Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965493AbbBCAZ0 (ORCPT ); Mon, 2 Feb 2015 19:25:26 -0500 Received: from mail-la0-f47.google.com ([209.85.215.47]:61831 "EHLO mail-la0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965313AbbBCAZT (ORCPT ); Mon, 2 Feb 2015 19:25:19 -0500 MIME-Version: 1.0 In-Reply-To: <20150129203531.GF19988@wotan.suse.de> References: <1422323467-16713-1-git-send-email-mcgrof@do-not-panic.com> <1422323467-16713-3-git-send-email-mcgrof@do-not-panic.com> <54C75BD60200007800059BDD@mail.emea.novell.com> <54C76334.2080003@citrix.com> <20150129203531.GF19988@wotan.suse.de> From: "Luis R. Rodriguez" Date: Mon, 2 Feb 2015 16:24:57 -0800 X-Google-Sender-Auth: 5TyCgmfmPLAjOV2jPUTfGnn-IEM Message-ID: Subject: Re: [PATCH v5 2/2] x86/xen: allow privcmd hypercalls to be preempted on 64-bit To: David Vrabel Cc: Jan Beulich , "Luis R. Rodriguez" , Andy Lutomirski , Steven Rostedt , Masami Hiramatsu , x86@kernel.org, Thomas Gleixner , Paul McKenney , xen-devel@lists.xenproject.org, boris.ostrovsky@oracle.com, Konrad Rzeszutek Wilk , Ingo Molnar , Borislav Petkov , kvm@vger.kernel.org, "linux-kernel@vger.kernel.org" , "H. Peter Anvin" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2571 Lines: 55 On Thu, Jan 29, 2015 at 12:35 PM, Luis R. Rodriguez wrote: > On Tue, Jan 27, 2015 at 10:06:44AM +0000, David Vrabel wrote: >> On 27/01/15 08:35, Jan Beulich wrote: >> >>>> On 27.01.15 at 02:51, wrote: >> > >> > Even if David told you this would be acceptable, I have to question >> > an abstract model of fixing issues on only 64-bit kernels - this may >> > be acceptable for distro purposes, but seems hardly the right >> > approach for upstream. If 32-bit ones are to become deliberately >> > broken, the XEN config option should become dependent on !X86_32. >> >> I'd rather have something omitted (keeping the current behaviour) than >> something that has not been tested at all. >> >> Obviously it would be preferable to to fix both 32-bit and 64-bit x86 >> (and ARM as well) but I'm not going to block an important bug fix for >> the majority use case (64-bit x86). > > Hey folks, what is the status of these patches? Any more feedback? As I waited I decided to finally install a 32-bit OS but I found now that as of Xen commit 5d1181a5 which went upstream as of xen 4.3 Xen no longer supports 32-bit for x86. So -- Xen no loner even builds on 32-bit systems. The latest version I could use then would be Xen 4.2 but the even the stable-4.2 branch fails to build for me even after fixing quite a bit of compile failures, I'm just going to give up now. I want to build Xen as I'm relying on some customized emulated delays on the hypervisor in order to test the issue, otherwise I'd have to dedicate a huge system to reproduce this issue. While it is possible folks on old xen may use newer kernels this issue is likely not a high priority on those 32-bit systems and likely hard to reproduce there. When and if someone is able to test this on a 32-bit kernel / hypervisor then they can test the small patch below. Can we move forward with the 64-bit part then? diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S index 000d419..b4b1f42 100644 --- a/arch/x86/kernel/entry_32.S +++ b/arch/x86/kernel/entry_32.S @@ -982,6 +982,8 @@ ENTRY(xen_hypervisor_callback) ENTRY(xen_do_upcall) 1: mov %esp, %eax call xen_evtchn_do_upcall + movl %esp,%eax + call xen_end_upcall jmp ret_from_intr CFI_ENDPROC ENDPROC(xen_hypervisor_callback) -- 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/