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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 697A8C31E40 for ; Mon, 12 Aug 2019 22:18:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C255206A2 for ; Mon, 12 Aug 2019 22:18:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726729AbfHLWSM (ORCPT ); Mon, 12 Aug 2019 18:18:12 -0400 Received: from mga12.intel.com ([192.55.52.136]:56539 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbfHLWSM (ORCPT ); Mon, 12 Aug 2019 18:18:12 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Aug 2019 15:18:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,379,1559545200"; d="scan'208";a="327494056" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.41]) by orsmga004.jf.intel.com with ESMTP; 12 Aug 2019 15:18:11 -0700 Date: Mon, 12 Aug 2019 15:18:11 -0700 From: Sean Christopherson To: Yang Weijiang Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, mst@redhat.com, rkrcmar@redhat.com, jmattson@google.com Subject: Re: [PATCH v6 2/8] KVM: x86: Add a helper function for CPUID(0xD,n>=1) enumeration Message-ID: <20190812221811.GB4996@linux.intel.com> References: <20190725031246.8296-1-weijiang.yang@intel.com> <20190725031246.8296-3-weijiang.yang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190725031246.8296-3-weijiang.yang@intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 25, 2019 at 11:12:40AM +0800, Yang Weijiang wrote: > To make the code look clean, wrap CPUID(0xD,n>=1) enumeration > code in a helper function now. > > Signed-off-by: Yang Weijiang > --- > arch/x86/kvm/cpuid.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 44 insertions(+) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 4992e7c99588..29cbde7538a3 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -313,6 +313,50 @@ static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, > return 0; > } > > +static inline int __do_cpuid_dx_leaf(struct kvm_cpuid_entry2 *entry, int *nent, 'dx' makes me think of the generic reference to RDX vs EDX. Maybe __do_cpuid_0xd_leaf()? > + int maxnent, u64 xss_mask, u64 xcr0_mask, > + u32 eax_mask) > +{ > + int idx, i; > + u64 mask; > + u64 supported; > + > + for (idx = 1, i = 1; idx < 64; ++idx) { Rather than loop here, I think it makes sense to loop in the caller to make the code consistent with do_cpuid_7_mask() added by commit 54d360d41211 ("KVM: cpuid: extract do_cpuid_7_mask and support multiple subleafs") > + mask = ((u64)1 << idx); > + if (*nent >= maxnent) > + return -EINVAL; > + > + do_cpuid_1_ent(&entry[i], 0xD, idx); > + if (idx == 1) { > + entry[i].eax &= eax_mask; > + cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); > + supported = xcr0_mask | xss_mask; > + entry[i].ebx = 0; > + entry[i].edx = 0; > + entry[i].ecx &= xss_mask; > + if (entry[i].eax & (F(XSAVES) | F(XSAVEC))) { > + entry[i].ebx = > + xstate_required_size(supported, > + true); > + } > + } else { > + supported = (entry[i].ecx & 1) ? xss_mask : > + xcr0_mask; > + if (entry[i].eax == 0 || !(supported & mask)) > + continue; > + entry[i].ecx &= 1; > + entry[i].edx = 0; > + if (entry[i].ecx) > + entry[i].ebx = 0; > + } > + entry[i].flags |= > + KVM_CPUID_FLAG_SIGNIFCANT_INDEX; > + ++*nent; > + ++i; > + } > + return 0; > +} > + Extracting code into a helper should be done in the same patch that the existing code is replaced with a call to the helper, i.e. the chunk of the next patch that invokes the helper should be squashed with this patch. > static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > u32 index, int *nent, int maxnent) > { > -- > 2.17.2 >