From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) by kanga.kvack.org (Postfix) with ESMTP id 03D526B0003 for ; Thu, 1 Nov 2018 11:10:00 -0400 (EDT) Received: by mail-oi1-f197.google.com with SMTP id w126-v6so14766085oib.18 for ; Thu, 01 Nov 2018 08:09:59 -0700 (PDT) Received: from scalemp.com (www.scalemp.com. [169.44.78.149]) by mx.google.com with ESMTPS id h204-v6si8455118oib.58.2018.11.01.08.09.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 01 Nov 2018 08:09:58 -0700 (PDT) Subject: Re: [PATCH] x86/build: Build VSMP support only if selected References: <20181030230905.xHZmM%akpm@linux-foundation.org> <9e14d183-55a4-8299-7a18-0404e50bf004@infradead.org> <054cd800-5124-f897-0069-aba49f8eb654@suse.com> From: Eial Czerwacki Message-ID: <3c75860d-e3d7-8c28-6120-f6056200f941@scalemp.com> Date: Thu, 1 Nov 2018 17:09:50 +0200 MIME-Version: 1.0 In-Reply-To: <054cd800-5124-f897-0069-aba49f8eb654@suse.com> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Juergen Gross Cc: Thomas Gleixner , Randy Dunlap , "Shai Fultheim (Shai@ScaleMP.com)" , Andrew Morton , "broonie@kernel.org" , "mhocko@suse.cz" , Stephen Rothwell , "linux-next@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-mm@kvack.org" , LKML , "mm-commits@vger.kernel.org" , X86 ML , 'Oren Twaig' Greetings, On 11/01/2018 03:45 PM, Juergen Gross wrote: > On 01/11/2018 14:10, Eial Czerwacki wrote: >> Greetings, >> >> On 11/01/2018 12:39 PM, Shai Fultheim (Shai@ScaleMP.com) wrote: >>> On 01/11/18 11:37, Thomas Gleixner wrote: >>> >>>> VSMP support is built even if CONFIG_X86_VSMP is not set. This leads to a build >>>> breakage when CONFIG_PCI is disabled as well. >>>> >>>> Build VSMP code only when selected. >>> >>> This patch disables detect_vsmp_box() on systems without CONFIG_X86_VSMP, due to >>> the recent 6da63eb241a05b0e676d68975e793c0521387141. This is significant >>> regression that will affect significant number of deployments. >>> >>> We will reply shortly with an updated patch that fix the dependency on pv_irq_ops, >>> and revert to CONFIG_PARAVIRT, with proper protection for CONFIG_PCI. >>> >> >> here is the proper patch which fixes the issue on hand: >> From ebff534f8cfa55d7c3ab798c44abe879f3fbe2b8 Mon Sep 17 00:00:00 2001 >> From: Eial Czerwacki >> Date: Thu, 1 Nov 2018 15:08:32 +0200 >> Subject: [PATCH] x86/build: Build VSMP support only if CONFIG_PCI is >> selected >> >> vsmp dependency of pv_irq_ops removed some years ago, so now let's clean >> it up from vsmp_64.c. >> >> In short, "cap & ctl & (1 << 4)" was always returning 0, as such we can >> remove all the PARAVIRT/PARAVIRT_XXL code handling that. >> >> However, the rest of the code depends on CONFIG_PCI, so fix it accordingly. >> >> Signed-off-by: Eial Czerwacki >> Acked-by: Shai Fultheim >> --- >> arch/x86/Kconfig | 1 - >> arch/x86/kernel/vsmp_64.c | 80 >> +++-------------------------------------------- >> 2 files changed, 5 insertions(+), 76 deletions(-) >> >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index c51c989..4b187ca 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -524,7 +524,6 @@ config X86_VSMP >> bool "ScaleMP vSMP" >> select HYPERVISOR_GUEST >> select PARAVIRT > > Do you really still need PARAVIRT and HYPERVISOR_GUEST? > Maybe you want IRQ_REMAP instead? > Better performance is achieved with PARAVIRTed kernel. Hence we keep them both in. >> - select PARAVIRT_XXL >> depends on X86_64 && PCI >> depends on X86_EXTENDED_PLATFORM >> depends on SMP >> diff --git a/arch/x86/kernel/vsmp_64.c b/arch/x86/kernel/vsmp_64.c >> index 1eae5af..c6d2b76 100644 >> --- a/arch/x86/kernel/vsmp_64.c >> +++ b/arch/x86/kernel/vsmp_64.c >> @@ -26,64 +26,7 @@ >> >> #define TOPOLOGY_REGISTER_OFFSET 0x10 >> >> -#if defined CONFIG_PCI && defined CONFIG_PARAVIRT_XXL >> -/* >> - * Interrupt control on vSMPowered systems: >> - * ~AC is a shadow of IF. If IF is 'on' AC should be 'off' >> - * and vice versa. >> - */ >> - >> -asmlinkage __visible unsigned long vsmp_save_fl(void) >> -{ >> - unsigned long flags = native_save_fl(); >> - >> - if (!(flags & X86_EFLAGS_IF) || (flags & X86_EFLAGS_AC)) >> - flags &= ~X86_EFLAGS_IF; >> - return flags; >> -} >> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_save_fl); >> - >> -__visible void vsmp_restore_fl(unsigned long flags) >> -{ >> - if (flags & X86_EFLAGS_IF) >> - flags &= ~X86_EFLAGS_AC; >> - else >> - flags |= X86_EFLAGS_AC; >> - native_restore_fl(flags); >> -} >> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_restore_fl); >> - >> -asmlinkage __visible void vsmp_irq_disable(void) >> -{ >> - unsigned long flags = native_save_fl(); >> - >> - native_restore_fl((flags & ~X86_EFLAGS_IF) | X86_EFLAGS_AC); >> -} >> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_disable); >> - >> -asmlinkage __visible void vsmp_irq_enable(void) >> -{ >> - unsigned long flags = native_save_fl(); >> - >> - native_restore_fl((flags | X86_EFLAGS_IF) & (~X86_EFLAGS_AC)); >> -} >> -PV_CALLEE_SAVE_REGS_THUNK(vsmp_irq_enable); >> - >> -static unsigned __init vsmp_patch(u8 type, void *ibuf, >> - unsigned long addr, unsigned len) >> -{ >> - switch (type) { >> - case PARAVIRT_PATCH(irq.irq_enable): >> - case PARAVIRT_PATCH(irq.irq_disable): >> - case PARAVIRT_PATCH(irq.save_fl): >> - case PARAVIRT_PATCH(irq.restore_fl): >> - return paravirt_patch_default(type, ibuf, addr, len); >> - default: >> - return native_patch(type, ibuf, addr, len); >> - } >> - >> -} >> - >> +#if defined CONFIG_PCI >> static void __init set_vsmp_pv_ops(void) > > Wouldn't be a rename of the function be appropriate now? you are correct, I'll fix and resend the patch. > > > Juergen >