Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753718Ab2JKP5A (ORCPT ); Thu, 11 Oct 2012 11:57:00 -0400 Received: from cantor2.suse.de ([195.135.220.15]:35822 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752946Ab2JKP44 convert rfc822-to-8bit (ORCPT ); Thu, 11 Oct 2012 11:56:56 -0400 Subject: Re: linux-next: manual merge of the kvm-ppc tree with the powerpc-merge tree Mime-Version: 1.0 (Apple Message framework v1278) Content-Type: text/plain; charset=us-ascii From: Alexander Graf In-Reply-To: <1349970603.6903.2@snotra> Date: Thu, 11 Oct 2012 17:56:51 +0200 Cc: Tabi Timur-B04825 , Stephen Rothwell , "linux-kernel@vger.kernel.org" , David Howells , "linux-next@vger.kernel.org" , Paul Mackerras , "linuxppc-dev@lists.ozlabs.org" Content-Transfer-Encoding: 8BIT Message-Id: References: <1349970603.6903.2@snotra> To: Scott Wood X-Mailer: Apple Mail (2.1278) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1850 Lines: 35 On 11.10.2012, at 17:50, Scott Wood wrote: > On 10/11/2012 08:04:58 AM, Alexander Graf wrote: >> On 11.10.2012, at 05:32, Tabi Timur-B04825 wrote: >> > On Wed, Oct 10, 2012 at 9:47 PM, Stephen Rothwell wrote: >> > >> >> Commit 549d62d889b4 ("KVM: PPC: use definitions in epapr header >> >> for hcalls") from the kvm-ppc tree added an include of asm/epapr_hcall.h >> >> to the user visible part of asm/kvm_para.h so asm/epapr_hcall.h became a >> >> user visible header file. >> > >> > Any real user-space code that tries to call any of the functions in >> > epapr_hcall.h will cause an exception. > > Actually it'll cause a linker error, as of the "Don't use hardcoded opcode for ePAPR hcall invocation" patch. > >> > Claiming that kernel header files that KVM needs are suddenly >> > user-space header files doesn't make much sense to me, but I guess >> > it's not my decision. >> This is about kvm_host.h, which is the part that is exported to user space. It usually contains constants and structs that are required for the API. > > s/kvm_host/kvm_para/ > > I'm not sure anything in kvm_para.h or epapr_hcalls.h would be of use to userspace, but it would be of use to the guest OS, so it's still not kernel-internal. > > The variable externs should be #ifdef __KERNEL__ as David points out. The asm stuff could still be useful in a guest OS if the guest provides epapr_hypercall_start. I don't think we should worry about guest kernel code potentially having use for this. Let's make the user space headers be great for user space usage, not for guest code usage :). Alex-- 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/