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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL 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 1D867C433DB for ; Mon, 1 Mar 2021 17:50:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CDC4E65042 for ; Mon, 1 Mar 2021 17:50:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239012AbhCARu3 (ORCPT ); Mon, 1 Mar 2021 12:50:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238717AbhCARrh (ORCPT ); Mon, 1 Mar 2021 12:47:37 -0500 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 13C4FC061793 for ; Mon, 1 Mar 2021 09:46:27 -0800 (PST) Received: by mail-pg1-x529.google.com with SMTP id a23so2255808pga.8 for ; Mon, 01 Mar 2021 09:46:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=d6E6zqEbjqh+dwazTT0oLku5dnRE/qNGLB3SDKN9dOw=; b=V3umcLnJr+393bucClK75f1l/HHDLkirK5dzlN9sgGKsRZMDmC6Me94xVCuoN4NqNp qcTL3MjWoKS5pDN7p6Efq6YHyYdSOutxT01s6V1iHqoxv3fl3DBPZ1yhDBuXs3TuxpIq x44r9Aw4XSYNCd/1ff8nPZOpl4BSU001+B8uUpS3H9hKKPntWDWv/vQlCMRTQYDxtHqr 1Qgx4hpd6s4+llVp9TFvA6VrVfN8/d6BUhmnB1NLcGkvxMKa7r22sonNJUtVo9JNbzeo SMzTkVuFMlExynASWBJI4bPMPzEpV+Lhcx5au3cj1WGYQSO418KYkVnrAwqbmnuURQLo dT7A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=d6E6zqEbjqh+dwazTT0oLku5dnRE/qNGLB3SDKN9dOw=; b=LQNcqXJR0KHATD+l1v1xo9n/iSyC1W3idrXEJ9bSJe9MraTUeoxA677wNd6vB0/bvP ZfGHxYHXzt/W/sColYsbAhxAv8QcR/Gmwebx2eD28EeoRXhk/r+yegmfBT4OLQUwZvDc rYGJgieguz/u/D/B8tasldYN7GhuqEluZh5ScGRmL9dakr9m4KZbCFGGquIe3Bv1Od4n 2KWHgyl4FaB9e8qRGf14Dx2UEIbIyjuT9mG5RJKRf0muT3eQv2vwXvtt2z0k8w7QfS9a XQz2LcoLE1Ecand8bLp2gnkgSqqSPQb8CCzmKvO4bzDCFHOCxfQg4lIlFuYQ2wo/zTVU 28jw== X-Gm-Message-State: AOAM532Yw3RxZu3YNJi0do78om04fcZYvZr6oTgYjuFgLgr2pfhml5IO GXxJt7EfHBpm0mIv5qtSpAMQ6w== X-Google-Smtp-Source: ABdhPJxwUl3cOs7feycakrWn32IxbWrdJjJSqGzoDLlyubX5TOmfjlzvs4DgizGVyGqux61oa7xILw== X-Received: by 2002:a62:7797:0:b029:1ed:7b10:84c2 with SMTP id s145-20020a6277970000b02901ed7b1084c2mr15949057pfc.47.1614620786279; Mon, 01 Mar 2021 09:46:26 -0800 (PST) Received: from google.com ([2620:15c:f:10:5d06:6d3c:7b9:20c9]) by smtp.gmail.com with ESMTPSA id b1sm19387523pfp.145.2021.03.01.09.46.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 01 Mar 2021 09:46:25 -0800 (PST) Date: Mon, 1 Mar 2021 09:46:19 -0800 From: Sean Christopherson To: Yang Weijiang Cc: pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vitaly Kuznetsov Subject: Re: [PATCH v2] KVM: nVMX: Sync L2 guest CET states between L1/L2 Message-ID: References: <20210225030951.17099-1-weijiang.yang@intel.com> <20210225030951.17099-2-weijiang.yang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210225030951.17099-2-weijiang.yang@intel.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org +Vitaly On Thu, Feb 25, 2021, Yang Weijiang wrote: > These fields are rarely updated by L1 QEMU/KVM, sync them when L1 is trying to > read/write them and after they're changed. If CET guest entry-load bit is not > set by L1 guest, migrate them to L2 manaully. > > Suggested-by: Sean Christopherson > Signed-off-by: Yang Weijiang > > change in v2: > - Per Sean's review feedback, change CET guest states as rarely-updated fields. > And also migrate L1's CET states to L2 if the entry-load bit is not set. > - Opportunistically removed one blank line. > --- > arch/x86/kvm/cpuid.c | 1 - > arch/x86/kvm/vmx/nested.c | 29 +++++++++++++++++++++++++++++ > arch/x86/kvm/vmx/vmx.h | 3 +++ > 3 files changed, 32 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 46087bca9418..afc97122c05c 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -143,7 +143,6 @@ void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) > } > vcpu->arch.guest_supported_xss = > (((u64)best->edx << 32) | best->ecx) & supported_xss; > - > } else { > vcpu->arch.guest_supported_xss = 0; > } > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 9728efd529a1..1703b8874fad 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -2516,6 +2516,12 @@ static void prepare_vmcs02_rare(struct vcpu_vmx *vmx, struct vmcs12 *vmcs12) > vmcs_write32(VM_ENTRY_MSR_LOAD_COUNT, vmx->msr_autoload.guest.nr); > > set_cr4_guest_host_mask(vmx); > + > + if (kvm_cet_supported()) { This needs to be conditioned on CET coming from vmcs12, it's on the loading of host state on VM-Exit that is unconditional (if CET is supported). if (kvm_cet_supported() && vmx->nested.nested_run_pending && (vmcs12->vm_entry_controls & VM_ENTRY_LOAD_CET_STATE)) { I also assume these should be guarded by one of the eVMCS fields, though a quick search of the public docs didn't provide a hit on the CET fields. Vitaly, any idea if these will be GUEST_GRP2 or something else? > + vmcs_writel(GUEST_SSP, vmcs12->guest_ssp); > + vmcs_writel(GUEST_S_CET, vmcs12->guest_s_cet); > + vmcs_writel(GUEST_INTR_SSP_TABLE, vmcs12->guest_ssp_tbl); > + } > }