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 X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 8E149C433E0 for ; Tue, 16 Feb 2021 03:09:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B77E64DE8 for ; Tue, 16 Feb 2021 03:09:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229652AbhBPDJL (ORCPT ); Mon, 15 Feb 2021 22:09:11 -0500 Received: from mail.kernel.org ([198.145.29.99]:39988 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229497AbhBPDJL (ORCPT ); Mon, 15 Feb 2021 22:09:11 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id DCBED64D9D; Tue, 16 Feb 2021 03:08:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613444910; bh=PEZDoewzicDcK1rp22MAeNU/BCgJy7YEanIWt6BZX+Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=G0BdwyUPJpRwk/U5EL7x097w+tm0+b6ItMVTMvhlZQVWPCzrgnhI+Tcv3m6FmbcIK DEN8QhjsV/1Sr5G8JcCXtmlO29jeOUI94ngvSdsnOR4IAOD4D0G1lt/0EdwjCOLx4W DKodPCUMXGf/mRKt8nOaH9iL4PDubQnNXN27lqL1IaiB1Bp8pq7t8LZavevqHQrSEf uNrv8hoGtCOmaiYR+qbf1j7aXa4+4qfF80IJGKuA7gxVLtWmjkGwCeZ5/VUZYF/0fB jltmBzvuf55UNxyt27xMZ0MlP64LLvnYU+rU4CjjedZQ1ZlAqGDs+Z4lY+j5Two02T hp9zBZWdMI2Qg== Date: Tue, 16 Feb 2021 05:08:17 +0200 From: Jarkko Sakkinen To: Kai Huang Cc: linux-sgx@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, seanjc@google.com, 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 Subject: Re: [RFC PATCH v5 13/26] x86/sgx: Add helpers to expose ECREATE and EINIT to KVM Message-ID: References: <4b8921da8e0d037b1e99d5cc92eea8f8470cf2e0.1613221549.git.kai.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4b8921da8e0d037b1e99d5cc92eea8f8470cf2e0.1613221549.git.kai.huang@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Sun, Feb 14, 2021 at 02:29:15AM +1300, Kai Huang wrote: > From: Sean Christopherson > > The host kernel must intercept ECREATE to be able to impose policies on > guests. When it does this, the host kernel runs ECREATE against the > userspace mapping of the virtualized EPC. > > Provide wrappers around __ecreate() and __einit() to hide the ugliness > of overloading the ENCLS return value to encode multiple error formats > in a single int. KVM will trap-and-execute ECREATE and EINIT as part > of SGX virtualization, and on an exception, KVM needs the trapnr so that > it can inject the correct fault into the guest. > > Signed-off-by: Sean Christopherson > Signed-off-by: Kai Huang > --- > v4->v5: > > - No code change. > > v3->v4: > > - Added one new line before last return in sgx_virt_einit(), per Jarkko. > > v2->v3: > > - Added kdoc for sgx_virt_ecreate() and sgx_virt_einit(), per Jarkko. > - Changed to use CONFIG_X86_SGX_KVM. > > --- > arch/x86/include/asm/sgx.h | 16 ++++++ > arch/x86/kernel/cpu/sgx/virt.c | 94 ++++++++++++++++++++++++++++++++++ > 2 files changed, 110 insertions(+) > create mode 100644 arch/x86/include/asm/sgx.h > > diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h > new file mode 100644 > index 000000000000..8a3ea3e1efbe > --- /dev/null > +++ b/arch/x86/include/asm/sgx.h > @@ -0,0 +1,16 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +#ifndef _ASM_X86_SGX_H > +#define _ASM_X86_SGX_H > + > +#include > + > +#ifdef CONFIG_X86_SGX_KVM > +struct sgx_pageinfo; > + > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > + int *trapnr); > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > + void __user *secs, u64 *lepubkeyhash, int *trapnr); s/virt/vepc/g > +#endif > + > +#endif /* _ASM_X86_SGX_H */ > diff --git a/arch/x86/kernel/cpu/sgx/virt.c b/arch/x86/kernel/cpu/sgx/virt.c > index 47542140f8c1..016bad7cff8d 100644 > --- a/arch/x86/kernel/cpu/sgx/virt.c > +++ b/arch/x86/kernel/cpu/sgx/virt.c Rename as vepc.c. > @@ -257,3 +257,97 @@ int __init sgx_vepc_init(void) > > return misc_register(&sgx_vepc_dev); > } > + > +/** > + * sgx_virt_ecreate() - Run ECREATE on behalf of guest > + * @pageinfo: Pointer to PAGEINFO structure > + * @secs: Userspace pointer to SECS page > + * @trapnr: trap number injected to guest in case of ECREATE error > + * > + * Run ECREATE on behalf of guest after KVM traps ECREATE for the purpose > + * of enforcing policies of guest's enclaves, and return the trap number > + * which should be injected to guest in case of any ECREATE error. > + * > + * Return: > + * - 0: ECREATE was successful. > + * - -EFAULT: ECREATE returned error. > + */ > +int sgx_virt_ecreate(struct sgx_pageinfo *pageinfo, void __user *secs, > + int *trapnr) > +{ > + int ret; > + > + /* > + * @secs is userspace address, and it's not guaranteed @secs points at > + * an actual EPC page. It's also possible to generate a kernel mapping > + * to physical EPC page by resolving PFN but using __uaccess_xx() is > + * simpler. > + */ > + __uaccess_begin(); > + ret = __ecreate(pageinfo, (void *)secs); > + __uaccess_end(); > + > + if (encls_faulted(ret)) { > + *trapnr = ENCLS_TRAPNR(ret); > + return -EFAULT; > + } > + > + /* ECREATE doesn't return an error code, it faults or succeeds. */ > + WARN_ON_ONCE(ret); Empty line. > + return 0; > +} > +EXPORT_SYMBOL_GPL(sgx_virt_ecreate); > + > +static int __sgx_virt_einit(void __user *sigstruct, void __user *token, > + void __user *secs) > +{ > + int ret; > + > + __uaccess_begin(); > + ret = __einit((void *)sigstruct, (void *)token, (void *)secs); > + __uaccess_end(); Ditto. > + return ret; > +} > + > +/** > + * sgx_virt_einit() - Run EINIT on behalf of guest > + * @sigstruct: Userspace pointer to SIGSTRUCT structure > + * @token: Userspace pointer to EINITTOKEN structure > + * @secs: Userspace pointer to SECS page > + * @lepubkeyhash: Pointer to guest's *virtual* SGX_LEPUBKEYHASH MSR > + * values > + * @trapnr: trap number injected to guest in case of EINIT error > + * > + * Run EINIT on behalf of guest after KVM traps EINIT. If SGX_LC is available > + * in host, SGX driver may rewrite the hardware values at wish, therefore KVM > + * needs to update hardware values to guest's virtual MSR values in order to > + * ensure EINIT is executed with expected hardware values. > + * > + * Return: > + * - 0: EINIT was successful. > + * - -EFAULT: EINIT returned error. > + */ > +int sgx_virt_einit(void __user *sigstruct, void __user *token, > + void __user *secs, u64 *lepubkeyhash, int *trapnr) > +{ > + int ret; > + > + if (!boot_cpu_has(X86_FEATURE_SGX_LC)) { > + ret = __sgx_virt_einit(sigstruct, token, secs); > + } else { > + preempt_disable(); > + > + sgx_update_lepubkeyhash(lepubkeyhash); > + > + ret = __sgx_virt_einit(sigstruct, token, secs); > + preempt_enable(); > + } > + > + if (encls_faulted(ret)) { > + *trapnr = ENCLS_TRAPNR(ret); > + return -EFAULT; > + } > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(sgx_virt_einit); > -- > 2.29.2 > > /Jarkko