[PATCH v2 00/14] x86: Support for CET Supervisor Shadow Stacks

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

This series implements Shadow Stack support for Xen to use.

You'll need a CET-capable toolchain (Binutils >= 2.29 or LLVM >= 7), but no
specific compiler support required.

CET-SS makes PV32 unusable, so using shadow stacks prevents the use of 32bit
PV guests.  Compatibilty can be obtained using PV Shim.

See patches for individual changes.

Andrew Cooper (14):
  x86/traps: Clean up printing in {do_reserved,fatal}_trap()
  x86/traps: Factor out extable_fixup() and make printing consistent
  x86/shstk: Introduce Supervisor Shadow Stack support
  x86/traps: Implement #CP handler and extend #PF for shadow stacks
  x86/shstk: Re-layout the stack block for shadow stacks
  x86/shstk: Create shadow stacks
  x86/cpu: Adjust enable_nmis() to be shadow stack compatible
  x86/cpu: Adjust reset_stack_and_jump() to be shadow stack compatible
  x86/spec-ctrl: Adjust DO_OVERWRITE_RSB to be shadow stack compatible
  x86/extable: Adjust extable handling to be shadow stack compatible
  x86/alt: Adjust _alternative_instructions() to not create shadow stacks
  x86/entry: Adjust guest paths to be shadow stack compatible
  x86/S3: Save and restore Shadow Stack configuration
  x86/shstk: Activate Supervisor Shadow Stacks

 docs/misc/xen-command-line.pandoc   |  25 ++++
 xen/arch/x86/Kconfig                |  18 +++
 xen/arch/x86/acpi/wakeup_prot.S     |  58 +++++++++
 xen/arch/x86/alternative.c          |  14 +++
 xen/arch/x86/boot/x86_64.S          |  35 +++++-
 xen/arch/x86/cpu/common.c           |  39 +++++-
 xen/arch/x86/crash.c                |   7 ++
 xen/arch/x86/mm.c                   |  46 ++++---
 xen/arch/x86/setup.c                |  56 +++++++++
 xen/arch/x86/smpboot.c              |   3 +-
 xen/arch/x86/spec_ctrl.c            |   8 ++
 xen/arch/x86/traps.c                | 239 ++++++++++++++++++++++++++----------
 xen/arch/x86/x86_64/compat/entry.S  |   1 +
 xen/arch/x86/x86_64/entry.S         |  50 +++++++-
 xen/include/asm-x86/asm_defns.h     |   8 +-
 xen/include/asm-x86/config.h        |   5 +
 xen/include/asm-x86/cpufeature.h    |   1 +
 xen/include/asm-x86/cpufeatures.h   |   1 +
 xen/include/asm-x86/current.h       |  60 +++++++--
 xen/include/asm-x86/mm.h            |   1 -
 xen/include/asm-x86/msr-index.h     |   3 +
 xen/include/asm-x86/page.h          |   1 +
 xen/include/asm-x86/processor.h     |  60 ++++++---
 xen/include/asm-x86/spec_ctrl_asm.h |  16 ++-
 xen/include/asm-x86/x86-defns.h     |  35 ++++++
 xen/include/asm-x86/x86_64/page.h   |   1 +
 xen/scripts/Kconfig.include         |   4 +
 27 files changed, 664 insertions(+), 131 deletions(-)

-- 
2.11.0