Re: [PATCH] x86: perf: insn: Tweak opcode map for Intel CET instructions

From: Masami Hiramatsu <mhiramat@kernel.org>
To: Mingbo Zhang <whensungoes@gmail.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Adrian Hunter <adrian.hunter@intel.com>,
	Arnaldo Carvalho de Melo <acme@redhat.com>,
	Andi Kleen <ak@linux.intel.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86: perf: insn: Tweak opcode map for Intel CET instructions
Date: Thu, 26 Mar 2020 10:31:53 +0900	[thread overview]
Message-ID: <20200326103153.de709903f26fee0918414bd2@kernel.org> (raw)
In-Reply-To: <20200303045033.6137-1-whensungoes@gmail.com>

Hi,

On Mon,  2 Mar 2020 23:50:30 -0500
Mingbo Zhang <whensungoes@gmail.com> wrote:

> Intel CET instructions are not described in the Intel SDM. When trying to
> get the instruction length, the following instructions get wrong (missing
> ModR/M byte).
> 
> RDSSPD r32
> RSDDPQ r64
> ENDBR32
> ENDBR64
> WRSSD r/m32, r32
> WRSSQ r/m64, r64
> 
> RDSSPD/Q and ENDBR32/64 use the same opcode (f3 0f 1e) slot, which is
> described in SDM as Reserved-NOP with no encoding characters, and got an
> empty slot in the opcode map. WRSSD/Q (0f 38 f6) also got an empty slot.
> 

This looks good to me. BTW, wouldn't we need to add decode test cases to perf?

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thank you,

> Signed-off-by: Mingbo Zhang <whensungoes@gmail.com>
> ---
>  arch/x86/lib/x86-opcode-map.txt       | 4 ++--
>  tools/arch/x86/lib/x86-opcode-map.txt | 4 ++--
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/lib/x86-opcode-map.txt b/arch/x86/lib/x86-opcode-map.txt
> index 53adc1762ec0..0e3434c882d4 100644
> --- a/arch/x86/lib/x86-opcode-map.txt
> +++ b/arch/x86/lib/x86-opcode-map.txt
> @@ -366,7 +366,7 @@ AVXcode: 1
>  1b: BNDCN Gv,Ev (F2) | BNDMOV Ev,Gv (66) | BNDMK Gv,Ev (F3) | BNDSTX Ev,Gv
>  1c: Grp20 (1A),(1C)
>  1d:
> -1e:
> +1e: NOP Gy,Gy
>  1f: NOP Ev
>  # 0x0f 0x20-0x2f
>  20: MOV Rd,Cd
> @@ -804,7 +804,7 @@ f1: MOVBE My,Gy | MOVBE Mw,Gw (66) | CRC32 Gd,Ey (F2) | CRC32 Gd,Ew (66&F2)
>  f2: ANDN Gy,By,Ey (v)
>  f3: Grp17 (1A)
>  f5: BZHI Gy,Ey,By (v) | PEXT Gy,By,Ey (F3),(v) | PDEP Gy,By,Ey (F2),(v)
> -f6: ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v)
> +f6: NOP Ey,Gy | ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v)
>  f7: BEXTR Gy,Ey,By (v) | SHLX Gy,Ey,By (66),(v) | SARX Gy,Ey,By (F3),(v) | SHRX Gy,Ey,By (F2),(v)
>  f8: MOVDIR64B Gv,Mdqq (66) | ENQCMD Gv,Mdqq (F2) | ENQCMDS Gv,Mdqq (F3)
>  f9: MOVDIRI My,Gy
> diff --git a/tools/arch/x86/lib/x86-opcode-map.txt b/tools/arch/x86/lib/x86-opcode-map.txt
> index 53adc1762ec0..0e3434c882d4 100644
> --- a/tools/arch/x86/lib/x86-opcode-map.txt
> +++ b/tools/arch/x86/lib/x86-opcode-map.txt
> @@ -366,7 +366,7 @@ AVXcode: 1
>  1b: BNDCN Gv,Ev (F2) | BNDMOV Ev,Gv (66) | BNDMK Gv,Ev (F3) | BNDSTX Ev,Gv
>  1c: Grp20 (1A),(1C)
>  1d:
> -1e:
> +1e: NOP Gy,Gy
>  1f: NOP Ev
>  # 0x0f 0x20-0x2f
>  20: MOV Rd,Cd
> @@ -804,7 +804,7 @@ f1: MOVBE My,Gy | MOVBE Mw,Gw (66) | CRC32 Gd,Ey (F2) | CRC32 Gd,Ew (66&F2)
>  f2: ANDN Gy,By,Ey (v)
>  f3: Grp17 (1A)
>  f5: BZHI Gy,Ey,By (v) | PEXT Gy,By,Ey (F3),(v) | PDEP Gy,By,Ey (F2),(v)
> -f6: ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v)
> +f6: NOP Ey,Gy | ADCX Gy,Ey (66) | ADOX Gy,Ey (F3) | MULX By,Gy,rDX,Ey (F2),(v)
>  f7: BEXTR Gy,Ey,By (v) | SHLX Gy,Ey,By (66),(v) | SARX Gy,Ey,By (F3),(v) | SHRX Gy,Ey,By (F2),(v)
>  f8: MOVDIR64B Gv,Mdqq (66) | ENQCMD Gv,Mdqq (F2) | ENQCMDS Gv,Mdqq (F3)
>  f9: MOVDIRI My,Gy
> -- 
> 2.25.1
> 

-- 
Masami Hiramatsu <mhiramat@kernel.org>