. */
+enum {
+ VMCI_INTR_TYPE_INTX = 0,
+ VMCI_INTR_TYPE_MSI = 1,
+ VMCI_INTR_TYPE_MSIX = 2,
+};
+
+/* Maximum MSI/MSI-X interrupt vectors in the device. */
+#define VMCI_MAX_INTRS 2
+
+/*
+ * Supported interrupt vectors. There is one for each ICR value above,
+ * but here they indicate the position in the vector array/message ID.
+ */
+enum {
+ VMCI_INTR_DATAGRAM = 0,
+ VMCI_INTR_NOTIFICATION = 1,
+};
+
+/*
+ * A single VMCI device has an upper limit of 128MB on the amount of
+ * memory that can be used for queue pairs.
+ */
+#define VMCI_MAX_GUEST_QP_MEMORY (128 * 1024 * 1024)
+
+/*
+ * Queues with pre-mapped data pages must be small, so that we don't pin
+ * too much kernel memory (especially on vmkernel). We limit a queuepair to
+ * 32 KB, or 16 KB per queue for symmetrical pairs.
+ */
+#define VMCI_MAX_PINNED_QP_MEMORY (32 * 1024)
+
+/*
+ * We have a fixed set of resource IDs available in the VMX.
+ * This allows us to have a very simple implementation since we statically
+ * know how many will create datagram handles. If a new caller arrives and
+ * we have run out of slots we can manually increment the maximum size of
+ * available resource IDs.
+ *
+ * VMCI reserved hypervisor datagram resource IDs.
+ */
+enum {
+ VMCI_RESOURCES_QUERY = 0,
+ VMCI_GET_CONTEXT_ID = 1,
+ VMCI_SET_NOTIFY_BITMAP = 2,
+ VMCI_DOORBELL_LINK = 3,
+ VMCI_DOORBELL_UNLINK = 4,
+ VMCI_DOORBELL_NOTIFY = 5,
+ /*
+ * VMCI_DATAGRAM_REQUEST_MAP and VMCI_DATAGRAM_REMOVE_MAP are
+ * obsoleted by the removal of VM to VM communication.
+ */
+ VMCI_DATAGRAM_REQUEST_MAP = 6,
+ VMCI_DATAGRAM_REMOVE_MAP = 7,
+ VMCI_EVENT_SUBSCRIBE = 8,
+ VMCI_EVENT_UNSUBSCRIBE = 9,
+ VMCI_QUEUEPAIR_ALLOC = 10,
+ VMCI_QUEUEPAIR_DETACH = 11,
+
+ /*
+ * VMCI_VSOCK_VMX_LOOKUP was assigned to 12 for Fusion 3.0/3.1,
+ * WS 7.0/7.1 and ESX 4.1
+ */
+ VMCI_HGFS_TRANSPORT = 13,
+ VMCI_UNITY_PBRPC_REGISTER = 14,
+ VMCI_RPC_PRIVILEGED = 15,
+ VMCI_RPC_UNPRIVILEGED = 16,
+ VMCI_RESOURCE_MAX = 17,
+};
+
+/*
+ * struct vmci_handle - Ownership information structure
+ * @context: The VMX context ID.
+ * @resource: The resource ID (used for locating in resource hash).
+ *
+ * The vmci_handle structure is used to track resources used within
+ * vmw_vmci.
+ */
+struct vmci_handle {
+ u32 context;
+ u32 resource;
+};
+
+#define vmci_make_handle(_cid, _rid) \
+ (struct vmci_handle){ .context = _cid, .resource = _rid }
+
+static inline bool vmci_handle_is_equal(struct vmci_handle h1,
+ struct vmci_handle h2)
+{
+ return h1.context == h2.context && h1.resource == h2.resource;
+}
+
+#define VMCI_INVALID_ID ~0
+static const struct vmci_handle VMCI_INVALID_HANDLE = {
+ .context = VMCI_INVALID_ID,
+ .resource = VMCI_INVALID_ID
+};
+
+static inline bool vmci_handle_is_invalid(struct vmci_handle h)
+{
+ return vmci_handle_is_equal(h, VMCI_INVALID_HANDLE);
+}
+
+/*
+ * The below defines can be used to send anonymous requests.
+ * This also indicates that no response is expected.
+ */
+#define VMCI_ANON_SRC_CONTEXT_ID VMCI_INVALID_ID
+#define VMCI_ANON_SRC_RESOURCE_ID VMCI_INVALID_ID
+static const struct vmci_handle VMCI_ANON_SRC_HANDLE = {
+ .context = VMCI_ANON_SRC_CONTEXT_ID,
+ .resource = VMCI_ANON_SRC_RESOURCE_ID
+};
+
+/* The lowest 16 context ids are reserved for internal use. */
+#define VMCI_RESERVED_CID_LIMIT ((u32) 16)
+
+/*
+ * Hypervisor context id, used for calling into hypervisor
+ * supplied services from the VM.
+ */
+#define VMCI_HYPERVISOR_CONTEXT_ID 0
+
+/*
+ * Well-known context id, a logical context that contains a set of
+ * well-known services. This context ID is now obsolete.
+ */
+#define VMCI_WELL_KNOWN_CONTEXT_ID 1
+
+/*
+ * Context ID used by host endpoints.
+ */
+#define VMCI_HOST_CONTEXT_ID 2
+
+#define VMCI_CONTEXT_IS_VM(_cid) (VMCI_INVALID_ID != (_cid) && \
+ (_cid) > VMCI_HOST_CONTEXT_ID)
+
+/*
+ * The VMCI_CONTEXT_RESOURCE_ID is used together with vmci_make_handle to make
+ * handles that refer to a specific context.
+ */
+#define VMCI_CONTEXT_RESOURCE_ID 0
+
+/*
+ * VMCI error codes.
+ */
+enum {
+ VMCI_SUCCESS_QUEUEPAIR_ATTACH = 5,
+ VMCI_SUCCESS_QUEUEPAIR_CREATE = 4,
+ VMCI_SUCCESS_LAST_DETACH = 3,
+ VMCI_SUCCESS_ACCESS_GRANTED = 2,
+ VMCI_SUCCESS_ENTRY_DEAD = 1,
+ VMCI_SUCCESS = 0,
+ VMCI_ERROR_INVALID_RESOURCE = (-1),
+ VMCI_ERROR_INVALID_ARGS = (-2),
+ VMCI_ERROR_NO_MEM = (-3),
+ VMCI_ERROR_DATAGRAM_FAILED = (-4),
+ VMCI_ERROR_MORE_DATA = (-5),
+ VMCI_ERROR_NO_MORE_DATAGRAMS = (-6),
+ VMCI_ERROR_NO_ACCESS = (-7),
+ VMCI_ERROR_NO_HANDLE = (-8),
+ VMCI_ERROR_DUPLICATE_ENTRY = (-9),
+ VMCI_ERROR_DST_UNREACHABLE = (-10),
+ VMCI_ERROR_PAYLOAD_TOO_LARGE = (-11),
+ VMCI_ERROR_INVALID_PRIV = (-12),
+ VMCI_ERROR_GENERIC = (-13),
+ VMCI_ERROR_PAGE_ALREADY_SHARED = (-14),
+ VMCI_ERROR_CANNOT_SHARE_PAGE = (-15),
+ VMCI_ERROR_CANNOT_UNSHARE_PAGE = (-16),
+ VMCI_ERROR_NO_PROCESS = (-17),
+ VMCI_ERROR_NO_DATAGRAM = (-18),
+ VMCI_ERROR_NO_RESOURCES = (-19),
+ VMCI_ERROR_UNAVAILABLE = (-20),
+ VMCI_ERROR_NOT_FOUND = (-21),
+ VMCI_ERROR_ALREADY_EXISTS = (-22),
+ VMCI_ERROR_NOT_PAGE_ALIGNED = (-23),
+ VMCI_ERROR_INVALID_SIZE = (-24),
+ VMCI_ERROR_REGION_ALREADY_SHARED = (-25),
+ VMCI_ERROR_TIMEOUT = (-26),
+ VMCI_ERROR_DATAGRAM_INCOMPLETE = (-27),
+ VMCI_ERROR_INCORRECT_IRQL = (-28),
+ VMCI_ERROR_EVENT_UNKNOWN = (-29),
+ VMCI_ERROR_OBSOLETE = (-30),
+ VMCI_ERROR_QUEUEPAIR_MISMATCH = (-31),
+ VMCI_ERROR_QUEUEPAIR_NOTSET = (-32),
+ VMCI_ERROR_QUEUEPAIR_NOTOWNER = (-33),
+ VMCI_ERROR_QUEUEPAIR_NOTATTACHED = (-34),
+ VMCI_ERROR_QUEUEPAIR_NOSPACE = (-35),
+ VMCI_ERROR_QUEUEPAIR_NODATA = (-36),
+ VMCI_ERROR_BUSMEM_INVALIDATION = (-37),
+ VMCI_ERROR_MODULE_NOT_LOADED = (-38),
+ VMCI_ERROR_DEVICE_NOT_FOUND = (-39),
+ VMCI_ERROR_QUEUEPAIR_NOT_READY = (-40),
+ VMCI_ERROR_WOULD_BLOCK = (-41),
+
+ /* VMCI clients should return error code within this range */
+ VMCI_ERROR_CLIENT_MIN = (-500),
+ VMCI_ERROR_CLIENT_MAX = (-550),
+
+ /* Internal error codes. */
+ VMCI_SHAREDMEM_ERROR_BAD_CONTEXT = (-1000),
+};
+
+/* VMCI reserved events. */
+enum {
+ /* Only applicable to guest endpoints */
+ VMCI_EVENT_CTX_ID_UPDATE = 0,
+
+ /* Applicable to guest and host */
+ VMCI_EVENT_CTX_REMOVED = 1,
+
+ /* Only applicable to guest endpoints */
+ VMCI_EVENT_QP_RESUMED = 2,
+
+ /* Applicable to guest and host */
+ VMCI_EVENT_QP_PEER_ATTACH = 3,
+
+ /* Applicable to guest and host */
+ VMCI_EVENT_QP_PEER_DETACH = 4,
+
+ /*
+ * Applicable to VMX and vmk. On vmk,
+ * this event has the Context payload type.
+ */
+ VMCI_EVENT_MEM_ACCESS_ON = 5,
+
+ /*
+ * Applicable to VMX and vmk. Same as
+ * above for the payload type.
+ */
+ VMCI_EVENT_MEM_ACCESS_OFF = 6,
+ VMCI_EVENT_MAX = 7,
+};
+
+/*
+ * Of the above events, a few are reserved for use in the VMX, and
+ * other endpoints (guest and host kernel) should not use them. For
+ * the rest of the events, we allow both host and guest endpoints to
+ * subscribe to them, to maintain the same API for host and guest
+ * endpoints.
+ */
+#define VMCI_EVENT_VALID_VMX(_event) ((_event) == VMCI_EVENT_MEM_ACCESS_ON || \
+ (_event) == VMCI_EVENT_MEM_ACCESS_OFF)
+
+#define VMCI_EVENT_VALID(_event) ((_event) < VMCI_EVENT_MAX && \
+ !VMCI_EVENT_VALID_VMX(_event))
+
+/* Reserved guest datagram resource ids. */
+#define VMCI_EVENT_HANDLER 0
+
+/*
+ * VMCI coarse-grained privileges (per context or host
+ * process/endpoint. An entity with the restricted flag is only
+ * allowed to interact with the hypervisor and trusted entities.
+ */
+enum {
+ VMCI_NO_PRIVILEGE_FLAGS = 0,
+ VMCI_PRIVILEGE_FLAG_RESTRICTED = 1,
+ VMCI_PRIVILEGE_FLAG_TRUSTED = 2,
+ VMCI_PRIVILEGE_ALL_FLAGS = (VMCI_PRIVILEGE_FLAG_RESTRICTED |
+ VMCI_PRIVILEGE_FLAG_TRUSTED),
+ VMCI_DEFAULT_PROC_PRIVILEGE_FLAGS = VMCI_NO_PRIVILEGE_FLAGS,
+ VMCI_LEAST_PRIVILEGE_FLAGS = VMCI_PRIVILEGE_FLAG_RESTRICTED,
+ VMCI_MAX_PRIVILEGE_FLAGS = VMCI_PRIVILEGE_FLAG_TRUSTED,
+};
+
+/* 0 through VMCI_RESERVED_RESOURCE_ID_MAX are reserved. */
+#define VMCI_RESERVED_RESOURCE_ID_MAX 1023
+
+/*
+ * Driver version.
+ *
+ * Increment major version when you make an incompatible change.
+ * Compatibility goes both ways (old driver with new executable
+ * as well as new driver with old executable).
+ */
+
+/* Never change VMCI_VERSION_SHIFT_WIDTH */
+#define VMCI_VERSION_SHIFT_WIDTH 16
+#define VMCI_MAKE_VERSION(_major, _minor) \
+ ((_major) << VMCI_VERSION_SHIFT_WIDTH | (u16) (_minor))
+
+#define VMCI_VERSION_MAJOR(v) ((u32) (v) >> VMCI_VERSION_SHIFT_WIDTH)
+#define VMCI_VERSION_MINOR(v) ((u16) (v))
+
+/*
+ * VMCI_VERSION is always the current version. Subsequently listed
+ * versions are ways of detecting previous versions of the connecting
+ * application (i.e., VMX).
+ *
+ * VMCI_VERSION_NOVMVM: This version removed support for VM to VM
+ * communication.
+ *
+ * VMCI_VERSION_NOTIFY: This version introduced doorbell notification
+ * support.
+ *
+ * VMCI_VERSION_HOSTQP: This version introduced host end point support
+ * for hosted products.
+ *
+ * VMCI_VERSION_PREHOSTQP: This is the version prior to the adoption of
+ * support for host end-points.
+ *
+ * VMCI_VERSION_PREVERS2: This fictional version number is intended to
+ * represent the version of a VMX which doesn't call into the driver
+ * with ioctl VERSION2 and thus doesn't establish its version with the
+ * driver.
+ */
+
+#define VMCI_VERSION VMCI_VERSION_NOVMVM
+#define VMCI_VERSION_NOVMVM VMCI_MAKE_VERSION(11, 0)
+#define VMCI_VERSION_NOTIFY VMCI_MAKE_VERSION(10, 0)
+#define VMCI_VERSION_HOSTQP VMCI_MAKE_VERSION(9, 0)
+#define VMCI_VERSION_PREHOSTQP VMCI_MAKE_VERSION(8, 0)
+#define VMCI_VERSION_PREVERS2 VMCI_MAKE_VERSION(1, 0)
+
+#define VMCI_SOCKETS_MAKE_VERSION(_p) \
+ ((((_p)[0] & 0xFF) << 24) | (((_p)[1] & 0xFF) << 16) | ((_p)[2]))
+
+/*
+ * The VMCI IOCTLs. We use identity code 7, as noted in ioctl-number.h, and
+ * we start at sequence 9f. This gives us the same values that our shipping
+ * products use, starting at 1951, provided we leave out the direction and
+ * structure size. Note that VMMon occupies the block following us, starting
+ * at 2001.
+ */
+#define IOCTL_VMCI_VERSION _IO(7, 0x9f) /* 1951 */
+#define IOCTL_VMCI_INIT_CONTEXT _IO(7, 0xa0)
+#define IOCTL_VMCI_QUEUEPAIR_SETVA _IO(7, 0xa4)
+#define IOCTL_VMCI_NOTIFY_RESOURCE _IO(7, 0xa5)
+#define IOCTL_VMCI_NOTIFICATIONS_RECEIVE _IO(7, 0xa6)
+#define IOCTL_VMCI_VERSION2 _IO(7, 0xa7)
+#define IOCTL_VMCI_QUEUEPAIR_ALLOC _IO(7, 0xa8)
+#define IOCTL_VMCI_QUEUEPAIR_SETPAGEFILE _IO(7, 0xa9)
+#define IOCTL_VMCI_QUEUEPAIR_DETACH _IO(7, 0xaa)
+#define IOCTL_VMCI_DATAGRAM_SEND _IO(7, 0xab)
+#define IOCTL_VMCI_DATAGRAM_RECEIVE _IO(7, 0xac)
+#define IOCTL_VMCI_CTX_ADD_NOTIFICATION _IO(7, 0xaf)
+#define IOCTL_VMCI_CTX_REMOVE_NOTIFICATION _IO(7, 0xb0)
+#define IOCTL_VMCI_CTX_GET_CPT_STATE _IO(7, 0xb1)
+#define IOCTL_VMCI_CTX_SET_CPT_STATE _IO(7, 0xb2)
+#define IOCTL_VMCI_GET_CONTEXT_ID _IO(7, 0xb3)
+#define IOCTL_VMCI_SOCKETS_VERSION _IO(7, 0xb4)
+#define IOCTL_VMCI_SOCKETS_GET_AF_VALUE _IO(7, 0xb8)
+#define IOCTL_VMCI_SOCKETS_GET_LOCAL_CID _IO(7, 0xb9)
+#define IOCTL_VMCI_SET_NOTIFY _IO(7, 0xcb) /* 1995 */
+/*IOCTL_VMMON_START _IO(7, 0xd1)*/ /* 2001 */
+
+/*
+ * struct vmci_queue_header - VMCI Queue Header information.
+ *
+ * A Queue cannot stand by itself as designed. Each Queue's header
+ * contains a pointer into itself (the producer_tail) and into its peer
+ * (consumer_head). The reason for the separation is one of
+ * accessibility: Each end-point can modify two things: where the next
+ * location to enqueue is within its produce_q (producer_tail); and
+ * where the next dequeue location is in its consume_q (consumer_head).
+ *
+ * An end-point cannot modify the pointers of its peer (guest to
+ * guest; NOTE that in the host both queue headers are mapped r/w).
+ * But, each end-point needs read access to both Queue header
+ * structures in order to determine how much space is used (or left)
+ * in the Queue. This is because for an end-point to know how full
+ * its produce_q is, it needs to use the consumer_head that points into
+ * the produce_q but -that- consumer_head is in the Queue header for
+ * that end-points consume_q.
+ *
+ * Thoroughly confused? Sorry.
+ *
+ * producer_tail: the point to enqueue new entrants. When you approach
+ * a line in a store, for example, you walk up to the tail.
+ *
+ * consumer_head: the point in the queue from which the next element is
+ * dequeued. In other words, who is next in line is he who is at the
+ * head of the line.
+ *
+ * Also, producer_tail points to an empty byte in the Queue, whereas
+ * consumer_head points to a valid byte of data (unless producer_tail ==
+ * consumer_head in which case consumer_head does not point to a valid
+ * byte of data).
+ *
+ * For a queue of buffer 'size' bytes, the tail and head pointers will be in
+ * the range [0, size-1].
+ *
+ * If produce_q_header->producer_tail == consume_q_header->consumer_head
+ * then the produce_q is empty.
+ */
+struct vmci_queue_header {
+ /* All fields are 64bit and aligned. */
+ struct vmci_handle handle; /* Identifier. */
+ atomic64_t producer_tail; /* Offset in this queue. */
+ atomic64_t consumer_head; /* Offset in peer queue. */
+};
+
+/*
+ * struct vmci_datagram - Base struct for vmci datagrams.
+ * @dst: A vmci_handle that tracks the destination of the datagram.
+ * @src: A vmci_handle that tracks the source of the datagram.
+ * @payload_size: The size of the payload.
+ *
+ * vmci_datagram structs are used when sending vmci datagrams. They include
+ * the necessary source and destination information to properly route
+ * the information along with the size of the package.
+ */
+struct vmci_datagram {
+ struct vmci_handle dst;
+ struct vmci_handle src;
+ u64 payload_size;
+};
+
+/*
+ * Second flag is for creating a well-known handle instead of a per context
+ * handle. Next flag is for deferring datagram delivery, so that the
+ * datagram callback is invoked in a delayed context (not interrupt context).
+ */
+#define VMCI_FLAG_DG_NONE 0
+#define VMCI_FLAG_WELLKNOWN_DG_HND 0x1
+#define VMCI_FLAG_ANYCID_DG_HND 0x2
+#define VMCI_FLAG_DG_DELAYED_CB 0x4
+
+/*
+ * Maximum supported size of a VMCI datagram for routable datagrams.
+ * Datagrams going to the hypervisor are allowed to be larger.
+ */
+#define VMCI_MAX_DG_SIZE (17 * 4096)
+#define VMCI_MAX_DG_PAYLOAD_SIZE (VMCI_MAX_DG_SIZE - \
+ sizeof(struct vmci_datagram))
+#define VMCI_DG_PAYLOAD(_dg) (void *)((char *)(_dg) + \
+ sizeof(struct vmci_datagram))
+#define VMCI_DG_HEADERSIZE sizeof(struct vmci_datagram)
+#define VMCI_DG_SIZE(_dg) (VMCI_DG_HEADERSIZE + (size_t)(_dg)->payload_size)
+#define VMCI_DG_SIZE_ALIGNED(_dg) ((VMCI_DG_SIZE(_dg) + 7) & (~((size_t) 0x7)))
+#define VMCI_MAX_DATAGRAM_QUEUE_SIZE (VMCI_MAX_DG_SIZE * 2)
+
+struct vmci_event_payload_qp {
+ struct vmci_handle handle; /* queue_pair handle. */
+ u32 peer_id; /* Context id of attaching/detaching VM. */
+ u32 _pad;
+};
+
+/* Flags for VMCI queue_pair API. */
+enum {
+ /* Fail alloc if QP not created by peer. */
+ VMCI_QPFLAG_ATTACH_ONLY = 1 << 0,
+
+ /* Only allow attaches from local context. */
+ VMCI_QPFLAG_LOCAL = 1 << 1,
+
+ /* Host won't block when guest is quiesced. */
+ VMCI_QPFLAG_NONBLOCK = 1 << 2,
+
+ /* Pin data pages in ESX. Used with NONBLOCK */
+ VMCI_QPFLAG_PINNED = 1 << 3,
+
+ /* Update the following flag when adding new flags. */
+ VMCI_QP_ALL_FLAGS = (VMCI_QPFLAG_ATTACH_ONLY | VMCI_QPFLAG_LOCAL |
+ VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED),
+
+ /* Convenience flags */
+ VMCI_QP_ASYMM = (VMCI_QPFLAG_NONBLOCK | VMCI_QPFLAG_PINNED),
+ VMCI_QP_ASYMM_PEER = (VMCI_QPFLAG_ATTACH_ONLY | VMCI_QP_ASYMM),
+};
+
+/*
+ * We allow at least 1024 more event datagrams from the hypervisor past the
+ * normally allowed datagrams pending for a given context. We define this
+ * limit on event datagrams from the hypervisor to guard against DoS attack
+ * from a malicious VM which could repeatedly attach to and detach from a queue
+ * pair, causing events to be queued at the destination VM. However, the rate
+ * at which such events can be generated is small since it requires a VM exit
+ * and handling of queue pair attach/detach call at the hypervisor. Event
+ * datagrams may be queued up at the destination VM if it has interrupts
+ * disabled or if it is not draining events for some other reason. 1024
+ * datagrams is a grossly conservative estimate of the time for which
+ * interrupts may be disabled in the destination VM, but at the same time does
+ * not exacerbate the memory pressure problem on the host by much (size of each
+ * event datagram is small).
+ */
+#define VMCI_MAX_DATAGRAM_AND_EVENT_QUEUE_SIZE \
+ (VMCI_MAX_DATAGRAM_QUEUE_SIZE + \
+ 1024 * (sizeof(struct vmci_datagram) + \
+ sizeof(struct vmci_event_data_max)))
+
+/*
+ * Struct used for querying, via VMCI_RESOURCES_QUERY, the availability of
+ * hypervisor resources. Struct size is 16 bytes. All fields in struct are
+ * aligned to their natural alignment.
+ */
+struct vmci_resource_query_hdr {
+ struct vmci_datagram hdr;
+ u32 num_resources;
+ u32 _padding;
+};
+
+/*
+ * Convenience struct for negotiating vectors. Must match layout of
+ * VMCIResourceQueryHdr minus the struct vmci_datagram header.
+ */
+struct vmci_resource_query_msg {
+ u32 num_resources;
+ u32 _padding;
+ u32 resources[1];
+};
+
+/*
+ * The maximum number of resources that can be queried using
+ * VMCI_RESOURCE_QUERY is 31, as the result is encoded in the lower 31
+ * bits of a positive return value. Negative values are reserved for
+ * errors.
+ */
+#define VMCI_RESOURCE_QUERY_MAX_NUM 31
+
+/* Maximum size for the VMCI_RESOURCE_QUERY request. */
+#define VMCI_RESOURCE_QUERY_MAX_SIZE \
+ (sizeof(struct vmci_resource_query_hdr) + \
+ sizeof(u32) * VMCI_RESOURCE_QUERY_MAX_NUM)
+
+/*
+ * Struct used for setting the notification bitmap. All fields in
+ * struct are aligned to their natural alignment.
+ */
+struct vmci_notify_bm_set_msg {
+ struct vmci_datagram hdr;
+ u32 bitmap_ppn;
+ u32 _pad;
+};
+
+/*
+ * Struct used for linking a doorbell handle with an index in the
+ * notify bitmap. All fields in struct are aligned to their natural
+ * alignment.
+ */
+struct vmci_doorbell_link_msg {
+ struct vmci_datagram hdr;
+ struct vmci_handle handle;
+ u64 notify_idx;
+};
+
+/*
+ * Struct used for unlinking a doorbell handle from an index in the
+ * notify bitmap. All fields in struct are aligned to their natural
+ * alignment.
+ */
+struct vmci_doorbell_unlink_msg {
+ struct vmci_datagram hdr;
+ struct vmci_handle handle;
+};
+
+/*
+ * Struct used for generating a notification on a doorbell handle. All
+ * fields in struct are aligned to their natural alignment.
+ */
+struct vmci_doorbell_notify_msg {
+ struct vmci_datagram hdr;
+ struct vmci_handle handle;
+};
+
+/*
+ * This struct is used to contain data for events. Size of this struct is a
+ * multiple of 8 bytes, and all fields are aligned to their natural alignment.
+ */
+struct vmci_event_data {
+ u32 event; /* 4 bytes. */
+ u32 _pad;
+ /* Event payload is put here. */
+};
+
+/*
+ * Define the different VMCI_EVENT payload data types here. All structs must
+ * be a multiple of 8 bytes, and fields must be aligned to their natural
+ * alignment.
+ */
+struct vmci_event_payld_ctx {
+ u32 context_id; /* 4 bytes. */
+ u32 _pad;
+};
+
+struct vmci_event_payld_qp {
+ struct vmci_handle handle; /* queue_pair handle. */
+ u32 peer_id; /* Context id of attaching/detaching VM. */
+ u32 _pad;
+};
+
+/*
+ * We define the following struct to get the size of the maximum event
+ * data the hypervisor may send to the guest. If adding a new event
+ * payload type above, add it to the following struct too (inside the
+ * union).
+ */
+struct vmci_event_data_max {
+ struct vmci_event_data event_data;
+ union {
+ struct vmci_event_payld_ctx context_payload;
+ struct vmci_event_payld_qp qp_payload;
+ } ev_data_payload;
+};
+
+/*
+ * Struct used for VMCI_EVENT_SUBSCRIBE/UNSUBSCRIBE and
+ * VMCI_EVENT_HANDLER messages. Struct size is 32 bytes. All fields
+ * in struct are aligned to their natural alignment.
+ */
+struct vmci_event_msg {
+ struct vmci_datagram hdr;
+
+ /* Has event type and payload. */
+ struct vmci_event_data event_data;
+
+ /* Payload gets put here. */
+};
+
+/* Event with context payload. */
+struct vmci_event_ctx {
+ struct vmci_event_msg msg;
+ struct vmci_event_payld_ctx payload;
+};
+
+/* Event with QP payload. */
+struct vmci_event_qp {
+ struct vmci_event_msg msg;
+ struct vmci_event_payld_qp payload;
+};
+
+/*
+ * Structs used for queue_pair alloc and detach messages. We align fields of
+ * these structs to 64bit boundaries.
+ */
+struct vmci_qp_alloc_msg {
+ struct vmci_datagram hdr;
+ struct vmci_handle handle;
+ u32 peer;
+ u32 flags;
+ u64 produce_size;
+ u64 consume_size;
+ u64 num_ppns;
+
+ /* List of PPNs placed here. */
+};
+
+struct vmci_qp_detach_msg {
+ struct vmci_datagram hdr;
+ struct vmci_handle handle;
+};
+
+/* VMCI Doorbell API. */
+#define VMCI_FLAG_DELAYED_CB 0x01
+
+typedef void (*vmci_callback) (void *client_data);
+
+/*
+ * struct vmci_qp - A vmw_vmci queue pair handle.
+ *
+ * This structure is used as a handle to a queue pair created by
+ * VMCI. It is intentionally left opaque to clients.
+ */
+struct vmci_qp;
+
+/* Callback needed for correctly waiting on events. */
+typedef int (*vmci_datagram_recv_cb) (void *client_data,
+ struct vmci_datagram *msg);
+
+/* VMCI Event API. */
+typedef void (*vmci_event_cb) (u32 sub_id, const struct vmci_event_data *ed,
+ void *client_data);
+
+/*
+ * We use the following inline function to access the payload data
+ * associated with an event data.
+ */
+static inline const void *
+vmci_event_data_const_payload(const struct vmci_event_data *ev_data)
+{
+ return (const char *)ev_data + sizeof(*ev_data);
+}
+
+static inline void *vmci_event_data_payload(struct vmci_event_data *ev_data)
+{
+ return (void *)vmci_event_data_const_payload(ev_data);
+}
+
+/*
+ * Helper to add a given offset to a head or tail pointer. Wraps the
+ * value of the pointer around the max size of the queue.
+ */
+static inline void vmci_qp_add_pointer(atomic64_t *var,
+ size_t add,
+ u64 size)
+{
+ u64 new_val = atomic64_read(var);
+
+ if (new_val >= size - add)
+ new_val -= size;
+
+ new_val += add;
+
+ atomic64_set(var, new_val);
+}
+
+/*
+ * Helper routine to get the Producer Tail from the supplied queue.
+ */
+static inline u64
+vmci_q_header_producer_tail(const struct vmci_queue_header *q_header)
+{
+ struct vmci_queue_header *qh = (struct vmci_queue_header *)q_header;
+ return atomic64_read(&qh->producer_tail);
+}
+
+/*
+ * Helper routine to get the Consumer Head from the supplied queue.
+ */
+static inline u64
+vmci_q_header_consumer_head(const struct vmci_queue_header *q_header)
+{
+ struct vmci_queue_header *qh = (struct vmci_queue_header *)q_header;
+ return atomic64_read(&qh->consumer_head);
+}
+
+/*
+ * Helper routine to increment the Producer Tail. Fundamentally,
+ * vmci_qp_add_pointer() is used to manipulate the tail itself.
+ */
+static inline void
+vmci_q_header_add_producer_tail(struct vmci_queue_header *q_header,
+ size_t add,
+ u64 queue_size)
+{
+ vmci_qp_add_pointer(&q_header->producer_tail, add, queue_size);
+}
+
+/*
+ * Helper routine to increment the Consumer Head. Fundamentally,
+ * vmci_qp_add_pointer() is used to manipulate the head itself.
+ */
+static inline void
+vmci_q_header_add_consumer_head(struct vmci_queue_header *q_header,
+ size_t add,
+ u64 queue_size)
+{
+ vmci_qp_add_pointer(&q_header->consumer_head, add, queue_size);
+}
+
+/*
+ * Helper routine for getting the head and the tail pointer for a queue.
+ * Both the VMCIQueues are needed to get both the pointers for one queue.
+ */
+static inline void
+vmci_q_header_get_pointers(const struct vmci_queue_header *produce_q_header,
+ const struct vmci_queue_header *consume_q_header,
+ u64 *producer_tail,
+ u64 *consumer_head)
+{
+ if (producer_tail)
+ *producer_tail = vmci_q_header_producer_tail(produce_q_header);
+
+ if (consumer_head)
+ *consumer_head = vmci_q_header_consumer_head(consume_q_header);
+}
+
+static inline void vmci_q_header_init(struct vmci_queue_header *q_header,
+ const struct vmci_handle handle)
+{
+ q_header->handle = handle;
+ atomic64_set(&q_header->producer_tail, 0);
+ atomic64_set(&q_header->consumer_head, 0);
+}
+
+/*
+ * Finds available free space in a produce queue to enqueue more
+ * data or reports an error if queue pair corruption is detected.
+ */
+static s64
+vmci_q_header_free_space(const struct vmci_queue_header *produce_q_header,
+ const struct vmci_queue_header *consume_q_header,
+ const u64 produce_q_size)
+{
+ u64 tail;
+ u64 head;
+ u64 free_space;
+
+ tail = vmci_q_header_producer_tail(produce_q_header);
+ head = vmci_q_header_consumer_head(consume_q_header);
+
+ if (tail >= produce_q_size || head >= produce_q_size)
+ return VMCI_ERROR_INVALID_SIZE;
+
+ /*
+ * Deduct 1 to avoid tail becoming equal to head which causes
+ * ambiguity. If head and tail are equal it means that the
+ * queue is empty.
+ */
+ if (tail >= head)
+ free_space = produce_q_size - (tail - head) - 1;
+ else
+ free_space = head - tail - 1;
+
+ return free_space;
+}
+
+/*
+ * vmci_q_header_free_space() does all the heavy lifting of
+ * determing the number of free bytes in a Queue. This routine,
+ * then subtracts that size from the full size of the Queue so
+ * the caller knows how many bytes are ready to be dequeued.
+ * Results:
+ * On success, available data size in bytes (up to MAX_INT64).
+ * On failure, appropriate error code.
+ */
+static inline s64
+vmci_q_header_buf_ready(const struct vmci_queue_header *consume_q_header,
+ const struct vmci_queue_header *produce_q_header,
+ const u64 consume_q_size)
+{
+ s64 free_space;
+
+ free_space = vmci_q_header_free_space(consume_q_header,
+ produce_q_header, consume_q_size);
+ if (free_space < VMCI_SUCCESS)
+ return free_space;
+
+ return consume_q_size - free_space - 1;
+}
+
+
+#endif /* _VMW_VMCI_DEF_H_ */