include/hw/remote/mpqemu-link.h

   1 /*
   2  * Communication channel between QEMU and remote device process
   3  *
   4  * Copyright © 2018, 2021 Oracle and/or its affiliates.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #ifndef MPQEMU_LINK_H
  12 #define MPQEMU_LINK_H
  13
  14 #include "qom/object.h"
  15 #include "qemu/thread.h"
  16 #include "io/channel.h"
  17 #include "exec/hwaddr.h"
  18
  19 #define REMOTE_MAX_FDS 8
  20
  21 #define MPQEMU_MSG_HDR_SIZE offsetof(MPQemuMsg, data.u64)
  22
  23 /**
  24  * MPQemuCmd:
  25  *
  26  * MPQemuCmd enum type to specify the command to be executed on the remote
  27  * device.
  28  *
  29  * This uses a private protocol between QEMU and the remote process. vfio-user
  30  * protocol would supersede this in the future.
  31  *
  32  */
  33 typedef enum {
  34     MPQEMU_CMD_SYNC_SYSMEM,
  35     MPQEMU_CMD_MAX,
  36 } MPQemuCmd;
  37
  38 typedef struct {
  39     hwaddr gpas[REMOTE_MAX_FDS];
  40     uint64_t sizes[REMOTE_MAX_FDS];
  41     off_t offsets[REMOTE_MAX_FDS];
  42 } SyncSysmemMsg;
  43
  44 /**
  45  * MPQemuMsg:
  46  * @cmd: The remote command
  47  * @size: Size of the data to be shared
  48  * @data: Structured data
  49  * @fds: File descriptors to be shared with remote device
  50  *
  51  * MPQemuMsg Format of the message sent to the remote device from QEMU.
  52  *
  53  */
  54
  55 typedef struct {
  56     int cmd;
  57     size_t size;
  58
  59     union {
  60         uint64_t u64;
  61         SyncSysmemMsg sync_sysmem;
  62     } data;
  63
  64     int fds[REMOTE_MAX_FDS];
  65     int num_fds;
  66 } MPQemuMsg;
  67
  68 bool mpqemu_msg_send(MPQemuMsg *msg, QIOChannel *ioc, Error **errp);
  69 bool mpqemu_msg_recv(MPQemuMsg *msg, QIOChannel *ioc, Error **errp);
  70
  71 bool mpqemu_msg_valid(MPQemuMsg *msg);
  72
  73 #endif