On Tue, May 01, 2012 at 04:31:44PM +0100, Stefan Hajnoczi wrote:
From: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> --- qemu-options.hx | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+)
diff --git a/qemu-options.hx b/qemu-options.hx index a169792..ccf4d1d 100644 --- a/qemu-options.hx +++ b/qemu-options.hx @@ -2724,6 +2724,48 @@ DEF("qtest-log", HAS_ARG, QEMU_OPTION_qtest_log, "-qtest-log LOG specify tracing options\n", QEMU_ARCH_ALL)
+DEF("open-hook-fd", HAS_ARG, QEMU_OPTION_open_hook_fd, + "-open-hook-fd <fd>\n" + " delegate opens to external process using <fd>\n", QEMU_ARCH_ALL) +STEXI +@item -open-hook-fd @var{fd} +@findex -open-hook-fd +Delegates open()s to an external process using @var<fd> to communicate commands. +@var<fd> should be an open Unix Domain socket pipe that file descriptors can be +received from. The protocol the socket uses is a simple request/response initiated +by the client. All integers are in host byte order. It is assumed that this protocol +is only ever used on the same physical machine. It is currently defined as: + +u32 message_size +u32 command +u8 payload[message_size - 8] + +The contents of payload depend on command. Currently the following commands are +defined: + +1. QEMU_OPEN (1) + +The full message will be: + +u32 message_size +u32 command = 1 +u32 flags (O_ flags defined by libc) +u32 mode (mode_t flags as defined by libc) +u16 filename_len; +u8 filename[filename_len] + +The server will then respond with: + +u32 message_size +u32 command = 1 +s32 result
If we're going for a binary protocol, then I'd like to see it defined based on the XDR specification, so we can auto-generate our data marshallers/demarshallers using existing tools / libraries and not have to write something custom by hand. Your spec here is close enough that it would not be significant work. The changes would be - Everything is always big-endian - Each field has 4-byte alignment - Strings would have a u32 length, and the payload padded with NUL to the 4 byte boundary Daniel. -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|