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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 AAA66C4332E for ; Tue, 2 Mar 2021 11:02:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 700F964F0B for ; Tue, 2 Mar 2021 11:02:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1446413AbhCBKxz (ORCPT ); Tue, 2 Mar 2021 05:53:55 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:60616 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349554AbhCBKhc (ORCPT ); Tue, 2 Mar 2021 05:37:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614681345; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ntJc1vtjNdieqIbSV3Z/3YUY9v5a7BvhLBCSmXa57ec=; b=W2sKV4DakW72HGw5SHEZvkB4MQBdvc1fle0AH6gXnnL91tpt/u+kkt9upBt43cGKp6XuVs iKrMMtt1eZapTm5GHf/vLMSd12jATGQDmvr4wu9BKkfO/GAERnlYSjnXA1KbiJs/pYMirW 8NrusSiF1aWDDiUpqQbuG5mIAj3ToTQ= Received: from mail-ej1-f71.google.com (mail-ej1-f71.google.com [209.85.218.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-46-WbVfILQwPhOwk3XUo5-wdg-1; Tue, 02 Mar 2021 05:35:43 -0500 X-MC-Unique: WbVfILQwPhOwk3XUo5-wdg-1 Received: by mail-ej1-f71.google.com with SMTP id 11so1722597ejz.20 for ; Tue, 02 Mar 2021 02:35:43 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version; bh=ntJc1vtjNdieqIbSV3Z/3YUY9v5a7BvhLBCSmXa57ec=; b=X38VNBnBnrZaQc8UWgkfPquxSXyKafF94UtOxHVeuq2kV3lMvkf13JsVlRro4ru7R1 P/DiyusolFNPZJpbUHdCgPuqSKVjPKgioZwUUduxv62Nc3OFL7IXyrDR8JfZGZJH2Aq4 CUdWdLmfjHkIh957x12JxiJaZKXVKPZCPOBATV4aZ0syRmdqnl2VH7h3mSgYCcGAyE8g cKviimF6+RrZyatN9YYgUI7AvgP8flTB4EObhE7pob1TNTvdJak730B0YuNSxqIS/MU/ rb4d/P4SARY4LSyG6/Rvfhj5lVY62bmVDf/5RLYOM3WqNKGxWJZHrpKuYwZacWgX1r7C lt7Q== X-Gm-Message-State: AOAM533zHHdhqkwGfxmkZP8JfucRwmIbUMmAGwvnGCjRFsb9IXPImJXo 9BIui/hpNfCFFDAwBOtlv30YLdzj8NQOu5TG6wYFCVYVxXnvPvXB7GeOmqWrAXNrDEDS/WuHCwm Ntu903IzDcGg7ZN9Hr7URUj+SSRMjhwok1HaUbeYAGGij88L5Xdb6musaK8jIMGSU0jB/JYiuv2 4A X-Received: by 2002:aa7:cd8d:: with SMTP id x13mr19660736edv.286.1614681342669; Tue, 02 Mar 2021 02:35:42 -0800 (PST) X-Google-Smtp-Source: ABdhPJw2fUeTTgU9ANlcwXLzW5t2ozKbQnPsSw5DdDXqr1gn7k47UtfpI8PCZXXOIsYe5YbLpxSGMg== X-Received: by 2002:aa7:cd8d:: with SMTP id x13mr19660724edv.286.1614681342468; Tue, 02 Mar 2021 02:35:42 -0800 (PST) Received: from vitty.brq.redhat.com (g-server-2.ign.cz. [91.219.240.2]) by smtp.gmail.com with ESMTPSA id v1sm16893126ejd.3.2021.03.02.02.35.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Mar 2021 02:35:41 -0800 (PST) From: Vitaly Kuznetsov To: Sean Christopherson , Yang Weijiang Cc: pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] KVM: nVMX: Sync L2 guest CET states between L1/L2 In-Reply-To: References: <20210225030951.17099-1-weijiang.yang@intel.com> <20210225030951.17099-2-weijiang.yang@intel.com> Date: Tue, 02 Mar 2021 11:35:41 +0100 Message-ID: <87y2f5etc2.fsf@vitty.brq.redhat.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sean Christopherson writes: > +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? > The latest published TLFS I see is 6.0b and it doesn't list anything CET related in eVMCS v1.0 :-( So I agree with Paolo: we just need to adjust EVMCS1_UNSUPPORTED_VMENTRY_CTRL/ EVMCS1_UNSUPPORTED_VMEXIT_CTRL for now and enable it separately later. >> + 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); >> + } >> } > -- Vitaly