Re: [PATCH 1/4] x86/xen/entry: Rename xenpv_exc_nmi to noist_exc_nmi

From: Thomas Gleixner <tglx@linutronix.de>
To: Lai Jiangshan <jiangshanlai@gmail.com>, linux-kernel@vger.kernel.org
Cc: Lai Jiangshan <laijs@linux.alibaba.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Andi Kleen <ak@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, Josh Poimboeuf <jpoimboe@redhat.com>,
	Uros Bizjak <ubizjak@gmail.com>,
	Maxim Levitsky <mlevitsk@redhat.com>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	Boris Ostrovsky <boris.ostrovsky@oracle.com>,
	Juergen Gross <jgross@suse.com>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Alexandre Chartre <alexandre.chartre@oracle.com>,
	Joerg Roedel <jroedel@suse.de>, Jian Cai <caij2003@gmail.com>,
	xen-devel@lists.xenproject.org
Subject: Re: [PATCH 1/4] x86/xen/entry: Rename xenpv_exc_nmi to noist_exc_nmi
Date: Mon, 03 May 2021 21:05:29 +0200	[thread overview]
Message-ID: <87r1ind4ee.ffs@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20210426230949.3561-2-jiangshanlai@gmail.com>

On Tue, Apr 27 2021 at 07:09, Lai Jiangshan wrote:
> From: Lai Jiangshan <laijs@linux.alibaba.com>
>
> There is no any functionality change intended.  Just rename it and
> move it to arch/x86/kernel/nmi.c so that we can resue it later in
> next patch for early NMI and kvm.

'Reuse it later' is not really a proper explanation why this change it
necessary.

Also this can be simplified by using aliasing which keeps the name
spaces intact.

Thanks,

        tglx

---       

--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -135,6 +135,9 @@ static __always_inline void __##func(str
 #define DEFINE_IDTENTRY_RAW(func)					\
 __visible noinstr void func(struct pt_regs *regs)
 
+#define DEFINE_IDTENTRY_RAW_ALIAS(alias, func)				\
+__visible noinstr void func(struct pt_regs *regs) __alias(alias)
+
 /**
  * DECLARE_IDTENTRY_RAW_ERRORCODE - Declare functions for raw IDT entry points
  *				    Error code pushed by hardware
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -524,6 +524,8 @@ DEFINE_IDTENTRY_RAW(exc_nmi)
 		mds_user_clear_cpu_buffers();
 }
 
+DEFINE_IDTENTRY_RAW_ALIAS(exc_nmi, xenpv_exc_nmi);
+
 void stop_nmi(void)
 {
 	ignore_nmis++;
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -565,12 +565,6 @@ static void xen_write_ldt_entry(struct d
 
 void noist_exc_debug(struct pt_regs *regs);
 
-DEFINE_IDTENTRY_RAW(xenpv_exc_nmi)
-{
-	/* On Xen PV, NMI doesn't use IST.  The C part is the same as native. */
-	exc_nmi(regs);
-}
-
 DEFINE_IDTENTRY_RAW_ERRORCODE(xenpv_exc_double_fault)
 {
 	/* On Xen PV, DF doesn't use IST.  The C part is the same as native. */
