[Crash-utility] Xen Hypervisor analysis

[Dave Anderson]

Gentlemen,

Our QA guys have started spending some time with Xen hypervisor
crash analysis, and one obvious shortcoming is the implementation
of the "search" command.

I don't see how it ever could have worked correctly, but in
its current state, it either causes segmentation violations,
or quietly runs but doesn't find anything.

The primary problem is that the search command code is very
linux-specific, and so the search command or command-options
typically go off into the weeds trying to handle the addresses
as linux virtual addresses.

Here's what I plan to do for the Xen hypervisor search command:

  1. Disallow the "-u" option, which is nonsensical.
  2. Disallow the "-k" option, because of the various identity-mapped
     and virtual address ranges used by the various architectures
     is more than I care to deal with.
  3. Do not translate the virtual addresses to physical before
     reading the memory, i.e., just keep the addresses virtual.
  4. Require either a "-s <address>" starting address or a Xen hypervisor
     symbol as the starting address.
  5. While cycling through memory, as soon as a page is encountered
     that cannot be read, the search will be stopped.

I'm hoping to get a new release out shortly, and you can see what
I plan to do.  If you guys have a desire to extend the capability
beyond 1-5 above, send me patches.

Thanks,
   Dave Anderson