Subject: hypervisor call trace module

From: Anton Blanchard <[email-masked]>
Date: Tue, 27 Oct 2009 16:02:23 +1100

Here is an example of using the hcall tracepoints. This kernel
module provides strace like functionality for hypervisor hcalls:

-> 0x64(ff000002, 1, 2, d0000000034d7a71, f, c000000000a6f388, 1, c000000000989008, c000000000a3f480)
  <- 0x64()

Which was an EOI (opcode 0x64) of 0xff000002

There are a number of drivers that carry a lot of hcall related debug
code just in case we have to chase down a bug. I'm hoping hcall tracepoints
could replace it all and allow for much more powerful debugging.

Anton