From nobody Sat Apr 11 22:27:13 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46181C00140 for ; Fri, 5 Aug 2022 17:30:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240883AbiHERaB (ORCPT ); Fri, 5 Aug 2022 13:30:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241038AbiHER3y (ORCPT ); Fri, 5 Aug 2022 13:29:54 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0847C18E23 for ; Fri, 5 Aug 2022 10:29:53 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id m5-20020a2598c5000000b0066faab590c5so2534423ybo.7 for ; Fri, 05 Aug 2022 10:29:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:reply-to:from:to:cc; bh=5nd+QHkezC7wDBMujecCebsDnqxzcfp3VqzkbDB+1ZY=; b=DnOb8bwV0reEzqOE8dLWn32Z17o+ZPD0gWkotVkH8nAS6CICHPt1fGcC2ElNxJdPQK wnb7dFEtlt1+0LPYQ3A367GH31qiMZA9pd2frkidQmgLtLCYGSShnhiPkjUMrEoKcp1Y JCHhRtoHKzO/W6iEa2RJBeP8cNZ0UN1oxhKSl8Fc3XvoXbg3zXigmcFeSjpptBgKyZPN Rm7xXwAYACIxIFybgTQ8usbzS+7Za0xZDy1f8ivYjwnIq0NVtY9x9VVnb/h9V3CDDSji cK8eMa+GIi7M4aZbZ59iQt+YVT6HZjUAsGQuZ4qMpX4BtZ/n/DqTAvSbUVYJUPwXmuht 5K6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc; bh=5nd+QHkezC7wDBMujecCebsDnqxzcfp3VqzkbDB+1ZY=; b=bCzqAyi/LIhtvkR5+6U26nX5Gt2EHqtPrtcQeHD/Hi/SCgeb+SdU/cyA73a5d19oZi 8Xbpf507lO6Z0ryGdXEHUYZttsvQBQJKcDDHvas7au28RYgEBhnshIHx81YJ60s4dKDy sJKXqb9T65mPESbnfk2ItV0UTsjQmwdBQSo78gpu7kBej4IkmjQ3T0pITqseBBtY66ee jj4/I1GEe17ZTqIvKLYEtEc1UTLymXOW5SMkM9gjkFoajeUjHknQTqonNZFm2NcD5wiN k044XxupHEJgLYToEQIZ8IiutWJOmqrDHGOQm5ZouUqZjtiK9y8NxBIVOZTpSi3a4zUR kwLQ== X-Gm-Message-State: ACgBeo0cHNKquAtk27PCk6/8Fa25JMT6yRcQAavIdiU9YNhhxz+L3om7 Vmg8VQ012krEZqPGXIL2MDcv4AzrP3Q= X-Google-Smtp-Source: AA6agR6FXspFxnD/imEsB3LwRU4R1AlGUQznLhWzTAZ2mHOmrtn7vyMPakxXn/YCpqQ0NP4u6NlmA2MURVc= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a81:2f13:0:b0:329:5766:5bb7 with SMTP id v19-20020a812f13000000b0032957665bb7mr1974435ywv.391.1659720592290; Fri, 05 Aug 2022 10:29:52 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 5 Aug 2022 17:29:44 +0000 In-Reply-To: <20220805172945.35412-1-seanjc@google.com> Message-Id: <20220805172945.35412-3-seanjc@google.com> Mime-Version: 1.0 References: <20220805172945.35412-1-seanjc@google.com> X-Mailer: git-send-email 2.37.1.559.g78731f0fdb-goog Subject: [RFC PATCH 2/3] KVM: x86: Generate set of VMX feature MSRs using first/last definitions From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Like Xu Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add VMX MSRs to the runtime list of feature MSRs by iterating over the range of emulated MSRs instead of manually defining each MSR in the "all" list. Using the range definition reduces the cost of emulating a new VMX MSR, e.g. prevents forgetting to add an MSR to the list. Extracting the VMX MSRs from the "all" list, which is a compile-time constant, also shrinks the list to the point where the compiler can heavily optimize code that iterates over the list. No functional change intended. Signed-off-by: Sean Christopherson --- arch/x86/kvm/x86.c | 53 +++++++++++++++++++--------------------------- 1 file changed, 22 insertions(+), 31 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 33560bfa0cac..a1c65b77fb16 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1526,36 +1526,19 @@ static u32 emulated_msrs[ARRAY_SIZE(emulated_msrs_a= ll)]; static unsigned num_emulated_msrs; =20 /* - * List of msr numbers which are used to expose MSR-based features that - * can be used by a hypervisor to validate requested CPU features. + * List of MSRs that control the existence of MSR-based features, i.e. MSRs + * that are effectively CPUID leafs. VMX MSRs are also included in the se= t of + * feature MSRs, but are handled separately to allow expedited lookups. */ -static const u32 msr_based_features_all[] =3D { - MSR_IA32_VMX_BASIC, - MSR_IA32_VMX_TRUE_PINBASED_CTLS, - MSR_IA32_VMX_PINBASED_CTLS, - MSR_IA32_VMX_TRUE_PROCBASED_CTLS, - MSR_IA32_VMX_PROCBASED_CTLS, - MSR_IA32_VMX_TRUE_EXIT_CTLS, - MSR_IA32_VMX_EXIT_CTLS, - MSR_IA32_VMX_TRUE_ENTRY_CTLS, - MSR_IA32_VMX_ENTRY_CTLS, - MSR_IA32_VMX_MISC, - MSR_IA32_VMX_CR0_FIXED0, - MSR_IA32_VMX_CR0_FIXED1, - MSR_IA32_VMX_CR4_FIXED0, - MSR_IA32_VMX_CR4_FIXED1, - MSR_IA32_VMX_VMCS_ENUM, - MSR_IA32_VMX_PROCBASED_CTLS2, - MSR_IA32_VMX_EPT_VPID_CAP, - MSR_IA32_VMX_VMFUNC, - +static const u32 msr_based_features_all_except_vmx[] =3D { MSR_F10H_DECFG, MSR_IA32_UCODE_REV, MSR_IA32_ARCH_CAPABILITIES, MSR_IA32_PERF_CAPABILITIES, }; =20 -static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all)]; +static u32 msr_based_features[ARRAY_SIZE(msr_based_features_all_except_vmx= ) + + (KVM_LAST_EMULATED_VMX_MSR - KVM_FIRST_EMULATED_VMX_MSR + 1)]; static unsigned int num_msr_based_features; =20 static u64 kvm_get_arch_capabilities(void) @@ -6868,6 +6851,18 @@ long kvm_arch_vm_ioctl(struct file *filp, return r; } =20 +static void kvm_proble_feature_msr(u32 msr_index) +{ + struct kvm_msr_entry msr =3D { + .index =3D msr_index, + }; + + if (kvm_get_msr_feature(&msr)) + return; + + msr_based_features[num_msr_based_features++] =3D msr_index; +} + static void kvm_init_msr_list(void) { u32 dummy[2]; @@ -6954,15 +6949,11 @@ static void kvm_init_msr_list(void) emulated_msrs[num_emulated_msrs++] =3D emulated_msrs_all[i]; } =20 - for (i =3D 0; i < ARRAY_SIZE(msr_based_features_all); i++) { - struct kvm_msr_entry msr; + for (i =3D KVM_FIRST_EMULATED_VMX_MSR; i <=3D KVM_LAST_EMULATED_VMX_MSR; = i++) + kvm_proble_feature_msr(i); =20 - msr.index =3D msr_based_features_all[i]; - if (kvm_get_msr_feature(&msr)) - continue; - - msr_based_features[num_msr_based_features++] =3D msr_based_features_all[= i]; - } + for (i =3D 0; i < ARRAY_SIZE(msr_based_features_all_except_vmx); i++) + kvm_proble_feature_msr(msr_based_features_all_except_vmx[i]); } =20 static int vcpu_mmio_write(struct kvm_vcpu *vcpu, gpa_t addr, int len, --=20 2.37.1.559.g78731f0fdb-goog