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, USER_AGENT_SANE_1 autolearn=unavailable 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 CBA9CC2BA83 for ; Fri, 7 Feb 2020 19:47:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9386222C2 for ; Fri, 7 Feb 2020 19:47:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727071AbgBGTrD (ORCPT ); Fri, 7 Feb 2020 14:47:03 -0500 Received: from mga17.intel.com ([192.55.52.151]:7172 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726974AbgBGTrD (ORCPT ); Fri, 7 Feb 2020 14:47:03 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Feb 2020 11:47:02 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,414,1574150400"; d="scan'208";a="404920287" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.202]) by orsmga005.jf.intel.com with ESMTP; 07 Feb 2020 11:47:01 -0800 Date: Fri, 7 Feb 2020 11:47:02 -0800 From: Sean Christopherson To: Vitaly Kuznetsov Cc: Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Paolo Bonzini Subject: Re: [PATCH 03/61] KVM: x86: Simplify handling of Centaur CPUID leafs Message-ID: <20200207194701.GL2401@linux.intel.com> References: <20200201185218.24473-1-sean.j.christopherson@intel.com> <20200201185218.24473-4-sean.j.christopherson@intel.com> <87pnerg3hp.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87pnerg3hp.fsf@vitty.brq.redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Feb 06, 2020 at 04:05:54PM +0100, Vitaly Kuznetsov wrote: > Sean Christopherson writes: > > > Refactor the handling of the Centaur-only CPUID leaf to detect the leaf > > via a runtime query instead of adding a one-off callback in the static > > array. When the callback was introduced, there were additional fields > > in the array's structs, and more importantly, retpoline wasn't a thing. > > > > No functional change intended. > > > > Signed-off-by: Sean Christopherson > > --- > > arch/x86/kvm/cpuid.c | 32 ++++++++++---------------------- > > 1 file changed, 10 insertions(+), 22 deletions(-) > > > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > > index f49fdd06f511..de52cbb46171 100644 > > --- a/arch/x86/kvm/cpuid.c > > +++ b/arch/x86/kvm/cpuid.c > > @@ -829,15 +829,7 @@ static int do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 func, > > return __do_cpuid_func(entry, func, nent, maxnent); > > } > > > > -struct kvm_cpuid_param { > > - u32 func; > > - bool (*qualifier)(const struct kvm_cpuid_param *param); > > -}; > > - > > -static bool is_centaur_cpu(const struct kvm_cpuid_param *param) > > -{ > > - return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; > > -} > > +#define CENTAUR_CPUID_SIGNATURE 0xC0000000 > > arch/x86/kernel/cpu/centaur.c also hardcodes the value, would make sense > to put it to some x86 header instead. Ya, I just didn't want to touch non-KVM code in a 60+ patch series. > > static int get_cpuid_func(struct kvm_cpuid_entry2 *entries, u32 func, > > int *nent, int maxnent, unsigned int type) > > @@ -845,6 +837,10 @@ static int get_cpuid_func(struct kvm_cpuid_entry2 *entries, u32 func, > > u32 limit; > > int r; > > > > + if (func == CENTAUR_CPUID_SIGNATURE && > > + boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR) > > + return 0; > > + > > r = do_cpuid_func(&entries[*nent], func, nent, maxnent, type); > > if (r) > > return r; > > @@ -896,11 +892,8 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, > > struct kvm_cpuid_entry2 *cpuid_entries; > > int nent = 0, r = -E2BIG, i; > > > > - static const struct kvm_cpuid_param param[] = { > > - { .func = 0 }, > > - { .func = 0x80000000 }, > > - { .func = 0xC0000000, .qualifier = is_centaur_cpu }, > > - { .func = KVM_CPUID_SIGNATURE }, > > + static const u32 funcs[] = { > > + 0, 0x80000000, CENTAUR_CPUID_SIGNATURE, KVM_CPUID_SIGNATURE, > > }; > > > > if (cpuid->nent < 1) > > @@ -918,14 +911,9 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, > > goto out; > > > > r = 0; > > - for (i = 0; i < ARRAY_SIZE(param); i++) { > > - const struct kvm_cpuid_param *ent = ¶m[i]; > > - > > - if (ent->qualifier && !ent->qualifier(ent)) > > - continue; > > - > > - r = get_cpuid_func(cpuid_entries, ent->func, &nent, > > - cpuid->nent, type); > > + for (i = 0; i < ARRAY_SIZE(funcs); i++) { > > + r = get_cpuid_func(cpuid_entries, funcs[i], &nent, cpuid->nent, > > + type); > > if (r) > > goto out_free; > > } > > Reviewed-by: Vitaly Kuznetsov > > -- > Vitaly >