On Tue, Apr 27, 2010 at 5:10 PM, Jan Kiszka <jan.kis...@siemens.com> wrote: > Jun Koi wrote: >> Hi, >> >> I am trying to debug a VM using gdb. I connected gdb to Qemu (latest >> code from git repo), and issued below command: >> >> ... >> (gdb) watch *0x77f44cd8 >> (gdb) c >> >> The idea is to catch the write access to address 0x77f44cd8. >> >> But after the "c" command, I saw that the window title of my VM >> continuously flip between "QEMU [Stopped]" and "QEMU", non-stop. >> This makes the VM unusable. >> >> Is it a bug? Anybody sees the same problem? > > I would bet your watchpoint was established by gdb as a software > watchpoint. In that case gdb will step through the target, checking > after each instruction if the memory changed.
But that is certainly not the reason of the symptom I saw. > > Is that address valid at the time gdb wants to install it? I saw gdb > choosing a software watchpoint before when it wasn't. Yes, that address is valid. thanks, J
