Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934445AbdDFPVa (ORCPT ); Thu, 6 Apr 2017 11:21:30 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:48368 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932662AbdDFPVX (ORCPT ); Thu, 6 Apr 2017 11:21:23 -0400 Date: Thu, 6 Apr 2017 17:20:40 +0200 From: Daniel Kiper To: Juergen Gross Cc: Julien Grall , Boris Ostrovsky , xen-devel@lists.xen.org, sstabellini@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64: xen: Implement EFI reset_system callback Message-ID: <20170406152040.GH4372@olila.local.net-space.pl> References: <20170405181417.15985-1-julien.grall@arm.com> <3f6f5853-cd08-8afc-f71a-b0c1545c7564@arm.com> <20170406142710.GE4372@olila.local.net-space.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2103 Lines: 57 On Thu, Apr 06, 2017 at 04:38:24PM +0200, Juergen Gross wrote: > On 06/04/17 16:27, Daniel Kiper wrote: > > On Thu, Apr 06, 2017 at 09:32:32AM +0100, Julien Grall wrote: > >> Hi Juergen, > >> > >> On 06/04/17 07:23, Juergen Gross wrote: > >>> On 05/04/17 21:49, Boris Ostrovsky wrote: > >>>> On 04/05/2017 02:14 PM, Julien Grall wrote: > >>>>> The x86 code has theoritically a similar issue, altought EFI does not > >>>>> seem to be the preferred method. I have left it unimplemented on x86 and > >>>>> CCed Linux Xen x86 maintainers to know their view here. > >>>> > >>>> (+Daniel) > >>>> > >>>> This could be a problem for x86 as well, at least theoretically. > >>>> xen_machine_power_off() may call pm_power_off(), which is efi.reset_system. > >>>> > >>>> So I think we should have a similar routine there. > >>> > >>> +1 > >>> > >>> I don't see any problem with such a routine added, in contrast to > >>> potential "reboots" instead of power off without it. > >>> > >>> So I think this dummy xen_efi_reset_system() should be added to > >>> drivers/xen/efi.c instead. > >> > >> I will resend the patch during day with xen_efi_reset_system moved > >> to common code and implement the x86 counterpart (thought, I will > >> not be able to test it). > > > > I think that this is ARM specific issue. On x86 machine_restart() calls > > xen_restart(). Hence, everything works. So, I think that it should be > > fixed only for ARM. Anyway, please CC me when you send a patch. > > What about xen_machine_power_off() (as stated in Boris' mail)? Guys what do you think about that: --- a/drivers/firmware/efi/reboot.c +++ b/drivers/firmware/efi/reboot.c @@ -55,7 +55,7 @@ static void efi_power_off(void) static int __init efi_shutdown_init(void) { - if (!efi_enabled(EFI_RUNTIME_SERVICES)) + if (!efi_enabled(EFI_RUNTIME_SERVICES) || efi_enabled(EFI_PARAVIRT)) return -ENODEV; if (efi_poweroff_required()) Julien, for ARM64 please take a look at arch/arm64/kernel/efi.c:efi_poweroff_required(void). I hope that tweaks for both files should solve our problem. Daniel