[kvm-unit-tests PATCH v3 00/20] x86: Better backtraces for leaf functions

[Sean Christopherson <seanjc@google.com>]

Finally re-posting Mathias' work to provide better backtraces on x86, which
was blocked by a fatal bug in the nVMX SIPI test that was exposed by the
stack frame side effects.  This has been sitting on my local system(s) for
something like 5 months, and I all but forgot I hadn't posted it.

Most of this series is cleaning up the nVMX and nSVM to play nice with
multi-CPU tests.  Then to fix the race in the problematic SIPI, abuse the
VM-Entry MSR load list to atomically detect VM-Enter (I'm still proud of
that hack).

For gory details:

https://lore.kernel.org/all/3bac29b9-4c49-4e5d-997e-9e4019a2fceb@grsecurity.net

Mathias Krause (3):
  x86/vmx: Initialize test stage in SIPI test *before* launching AP
    thread
  x86: Better backtraces for leaf functions
  x86: Prevent realmode test code instrumentation with nop-mcount

Sean Christopherson (17):
  x86/vmx: Drop unused SYSENTER "support" in nested VMX infrastructure
  x86/vmx: Drop unused guest_regs "support" in nested VMX infrastructure
  x86/svm: Sort (and swap) GPRs by their index, not alphabetically
  x86: Dedup guest/host context switch of registers across SVM and VMX
  x86/virt: Use macro shenanigans to get reg offsets when swapping
    guest/host regs
  x86/virt: Track "guest regs" using per-CPU variable
  x86/svm: Don't VMLOAD/VMSAVE "guest" state around VMRUN
  x86/vmx: Use separate VMCSes for BSP vs. AP in INIT test
  x86/vmx: Swap GPRs after checking "launched" status
  x86/vmx: Track VMCS "launched" state per-CPU
  x86/vmx: Track "is this CPU in guest mode" per-CPU
  x86/vmx: Communicate hypercalls via RAX, not a global field
  x86/kvmclock: Replace spaces with tabs
  x86/kvmclock: Skip kvmclock test when not running on KVM with
    CLOCKSOURCE2
  x86/vmx: Tag "struct vmx_msr_entry" as needing to be 16-byte aligned
  x86/smp: Align the stack to a 16-byte boundary when invoking SMP
    function calls
  x86/vmx: Write to KVM's WALL_CLOCK MSR via VM-Entry load list sync in
    SIPI test

 lib/x86/processor.h |  15 +++
 lib/x86/smp.c       |  21 ++++-
 lib/x86/smp.h       |  32 +++++++
 lib/x86/virt.h      |  61 ++++++++++++
 x86/Makefile.common |  14 +++
 x86/kvmclock.c      |  42 ++++-----
 x86/kvmclock.h      |   2 +
 x86/kvmclock_test.c | 225 +++++++++++++++++++++++---------------------
 x86/realmode.c      |   3 +
 x86/svm.c           |  19 ++--
 x86/svm.h           |  61 ++----------
 x86/svm_tests.c     |   5 +-
 x86/vmx.c           | 121 +++++++++++-------------
 x86/vmx.h           |  72 +-------------
 x86/vmx_tests.c     | 134 ++++++++++++++++----------
 15 files changed, 443 insertions(+), 384 deletions(-)
 create mode 100644 lib/x86/virt.h


base-commit: 4d60e2429d63dc0c24990114a8afc89e86c187cc
-- 
2.54.0.563.g4f69b47b94-goog