From nobody Thu Dec 18 20:22:22 2025 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 725B2C04A94 for ; Mon, 14 Aug 2023 07:44:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234295AbjHNHnw (ORCPT ); Mon, 14 Aug 2023 03:43:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42130 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234257AbjHNHna (ORCPT ); Mon, 14 Aug 2023 03:43:30 -0400 Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 93EA8115 for ; Mon, 14 Aug 2023 00:43:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1691999007; x=1723535007; h=subject:from:to:cc:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ZKEMKTZcxb+bR5sevS5HirhkX4iYwm8FNvR5plo9bz8=; b=VWEVNru1WosXoIKBAKM58S325WdDeF7SUP2fNWcoO1+fV7uNAWSDM1Z1 Ql/6nLLzQpVrCAVAq7ERS0bDt0rcA7Bcjsoa3IAPSJeejHcrqYri7oGH5 vz15PBBIg7AuvfMz1LLDqqagoLt01tSQ11UiLe59YEv8mJ+YBn2Us2az1 1ezX/hzU8c7HbF0xCT/9+8E6+AX+KofTXZ2c7rS7jhN1wWovydkezHZGp Oi6QlQ0l/4LkYfRZVbaKDa/ujR+CN5FUvqy/A5yHczNyBwX7hURBhS3sB IA9V4DGEHKvPnu36mTxEK2Hz4ZDKAtWNg08BoP9SZwYPSlCuGE7wzupVY w==; X-IronPort-AV: E=McAfee;i="6600,9927,10801"; a="438314730" X-IronPort-AV: E=Sophos;i="6.01,172,1684825200"; d="scan'208";a="438314730" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2023 00:43:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10801"; a="907142138" X-IronPort-AV: E=Sophos;i="6.01,172,1684825200"; d="scan'208";a="907142138" Received: from navanban-mobl.amr.corp.intel.com (HELO dwillia2-xfh.jf.intel.com) ([10.209.127.25]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Aug 2023 00:43:27 -0700 Subject: [PATCH v2 3/5] virt: sevguest: Prep for kernel internal {get, get_ext}_report() From: Dan Williams To: linux-coco@lists.linux.dev Cc: Borislav Petkov , Tom Lendacky , Dionna Glaze , Brijesh Singh , peterz@infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org Date: Mon, 14 Aug 2023 00:43:26 -0700 Message-ID: <169199900677.1782217.12516417657696965559.stgit@dwillia2-xfh.jf.intel.com> In-Reply-To: <169199898909.1782217.10899362240465838600.stgit@dwillia2-xfh.jf.intel.com> References: <169199898909.1782217.10899362240465838600.stgit@dwillia2-xfh.jf.intel.com> User-Agent: StGit/0.18-3-g996c MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In preparation for using the TSM key facility to convey attestation blobs to userspace, add an argument to flag whether @arg is a user buffer or a kernel buffer. While TSM keys is meant to replace existing confidenital computing ioctl() implementations for attestation report retrieval the old ioctl() path needs to stick around for a deprecation period. No behavior change intended, just introduce the copy wrappers and @type argument. Note that these wrappers are similar to copy_{to,from}_sockptr(). If this approach moves forward that concept is something that can be generalized into a helper with a generic name. Cc: Borislav Petkov Cc: Tom Lendacky Cc: Dionna Glaze Cc: Brijesh Singh Signed-off-by: Dan Williams Reviewed-by: Dionna Glaze --- drivers/virt/coco/sev-guest/sev-guest.c | 48 ++++++++++++++++++++++++---= ---- 1 file changed, 37 insertions(+), 11 deletions(-) diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/se= v-guest/sev-guest.c index 97dbe715e96a..f48c4764a7a2 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -470,7 +470,32 @@ static int handle_guest_request(struct snp_guest_dev *= snp_dev, u64 exit_code, return 0; } =20 -static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_requ= est_ioctl *arg) +enum snp_arg_type { + SNP_UARG, + SNP_KARG, +}; + +static unsigned long copy_from(void *to, unsigned long from, unsigned long= n, + enum snp_arg_type type) +{ + if (type =3D=3D SNP_UARG) + return copy_from_user(to, (void __user *)from, n); + memcpy(to, (void *)from, n); + return 0; +} + +static unsigned long copy_to(unsigned long to, const void *from, + unsigned long n, enum snp_arg_type type) +{ + if (type =3D=3D SNP_UARG) + return copy_to_user((void __user *)to, from, n); + memcpy((void *)to, from, n); + return 0; +} + +static int get_report(struct snp_guest_dev *snp_dev, + struct snp_guest_request_ioctl *arg, + enum snp_arg_type type) { struct snp_guest_crypto *crypto =3D snp_dev->crypto; struct snp_report_resp *resp; @@ -482,7 +507,7 @@ static int get_report(struct snp_guest_dev *snp_dev, st= ruct snp_guest_request_io if (!arg->req_data || !arg->resp_data) return -EINVAL; =20 - if (copy_from_user(&req, (void __user *)arg->req_data, sizeof(req))) + if (copy_from(&req, arg->req_data, sizeof(req), type)) return -EFAULT; =20 /* @@ -501,7 +526,7 @@ static int get_report(struct snp_guest_dev *snp_dev, st= ruct snp_guest_request_io if (rc) goto e_free; =20 - if (copy_to_user((void __user *)arg->resp_data, resp, sizeof(*resp))) + if (copy_to(arg->resp_data, resp, sizeof(*resp), type)) rc =3D -EFAULT; =20 e_free: @@ -550,7 +575,9 @@ static int get_derived_key(struct snp_guest_dev *snp_de= v, struct snp_guest_reque return rc; } =20 -static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_= request_ioctl *arg) +static int get_ext_report(struct snp_guest_dev *snp_dev, + struct snp_guest_request_ioctl *arg, + enum snp_arg_type type) { struct snp_guest_crypto *crypto =3D snp_dev->crypto; struct snp_ext_report_req req; @@ -562,7 +589,7 @@ static int get_ext_report(struct snp_guest_dev *snp_dev= , struct snp_guest_reques if (!arg->req_data || !arg->resp_data) return -EINVAL; =20 - if (copy_from_user(&req, (void __user *)arg->req_data, sizeof(req))) + if (copy_from(&req, arg->req_data, sizeof(req), type)) return -EFAULT; =20 /* userspace does not want certificate data */ @@ -611,14 +638,13 @@ static int get_ext_report(struct snp_guest_dev *snp_d= ev, struct snp_guest_reques if (ret) goto e_free; =20 - if (npages && - copy_to_user((void __user *)req.certs_address, snp_dev->certs_data, - req.certs_len)) { + if (npages && copy_to(req.certs_address, snp_dev->certs_data, + req.certs_len, type)) { ret =3D -EFAULT; goto e_free; } =20 - if (copy_to_user((void __user *)arg->resp_data, resp, sizeof(*resp))) + if (copy_to(arg->resp_data, resp, sizeof(*resp), type)) ret =3D -EFAULT; =20 e_free: @@ -653,13 +679,13 @@ static long snp_guest_ioctl(struct file *file, unsign= ed int ioctl, unsigned long =20 switch (ioctl) { case SNP_GET_REPORT: - ret =3D get_report(snp_dev, &input); + ret =3D get_report(snp_dev, &input, SNP_UARG); break; case SNP_GET_DERIVED_KEY: ret =3D get_derived_key(snp_dev, &input); break; case SNP_GET_EXT_REPORT: - ret =3D get_ext_report(snp_dev, &input); + ret =3D get_ext_report(snp_dev, &input, SNP_UARG); break; default: break;