From patchwork Wed Feb 9 18:10:38 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brijesh Singh X-Patchwork-Id: 12740744 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 0D792C433FE for ; Wed, 9 Feb 2022 18:16:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239477AbiBISQM (ORCPT ); Wed, 9 Feb 2022 13:16:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239262AbiBISOx (ORCPT ); Wed, 9 Feb 2022 13:14:53 -0500 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (mail-bn7nam10on2070.outbound.protection.outlook.com [40.107.92.70]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 78279C05CBA9; Wed, 9 Feb 2022 10:12:50 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=ZFyqyxx9mg8E67nvrjCb1+raQWAkH3DDn6Q+ogHs6VdIexKVrez1BHE2dlvcZKwt6g7ziAAm8iAMd68eGE+iGcrjJNLlwWqMp71H7rCc54QH2BMLY4PN/HPMaIZtXyzA7xbTKbjWT91DF9xG9eGAshMSFfC8Nh1sGLHNxEqvQUHP4RIfKFZ1m/A5lCfAmsl8STotESv2tQTvU6ucREHXz+4H5tYk8QO9V6tkYHa0VFpqC/JnTA/krRZSkEnDZnJ2yz7idn3W+Ggx+k/awRipVvJbe7kaWWG4jL8ILOwpzisfxsewwy1cqT65ge6b6xHzZk8k0gOSX8gjhdFVvDlsNA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=jhswYmnERXxICUPqhZGTbKwdFlBe4HJkgbVgye8BLO0=; b=VYn/bovMmwD141j3c/ZNQrs9aHSoNGzObAsDMe+Vjb6wK6dFEj7665eoU2Lisuaul/XTgauwgoNG2jUkksyqnnRvF94IwMk1kiq+5dRkLgQkcSqZbhdfupJO3N0u2H/C4Qzg17bZBnmRC9JxLoqEcmlLDIbdaU75dp2zDxB3FKGjzh0Ry9Fhik8/CChw4kZbwucJCA5NhDlatZKg6W1LFhIxDJHIseTxJglnNo0Sr3GWGKTAAW8jOGeLzm/PuB1aHTUf4eEVTEQQbV+VUkvbCvLejbrMtqbhVsRrs4XNF+fqFdaWZRgRtORqA/jL5B8kP/9xJZREB6VsfL5/fQm5lQ== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 165.204.84.17) smtp.rcpttodomain=kernel.org smtp.mailfrom=amd.com; dmarc=pass (p=quarantine sp=quarantine pct=100) action=none header.from=amd.com; dkim=none (message not signed); arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amd.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=jhswYmnERXxICUPqhZGTbKwdFlBe4HJkgbVgye8BLO0=; b=JSjMv6zL+6eG4gUwHTkVBElmml+Ti4AprLQzvF1AJ1rcrPzE5KFkuCk35jbb7Oq0AWyth9YHTmXPIops1OtrhFBj1tREXSofnWxdoSXBGWdf6abUNccbP1nnXQLMUVEB0nqc2Hn9/FSqPvZWwgwVngpUm+P6UEp2jeflRKVOcfs= Received: from MWHPR14CA0052.namprd14.prod.outlook.com (2603:10b6:300:81::14) by DM5PR12MB1403.namprd12.prod.outlook.com (2603:10b6:3:79::11) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4951.18; Wed, 9 Feb 2022 18:12:45 +0000 Received: from CO1NAM11FT009.eop-nam11.prod.protection.outlook.com (2603:10b6:300:81:cafe::b9) by MWHPR14CA0052.outlook.office365.com (2603:10b6:300:81::14) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4951.12 via Frontend Transport; Wed, 9 Feb 2022 18:12:44 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 165.204.84.17) smtp.mailfrom=amd.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=amd.com; Received-SPF: Pass (protection.outlook.com: domain of amd.com designates 165.204.84.17 as permitted sender) receiver=protection.outlook.com; client-ip=165.204.84.17; helo=SATLEXMB04.amd.com; Received: from SATLEXMB04.amd.com (165.204.84.17) by CO1NAM11FT009.mail.protection.outlook.com (10.13.175.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.20.4975.11 via Frontend Transport; Wed, 9 Feb 2022 18:12:44 +0000 Received: from sbrijesh-desktop.amd.com (10.180.168.240) by SATLEXMB04.amd.com (10.181.40.145) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.18; Wed, 9 Feb 2022 12:12:41 -0600 From: Brijesh Singh To: , , , , , , CC: Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , "Vitaly Kuznetsov" , Jim Mattson , "Andy Lutomirski" , Dave Hansen , Sergio Lopez , Peter Gonda , "Peter Zijlstra" , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Borislav Petkov , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , "Dr . David Alan Gilbert" , , , , , Brijesh Singh Subject: [PATCH v10 44/45] virt: sevguest: Add support to get extended report Date: Wed, 9 Feb 2022 12:10:38 -0600 Message-ID: <20220209181039.1262882-45-brijesh.singh@amd.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220209181039.1262882-1-brijesh.singh@amd.com> References: <20220209181039.1262882-1-brijesh.singh@amd.com> MIME-Version: 1.0 X-Originating-IP: [10.180.168.240] X-ClientProxiedBy: SATLEXMB04.amd.com (10.181.40.145) To SATLEXMB04.amd.com (10.181.40.145) X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: b88ed234-3eb1-40a2-fe8f-08d9ebf7c511 X-MS-TrafficTypeDiagnostic: DM5PR12MB1403:EE_ X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:2331; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:SATLEXMB04.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230001)(4636009)(36840700001)(40470700004)(46966006)(5660300002)(7696005)(36756003)(8676002)(8936002)(508600001)(70586007)(6666004)(70206006)(40460700003)(83380400001)(54906003)(82310400004)(4326008)(110136005)(47076005)(2906002)(316002)(16526019)(26005)(1076003)(356005)(36860700001)(426003)(2616005)(86362001)(186003)(44832011)(7416002)(336012)(7406005)(81166007)(2101003)(36900700001);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Feb 2022 18:12:44.3345 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: b88ed234-3eb1-40a2-fe8f-08d9ebf7c511 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[SATLEXMB04.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CO1NAM11FT009.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR12MB1403 Precedence: bulk List-ID: X-Mailing-List: platform-driver-x86@vger.kernel.org Version 2 of GHCB specification defines Non-Automatic-Exit(NAE) to get the extended guest report. It is similar to the SNP_GET_REPORT ioctl. The main difference is related to the additional data that will be returned. The additional data returned is a certificate blob that can be used by the SNP guest user. The certificate blob layout is defined in the GHCB specification. The driver simply treats the blob as a opaque data and copies it to userspace. Signed-off-by: Brijesh Singh --- Documentation/virt/coco/sevguest.rst | 23 +++++++ drivers/virt/coco/sevguest/sevguest.c | 93 ++++++++++++++++++++++++++- include/uapi/linux/sev-guest.h | 13 ++++ 3 files changed, 127 insertions(+), 2 deletions(-) diff --git a/Documentation/virt/coco/sevguest.rst b/Documentation/virt/coco/sevguest.rst index ae2e76f59435..0f352056572d 100644 --- a/Documentation/virt/coco/sevguest.rst +++ b/Documentation/virt/coco/sevguest.rst @@ -95,6 +95,29 @@ on the various fields passed in the key derivation request. On success, the snp_derived_key_resp.data contains the derived key value. See the SEV-SNP specification for further details. + +2.3 SNP_GET_EXT_REPORT +---------------------- +:Technology: sev-snp +:Type: guest ioctl +:Parameters (in/out): struct snp_ext_report_req +:Returns (out): struct snp_report_resp on success, -negative on error + +The SNP_GET_EXT_REPORT ioctl is similar to the SNP_GET_REPORT. The difference is +related to the additional certificate data that is returned with the report. +The certificate data returned is being provided by the hypervisor through the +SNP_SET_EXT_CONFIG. + +The ioctl uses the SNP_GUEST_REQUEST (MSG_REPORT_REQ) command provided by the SEV-SNP +firmware to get the attestation report. + +On success, the snp_ext_report_resp.data will contain the attestation report +and snp_ext_report_req.certs_address will contain the certificate blob. If the +length of the blob is smaller than expected then snp_ext_report_req.certs_len will +be updated with the expected value. + +See GHCB specification for further detail on how to parse the certificate blob. + Reference --------- diff --git a/drivers/virt/coco/sevguest/sevguest.c b/drivers/virt/coco/sevguest/sevguest.c index 2062f94fdc38..b840cf426f38 100644 --- a/drivers/virt/coco/sevguest/sevguest.c +++ b/drivers/virt/coco/sevguest/sevguest.c @@ -41,6 +41,7 @@ struct snp_guest_dev { struct device *dev; struct miscdevice misc; + void *certs_data; struct snp_guest_crypto *crypto; struct snp_guest_msg *request, *response; struct snp_secrets_page_layout *layout; @@ -431,6 +432,83 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque return rc; } +static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_ioctl *arg) +{ + struct snp_guest_crypto *crypto = snp_dev->crypto; + struct snp_ext_report_req req = {0}; + struct snp_report_resp *resp; + int ret, npages = 0, resp_len; + + lockdep_assert_held(&snp_cmd_mutex); + + if (!arg->req_data || !arg->resp_data) + return -EINVAL; + + if (copy_from_user(&req, (void __user *)arg->req_data, sizeof(req))) + return -EFAULT; + + if (req.certs_len) { + if (req.certs_len > SEV_FW_BLOB_MAX_SIZE || + !IS_ALIGNED(req.certs_len, PAGE_SIZE)) + return -EINVAL; + } + + if (req.certs_address && req.certs_len) { + if (!access_ok(req.certs_address, req.certs_len)) + return -EFAULT; + + /* + * Initialize the intermediate buffer with all zeros. This buffer + * is used in the guest request message to get the certs blob from + * the host. If host does not supply any certs in it, then copy + * zeros to indicate that certificate data was not provided. + */ + memset(snp_dev->certs_data, 0, req.certs_len); + + npages = req.certs_len >> PAGE_SHIFT; + } + + /* + * The intermediate response buffer is used while decrypting the + * response payload. Make sure that it has enough space to cover the + * authtag. + */ + resp_len = sizeof(resp->data) + crypto->a_len; + resp = kzalloc(resp_len, GFP_KERNEL_ACCOUNT); + if (!resp) + return -ENOMEM; + + snp_dev->input.data_npages = npages; + ret = handle_guest_request(snp_dev, SVM_VMGEXIT_EXT_GUEST_REQUEST, arg->msg_version, + SNP_MSG_REPORT_REQ, &req.data, + sizeof(req.data), resp->data, resp_len, &arg->fw_err); + + /* If certs length is invalid then copy the returned length */ + if (arg->fw_err == SNP_GUEST_REQ_INVALID_LEN) { + req.certs_len = snp_dev->input.data_npages << PAGE_SHIFT; + + if (copy_to_user((void __user *)arg->req_data, &req, sizeof(req))) + ret = -EFAULT; + } + + if (ret) + goto e_free; + + if (req.certs_address && req.certs_len && + copy_to_user((void __user *)req.certs_address, snp_dev->certs_data, + req.certs_len)) { + ret = -EFAULT; + goto e_free; + } + + if (copy_to_user((void __user *)arg->resp_data, resp, sizeof(*resp))) + ret = -EFAULT; + +e_free: + kfree(resp); + return ret; +} + static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long arg) { struct snp_guest_dev *snp_dev = to_snp_dev(file); @@ -463,6 +541,9 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long case SNP_GET_DERIVED_KEY: ret = get_derived_key(snp_dev, &input); break; + case SNP_GET_EXT_REPORT: + ret = get_ext_report(snp_dev, &input); + break; default: break; } @@ -590,10 +671,14 @@ static int __init snp_guest_probe(struct platform_device *pdev) if (!snp_dev->response) goto e_free_request; + snp_dev->certs_data = alloc_shared_pages(SEV_FW_BLOB_MAX_SIZE); + if (!snp_dev->certs_data) + goto e_free_response; + ret = -EIO; snp_dev->crypto = init_crypto(snp_dev, snp_dev->vmpck, VMPCK_KEY_LEN); if (!snp_dev->crypto) - goto e_free_response; + goto e_free_cert_data; misc = &snp_dev->misc; misc->minor = MISC_DYNAMIC_MINOR; @@ -603,14 +688,17 @@ static int __init snp_guest_probe(struct platform_device *pdev) /* initial the input address for guest request */ snp_dev->input.req_gpa = __pa(snp_dev->request); snp_dev->input.resp_gpa = __pa(snp_dev->response); + snp_dev->input.data_gpa = __pa(snp_dev->certs_data); ret = misc_register(misc); if (ret) - goto e_free_response; + goto e_free_cert_data; dev_info(dev, "Initialized SNP guest driver (using vmpck_id %d)\n", vmpck_id); return 0; +e_free_cert_data: + free_shared_pages(snp_dev->certs_data, SEV_FW_BLOB_MAX_SIZE); e_free_response: free_shared_pages(snp_dev->response, sizeof(struct snp_guest_msg)); e_free_request: @@ -624,6 +712,7 @@ static int __exit snp_guest_remove(struct platform_device *pdev) { struct snp_guest_dev *snp_dev = platform_get_drvdata(pdev); + free_shared_pages(snp_dev->certs_data, SEV_FW_BLOB_MAX_SIZE); free_shared_pages(snp_dev->response, sizeof(struct snp_guest_msg)); free_shared_pages(snp_dev->request, sizeof(struct snp_guest_msg)); deinit_crypto(snp_dev->crypto); diff --git a/include/uapi/linux/sev-guest.h b/include/uapi/linux/sev-guest.h index 598367f12064..256aaeff7e65 100644 --- a/include/uapi/linux/sev-guest.h +++ b/include/uapi/linux/sev-guest.h @@ -56,6 +56,16 @@ struct snp_guest_request_ioctl { __u64 fw_err; }; +struct snp_ext_report_req { + struct snp_report_req data; + + /* where to copy the certificate blob */ + __u64 certs_address; + + /* length of the certificate blob */ + __u32 certs_len; +}; + #define SNP_GUEST_REQ_IOC_TYPE 'S' /* Get SNP attestation report */ @@ -64,4 +74,7 @@ struct snp_guest_request_ioctl { /* Get a derived key from the root */ #define SNP_GET_DERIVED_KEY _IOWR(SNP_GUEST_REQ_IOC_TYPE, 0x1, struct snp_guest_request_ioctl) +/* Get SNP extended report as defined in the GHCB specification version 2. */ +#define SNP_GET_EXT_REPORT _IOWR(SNP_GUEST_REQ_IOC_TYPE, 0x2, struct snp_guest_request_ioctl) + #endif /* __UAPI_LINUX_SEV_GUEST_H_ */