Peter - Thanks for the clarification, that makes perfect sense.
In this case, using GDB is clearly the best way to go about the tracing. I appreciate your time! -S On Thu, Jun 24, 2021 at 1:51 PM Peter Maydell <peter.mayd...@linaro.org> wrote: > On Thu, 24 Jun 2021 at 18:09, Steven Raasch <sraa...@gmail.com> wrote: > > NOTE: I do not yet understand how gdb interacts with the virtual > machine. I have experience with GDB, but only at a linux app-debug level. I > don't grok how gdb on a linux host works with QEMU running a windows guest. > > My *assumption* is that the VM continues to run while an app is being > debugged with GDB can be stopped, stepped, etc. If this is the case, I > would expect that the VM's sense of time will continue to move forward > while the app is paused. This would be an issue for my time-sensitive app. > > No, that's not how it works. A gdb connected to QEMU's gdbstub is a > bit like a hardware JTAG debugger connected to a real CPU, if that > helps. When gdb gets control the entire VM is stopped; stepping > steps one instruction of whatever the VM is doing. gdb and the > gdbstub have no understanding of individual processes running > inside the guest OS -- single stepping will happily step through > the app, into interrupt handlers, across the OS context switching > and into other processes, etc. > > -- PMM >
