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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFF6CEE49B7 for ; Fri, 25 Aug 2023 21:46:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231466AbjHYVqW (ORCPT ); Fri, 25 Aug 2023 17:46:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46128 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231628AbjHYVqN (ORCPT ); Fri, 25 Aug 2023 17:46:13 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 145C926BD for ; Fri, 25 Aug 2023 14:46:10 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id 3f1490d57ef6-d74a0f88457so1684373276.2 for ; Fri, 25 Aug 2023 14:46:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1692999969; x=1693604769; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=odPHPe5zFeL7gaKGcaVYt3urnmLAQ3hctBtrMI+qFRc=; b=x1X+gq2MNHdyg+JX1qqtqdxcUO2kaBiy8tBfkhCZ5MaylnPkC1GsPQ8OpPHi+1l820 bEwH8077zlnSdeqmpEIEREwJG2y+nCXOovwBkUnhk5QkIAh67hYH4nQxVK1otd2WsaNw DYmZ6Mae7mBldaxAWYa04JztrC6TURexrrEupK6c5Ws+ARn6OTOLCk1l2IO8C4m8/w5c AORM1FdX49kt2Ke0s8mhvpQTvuIFdVRj2oMg71710PuZBsple7IW3WOkQa5Ke2y84KsD HTcJevzkKblSp+wkytY84gdV0jayyYyl+3HJnTs969ZCY89aeNoNmcrgOKPazKgL2Xhg iecQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692999969; x=1693604769; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=odPHPe5zFeL7gaKGcaVYt3urnmLAQ3hctBtrMI+qFRc=; b=Kxtunsac03fQ7OTIZj5LEnHeLivmGB9FZWrpwe/rgEBoFvbx/DUXA67dmxgvBweUlN bomGA43f3nf3VxqaiAakF+sv97zo8bGK5c9BBYHYpKvfpj57UgYQV8sYeNO+kC2+Q3mN aE89hXKEkxno4Ne0uUL4wObRg6LvrHk83hAg3aYOZ2Ma6zBHkEYlzvNDlkcnTUeOUy5H dM5FbpsZaxyYajn0SYxDCYZNjosnncbYXuTfwj2ShSWYoydQB5nlGmiY4De0CKBC6OEz WRXdwCo9PAGZbFKf6kwVuSWGvthLIrGxgOQ0sGGhgVJBqfOBu7ybfeUdx8V8oTnsWxzD VhIw== X-Gm-Message-State: AOJu0Yy+tNsCpxieg6CCyEvNYGL0U2iDBF6idSk8uXfe2/EUDb0HDghm sBwciVElkVvNIF8umF7s7VTOZ0PK4OY= X-Google-Smtp-Source: AGHT+IFQHGmjTYl5KU/LvfBJtGvqeIT1isPlUH0UyZjHzrJ0Bsc+pqJxN+QJLl9WGVAC9fNl/+TvuiUlzNY= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a25:41c1:0:b0:d45:daf4:1fc5 with SMTP id o184-20020a2541c1000000b00d45daf41fc5mr482574yba.3.1692999969352; Fri, 25 Aug 2023 14:46:09 -0700 (PDT) Date: Fri, 25 Aug 2023 14:46:07 -0700 In-Reply-To: <20230714065356.20620-1-yan.y.zhao@intel.com> Mime-Version: 1.0 References: <20230714064656.20147-1-yan.y.zhao@intel.com> <20230714065356.20620-1-yan.y.zhao@intel.com> Message-ID: Subject: Re: [PATCH v4 08/12] KVM: x86: centralize code to get CD=1 memtype when guest MTRRs are honored From: Sean Christopherson To: Yan Zhao Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, chao.gao@intel.com, kai.huang@intel.com, robert.hoo.linux@gmail.com, yuan.yao@linux.intel.com Content-Type: text/plain; charset="us-ascii" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Jul 14, 2023, Yan Zhao wrote: > Centralize the code to get cache disabled memtype when guest MTRRs are > honored. If a TDP honors guest MTRRs, it is required to call the provided > API to get the memtype for CR0.CD=1. > > This is the preparation patch for later implementation of fine-grained gfn > zap for CR0.CD toggles when guest MTRRs are honored. > > No functional change intended. > > Signed-off-by: Yan Zhao > --- > arch/x86/kvm/mtrr.c | 16 ++++++++++++++++ > arch/x86/kvm/vmx/vmx.c | 10 +++++----- > arch/x86/kvm/x86.h | 2 ++ > 3 files changed, 23 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c > index 3ce58734ad22..64c6daa659c8 100644 > --- a/arch/x86/kvm/mtrr.c > +++ b/arch/x86/kvm/mtrr.c > @@ -721,3 +721,19 @@ bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, > > return type == mtrr_default_type(mtrr_state); > } > + > +/* > + * this routine is supposed to be called when guest mtrrs are honored > + */ > +void kvm_honors_guest_mtrrs_get_cd_memtype(struct kvm_vcpu *vcpu, > + u8 *type, bool *ipat) I really don't like this helper. IMO it's a big net negative for the readability of vmx_get_mt_mask(). As I said in the previous version, I agree that splitting logic is generally undesirable, but in this case I strongly believe it's the lesser evil. > +{ > + if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED)) { > + *type = MTRR_TYPE_WRBACK; > + *ipat = false; > + } else { > + *type = MTRR_TYPE_UNCACHABLE; > + *ipat = true; > + } > +} > +EXPORT_SYMBOL_GPL(kvm_honors_guest_mtrrs_get_cd_memtype); > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index c1e93678cea4..7fec1ee23b54 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -7573,11 +7573,11 @@ static u8 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio) > return (MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT) | VMX_EPT_IPAT_BIT; > > if (kvm_read_cr0_bits(vcpu, X86_CR0_CD)) { > - if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_CD_NW_CLEARED)) > - return MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT; > - else > - return (MTRR_TYPE_UNCACHABLE << VMX_EPT_MT_EPTE_SHIFT) | > - VMX_EPT_IPAT_BIT; > + bool ipat; > + u8 cache; > + > + kvm_honors_guest_mtrrs_get_cd_memtype(vcpu, &cache, &ipat); > + return cache << VMX_EPT_MT_EPTE_SHIFT | (ipat ? VMX_EPT_IPAT_BIT : 0); > } > > return kvm_mtrr_get_guest_memory_type(vcpu, gfn) << VMX_EPT_MT_EPTE_SHIFT; > diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h > index 82e3dafc5453..e7733dc4dccc 100644 > --- a/arch/x86/kvm/x86.h > +++ b/arch/x86/kvm/x86.h > @@ -313,6 +313,8 @@ int kvm_mtrr_set_msr(struct kvm_vcpu *vcpu, u32 msr, u64 data); > int kvm_mtrr_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata); > bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn, > int page_num); > +void kvm_honors_guest_mtrrs_get_cd_memtype(struct kvm_vcpu *vcpu, > + u8 *type, bool *ipat); > bool kvm_vector_hashing_enabled(void); > void kvm_fixup_and_inject_pf_error(struct kvm_vcpu *vcpu, gva_t gva, u16 error_code); > int x86_decode_emulated_instruction(struct kvm_vcpu *vcpu, int emulation_type, > -- > 2.17.1 >