These patches apply to master (3-07-2011), and can also be obtained from: git://repo.or.cz/qemu/mdroth.git virtagent_v7
CHANGES IN V7: - Removed dependency on xmlrpc-c for data transport. Now using JSON via QEMU's qjson qobject<->json conversion routines. Binary encoding mechanisms such as Protocol Buffers and ASN.1/BER were considered, but due to limited library support, and limitations of isa/virtio serial transport that would have required an additional layer of encoding to reliably determine RPC boundaries during transport (more here: http://www.mail-archive.com/qemu-devel@nongnu.org/msg56237.html), qobject<->json seemed to be the most prudent route. - Logic to handle management/scheduling of bi-directional RPCs is now decoupled from transport layer for readability and better support for future additions such as session-level agents and threaded execution of RPCs. - Added thorough documentation of virtagent protocol to virtagent-manager.h - Improved documentation for RPCs - Fixes for guest agent lockfile handling - Removed viewdmesg/viewfile, will be replacing these with a more robust getfile RPC/command shortly - Workaround for guests that, in certain situations, fail to retrieve a pushed buffer from virtqueue in timely fashion (Rusty submitted patch several months ago, don't know the status) - Added guest agent support for switching isa-serial ports to RAW mode (previously reliant on socat intermediary) - Added tagging of RPCs to allow for multiple in-flight requests - qemu-va guest agent no longer builds as part of host tools target - Various other bug fixes and cleanups CHANGES IN V6: - Added a sentinel value to reliably detect the start of an "http" hdr. Used to skip past partially sent http content from previous "sessions" - Added http hdr tag (currently hardcoded for testing, will switch to uuid) to filter out valid-but-unexpected content in channel from previous "sessions" - Added timeout mechanism to avoid hanging monitor when agent isn't running - Added timed back-off on read's from a virtio-serial that result in ret=0 to avoid spinning if host isn't connected. - Added daemonize flags to qemu-va - Added sane defaults for channel type and virtio-serial port path - Various bug fixes for state machine/job handling logic CHANGES IN V5: - Dependency on virtproxy dropped, virtagent now handles transport and multiplexing of bi-directional RPCs internally - Removed duplification of qemu_set_fd_handler()-centered i/o code. Support for interacting with objects that use qemu_set_fd_handler() now available to tools via qemu-tools.c and a set of generalized utility functions - Fixed memory leaks in client/monitor functions - Various cleanups CHANGES IN V4: - Added guest agent capabilities negotiation - Added RPC/monitor command to invoke guest shutdown/reboot/powerdown - Added RPC/monitor command to the guest agent - Added guest startup notification ("hello") - Added syslog()'ing of guest agent RPCs - Various cleanups CHANGES IN V3: - Integrated virtagent server into virtproxy chardev. Usage examples below. - Consolidated RPC server/client setup into a pair of init routines - Fixed buffer overflow in agent_viewfile() and various memory leaks CHANGES IN V2: - All RPC communication is now done using asynchronous/non-blocking read/write handlers - Previously fork()'d RPC server loop is now integrated into qemu-vp/virtproxy i/o loop - Cleanups/suggestions from previous RFC OVERVIEW: There are a wide range of use cases motivating the need for a guest agent of some sort to extend the functionality/usability/control offered by QEMU. Some examples include graceful guest shutdown/reboot and notifications thereof, copy/paste syncing between host/guest, guest statistics gathering, file access, etc. Ideally these would all be served by a single, easilly extensible agent that can be deployed in a wide range of guests. Virtagent is an JSON RPC server, integrated into QEMU and a simple guest daemon, aimed at providing this type of functionality. DESIGN: There are actually 2 RPC servers: 1) a server in the guest agent which handles RPC requests from QEMU 2) a server in the host, integrated into the virtagent chardev, to handle RPC requests sent by the guest agent (mainly for handling asynchronous events reported by the agent). Communication is done via RPCs (JSON/HTTP between host and guest), albeit with a non-standard implementation that allows for multiplexing server/client RPC over a single virtio/isa serial channel. EXAMPLE USAGE: - Build into host: ./configure --target-list=x86_64-softmmu --enable-io-thread make - Build guest agent (in guest): ./configure --target-list=x86_64-softmmu --enabled-io-thread make qemu-va - Configure guest agent to talk to host via virtio-serial # start guest with virtio-serial/virtagent. for example (RHEL6): qemu \ -chardev virtagent,id=test0 \ -device virtio-serial \ -device virtserialport,chardev=test0,name=virtagent0 \ -monitor stdio ... # in the guest: sudo ./qemu-va -c virtio-serial -p /dev/virtio-ports/virtagent0 ... # monitor commands (qemu) va_ping status: success (qemu) va_viewfile /proc/meminfo MemTotal: 3985488 kB MemFree: 400524 kB Buffers: 220556 kB Cached: 2073160 kB SwapCached: 0 kB ... Hugepagesize: 2048 kB DirectMap4k: 8896 kB DirectMap2M: 4110336 kB (qemu) va_shutdown powerdown (qemu) KNOWN ISSUES/PLANS: - Implement RPCs for stateful open/read/close of guest files. - Implement RPC for guest script/command execution - Scan for sentinel value while reading http content as well to immediately detect truncated requests/responses and avoid accidentally consuming new ones - switch to standard logging/trace mechanisms - the client socket that qemu connects to send RPCs is a hardcoded filepath. This is unacceptable as the socket is channel/process specific and things will break when multiple guests are started. Makefile | 4 +- Makefile.objs | 2 +- Makefile.target | 2 +- cpus.c | 83 +------- hmp-commands.hx | 48 +++++ monitor.c | 1 + qemu-char.c | 44 ++++ qemu-char.h | 4 + qemu-ioh.c | 210 ++++++++++++++++++++ qemu-ioh.h | 43 ++++ qemu-tool.c | 115 +++++++++++- qemu-tool.h | 26 +++ qemu-va.c | 247 +++++++++++++++++++++++ qerror.c | 8 + qerror.h | 6 + qmp-commands.hx | 97 +++++++++ roms/seabios | 2 +- virtagent-common.c | 206 +++++++++++++++++++ virtagent-common.h | 95 +++++++++ virtagent-manager.c | 326 ++++++++++++++++++++++++++++++ virtagent-manager.h | 130 ++++++++++++ virtagent-server.c | 387 ++++++++++++++++++++++++++++++++++++ virtagent-server.h | 40 ++++ virtagent-transport.c | 432 ++++++++++++++++++++++++++++++++++++++++ virtagent.c | 524 +++++++++++++++++++++++++++++++++++++++++++++++++ virtagent.h | 51 +++++ vl.c | 86 ++------- 27 files changed, 3071 insertions(+), 148 deletions(-)