[PATCH for-4.5 0/2] Improve "Emulation failed" error message

[Andrew Cooper <andrew.cooper3@citrix.com>]

After wanting to improve this error for a long time, I have encountered two
cases in the past 2 days where I have needed more information than it
provided, so have finally gotten around to fixing it.

Patch 1 introduces a "print hex buffer" custom %p format (compatible with the
Linux equivelent), while Patch 2 improves the error message.

Konrad: I am requesting a release ack for this as it is a non-feature change
for the purpose of improving error messages.  Neither of the patches are
complicated (low risk of bugs/regressions), and if the worse comes to the
worst, they can safely be reverted.

Andrew Cooper (2):
  xen/vsprintf: Introduce %*ph extended format specifier for hex
    buffers
  x86/hvm: Improve "Emulation failed @" error messages

 docs/misc/printk-formats.txt      |    6 ++++++
 xen/arch/x86/hvm/emulate.c        |   41 +++++++++++++++++++++++++++++--------
 xen/arch/x86/hvm/io.c             |   11 +---------
 xen/arch/x86/hvm/vmx/realmode.c   |    9 +-------
 xen/common/vsprintf.c             |   25 ++++++++++++++++++++++
 xen/include/asm-x86/hvm/emulate.h |    3 +++
 6 files changed, 68 insertions(+), 27 deletions(-)