From patchwork Thu Oct 13 16:00:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dionna Amalie Glaze X-Patchwork-Id: 2088 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:4ac7:0:0:0:0:0 with SMTP id y7csp355239wrs; Thu, 13 Oct 2022 09:04:16 -0700 (PDT) X-Google-Smtp-Source: AMsMyM7RDEMeFDbE2hjoIVNYnZDGVs+XjPUqjwzSI4M+0H19JxbO8nuX2BkTF9laFW5uiAjW0mou X-Received: by 2002:a17:907:6d8f:b0:78d:9b5e:1a0f with SMTP id sb15-20020a1709076d8f00b0078d9b5e1a0fmr357418ejc.23.1665677056665; Thu, 13 Oct 2022 09:04:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1665677056; cv=none; d=google.com; s=arc-20160816; b=Bvt6CIg6pNWDMdgb4hiP5wFZ4Jd4rhVS7tCsnkHGV0L7n+EUpHgnOeSeo2bCzzrT1G +Xl6tyHmnTZUeUNnSssU8OY5pSn06gHHAO6vvEK07gDts9lTuVJVyBYBIxDgE1rXGpDq AfrQajwjArFasWUYmem1Dr9sN8ha8jmWuBpLTBtARkvQc1rxVJ6PPP548PwitsyHsIo6 N4LJj6GWMnXEuL4v2m1SaEsBJSIo2ahtK1xGnrZ34DvsdyUqa4KOw4Zvr7gaAwDP/wNY ZJzAKrUGTcNqP5MT9RQaCcqyQCCWzSnT6WcT1yYOoRUEfSo7UONOJLMSeYLfmoHhv/yr wBZw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:dkim-signature; bh=y7BIlHgNQlvppQZ+CGwKN1fA9G9Eb8Xq4ktO1Quy358=; b=VSI1XghtiljPaTVst8BIyEb4zd93pWnZTdgtQoYP0erIdDpp+FO2EexVe1TliVpqXE NVgCs+QdCO84zcgsTwYYlz4BJZPku8/S3RtUCRdXiD4DD4uXXdBCi28txWcvMK7impxd n6GBM0pL34EHKd6ZRhm8d9dzeL9UWucQxlHR+mG/uYCx0FAxFSJjvXhefPs6NrBfJh9T mmoyvgYUbxAi/5WJVMzruvgILV5Xv7MRv8ZMztPrA9daAG9JWng3lSW14gQrJ6ZimeBV X5OQ58chJxbzf5XG9T69C2sE1zjQ0zFjwouoVNjvckLzyN/VYf7n5szx5wOGSctAF7bt /O0Q== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=W7bVmX6R; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id i5-20020a17090671c500b0077083e6dde7si100748ejk.183.2022.10.13.09.03.43; Thu, 13 Oct 2022 09:04:16 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=W7bVmX6R; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229703AbiJMQBF (ORCPT + 99 others); Thu, 13 Oct 2022 12:01:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44196 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229678AbiJMQBC (ORCPT ); Thu, 13 Oct 2022 12:01:02 -0400 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C481A103DA8 for ; Thu, 13 Oct 2022 09:01:01 -0700 (PDT) Received: by mail-pg1-x549.google.com with SMTP id p24-20020a63f458000000b0043cd718c49dso1208377pgk.15 for ; Thu, 13 Oct 2022 09:01:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=y7BIlHgNQlvppQZ+CGwKN1fA9G9Eb8Xq4ktO1Quy358=; b=W7bVmX6RVPsZzOCX5yzg+9+z9D6fOazH4u8HtiPlmGwkDgHBCdyCbX+aKrFHKozu4I 0qAiaymzLZ7vUFoizZ0Cyo+vdMKsV3TDkw3EBe2ZKc7/skO48lcCISQNR15VShyQ6M/Y RKQQ89vfC89cBdy3V5LyC/0Zzz2Dt+xF2CEhWLGVxxXmWwhLDsGx8ogQBLM7dt3vOUyo rRpKUHCEfVjRUDPJouCQLPTliqHexJ7L82oYWzsBwrgv7fhaUrc9FcVHZx5AB5nSankc Q5Sgf97YDzq3/IyCyS/0fP1AkrW6ert8DnEfASQxm0EdmT3kQLTBJ4j2jJUDKS7OX8kH jb0Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=y7BIlHgNQlvppQZ+CGwKN1fA9G9Eb8Xq4ktO1Quy358=; b=4GbNTqrzw5W/vrdPuh/wQzmnPNSPAI7a8A0RodltGWxeTQ5g2IeuOI8X9NJItqX5oF E8SW7epNCmpsgf0+pErkzTK3G3e0MpTxDavfD9ZCo2w/1po+5yUL1KXs1nBP0kkX36oQ CMPJ9NSksrWrDdKTUCG6JIGlsjOP55hrggwLOXhkqaMCmaGEuhE1MHDH6TDcZHQz5gxS KxRF5/uj7QFirG82EHni1/g2uvPvbiXszoVOHhoAP25BXhj6qgeHcQGZ9aa3OVJhHTvZ Q1MsJs1VphlBDVyXs5lcJPOkjGuFeemaMPzgVhFmhieFZpdkVBZ6lLOwPW9waTg22BA1 T+Fw== X-Gm-Message-State: ACrzQf1yqeefNHt7MfGSMK2En3VdQpagH3JVSpcwrHfsilJ0HTxsyz8f dH9aZqfpLn7PA+Jur/hbdzgOuFpjARLUX4lsOrrrm4IPMhsK9Eu+KFb4ZDM9LiVObjygWibEyBk H0XRr1Akj9cDra/mMODXDdModeUyJXOkmcOgkkDBrDUT3xby4jk84FyKRVd032BSD6Hm1ofaSr4 lmA41aEXo= X-Received: from dionnaglaze.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2ee6]) (user=dionnaglaze job=sendgmr) by 2002:a62:2985:0:b0:544:77d4:f43b with SMTP id p127-20020a622985000000b0054477d4f43bmr199173pfp.9.1665676861215; Thu, 13 Oct 2022 09:01:01 -0700 (PDT) Date: Thu, 13 Oct 2022 16:00:40 +0000 In-Reply-To: <20221013160040.2858732-1-dionnaglaze@google.com> Mime-Version: 1.0 References: <20221013160040.2858732-1-dionnaglaze@google.com> X-Mailer: git-send-email 2.38.0.413.g74048e4d9e-goog Message-ID: <20221013160040.2858732-3-dionnaglaze@google.com> Subject: [PATCH 2/2] virt/coco/sev-guest: interpret VMM errors from guest request From: Dionna Glaze To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Dionna Glaze , Tom Lendacky , Paolo Bonzini , Joerg Roedel , Peter Gonda , Thomas Gleixner , Dave Hansen X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1746588985381431343?= X-GMAIL-MSGID: =?utf-8?q?1746588985381431343?= The GHCB specification states that the upper 32 bits of exitinfo2 are for the VMM's error codes. The sev-guest ABI has already locked in that the fw_err status of the input will be 64 bits, and that BIT_ULL(32) means that the extended guest request's data buffer was too small, so we have to keep that ABI. This patch deprecates the fw_err field name in the request to exitinfo2. We can still interpret the upper 32 bits of exitinfo2 for the user anyway in case the request gets throttled. That makes the interface more user-friendly. Cc: Tom Lendacky Cc: Paolo Bonzini Cc: Joerg Roedel Cc: Peter Gonda Cc: Thomas Gleixner Cc: Dave Hansen Signed-off-by: Dionna Glaze --- drivers/virt/coco/sev-guest/sev-guest.c | 34 +++++++++++++++++-------- include/uapi/linux/sev-guest.h | 17 +++++++++++-- 2 files changed, 38 insertions(+), 13 deletions(-) diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c index f422f9c58ba7..8bc435cbd7e3 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -303,9 +303,10 @@ static int enc_payload(struct snp_guest_dev *snp_dev, u64 seqno, int version, u8 static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, int msg_ver, u8 type, void *req_buf, size_t req_sz, void *resp_buf, - u32 resp_sz, __u64 *fw_err) + u32 resp_sz, __u64 *exitinfo2) { - unsigned long err; + unsigned long _exitinfo2 = 0; + unsigned int vmm_err; u64 seqno; int rc; @@ -322,9 +323,20 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in return rc; /* Call firmware to process the request */ - rc = snp_issue_guest_request(exit_code, &snp_dev->input, &err); - if (fw_err) - *fw_err = err; + rc = snp_issue_guest_request(exit_code, &snp_dev->input, &_exitinfo2); + if (exitinfo2) + *exitinfo2 = _exitinfo2; + + vmm_err = _exitinfo2 >> SNP_GUEST_VMM_ERR_SHIFT; + /* The host may return EBUSY if the request has been throttled. */ + if (vmm_err == SNP_GUEST_VMM_ERR_BUSY) + return -EAGAIN; + + if (vmm_err && vmm_err != SNP_GUEST_VMM_ERR_INVALID_LEN) { + pr_err("sev-guest: host returned unknown error code: %d\n", + vmm_err); + return -EINVAL; + } if (rc) return rc; @@ -378,7 +390,7 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg->msg_version, SNP_MSG_REPORT_REQ, &req, sizeof(req), resp->data, - resp_len, &arg->fw_err); + resp_len, &arg->exitinfo2); if (rc) goto e_free; @@ -418,7 +430,7 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque rc = handle_guest_request(snp_dev, SVM_VMGEXIT_GUEST_REQUEST, arg->msg_version, SNP_MSG_KEY_REQ, &req, sizeof(req), buf, resp_len, - &arg->fw_err); + &arg->exitinfo2); if (rc) return rc; @@ -480,10 +492,10 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques 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); + sizeof(req.data), resp->data, resp_len, &arg->exitinfo2); /* If certs length is invalid then copy the returned length */ - if (arg->fw_err == SNP_GUEST_REQ_INVALID_LEN) { + if (arg->vmm_error == SNP_GUEST_VMM_ERR_INVALID_LEN) { req.certs_len = snp_dev->input.data_npages << PAGE_SHIFT; if (copy_to_user((void __user *)arg->req_data, &req, sizeof(req))) @@ -518,7 +530,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long if (copy_from_user(&input, argp, sizeof(input))) return -EFAULT; - input.fw_err = 0xff; + input.exitinfo2 = 0xff; /* Message version must be non-zero */ if (!input.msg_version) @@ -549,7 +561,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long mutex_unlock(&snp_cmd_mutex); - if (input.fw_err && copy_to_user(argp, &input, sizeof(input))) + if (input.exitinfo2 && copy_to_user(argp, &input, sizeof(input))) return -EFAULT; return ret; diff --git a/include/uapi/linux/sev-guest.h b/include/uapi/linux/sev-guest.h index 256aaeff7e65..0654a652e4dc 100644 --- a/include/uapi/linux/sev-guest.h +++ b/include/uapi/linux/sev-guest.h @@ -12,6 +12,7 @@ #ifndef __UAPI_LINUX_SEV_GUEST_H_ #define __UAPI_LINUX_SEV_GUEST_H_ +#include #include struct snp_report_req { @@ -52,8 +53,15 @@ struct snp_guest_request_ioctl { __u64 req_data; __u64 resp_data; - /* firmware error code on failure (see psp-sev.h) */ - __u64 fw_err; + /* bits[63:32]: VMM error code, bits[31:0] firmware error code (see psp-sev.h) */ + union { + __u64 exitinfo2; + __u64 fw_err; /* Name deprecated in favor of others */ + struct { + __u32 fw_error; + __u32 vmm_error; + }; + }; }; struct snp_ext_report_req { @@ -77,4 +85,9 @@ struct snp_ext_report_req { /* 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) + +#define SNP_GUEST_VMM_ERR_SHIFT 32 +#define SNP_GUEST_VMM_ERR_INVALID_LEN 1 +#define SNP_GUEST_VMM_ERR_BUSY EBUSY + #endif /* __UAPI_LINUX_SEV_GUEST_H_ */