Re: [PATCH v2 0/7] Implement support for external IPT monitoring

["Michał Leszczyński" <michal.leszczynski@cert.pl>]

----- 19 cze 2020 o 1:34, Michał Leszczyński michal.leszczynski@cert.pl napisał(a):

> 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
> 
> Michal Leszczynski (7):
>  xen/mm: lift 32 item limit from mfn/gfn arrays
>  x86/vmx: add Intel PT MSR definitions
>  x86/vmx: add IPT cpu feature
>  x86/vmx: add do_vmtrace_op
>  tools/libxc: add xc_vmtrace_* functions
>  tools/libxl: add vmtrace_pt_size parameter
>  tools/proctrace: add proctrace tool
> 
> 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                    |  97 ++++++
> tools/libxl/libxl_types.idl                 |   2 +
> tools/libxl/libxl_x86.c                     |   5 +
> tools/proctrace/COPYING                     | 339 ++++++++++++++++++++
> tools/proctrace/Makefile                    |  50 +++
> tools/proctrace/proctrace.c                 | 153 +++++++++
> tools/xl/xl_parse.c                         |   4 +
> xen/arch/x86/hvm/hvm.c                      | 167 ++++++++++
> xen/arch/x86/hvm/vmx/vmcs.c                 |   4 +
> xen/arch/x86/hvm/vmx/vmx.c                  |  24 ++
> xen/arch/x86/mm.c                           |  37 +++
> xen/common/domain.c                         |   1 +
> xen/common/memory.c                         |  39 +--
> xen/include/asm-x86/cpufeature.h            |   1 +
> xen/include/asm-x86/hvm/hvm.h               |   9 +
> xen/include/asm-x86/hvm/vmx/vmcs.h          |  17 +
> xen/include/asm-x86/msr-index.h             |  37 +++
> xen/include/public/arch-x86/cpufeatureset.h |   1 +
> xen/include/public/hvm/hvm_op.h             |  23 ++
> xen/include/public/hvm/params.h             |   5 +-
> xen/include/public/memory.h                 |   1 +
> xen/include/xen/sched.h                     |   3 +
> 26 files changed, 1039 insertions(+), 23 deletions(-)
> create mode 100644 tools/libxc/xc_vmtrace.c
> create mode 100644 tools/proctrace/COPYING
> create mode 100644 tools/proctrace/Makefile
> create mode 100644 tools/proctrace/proctrace.c
> 
> --
> 2.20.1


Thanks for all comments related to v1. I did my best to address all of them and
thus almost all code was altered. Due to that, I've decided to post the next
version at this stage.