From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01A96C3A5A2 for ; Fri, 20 Sep 2019 15:12:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D43E82086A for ; Fri, 20 Sep 2019 15:12:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393377AbfITPMq (ORCPT ); Fri, 20 Sep 2019 11:12:46 -0400 Received: from foss.arm.com ([217.140.110.172]:46192 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387614AbfITPMp (ORCPT ); Fri, 20 Sep 2019 11:12:45 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9AC94337; Fri, 20 Sep 2019 08:12:44 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0D4343F575; Fri, 20 Sep 2019 08:12:42 -0700 (PDT) Date: Fri, 20 Sep 2019 16:12:40 +0100 From: Mark Rutland To: Thomas Gleixner Cc: LKML , x86@kernel.org, Peter Zijlstra , Andy Lutomirski , Catalin Marinas , Will Deacon , Marc Zyngier , Paolo Bonzini , kvm@vger.kernel.org, linux-arch@vger.kernel.org, James Morse Subject: Re: [RFC patch 00/15] entry: Provide generic implementation for host and guest entry/exit work Message-ID: <20190920151240.GB55224@lakrids.cambridge.arm.com> References: <20190919150314.054351477@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190919150314.054351477@linutronix.de> User-Agent: Mutt/1.11.1+11 (2f07cb52) (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thomas, As a heads-up, I'm going to be away next week, and I likely won't have the chance to look at this in detail before October. On Thu, Sep 19, 2019 at 05:03:14PM +0200, Thomas Gleixner wrote: > When working on a way to move out the posix cpu timer expiry out of the > timer interrupt context, I noticed that KVM is not handling pending task > work before entering a guest. A quick hack was to add that to the x86 KVM > handling loop. The discussion ended with a request to make this a generic > infrastructure possible with also moving the per arch implementations of > the enter from and return to user space handling generic. > > https://lore.kernel.org/r/89E42BCC-47A8-458B-B06A-D6A20D20512C@amacapital.net > > You asked for it, so don't complain that you have to review it :) I never asked for this! ;) > The series implements the syscall enter/exit and the general exit to > userspace work handling along with the pre guest enter functionality. > > The series converts x86 and ARM64. x86 is fully tested including selftests > etc. ARM64 is only compile tested for now as my only ARM64 testbox is not > available right now. I've been working on converting the arm64 entry code to C for a while now [1], gradually upstreaming the bits I can. James has picked up some of that [2] as a prerequisite for some RAS error handling, and I think building the arm64 bits atop of that would be preferable. IIUC that should get posted as a series come -rc1. Since there's immense scope for subtle breakage, I'd prefer that we do the arm64-specific asm->C conversion before migrating arm64 to generic code. That way us arm64 folk can ensure the asm->C conversion retains the existing behaviour, and it'll be easier for everyone to compare the arm64 and generic C implementations. Thanks, Mark. [1] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git [2] git://linux-arm.org/linux-jm.git -b deasm_sync_only/v1 > > Thanks, > > tglx > > --- > /Makefile | 3 > arch/Kconfig | 3 > arch/arm64/Kconfig | 1 > arch/arm64/include/asm/kvm_host.h | 1 > arch/arm64/kernel/entry.S | 18 - > arch/arm64/kernel/ptrace.c | 65 ------ > arch/arm64/kernel/signal.c | 45 ---- > arch/arm64/kernel/syscall.c | 49 ---- > arch/x86/Kconfig | 1 > arch/x86/entry/common.c | 265 +------------------------- > arch/x86/entry/entry_32.S | 13 - > arch/x86/entry/entry_64.S | 12 - > arch/x86/entry/entry_64_compat.S | 21 -- > arch/x86/include/asm/signal.h | 1 > arch/x86/include/asm/thread_info.h | 9 > arch/x86/kernel/signal.c | 2 > arch/x86/kvm/x86.c | 17 - > b/arch/arm64/include/asm/entry-common.h | 76 +++++++ > b/arch/x86/include/asm/entry-common.h | 104 ++++++++++ > b/include/linux/entry-common.h | 324 ++++++++++++++++++++++++++++++++ > b/kernel/entry/common.c | 220 +++++++++++++++++++++ > kernel/Makefile | 1 > 22 files changed, 776 insertions(+), 475 deletions(-) > >