From patchwork Fri Nov 11 01:42:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vishal Annapurve X-Patchwork-Id: 13039501 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 D84F0C4332F for ; Fri, 11 Nov 2022 01:43:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232496AbiKKBm6 (ORCPT ); Thu, 10 Nov 2022 20:42:58 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232420AbiKKBm4 (ORCPT ); Thu, 10 Nov 2022 20:42:56 -0500 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58A106317E for ; Thu, 10 Nov 2022 17:42:55 -0800 (PST) Received: by mail-pg1-x54a.google.com with SMTP id u63-20020a638542000000b004701a0aa835so1862621pgd.15 for ; Thu, 10 Nov 2022 17:42:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ICPUEkvZED2a6y3O08u4jS51b4sDHquP+b6CyeTgK60=; b=Po+B6TPu2lrVnybNXAiqDvhpQCVRuhqR8U6MzQPzoEhL3zHzlLB853eMltrQPYOG4x srbAOyf9uQM9B40jEI08EtOwmeRkfdgN/3qMtHDYwkyPkWZmPIy+SlVrgfiSJIGvjspM 4jrNIx5Bnh0jSfGeHpRK+6moj6y/QB/O+XLyYfbH/3MMy2mrwJZ52VsAVLymvt4QbYMN mzmidyyUSqloFTO2AymnHYj4fqI23/oV2tdnx3dqKCvb3dKiDoFj/78L+XG0tFH37342 htQ1uhw1f8Qvuzt4iDN/KFH/DiFD8Py/hI0nGXEdgvsNsqO+ia4f+pr2bAquCEvwVgf2 SQMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ICPUEkvZED2a6y3O08u4jS51b4sDHquP+b6CyeTgK60=; b=AYnHCbBBDK1cJTzxR2+OhEA9z51HJod3gODBjKMKRMhCR/aj7RdZV0ChshRqJcWOvd UySy8MZZEt3vcRVUHpsf5dAtTl51GfemFRdg4sLxMkRSMabl3CV29fJ/MxzE76wgtysP dJZs+56wToSAmgbU+9QTpOLydZSZGPDHMCibx9cgrGrA/RxdzNEvfTkvJj9q5ol0KNVC ag5fbtjHqv9kAWSeb58DoafYoITcnPdsobfRDlFgYyZBx2cYAY2ct+x6HKzvANAlluTW anzWJ0bb4FD1xm0YwArs3KB06Hjz4a+A2iHY4KzyCrH7viQ0iuGVfwYvK3VIq8c7IyH9 88iQ== X-Gm-Message-State: ANoB5pkTmWRAP/CeXY1J4PavoTdIN+FyyKismswdN6zR8jIx9eIYUE7I H31QkZmMv9DGJ/Uxfcu6cmQ8aAdrWxl4z6U0 X-Google-Smtp-Source: AA0mqf473aYDKC7Ae5CRuYu7Z65qsFzdE85vPlWihPbw2fuebWuEkwUwhbIysIQ+cvSLlcz+OOA3yPUaXKWigZ1J X-Received: from vannapurve2.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:41f8]) (user=vannapurve job=sendgmr) by 2002:a17:90b:e82:b0:20a:fee1:8f69 with SMTP id fv2-20020a17090b0e8200b0020afee18f69mr13844pjb.0.1668130974505; Thu, 10 Nov 2022 17:42:54 -0800 (PST) Date: Fri, 11 Nov 2022 01:42:39 +0000 In-Reply-To: <20221111014244.1714148-1-vannapurve@google.com> Mime-Version: 1.0 References: <20221111014244.1714148-1-vannapurve@google.com> X-Mailer: git-send-email 2.38.1.431.g37b22c650d-goog Message-ID: <20221111014244.1714148-2-vannapurve@google.com> Subject: [V1 PATCH 1/6] KVM: x86: Add support for testing private memory From: Vishal Annapurve To: x86@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: 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, chao.p.peng@linux.intel.com, 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, Vishal Annapurve Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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; + /* 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,