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 DF0F6C4332F for ; Tue, 22 Nov 2022 10:12:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232964AbiKVKMH (ORCPT ); Tue, 22 Nov 2022 05:12:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37960 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232645AbiKVKLr (ORCPT ); Tue, 22 Nov 2022 05:11:47 -0500 Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D918954B3C; Tue, 22 Nov 2022 02:11:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669111904; x=1700647904; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:in-reply-to; bh=usjdVgC5nTrsMPk+N8fokwP8pD99HC8BUV8bc4gHSuA=; b=HfctUD3QggyPX6zsCVtLICrnp+4l6+zBAxUgUW+joSiPYur6A/8YyUfA LbkyemKdOvF6fezsw1CdCzRm4V4wxqxKEG+o8OxCyPjQXWkvBpUp//CLn tAAe8Yuujo1pXALer2qrYmWbgSNwNzy9prgeigUgNhOxOZ90uExSDWF/0 hCYGlxcZmhvy+6T8Q3lgUOEB2jwAyC/NqILlLsfWIE9B/8gEdfQhvBmWW nWlops7Wyoc9NQFW7FiAbgLd1I4rjHBkeLN7tX1Mi2ak6ztGss4bysTof APsf1PZSb4sLGTl9WrXUlrhht7SqDvkchaHna8t0ixC1lOP4vKh3jcfRk g==; X-IronPort-AV: E=McAfee;i="6500,9779,10538"; a="400071024" X-IronPort-AV: E=Sophos;i="5.96,183,1665471600"; d="scan'208";a="400071024" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 22 Nov 2022 02:11:38 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10538"; a="704914294" X-IronPort-AV: E=Sophos;i="5.96,183,1665471600"; d="scan'208";a="704914294" Received: from chaop.bj.intel.com (HELO localhost) ([10.240.193.75]) by fmsmga008.fm.intel.com with ESMTP; 22 Nov 2022 02:11:28 -0800 Date: Tue, 22 Nov 2022 18:07:05 +0800 From: Chao Peng To: Vishal Annapurve Cc: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, pbonzini@redhat.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, shuah@kernel.org, yang.zhong@intel.com, ricarkol@google.com, aaronlewis@google.com, wei.w.wang@intel.com, kirill.shutemov@linux.intel.com, corbet@lwn.net, hughd@google.com, jlayton@kernel.org, bfields@fieldses.org, akpm@linux-foundation.org, yu.c.zhang@linux.intel.com, jun.nakajima@intel.com, dave.hansen@intel.com, michael.roth@amd.com, qperret@google.com, steven.price@arm.com, ak@linux.intel.com, david@redhat.com, luto@kernel.org, vbabka@suse.cz, marcorr@google.com, erdemaktas@google.com, pgonda@google.com, nikunj@amd.com, seanjc@google.com, diviness@google.com, maz@kernel.org, dmatlack@google.com, axelrasmussen@google.com, maciej.szmigiero@oracle.com, mizhang@google.com, bgardon@google.com, ackerleytng@google.com Subject: Re: [V1 PATCH 1/6] KVM: x86: Add support for testing private memory Message-ID: <20221122100705.GA619277@chaop.bj.intel.com> Reply-To: Chao Peng References: <20221111014244.1714148-1-vannapurve@google.com> <20221111014244.1714148-2-vannapurve@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221111014244.1714148-2-vannapurve@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 11, 2022 at 01:42:39AM +0000, Vishal Annapurve wrote: > Introduce HAVE_KVM_PRIVATE_MEM_TESTING config to be able to test fd based > approach to support private memory with non-confidential selftest VMs. > To support this testing few important aspects need to be considered from > the perspective of selftests - > * KVM needs to know whether the access from guest VM is private or shared. > Confidential VMs (SNP/TDX) carry a dedicated bit in gpa that can be used by > KVM to deduce the nature of the access. > Non-confidential VMs don't have mechanism to carry/convey such an > information to KVM. So KVM just relies on what attributes are set by > userspace VMM keeping the userspace VMM in the TCB for the testing > purposes. > * arch_private_mem_supported is updated to allow private memory logic to > work with non-confidential vm selftests. > > Signed-off-by: Vishal Annapurve > --- > arch/x86/kvm/mmu/mmu.c | 4 ++++ > arch/x86/kvm/mmu/mmu_internal.h | 4 +++- > virt/kvm/Kconfig | 4 ++++ > virt/kvm/kvm_main.c | 2 +- > 4 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 10017a9f26ee..b3118d00b284 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -4280,6 +4280,10 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault > > fault->gfn = fault->addr >> PAGE_SHIFT; > fault->slot = kvm_vcpu_gfn_to_memslot(vcpu, fault->gfn); > +#ifdef CONFIG_HAVE_KVM_PRIVATE_MEM_TESTING > + fault->is_private = kvm_slot_can_be_private(fault->slot) && > + kvm_mem_is_private(vcpu->kvm, fault->gfn); > +#endif > > if (page_fault_handle_page_track(vcpu, fault)) > return RET_PF_EMULATE; > diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h > index 5cdff5ca546c..2e759f39c2c5 100644 > --- a/arch/x86/kvm/mmu/mmu_internal.h > +++ b/arch/x86/kvm/mmu/mmu_internal.h > @@ -188,7 +188,6 @@ struct kvm_page_fault { > > /* Derived from mmu and global state. */ > const bool is_tdp; > - const bool is_private; > const bool nx_huge_page_workaround_enabled; > > /* > @@ -221,6 +220,9 @@ struct kvm_page_fault { > /* The memslot containing gfn. May be NULL. */ > struct kvm_memory_slot *slot; > > + /* Derived from encryption bits of the faulting GPA for CVMs. */ > + bool is_private; Either we can wrap it with the CONFIG_HAVE_KVM_PRIVATE_MEM_TESTING or if it looks ugly I can remove the "const" in my code. Chao > + > /* Outputs of kvm_faultin_pfn. */ > kvm_pfn_t pfn; > hva_t hva; > diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig > index 69ca59e82149..300876afb0ca 100644 > --- a/virt/kvm/Kconfig > +++ b/virt/kvm/Kconfig > @@ -93,3 +93,7 @@ config HAVE_KVM_RESTRICTED_MEM > config KVM_GENERIC_PRIVATE_MEM > bool > depends on HAVE_KVM_RESTRICTED_MEM > + > +config HAVE_KVM_PRIVATE_MEM_TESTING > + bool > + depends on KVM_GENERIC_PRIVATE_MEM > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index dae6a2c196ad..54e57b7f1c15 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1750,7 +1750,7 @@ static void kvm_replace_memslot(struct kvm *kvm, > > bool __weak kvm_arch_has_private_mem(struct kvm *kvm) > { > - return false; > + return IS_ENABLED(CONFIG_HAVE_KVM_PRIVATE_MEM_TESTING); > } > > static int check_memory_region_flags(struct kvm *kvm, > -- > 2.38.1.431.g37b22c650d-goog