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 A73F3C433E0 for ; Tue, 16 Feb 2021 03:10:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E67B64D9D for ; Tue, 16 Feb 2021 03:10:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229708AbhBPDKK (ORCPT ); Mon, 15 Feb 2021 22:10:10 -0500 Received: from mail.kernel.org ([198.145.29.99]:40052 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229703AbhBPDKJ (ORCPT ); Mon, 15 Feb 2021 22:10:09 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2F31F64DE8; Tue, 16 Feb 2021 03:09:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613444968; bh=H7pZrLgEmbVOB3J1+nLiVbNoH4kxBddNoDdxLu2lTog=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ImFdodrKuxejL8+eCSYq17Qkqd0T1w4/N64OJ1lsDM2U5GbTeKf5zWaICFLHEaRJg oUoyAOW+jsPK14phvJSPdD8RT+OVlVod5+xFr0OjQrEAT0VHN25ofQzVTiGCJyJWuU 0BXGOj52k9QPlHLdFVGbB1v2gCT3adt2DHJpTTv3tenIxM+4lPzs+6BMiYqbrZhU5o nF4t/OhNu3Lt4JC9sd1jNKmXNWK9W9z6y3FAXSB7+O5HM268OJa+PVoxZsQJQ0szB8 XNdTXXzaEV8FaVQ4Fu5CTkyF3NAR+fIpWR/rvQDTYSLbsN/FzPj4vMk7oPamXCfyfb FSsP4ENDhITgw== Date: Tue, 16 Feb 2021 05:09:14 +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: Precedence: bulk List-ID: X-Mailing-List: linux-sgx@vger.kernel.org On Tue, Feb 16, 2021 at 05:08:20AM +0200, Jarkko Sakkinen wrote: > 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); Remove exports. > > -- > > 2.29.2 > > > > > > /Jarkko