From patchwork Mon Mar 1 09:45:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Huang, Kai" X-Patchwork-Id: 12109375 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 0A501C433DB for ; Mon, 1 Mar 2021 09:52:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D218164E3F for ; Mon, 1 Mar 2021 09:52:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234343AbhCAJwV (ORCPT ); Mon, 1 Mar 2021 04:52:21 -0500 Received: from mga05.intel.com ([192.55.52.43]:62399 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234231AbhCAJr6 (ORCPT ); Mon, 1 Mar 2021 04:47:58 -0500 IronPort-SDR: 5AK/Y+RIGbQislAzQaPH+Uc3n7H5/SUkvudPMpF2E57lYHZ8djMdWPfzLt4SUZF2ijmYtVc+Rv 6CGefiENz0hA== X-IronPort-AV: E=McAfee;i="6000,8403,9909"; a="271409702" X-IronPort-AV: E=Sophos;i="5.81,215,1610438400"; d="scan'208";a="271409702" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Mar 2021 01:46:51 -0800 IronPort-SDR: OB3MIMRda1J9X8X9WTZOjWUGaM3oWkLrdNu8v1egEpiYojALrVjM+T+Q44liaAFCkmu8dnIvrI KsvP/B64XSBA== X-IronPort-AV: E=Sophos;i="5.81,215,1610438400"; d="scan'208";a="599267702" Received: from jscomeax-mobl.amr.corp.intel.com (HELO khuang2-desk.gar.corp.intel.com) ([10.252.139.76]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Mar 2021 01:46:46 -0800 From: Kai Huang To: kvm@vger.kernel.org, x86@kernel.org, linux-sgx@vger.kernel.org Cc: linux-kernel@vger.kernel.org, seanjc@google.com, jarkko@kernel.org, luto@kernel.org, dave.hansen@intel.com, rick.p.edgecombe@intel.com, haitao.huang@intel.com, pbonzini@redhat.com, bp@alien8.de, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, jmattson@google.com, joro@8bytes.org, vkuznets@redhat.com, wanpengli@tencent.com, Kai Huang Subject: [PATCH 23/25] KVM: VMX: Add ENCLS[EINIT] handler to support SGX Launch Control (LC) Date: Mon, 1 Mar 2021 22:45:56 +1300 Message-Id: <1360af19ec13d52f32d242ca8bff767188de9eb1.1614590788.git.kai.huang@intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Sean Christopherson Add a VM-Exit handler to trap-and-execute EINIT when SGX LC is enabled in the host. When SGX LC is enabled, the host kernel may rewrite the hardware values at will, e.g. to launch enclaves with different signers, thus KVM needs to intercept EINIT to ensure it is executed with the correct LE hash (even if the guest sees a hardwired hash). Switching the LE hash MSRs on VM-Enter/VM-Exit is not a viable option as writing the MSRs is prohibitively expensive, e.g. on SKL hardware each WRMSR is ~400 cycles. And because EINIT takes tens of thousands of cycles to execute, the ~1500 cycle overhead to trap-and-execute EINIT is unlikely to be noticed by the guest, let alone impact its overall SGX performance. Signed-off-by: Sean Christopherson Signed-off-by: Kai Huang --- arch/x86/kvm/vmx/sgx.c | 55 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/arch/x86/kvm/vmx/sgx.c b/arch/x86/kvm/vmx/sgx.c index cb8ad068807b..55be2ea90de5 100644 --- a/arch/x86/kvm/vmx/sgx.c +++ b/arch/x86/kvm/vmx/sgx.c @@ -259,6 +259,59 @@ static int handle_encls_ecreate(struct kvm_vcpu *vcpu) return kvm_skip_emulated_instruction(vcpu); } +static int handle_encls_einit(struct kvm_vcpu *vcpu) +{ + unsigned long sig_hva, secs_hva, token_hva, rflags; + struct vcpu_vmx *vmx = to_vmx(vcpu); + gva_t sig_gva, secs_gva, token_gva; + gpa_t sig_gpa, secs_gpa, token_gpa; + int ret, trapnr; + + if (sgx_get_encls_gva(vcpu, kvm_rbx_read(vcpu), 1808, 4096, &sig_gva) || + sgx_get_encls_gva(vcpu, kvm_rcx_read(vcpu), 4096, 4096, &secs_gva) || + sgx_get_encls_gva(vcpu, kvm_rdx_read(vcpu), 304, 512, &token_gva)) + return 1; + + /* + * Translate the SIGSTRUCT, SECS and TOKEN pointers from GVA to GPA. + * Resume the guest on failure to inject a #PF. + */ + if (sgx_gva_to_gpa(vcpu, sig_gva, false, &sig_gpa) || + sgx_gva_to_gpa(vcpu, secs_gva, true, &secs_gpa) || + sgx_gva_to_gpa(vcpu, token_gva, false, &token_gpa)) + return 1; + + /* + * ...and then to HVA. The order of accesses isn't architectural, i.e. + * KVM doesn't have to fully process one address at a time. Exit to + * userspace if a GPA is invalid. Note, all structures are aligned and + * cannot split pages. + */ + if (sgx_gpa_to_hva(vcpu, sig_gpa, &sig_hva) || + sgx_gpa_to_hva(vcpu, secs_gpa, &secs_hva) || + sgx_gpa_to_hva(vcpu, token_gpa, &token_hva)) + return 0; + + ret = sgx_virt_einit((void __user *)sig_hva, (void __user *)token_hva, + (void __user *)secs_hva, + vmx->msr_ia32_sgxlepubkeyhash, &trapnr); + + if (ret == -EFAULT) + return sgx_inject_fault(vcpu, secs_gva, trapnr); + + rflags = vmx_get_rflags(vcpu) & ~(X86_EFLAGS_CF | X86_EFLAGS_PF | + X86_EFLAGS_AF | X86_EFLAGS_SF | + X86_EFLAGS_OF); + if (ret) + rflags |= X86_EFLAGS_ZF; + else + rflags &= ~X86_EFLAGS_ZF; + vmx_set_rflags(vcpu, rflags); + + kvm_rax_write(vcpu, ret); + return kvm_skip_emulated_instruction(vcpu); +} + static inline bool encls_leaf_enabled_in_guest(struct kvm_vcpu *vcpu, u32 leaf) { if (!enable_sgx || !guest_cpuid_has(vcpu, X86_FEATURE_SGX)) @@ -291,6 +344,8 @@ int handle_encls(struct kvm_vcpu *vcpu) } else { if (leaf == ECREATE) return handle_encls_ecreate(vcpu); + if (leaf == EINIT) + return handle_encls_einit(vcpu); WARN(1, "KVM: unexpected exit on ENCLS[%u]", leaf); vcpu->run->exit_reason = KVM_EXIT_UNKNOWN; vcpu->run->hw.hardware_exit_reason = EXIT_REASON_ENCLS;