From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: Re: [PATCH 03/13] x86/paravirt: Convert native patch assembly code strings to macros Date: Fri, 17 Nov 2017 20:10:13 +0100 Message-ID: References: <20171117180713.e4up3dwrszpatka6@pd.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171117180713.e4up3dwrszpatka6@pd.tnic> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Borislav Petkov , Josh Poimboeuf Cc: Boris Ostrovsky , Rusty Russell , Mike Galbraith , xen-devel@lists.xenproject.org, Peter Zijlstra , Jiri Slaby , x86@kernel.org, linux-kernel@vger.kernel.org, Sasha Levin , Chris Wright , Thomas Gleixner , Andy Lutomirski , "H. Peter Anvin" , live-patching@vger.kernel.org, Alok Kataria , virtualization@lists.linux-foundation.org, Linus Torvalds , Ingo Molnar List-Id: virtualization@lists.linuxfoundation.org On 17/11/17 19:07, Borislav Petkov wrote: > On Wed, Oct 04, 2017 at 10:58:24AM -0500, Josh Poimboeuf wrote: >> Convert the hard-coded native patch assembly code strings to macros to >> facilitate sharing common code between 32-bit and 64-bit. >> >> These macros will also be used by a future patch which requires the GCC >> extended asm syntax of two '%' characters instead of one when specifying >> a register name. >> >> Signed-off-by: Josh Poimboeuf >> --- >> arch/x86/include/asm/special_insns.h | 24 ++++++++++++++++++++++++ >> arch/x86/kernel/paravirt_patch_32.c | 21 +++++++++++---------- >> arch/x86/kernel/paravirt_patch_64.c | 29 +++++++++++++++-------------- >> 3 files changed, 50 insertions(+), 24 deletions(-) >> >> diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h >> index ac402c6fc24b..0549c5f2c1b3 100644 >> --- a/arch/x86/include/asm/special_insns.h >> +++ b/arch/x86/include/asm/special_insns.h >> @@ -6,6 +6,30 @@ >> >> #include >> >> +#ifdef CONFIG_X86_64 >> +# define _REG_ARG1 "%rdi" >> +# define NATIVE_IDENTITY_32 "mov %edi, %eax" > > Yeah, that "identity" looks strange. How about NATIVE_NOOP and > NATIVE_NOOP_32 ? Those are not NOPs. They return the identical value which was passed to them. So identity isn't a bad name after all. > >> +# define NATIVE_USERGS_SYSRET64 "swapgs; sysretq" >> +#else >> +# define _REG_ARG1 "%eax" >> +#endif >> + >> +#define _REG_RET "%" _ASM_AX >> + >> +#define NATIVE_ZERO "xor " _REG_ARG1 ", " _REG_ARG1 > > NATIVE_ZERO_OUT > > I guess. NATIVE_ZERO reads like the native representation of 0 :-) NATIVE_ZERO_ARG1? Juergen