On 14 August 2017 at 07:26, Sam <batmanu...@gmail.com> wrote: > Hi all, > > I add some log like this in QEMU_SRC/hw/i386/pc.c > > +++ b/hw/i386/pc.c >> >> @@ -1364,6 +1364,13 @@ void pc_memory_init(PCMachineState *pcms, >> >> >>> linux_boot = (machine->kernel_filename != NULL); >> >> >>> + /* add for qemu start speed */ >> >> + time_t rawtime; >> >> + struct tm * timeinfo; >> >> + time ( &rawtime ); >> >> + timeinfo = localtime ( &rawtime ); >> >> + error_printf_unless_qmp("jpc_memory_init begin -- >>> %s\n",asctime(timeinfo)); >> >> + >> >> > Then I use `QEMU -D /qemu.log ...` command to start a vm, but I have seen > nothing in /qemu.log, I don't know why, and how to show my log while > starting qemu?
You haven't called a function that adds a message to the -d/-D qemu.log logging -- those are the ones declared in include/qemu/log.h. The function you have called is for printing error messages, which will be displayed to the QEMU monitor prompt if they were provoked by a monitor command, otherwise to stderr. It's not intended for general debug/progress logging. thanks -- PMM