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 4E1BEC4332F for ; Mon, 17 Oct 2022 14:53:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230133AbiJQOx1 (ORCPT ); Mon, 17 Oct 2022 10:53:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229949AbiJQOxZ (ORCPT ); Mon, 17 Oct 2022 10:53:25 -0400 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C3FB68CD1; Mon, 17 Oct 2022 07:53:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1666018398; x=1697554398; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=I4wfniHW10JfPeprn5rTb+kTvRXkxXZTaEZmmRNpMCk=; b=P8R4Dh4olIwXLAjxWflWJ5tLmVFc0gNEIKGdSW0s1WdPBjbDbeK4mdnp IeBEmYrdybRBOeEBW0e3OfTJhuD/BJm+m4xFTNVdgvUGStjGZ/gPyFGmm 2fdWUHlHLPk3TAh4PQ7JQ5JOlPwU0VJgXSEsycHLqxDJ2pBw/cLAZb82R Nf9QAqzkIamAMl/vebcQUKjpOC8T7zFi/7nXzwOMw1MhqAVrIOGnwJjNS 1kTD9F0XiNbmIFPrBGB5UwNEUhasB1KvuF3vezv9rPu+A2WqTK14lPp9y SPEbJIA0hubiF89W/60ihQzPLn4SMhrZZ3We3+O71Vd73sTL556F2Nrad A==; X-IronPort-AV: E=McAfee;i="6500,9779,10503"; a="370008643" X-IronPort-AV: E=Sophos;i="5.95,191,1661842800"; d="scan'208";a="370008643" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Oct 2022 07:53:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10503"; a="691384101" X-IronPort-AV: E=Sophos;i="5.95,191,1661842800"; d="scan'208";a="691384101" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.193.75]) by fmsmga008.fm.intel.com with ESMTP; 17 Oct 2022 07:53:06 -0700 Date: Mon, 17 Oct 2022 22:48:35 +0800 From: Chao Peng To: Sean Christopherson Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org, linux-doc@vger.kernel.org, qemu-devel@nongnu.org, Paolo Bonzini , Jonathan Corbet , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H . Peter Anvin" , Hugh Dickins , Jeff Layton , "J . Bruce Fields" , Andrew Morton , Shuah Khan , Mike Rapoport , Steven Price , "Maciej S . Szmigiero" , Vlastimil Babka , Vishal Annapurve , Yu Zhang , "Kirill A . Shutemov" , luto@kernel.org, jun.nakajima@intel.com, dave.hansen@intel.com, ak@linux.intel.com, david@redhat.com, aarcange@redhat.com, ddutile@redhat.com, dhildenb@redhat.com, Quentin Perret , Michael Roth , mhocko@suse.com, Muchun Song , wei.w.wang@intel.com Subject: Re: [PATCH v8 7/8] KVM: Handle page fault for private memory Message-ID: <20221017144835.GA3417432@chaop.bj.intel.com> Reply-To: Chao Peng References: <20220915142913.2213336-1-chao.p.peng@linux.intel.com> <20220915142913.2213336-8-chao.p.peng@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 14, 2022 at 06:57:20PM +0000, Sean Christopherson wrote: > On Thu, Sep 15, 2022, Chao Peng wrote: > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index a0f198cede3d..81ab20003824 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -3028,6 +3028,9 @@ int kvm_mmu_max_mapping_level(struct kvm *kvm, > > break; > > } > > > > + if (kvm_mem_is_private(kvm, gfn)) > > Rather than reload the Xarray info, which is unnecessary overhead, pass in > @is_private. The caller must hold mmu_lock, i.e. invalidations from > private<->shared conversions will be stalled and will zap the new SPTE if the > state is changed. Make sense. TDX/SEV should be easy to query that. Chao > > E.g. > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index d68944f07b4b..44eea47697d8 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -3072,8 +3072,8 @@ void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault > * Enforce the iTLB multihit workaround after capturing the requested > * level, which will be used to do precise, accurate accounting. > */ > - fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, > - fault->gfn, fault->max_level); > + fault->req_level = kvm_mmu_max_mapping_level(vcpu->kvm, slot, fault->gfn, > + fault->max_level, fault->is_private); > if (fault->req_level == PG_LEVEL_4K || fault->huge_page_disallowed) > return; > > @@ -6460,7 +6460,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, > */ > if (sp->role.direct && > sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, > - PG_LEVEL_NUM)) { > + PG_LEVEL_NUM, false)) { > kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); > > if (kvm_available_flush_tlb_with_range()) > diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h > index 7670c13ce251..9acdf72537ce 100644 > --- a/arch/x86/kvm/mmu/spte.h > +++ b/arch/x86/kvm/mmu/spte.h > @@ -315,6 +315,12 @@ static inline bool is_dirty_spte(u64 spte) > return dirty_mask ? spte & dirty_mask : spte & PT_WRITABLE_MASK; > } > > +static inline bool is_private_spte(u64 spte) > +{ > + /* FIXME: Query C-bit/S-bit for SEV/TDX. */ > + return false; > +} > + > static inline u64 get_rsvd_bits(struct rsvd_bits_validate *rsvd_check, u64 pte, > int level) > { > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index 672f0432d777..69ba00157e90 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -1767,8 +1767,9 @@ static void zap_collapsible_spte_range(struct kvm *kvm, > if (iter.gfn < start || iter.gfn >= end) > continue; > > - max_mapping_level = kvm_mmu_max_mapping_level(kvm, slot, > - iter.gfn, PG_LEVEL_NUM); > + max_mapping_level = kvm_mmu_max_mapping_level(kvm, slot, iter.gfn, > + PG_LEVEL_NUM, > + is_private_spte(iter.old_spte)); > if (max_mapping_level < iter.level) > continue; >