Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752831AbbGaNup (ORCPT ); Fri, 31 Jul 2015 09:50:45 -0400 Received: from mail-wi0-f173.google.com ([209.85.212.173]:36788 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751388AbbGaNun (ORCPT ); Fri, 31 Jul 2015 09:50:43 -0400 Date: Fri, 31 Jul 2015 15:50:38 +0200 From: Ingo Molnar To: Brian Gerst Cc: the arch/x86 maintainers , Linux Kernel Mailing List , "H. Peter Anvin" , Denys Vlasenko , Andy Lutomirski , Linus Torvalds Subject: Re: [PATCH 5/8] x86/vm86: Add a separate config option for hardware IRQ handling Message-ID: <20150731135038.GA24619@gmail.com> References: <1438148483-11932-1-git-send-email-brgerst@gmail.com> <1438148483-11932-6-git-send-email-brgerst@gmail.com> <20150731085750.GA8289@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2031 Lines: 58 * Brian Gerst wrote: > On Fri, Jul 31, 2015 at 4:57 AM, Ingo Molnar wrote: > > > > * Brian Gerst wrote: > > > >> Allow disabling hardware interrupt support for vm86. > >> > >> Signed-off-by: Brian Gerst > >> --- > >> arch/x86/Kconfig | 8 ++++++++ > >> arch/x86/include/asm/irq_vectors.h | 10 ---------- > >> arch/x86/include/asm/vm86.h | 20 ++++++++++++++++++-- > >> arch/x86/kernel/vm86_32.c | 12 ++++++++++-- > >> 4 files changed, 36 insertions(+), 14 deletions(-) > >> > >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > >> index cbd2d62..7c7ec31 100644 > >> --- a/arch/x86/Kconfig > >> +++ b/arch/x86/Kconfig > >> @@ -1067,6 +1067,14 @@ config VM86 > >> bool > >> default X86_LEGACY_VM86 > >> > >> +config VM86_INTERRUPTS > >> + bool "Enable VM86 interrupt support" > >> + default y > >> + depends on VM86 > >> + ---help--- > >> + This option allows VM86 programs to request interrupts for > >> + real mode hardware drivers. > > > > So I'm wondering what the justification for this is. People can disable vm86 > > already via CONFIG_X86_LEGACY_VM86. The extra config just uglifies the code > > unnecessarily. > > > > Thanks, > > > > Ingo > > Disabling even less-used code that could have system stability impact. We've > discouraged user-mode drivers for a very long time. Ironically, other than > being configured through the vm86 syscall, there isn't really anything > vm86-specific about it. All it does is register an IRQ handler that sends a > signal to the task. So is this actually used by anything? Could we get away with disabling it, just to see whether anything cares? Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/