On Mon, May 02, 2011 at 11:02:22AM +0200, Gerd Hoffmann wrote: > Hi, > > >The bigger hack called "qxl_terse" I didn't even send :) ok, so now I get > >to either keep this in my closet or think of how to do a minimal acceptable > >qemu logging infrastructure that would let me register a logging handle and > >use that to redirect to a chardev (they would all default to being muxed over > >stdio?) > > > >QemuLogger *qemu_create_logger(const char *logger_id); > > - logger_id is used to match to the chardev given on the command line > > - need to prevent collision, so probably easier to have a logger_id be an > > int > > and have that looked up to a string in an automatically generated table? > > What I have in mind is a simple dbg_print() function, integrated > with qdev and simliar to what the linux kernel has, i.e. something > like: > > int dbg_print(DeviceState *qdev, int loglevel, const char *fmt, ...); > > This can basically be used that as drop-in replacement for the > fprintf(stderr, fmt, ...) style found in many drivers. > > dbg_print would get the driver name via qdev->info->name, get the > instance via qdev->parent_bus->info->get_dev_path(), get a > timestamp, then create a standard prefix for all messages for easy > grepping. It would also check qdev->loglevel to figure whenever the > message should be printed or not. All devices get a property to set > qdev->loglevel, so all logging can be configured at runtime per > device. > > Messages go to stderr by default. A -debug switch could be added to > route them another way. > > Comments in the idea?
The thing with grepping is that it conflicts with using the monitor on stdout, which is why I wanted to use a chardev. And of course a chardev solves the need for grep (at least to get a coarse level - of course you still need to grep later). dbg_print takes care of making it standard to have a loglevel and prefix, sounds good, but I'd still like to know if it is acceptable to also redirect with -debug, I guess reusing the DeviceState then, instead of my added struct, so just letting DeviceState.debug_chardev == NULL by default, and settable with -debug <devname>,id=<chardev_id> > > cheers, > Gerd > >
