[v5,00/11] Implement support for external IPT monitoring

Message

Michał Leszczyński July 5, 2020, 6:54 p.m. UTC

Intel Processor Trace is an architectural extension available in modern Intel 
family CPUs. It allows recording the detailed trace of activity while the 
processor executes the code. One might use the recorded trace to reconstruct 
the code flow. It means, to find out the executed code paths, determine 
branches taken, and so forth.

The abovementioned feature is described in Intel(R) 64 and IA-32 Architectures 
Software Developer's Manual Volume 3C: System Programming Guide, Part 3, 
Chapter 36: "Intel Processor Trace."

This patch series implements an interface that Dom0 could use in order to 
enable IPT for particular vCPUs in DomU, allowing for external monitoring. Such 
a feature has numerous applications like malware monitoring, fuzzing, or 
performance testing.

Also thanks to Tamas K Lengyel for a few preliminary hints before
first version of this patch was submitted to xen-devel.

Changed since v1:
  * MSR_RTIT_CTL is managed using MSR load lists
  * other PT-related MSRs are modified only when vCPU goes out of context
  * trace buffer is now acquired as a resource
  * added vmtrace_pt_size parameter in xl.cfg, the size of trace buffer
    must be specified in the moment of domain creation
  * trace buffers are allocated on domain creation, destructed on
    domain destruction
  * HVMOP_vmtrace_ipt_enable/disable is limited to enabling/disabling PT
    these calls don't manage buffer memory anymore
  * lifted 32 MFN/GFN array limit when acquiring resources
  * minor code style changes according to review

Changed since v2:
  * trace buffer is now allocated on domain creation (in v2 it was
    allocated when hvm param was set)
  * restored 32-item limit in mfn/gfn arrays in acquire_resource
    and instead implemented hypercall continuations
  * code changes according to Jan's and Roger's review

Changed since v3:
  * vmtrace HVMOPs are not implemented as DOMCTLs
  * patches splitted up according to Andrew's comments
  * code changes according to v3 review on the mailing list

Changed since v4:
  * rebased to commit be63d9d4
  * fixed dependencies between patches
    (earlier patches don't reference further patches)
  * introduced preemption check in acquire_resource
  * moved buffer allocation to common code
  * splitted some patches according to code review
  * minor fixes according to code review

This patch series is available on GitHub:
https://github.com/icedevml/xen/tree/ipt-patch-v5


Michal Leszczynski (11):
  memory: batch processing in acquire_resource()
  x86/vmx: add Intel PT MSR definitions
  x86/vmx: add IPT cpu feature
  common: add vmtrace_pt_size domain parameter
  tools/libxl: add vmtrace_pt_size parameter
  x86/hvm: processor trace interface in HVM
  x86/vmx: implement IPT in VMX
  x86/mm: add vmtrace_buf resource type
  x86/domctl: add XEN_DOMCTL_vmtrace_op
  tools/libxc: add xc_vmtrace_* functions
  tools/proctrace: add proctrace tool

 docs/man/xl.cfg.5.pod.in                    |  11 ++
 tools/golang/xenlight/helpers.gen.go        |   2 +
 tools/golang/xenlight/types.gen.go          |   1 +
 tools/libxc/Makefile                        |   1 +
 tools/libxc/include/xenctrl.h               |  39 +++++
 tools/libxc/xc_vmtrace.c                    |  73 +++++++++
 tools/libxl/libxl.h                         |   8 +
 tools/libxl/libxl_create.c                  |   1 +
 tools/libxl/libxl_types.idl                 |   2 +
 tools/proctrace/Makefile                    |  48 ++++++
 tools/proctrace/proctrace.c                 | 163 ++++++++++++++++++++
 tools/xl/xl_parse.c                         |  22 +++
 xen/arch/x86/domain.c                       |  19 +++
 xen/arch/x86/domctl.c                       |  48 ++++++
 xen/arch/x86/hvm/vmx/vmcs.c                 |  15 +-
 xen/arch/x86/hvm/vmx/vmx.c                  | 109 +++++++++++++
 xen/common/domain.c                         |  33 ++++
 xen/common/memory.c                         |  77 ++++++++-
 xen/include/asm-x86/cpufeature.h            |   1 +
 xen/include/asm-x86/hvm/hvm.h               |  20 +++
 xen/include/asm-x86/hvm/vmx/vmcs.h          |   4 +
 xen/include/asm-x86/hvm/vmx/vmx.h           |  14 ++
 xen/include/asm-x86/msr-index.h             |  24 +++
 xen/include/public/arch-x86/cpufeatureset.h |   1 +
 xen/include/public/domctl.h                 |  27 ++++
 xen/include/public/memory.h                 |   1 +
 xen/include/xen/domain.h                    |   2 +
 xen/include/xen/sched.h                     |   8 +
 28 files changed, 768 insertions(+), 6 deletions(-)
 create mode 100644 tools/libxc/xc_vmtrace.c
 create mode 100644 tools/proctrace/Makefile
 create mode 100644 tools/proctrace/proctrace.c