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 B7AF6C433EF for ; Thu, 14 Apr 2022 10:04:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241471AbiDNKG6 (ORCPT ); Thu, 14 Apr 2022 06:06:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241081AbiDNKGy (ORCPT ); Thu, 14 Apr 2022 06:06:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3B84924F07 for ; Thu, 14 Apr 2022 03:04:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649930669; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yuBcaeBniy5n5/L8X5921bwDC++5b8Xw6Z88KRpE9bQ=; b=H6ThkuHQRkp0+KobMoIe4k1h+ICTCF7M03QuUQVfPghUjePcRurMyzgFUwPCCSMo4Fy/Ey Xnybm/UL6i6HY/U4brYH9R0SUP+6HXyDU2xE2lqa7R5mQfwNN5P6izDpRphFF81V4+JVBZ uqGwofKnqyI7XkwBUcYcLRf8pP84xps= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-489-lfkcvLJfP2iUfNlDxr3NnQ-1; Thu, 14 Apr 2022 06:04:26 -0400 X-MC-Unique: lfkcvLJfP2iUfNlDxr3NnQ-1 Received: by mail-wm1-f72.google.com with SMTP id j20-20020a05600c1c1400b0038eb5cb35ecso4255301wms.9 for ; Thu, 14 Apr 2022 03:04:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=yuBcaeBniy5n5/L8X5921bwDC++5b8Xw6Z88KRpE9bQ=; b=BT0K/ZtQUBykOaxVGHG92ZyA7LcGvg5x498byn40Yv2RWydpR2Y/pHFlv0l0PgHT3w qhV6+5UAgk7aXNelvu6H2hZayEvwvNaR2haItB+Zv6bm/frkXnyw4yyhVxjKoJYBBOHA u46GY4tdr727Xw7i81pmBgHIJonI2Qy3DRHZ9EELOs+vZC1Q+xmgiAq8TZIiHnuFrAXM 6Yjsf+mhCKimLrEuHdQbjW8bpNrbpES38ypHo/HFPd5NRIBDrTDZ+8vXuwXAmlWTD0go semgljZsa9beHLPql6PJuz+rSbmBo1UKRfJ+h9OigVIbydE/YDxmYs7rdCz6OCP8ZtEw 0WWQ== X-Gm-Message-State: AOAM533p6TmgpdFMJ9aPEEwobJIzMKpXE5OgcTEc+eWPA/bLfliBilnW BwntLR2ahFYk9chU4igh3mty3kY+fCfsFmmBEfj0nvMpt2zh8jGPgSWPFCuSa6TmqT5Za4l2PQj 7OGGZtMTcTemqbuOgC1a3/bvh X-Received: by 2002:a05:600c:3ba9:b0:38e:c8c6:ae0d with SMTP id n41-20020a05600c3ba900b0038ec8c6ae0dmr2410328wms.120.1649930664853; Thu, 14 Apr 2022 03:04:24 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyWW/CBrPwe+sYaoZNvV9T6UgMbQHF1faFSZFy0/f2vgkvI5kJx/Q5UzWAjnkbtTzqBMnumbg== X-Received: by 2002:a05:600c:3ba9:b0:38e:c8c6:ae0d with SMTP id n41-20020a05600c3ba900b0038ec8c6ae0dmr2410293wms.120.1649930664610; Thu, 14 Apr 2022 03:04:24 -0700 (PDT) Received: from ?IPV6:2001:b07:6468:f312:c8dd:75d4:99ab:290a? ([2001:b07:6468:f312:c8dd:75d4:99ab:290a]) by smtp.googlemail.com with ESMTPSA id r14-20020a0560001b8e00b00205918bd86esm1395196wru.78.2022.04.14.03.04.21 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 Apr 2022 03:04:24 -0700 (PDT) Message-ID: <658729a1-a4a1-a353-50d6-ef71e83a4375@redhat.com> Date: Thu, 14 Apr 2022 12:04:20 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [RFC PATCH V3 3/4] KVM: X86: Alloc role.pae_root shadow page Content-Language: en-US To: Lai Jiangshan Cc: Sean Christopherson , LKML , kvm@vger.kernel.org, Lai Jiangshan , Jonathan Corbet , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , X86 ML , "H. Peter Anvin" , linux-doc@vger.kernel.org References: <20220330132152.4568-1-jiangshanlai@gmail.com> <20220330132152.4568-4-jiangshanlai@gmail.com> <683974e7-5801-e289-8fa4-c8a8d21ec1b2@redhat.com> From: Paolo Bonzini In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/14/22 11:32, Lai Jiangshan wrote: > kvm_mmu_free_roots() can not free those new types of sp if they are still > valid. And different vcpu can use the same pae root sp if the guest cr3 > of the vcpus are the same. Right, but then load_pdptrs only needs to zap the page before (or instead of) calling kvm_mmu_free_roots(). Paolo > And new pae root can be put in prev_root too (not implemented yet) > because they are not too special anymore. As long as sp->gfn, sp->pae_off, > sp->role are matched, they can be reused.