Re: [PATCH v4 00/10] Implement support for external IPT monitoring

From: Hubert Jasudowicz <hubert.jasudowicz@cert.pl>
To: "Michał Leszczyński" <michal.leszczynski@cert.pl>,
	xen-devel@lists.xenproject.org
Cc: "Kevin Tian" <kevin.tian@intel.com>,
	"Stefano Stabellini" <sstabellini@kernel.org>,
	tamas.lengyel@intel.com, "Jan Beulich" <jbeulich@suse.com>,
	"Wei Liu" <wl@xen.org>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Ian Jackson" <ian.jackson@eu.citrix.com>,
	"George Dunlap" <george.dunlap@citrix.com>,
	luwei.kang@intel.com, "Jun Nakajima" <jun.nakajima@intel.com>,
	"Anthony PERARD" <anthony.perard@citrix.com>,
	"Julien Grall" <julien@xen.org>,
	"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH v4 00/10] Implement support for external IPT monitoring
Date: Tue, 30 Jun 2020 14:48:25 +0200	[thread overview]
Message-ID: <a6b3851d-fa3c-1d81-e781-d8765249cc34@cert.pl> (raw)
In-Reply-To: <cover.1593519420.git.michal.leszczynski@cert.pl>

On 6/30/20 2:33 PM, Michał Leszczyński wrote:
> From: Michal Leszczynski <michal.leszczynski@cert.pl>
> 
> 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
> 
> 
> Michal Leszczynski (10):
>   x86/vmx: add Intel PT MSR definitions
>   x86/vmx: add IPT cpu feature
>   tools/libxl: add vmtrace_pt_size parameter
>   x86/vmx: implement processor tracing for VMX
>   common/domain: allocate vmtrace_pt_buffer
>   memory: batch processing in acquire_resource()
>   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                    |  10 +
>  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/COPYING                     | 339 ++++++++++++++++++++
>  tools/proctrace/Makefile                    |  48 +++
>  tools/proctrace/proctrace.c                 | 163 ++++++++++
>  tools/xl/xl_parse.c                         |  20 ++
>  xen/arch/x86/domain.c                       |  11 +
>  xen/arch/x86/domctl.c                       |  48 +++
>  xen/arch/x86/hvm/vmx/vmcs.c                 |   7 +-
>  xen/arch/x86/hvm/vmx/vmx.c                  |  89 +++++
>  xen/arch/x86/mm.c                           |  25 ++
>  xen/common/domain.c                         |  46 +++
>  xen/common/memory.c                         |  32 +-
>  xen/include/asm-x86/cpufeature.h            |   1 +
>  xen/include/asm-x86/domain.h                |   4 +
>  xen/include/asm-x86/hvm/hvm.h               |  38 +++
>  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             |  37 +++
>  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                     |   4 +
>  31 files changed, 1094 insertions(+), 4 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
> 

FYI, this patchset is also available at:
https://github.com/icedevml/xen/tree/ipt-patch-v4

Hubert Jasudowicz