Network-connected analog processor QEMU monitor

1. QEMU monitor supports remote telnet access:

[Root@kvm-host ~]# qemu-system-x86_64-enable-kvm-smp 2-m 1024 vm2.img-monitor

For the-monitor option here, make the following note:

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Tcp–raw TCP sockets #下面第2点, my example is raw TCP socket Telnet–the Telnet protocol is used instead of raw TCP sockets. This is the preferred option over TCP as, can break out of the monitor using Ctrl-then typing quit. You can "T break out of the" monitor like this "connecting with the raw socket option 10.1.77.82–listen on this host/ip only. can use 127.0.0.1 if your want to only allow connections locally. If you are want to listen on the "any" IP address on the server, just leave this blank so your end up with two consecutive colons ie “::” . 4444–port number to listen on. Server–listening in Server mode Nowait–qemu'll wait for a client socket application to connect to the port before continuing unless this option are use D. In most cases you'll want to use the NOWAIT option.

Connect to remote Qemu monitor via telnet:

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jay@jay-linux:~$ telnet 10.1.77.82 4444 Trying 10.1.77.82 ... Connected to 10.1.77.82. Escape character is ' ^] '. QEMU 1.7.50 monitor-type ' help ' for more information (QEMU) Info KVM KVM support:enabled (QEMU) Info status VM status:running (QEMU) Help migrate Migrate [-d] [-b] [-i] URI--migrate to URI (using-d to Don't wait for completion) -B for migration without shared storage with full copy of disk I-migration without shared storage with incremental copy of disk (base image shared between SRC and destination) (QEMU) Ctrl +] (disconnect telnet connection) Telnet> quit (exit Telnet) Connection closed.

2. QEMU monitor supports remote access to RAW sockets:

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[Root@kvm-host ~]# qemu-system-x86_64-enable-kvm-smp 2-m 1024 vm2.img-monitor

You can use Netcat to connect to this socket:

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jay@jay-linux:~$ NC 10.1.77.82 4444 QEMU 1.7.50 monitor-type ' help ' for more information (QEMU) Info KVM Info KVM KVM support:enabled (QEMU) ^c

I wrote a socket program for example to connect monitor, the effect is as follows:

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jay@jay-linux:~/workspace/c-cpp.git/c2013$./monitor_client Sending command ' info KVM ' To remote QEMU monitor Output from Qemu monitor:qemu 1.7.50 monitor-type "Help" for more information ??,? Output from QEMU Monitor: (QEMU) Info KVM KVM support:enabled (QEMU)

The above example of the socket program that connects to monitor is:

Https://github.com/smilejay/c-cpp/blob/master/c2013/socket_qemu_monitor_client.c

The code is as follows

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/* SOCKET_QEMU_MONITOR_CLINET.C * Connect to remote QEMU monitor sockets and sending a command to the monitor. * Author:jay <smile665@gmail.com> */ #include <sys/types.h> #include <sys/socket.h> #include <stdio.h> #include <netinet/in.h> #include <arpa/inet.h> #include <unistd.h> #include <stdlib.h> #include <string.h> int main (int argc, char *argv[]) { int sockfd; int Len; struct SOCKADDR_IN address; int result; Char *cmd = "info kvmn"; Char output[200]; /* Create A socket for the client. */ SOCKFD = socket (af_inet, sock_stream, 0); /* Name the socket, as agreed with the server. */ address.sin_family = af_inet; ADDRESS.SIN_ADDR.S_ADDR = inet_addr ("10.1.77.82"); Address.sin_port = htons (4444); Len = sizeof (address); * Now connect our sockets to the server ' s socket. */ result = Connect (SOCKFD, (struct sockaddr *) &address, Len); if (result = = 1) { Perror ("Oops:socket connetion failed."); Exit (1); } /* We can now read/write via SOCKFD. */ printf ("Sending command '%s ' to remote QEMU monitorn", cmd); Write (sockfd, cmd, strlen (cmd)); Read (sockfd, output, sizeof (output)); printf ("Output from QEMU Monitor:%SN", output); Read (sockfd, output, sizeof (output)); printf ("Output from QEMU Monitor:%SN", output); Close (SOCKFD); Exit (0); }