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 78EC8C6FD18 for ; Thu, 30 Mar 2023 01:16:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229753AbjC3BQA (ORCPT ); Wed, 29 Mar 2023 21:16:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44088 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229510AbjC3BP6 (ORCPT ); Wed, 29 Mar 2023 21:15:58 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11E0D19A; Wed, 29 Mar 2023 18:15:57 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id z19so16671676plo.2; Wed, 29 Mar 2023 18:15:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680138956; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=TihRUSuIbcyCr0lFNEjhUbfKbaamQ0uPf3hyuIDE6gQ=; b=RTCry2uEnJf3RnYi048V1AACEOoeINBihN3daGEThrK7Bq+36P6NP1q9dkpULWbie8 uQ+5BgrxGjr7TFybutkeCUNROz8jAAU2iJAYvbAeJat1n3Y84fIlGB5JO8bQN2fILctV weQomRf25JCSNirmMlrZaZXWqMY+Ndlv4D7ywqjsk4uGOFl2jRWEjPrDLVe+qEUwtVb7 gHIGhoXDOIjAZBJu0GAc9dXoeWWsZa95TZ3WNZxAeeqOtwj4ggXyBUQA91tbJh7MSABN 4Q8h5m17gFc6yi4pAJjEumavn5466GH9ZVOjZe9MX8KInbActnX91Mc0xDbj3tPgLqIk M2tQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680138956; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=TihRUSuIbcyCr0lFNEjhUbfKbaamQ0uPf3hyuIDE6gQ=; b=a97sSIxFPhaBR4gUofMdtd0njRI9NNvGYc0hJree1Mpwtx+Gn12tm6SVTz4HqnK9tG ytGf9e8vmBfWpLBxsvW0Yr7+/9DfE8x4QqcJK4yyiZSJfxa4mRhw7iXP46vj06maKiyx iCFxFyMCSn+UA87kITzduEAPzEsvgxaptBQPZZgpjx5Pmak7yb0a/DrGmuSLDyNa/vqQ Sxqw9ZAZmeWqSa3N0Ly1AbfJM1Ei376djTL7uYXs5DWzUT/QIbctv7AdU5tsFMPuUC5S RWZO6KYYfpewE/wKWYsn/KbeVr4XHP/7VDljvPHUf+6P+XyQTdC92+Q4S3R56CNPWhO6 pd/w== X-Gm-Message-State: AAQBX9dCnhsDQhgfBQ0gMOub4YCto9HApE82OPBoKPCaDpiRm6evN33j 89OAhqtfIauuR2USCUM/IAc= X-Google-Smtp-Source: AKy350bTyshcbmCc+pIoeONIBpErKFE3Gxut0UYm4dqDCX6T8TbmlSk/RhFbqlgU82sSChm+gMnTgQ== X-Received: by 2002:a17:903:7c3:b0:19c:b4e3:c65b with SMTP id ko3-20020a17090307c300b0019cb4e3c65bmr16884174plb.8.1680138956389; Wed, 29 Mar 2023 18:15:56 -0700 (PDT) Received: from localhost ([192.55.54.55]) by smtp.gmail.com with ESMTPSA id f12-20020a170902ab8c00b001a1a9a5e53fsm6979478plr.136.2023.03.29.18.15.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Mar 2023 18:15:55 -0700 (PDT) Date: Wed, 29 Mar 2023 18:15:54 -0700 From: Isaku Yamahata To: "Huang, Kai" Cc: "isaku.yamahata@gmail.com" , "Christopherson,, Sean" , "Shahar, Sagi" , "linux-kernel@vger.kernel.org" , "Aktas, Erdem" , "dmatlack@google.com" , "kvm@vger.kernel.org" , "zhi.wang.linux@gmail.com" , "pbonzini@redhat.com" , "Yamahata, Isaku" Subject: Re: [PATCH v13 057/113] KVM: TDX: MTRR: implement get_mt_mask() for TDX Message-ID: <20230330011554.GD1112017@ls.amr.corp.intel.com> References: <20230325011200.GB214881@ls.amr.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 27, 2023 at 09:54:40AM +0000, "Huang, Kai" wrote: > > diff -u b/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c > > --- b/arch/x86/kvm/vmx/tdx.c > > +++ b/arch/x86/kvm/vmx/tdx.c > > @@ -347,6 +347,25 @@ > > return 0; > > } > > > > +u8 tdx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio) > > +{ > > + /* TDX private GPA is always WB. */ > > + if (!(gfn & kvm_gfn_shared_mask(vcpu->kvm))) { > > Are you still passing a "raw" GFN? Could you explain why you choose this way? > > > + /* MMIO is only for shared GPA. */ > > + WARN_ON_ONCE(is_mmio); > > + return MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT; > > I guess it's better to include VMX_EPT_IPAT_BIT bit. On second thought, there is no need to check it. We can simply drop this check. u8 tdx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio) { if (is_mmio) return MTRR_TYPE_UNCACHABLE << VMX_EPT_MT_EPTE_SHIFT; if (!kvm_arch_has_noncoherent_dma(vcpu->kvm)) return (MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT) | VMX_EPT_IPAT_BIT; /* TDX enforces CR0.CD = 0 and KVM MTRR emulation enforces writeback. */ return MTRR_TYPE_WRBACK << VMX_EPT_MT_EPTE_SHIFT; } -- Isaku Yamahata