[PATCH 0/9] Intel Processor Trace virtulization enabling

[Luwei Kang]

From: Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx>

Hi All,

Here is a patch-series which adding Processor Trace enabling in KVM guest. You can get It's software developer manuals from:
https://software.intel.com/sites/default/files/managed/c5/15/architecture-instruction-set-extensions-programming-reference.pdf
In Chapter 5 INTEL PROCESSOR TRACE: VMX IMPROVEMENTS.

Introduction:
Intel Processor Trace (Intel PT) is an extension of Intel Architecture that captures information about software execution using dedicated hardware facilities that cause only minimal performance perturbation to the software being traced. Details on the Intel PT infrastructure and trace capabilities can be found in the Intel 64 and IA-32 Architectures Software Developerâs Manual, Volume 3C.

The suite of architecture changes serve to simplify the process of virtualizing Intel PT for use by a guest software. There are two primary elements to this new architecture support for VMX support improvements made for Intel PT.
1. Addition of a new guest IA32_RTIT_CTL value field to the VMCS.
  â This serves to speed and simplify the process of disabling trace on VM exit, and restoring it on VM entry.
2. Enabling use of EPT to redirect PT output. 
  â This enables the VMM to elect to virtualize the PT output buffer using EPT. In this mode, the CPU will treat PT output addresses as Guest Physical Addresses (GPAs) and translate them using EPT. This means that Intel PT output reads (of the ToPA table) and writes (of trace output) can cause EPT violations, and other output events.

Intel Processor Trace virtualization can be work in one of 4 possible modes by set new option "pt_mode". Default is host guest mode.
 a. system-wide: trace both host/guest and output to host buffer;
 b. host-only: only trace host and output to host buffer;
 c. guest-only: only trace guest and output to guest buffer;
 d. host-guest: trace host/guest simultaneous and output to their respective buffer.

Chao Peng (9):
  perf/x86/intel/pt: Move Intel-PT MSR bit definitions to a public
    header
  perf/x86/intel/pt: change pt_cap_get() to a public function
  KVM: x86: add Intel processor trace virtualization mode
  perf/x86/intel/pt: add Intel processor trace virtualization call backs
  KVM: x86: implement intel processor trace virtualization callbacks
  KVM: x86: add Intel processor trace cpuid emulataion
  KVM: x86: add Intel processor trace context for each vcpu
  KVM: x86: Implement Intel processor trace context switch
  KVM: x86: Disable intercept for Intel processor trace MSRs

 arch/x86/events/intel/pt.c       |  24 +++-
 arch/x86/events/intel/pt.h       |  55 ---------
 arch/x86/include/asm/intel_pt.h  |  36 ++++++
 arch/x86/include/asm/kvm_host.h  |   1 +
 arch/x86/include/asm/msr-index.h |  35 ++++++
 arch/x86/include/asm/vmx.h       |   8 ++
 arch/x86/kvm/cpuid.c             |  23 +++-
 arch/x86/kvm/svm.c               |   6 +
 arch/x86/kvm/vmx.c               | 247 ++++++++++++++++++++++++++++++++++++++-
 9 files changed, 373 insertions(+), 62 deletions(-)

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1.8.3.1