[PATCH 00/22] SRSO fixes/cleanups

[Josh Poimboeuf]

Here are several SRSO fixes and cleanups, based on tip/x86/urgent.

One of the patches also adds KVM support, though a corresponding patch
is still needed in QEMU.  I have a working QEMU patch which I can post
to qemu-devel.

Josh Poimboeuf (22):
  x86/srso: Fix srso_show_state() side effect
  x86/srso: Set CPUID feature bits independently of bug or mitigation
    status
  KVM: x86: Support IBPB_BRTYPE and SBPB
  x86/srso: Fix SBPB enablement for spec_rstack_overflow=off
  x86/srso: Fix SBPB enablement for mitigations=off
  x86/srso: Print actual mitigation if requested mitigation isn't
    possible
  x86/srso: Remove default case in srso_select_mitigation()
  x86/srso: Downgrade retbleed IBPB warning to informational message
  x86/srso: Simplify exit paths
  x86/srso: Print mitigation for retbleed IBPB case
  x86/srso: Slight simplification
  x86/srso: Remove redundant X86_FEATURE_ENTRY_IBPB check
  x86/srso: Fix vulnerability reporting for missing microcode
  x86/srso: Fix unret validation dependencies
  x86/alternatives: Remove faulty optimization
  x86/srso: Unexport untraining functions
  x86/srso: Disentangle rethunk-dependent options
  x86/rethunk: Use SYM_CODE_START[_LOCAL]_NOALIGN macros
  x86/srso: Improve i-cache locality for alias mitigation
  x86/retpoline: Remove .text..__x86.return_thunk section
  x86/nospec: Refactor UNTRAIN_RET[_*]
  x86/calldepth: Rename __x86_return_skl() to call_depth_return_thunk()

 Documentation/admin-guide/hw-vuln/srso.rst |  22 ++-
 arch/x86/include/asm/nospec-branch.h       |  69 ++++-----
 arch/x86/include/asm/processor.h           |   2 -
 arch/x86/kernel/alternative.c              |   8 -
 arch/x86/kernel/cpu/amd.c                  |  28 ++--
 arch/x86/kernel/cpu/bugs.c                 |  87 +++++------
 arch/x86/kernel/vmlinux.lds.S              |  10 +-
 arch/x86/kvm/cpuid.c                       |   4 +
 arch/x86/kvm/x86.c                         |   9 +-
 arch/x86/lib/retpoline.S                   | 171 +++++++++++----------
 include/linux/objtool.h                    |   3 +-
 scripts/Makefile.vmlinux_o                 |   3 +-
 12 files changed, 199 insertions(+), 217 deletions(-)

-- 
2.41.0