Execution Instruction Tracing

Execution Instruction Tracing

[Adnan Khaleel]

Hi there,

I'm a hardware designer and I'm interested in using Xen for a novel purpose and I'd like to know if this is possible at all.
One of my main problems has been the lack of decent execution traces for applications on real hardware. Needless to say this is a difficult task and I believe that virtual machine technology can play an important part in the solution. I recently posted a similar query to the Linux kernel develop group to see if there was a hack that would allow me to trace all instructions but apparently there isn't and most of the responses I got directed me to approach a full system emulator like Simics, SimNow, Bochs or qemu. All of these are wonderful pieces of software however I've worked with all of them and I've had problems with them trying to boot a modern operating system, be it Linux 2.6 or Win2k3, in a close to real configuration that is very stable. 

Since Xen includes a hypervisor, I want to explore the possibility of using that to record instructions executed; before we proceed any further I wanted to pose this question to the developers of Xen to see if this was indeed possible using a modified version of Xen. Although I have mentioned Win2k3 above, I would be more than happy if I could collect any traces using Linux, provided I can run a decent benchmark on it, say SpecJBB2000 or something similar. I've looked at the gdb-stub that Xen provides and that seems like an interesting way to start, however I would be interested in collecting system and user activity, along with identifiers for each. Additionally I would also like to obtain the process id of the current context.

I appreciate any responses or pointers you may have on this.

Sincerely,

Adnan Khaleel

Execution Instruction Tracing

[Adnan Khaleel]

Hi there,

I'm a hardware designer and I'm interested in using Xen for a novel purpose and I'd like to know if this is possible at all.
One of my main problems has been the lack of decent execution traces for applications on real hardware. Needless to say this is a difficult task and I believe that virtual machine technology can play an important part in the solution. I recently posted a similar query to the Linux kernel develop group to see if there was a hack that would allow me to trace all instructions but apparently there isn't and most of the responses I got directed me to approach a full system emulator like Simics, SimNow, Bochs or qemu. All of these are wonderful pieces of software however I've worked with all of them and I've had problems with them trying to boot a modern operating system, be it Linux 2.6 or Win2k3, in a close to real configuration that is very stable. 

Since Xen includes a hypervisor, I want to explore the possibility of using that to record instructions executed; before we proceed any further I wanted to pose this question to the developers of Xen to see if this was indeed possible using a modified version of Xen. Although I have mentioned Win2k3 above, I would be more than happy if I could collect any traces using Linux, provided I can run a decent benchmark on it, say SpecJBB2000 or something similar. I've looked at the gdb-stub that Xen provides and that seems like an interesting way to start, however I would be interested in collecting system and user activity, along with identifiers for each. Additionally I would also like to obtain the process id of the current context.

I appreciate any responses or pointers you may have on this.

Sincerely,

Adnan Khaleel