Re: [Patch v2 1/2] UefiCpuPkg/ArchitecturalMsr.h: Add RTIT TOPA table entry definition.

["Dong, Eric" <eric.dong@intel.com>]

Mike,

I found the attach pic can't show up. Append the content directly from sdm.

-----Original Message-----
From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Dong, Eric
Sent: Thursday, August 24, 2017 11:22 AM
To: Kinney, Michael D <michael.d.kinney@intel.com>; edk2-devel@lists.01.org
Cc: Ni, Ruiyu <ruiyu.ni@intel.com>
Subject: Re: [edk2] [Patch v2 1/2] UefiCpuPkg/ArchitecturalMsr.h: Add RTIT TOPA table entry definition.

Mike,

Add my comments below.

-----Original Message-----
From: Kinney, Michael D
Sent: Thursday, August 24, 2017 7:45 AM
To: Dong, Eric <eric.dong@intel.com>; edk2-devel@lists.01.org; Kinney, Michael D <michael.d.kinney@intel.com>
Cc: Ni, Ruiyu <ruiyu.ni@intel.com>
Subject: RE: [Patch v2 1/2] UefiCpuPkg/ArchitecturalMsr.h: Add RTIT TOPA table entry definition.



Hi Eric,



I see that the legal values for the Size field of RTIT_TOPA_TABLE_ENTRY are documented in the SDM.



I think we should add the enum for PROC_TRACE_MEM_SIZE into ArchitecturalMsr.h next to RTIT_TOPA_TABLE_ENTRY.

Maybe rename it to RTIT_TOPA_MEMORY_SIZE with enum names that start with "RtitTopaMemorySize".

[[Eric]] agree, update in the new patch.



The Copyright date in ArchitecturalMsr.h also needs to be updated.

[[Eric]] agree, update in the new patch.



The #define for MAX_TOPA_ENTRY_COUNT need a comment block that describes what it is and why it has a value of 2.  I see

2 entries are needed because the list of entries must be terminated by an entry with the END bit set to 1, so 2 entries are required to use a single valid entry.

[[Eric]] agree, update in the new patch.



ProcTrace.c: Please update programming of MSR_IA32_RTIT_OUTPUT_BASE to use the named bit fields from the structure.

ProcTrace.c: Please update programming of MSR_IA32_RTIT_OUTPUT_MASK_PTRS to use the named bit fields from the structure.

[[Eric]] I think current code is easy to write but it may touch the reserve bits. Agree to change to use the bit fields. Update in the new patches.



ProcTrace.c: I am confused by the programming MSR_IA32_RTIT_OUTPUT_MASK_PTRS to 0x7f.  That sets a Reserved field to all 1s.
[[Eric]] Copy from the sdm, default value is all 1. Write to it is ignored. So I think the original code is same as set the others bits all 0. I have update code to directly set other bits to 0. Please check the new patch.

[cid:image001.jpg@01D31CCB.2A4EEA30]

[[Eric]] Found the attached pic can't show, copy the context like below:

Table 35-9. IA32_RTIT_OUTPUT_MASK_PTRS MSR
Position         Bit Name          At Reset                               Bit Description
6:0                    LowerMask          7FH                                 Forced to 1, writes are ignored


ProcTrace.c: I see a mix of setting TopaEntryPtr using both bit fields and the Uint64 field.  Can we change to use only the bit fields.

[[Eric]] same reason as before, use Uint64 is easy to write but may touch the reserved bits. Update code to use bit fields.


Do we really need to set the address field in entry #1?  Isn't setting END to 1 enough?

[[Eric]] Copy below from sdm. This code point to the current table for a circular case.

    [cid:image002.jpg@01D31CCB.2A4EEA30]

[[Eric]] Found the attached pic can't show, copy the context like below:

35.2.6.2 Table of Physical Addresses (ToPA)
When IA32_RTIT_CTL.ToPA is set and IA32_RTIT_CTL.FabricEn is clear, the ToPA output mechanism is utilized. The
ToPA mechanism uses a linked list of tables; see Figure 35-1 for an illustrative example. Each entry in the table
contains some attribute bits, a pointer to an output region, and the size of the region. The last entry in the table
may hold a pointer to the next table. This pointer can either point to the top of the current table (for circular array)
or to the base of another table. The table size is not fixed, since the link to the next table can exist at any entry.




Thanks,

Mike



> -----Original Message-----

> From: Dong, Eric

> Sent: Thursday, August 17, 2017 8:29 PM

> To: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>

> Cc: Kinney, Michael D <michael.d.kinney@intel.com<mailto:michael.d.kinney@intel.com>>; Ni, Ruiyu

> <ruiyu.ni@intel.com<mailto:ruiyu.ni@intel.com>>

> Subject: [Patch v2 1/2] UefiCpuPkg/ArchitecturalMsr.h: Add RTIT TOPA

> table entry definition.

>

> Add RTIT TOPA table entry definition to architecturalMsr.h file.

>

> Cc: Michael Kinney <michael.d.kinney@intel.com<mailto:michael.d.kinney@intel.com>>

> Cc: Ruiyu Ni <ruiyu.ni@intel.com<mailto:ruiyu.ni@intel.com>>

> Contributed-under: TianoCore Contribution Agreement 1.1

> Signed-off-by: Eric Dong <eric.dong@intel.com<mailto:eric.dong@intel.com>>

> ---

>  UefiCpuPkg/Include/Register/ArchitecturalMsr.h | 55

> ++++++++++++++++++++++++++

>  1 file changed, 55 insertions(+)

>

> diff --git a/UefiCpuPkg/Include/Register/ArchitecturalMsr.h

> b/UefiCpuPkg/Include/Register/ArchitecturalMsr.h

> index 4f9c103..40c4383 100644

> --- a/UefiCpuPkg/Include/Register/ArchitecturalMsr.h

> +++ b/UefiCpuPkg/Include/Register/ArchitecturalMsr.h

> @@ -4534,6 +4534,61 @@ typedef union {

>    UINT64  Uint64;

>  } MSR_IA32_RTIT_OUTPUT_MASK_PTRS_REGISTER;

>

> +/**

> +  Format of ToPA table entries.

> +**/

> +typedef union {

> +  ///

> +  /// Individual bit fields

> +  ///

> +  struct {

> +    ///

> +    /// [Bit 0] END. See Section 35.2.6.2, "Table of Physical

> Addresses (ToPA)".

> +    ///

> +    UINT32  END:1;

> +    UINT32  Reserved1:1;

> +    ///

> +    /// [Bit 2] INT. See Section 35.2.6.2, "Table of Physical

> Addresses (ToPA)".

> +    ///

> +    UINT32  INT:1;

> +    UINT32  Reserved2:1;

> +    ///

> +    /// [Bit 4] STOP. See Section 35.2.6.2, "Table of Physical

> Addresses (ToPA)".

> +    ///

> +    UINT32  STOP:1;

> +    UINT32  Reserved3:1;

> +    ///

> +    /// [Bit 6:9] Indicates the size of the associated output

> region. See Section

> +    /// 35.2.6.2, "Table of Physical Addresses (ToPA)".

> +    ///

> +    UINT32  Size:4;

> +    UINT32  Reserved4:2;

> +    ///

> +    /// [Bit 12:31] Output Region Base Physical Address low part.

> +    /// [Bit 12:31] Output Region Base Physical Address [12:63]

> value to match.

> +    /// ATTENTION: The size of the address field is determined by

> the processor's

> +    /// physical-address width (MAXPHYADDR) in bits, as reported

> in

> +    /// CPUID.80000008H:EAX[7:0]. the above part of address

> reserved.

> +    /// True address field is [12:MAXPHYADDR-1], [MAXPHYADDR:63]

> is reserved part.

> +    /// Detail see Section 35.2.6.2, "Table of Physical Addresses

> (ToPA)".

> +    ///

> +    UINT32  Base:20;

> +    ///

> +    /// [Bit 32:63] Output Region Base Physical Address high

> part.

> +    /// [Bit 32:63] Output Region Base Physical Address [12:63]

> value to match.

> +    /// ATTENTION: The size of the address field is determined by

> the processor's

> +    /// physical-address width (MAXPHYADDR) in bits, as reported

> in

> +    /// CPUID.80000008H:EAX[7:0]. the above part of address

> reserved.

> +    /// True address field is [12:MAXPHYADDR-1], [MAXPHYADDR:63]

> is reserved part.

> +    /// Detail see Section 35.2.6.2, "Table of Physical Addresses

> (ToPA)".

> +    ///

> +    UINT32  BaseHi:32;

> +  } Bits;

> +  ///

> +  /// All bit fields as a 64-bit value

> +  ///

> +  UINT64  Uint64;

> +} RTIT_TOPA_TABLE_ENTRY;

>

>  /**

>    Trace Control Register (R/W). If (CPUID.(EAX=07H, ECX=0):EBX[25] =

> 1).

> --

> 2.7.0.windows.1


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