From patchwork Thu Nov 3 01:10:35 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: 14573 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp245703wru; Wed, 2 Nov 2022 18:13:26 -0700 (PDT) X-Google-Smtp-Source: AMsMyM6i4EIdSZuoCK8khUe+nbg20FyngH0AgeFnH4uAkTGZt9xL/5OLf8YqAps+XVgRq7o9wft+ X-Received: by 2002:a17:903:2490:b0:17f:bf7e:c521 with SMTP id p16-20020a170903249000b0017fbf7ec521mr27644350plw.161.1667438006682; Wed, 02 Nov 2022 18:13:26 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667438006; cv=none; d=google.com; s=arc-20160816; b=Z2mmqNbHMep8QqBcF9AAtOysoWI0nmETVDCcShjMG1QspZu3tshdBnkiU5Ei2QOCk0 2pGnEe/wx9/36+00ksJG+ewaBwaiAZ49KKZvyWhmvf6bYixKn/OoVXUfBgDIBAbRvh/n vJJCgmq3r0AvCibwENOi1FqOFcZjKLo1ewu8peQ8cpsbZ8m8kv/5wSB6fVWZrHCjMcaM mijwwZvdI4Ah9EBfb7s6Fv1k4AVg9wd8k8TvWLQDUom9eFCwo97UcWBh7Ktxbsn49tTb LIQtI2biRE9LzQbgAZ0JukZ6WmNsCd/2j2i3uwJR0hYiBL3IO9KWBh46/cKKEDkDSuPo 0h0A== 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=HyZsB0Vwzo7IzN1ked5Cd3Ddxr3Z9Vwhd+P65i1+rEk=; b=HmWTASAfLMQcfJ/sbJYEl1vc3FD06xGDTzipX5aHQVOq/5LClsID0caD4zLn8qKV8j 1ARKVROPiYSwW6tlZR/x5nKSV3egITgQ28jC5LIVnIQbVRfVcdVnIdCJWWYUI/74HUwt RPtTEfKZfIkwqywfd1aMn4h8a7lT4Z+AMsAMsy0mPn9EAyF7YjjsQfqvGeUH5FqMxD/0 iJgApuKXYVeMqu3sUnnDQ2JgMMWCwZWQV94IieCgMm/u+kpTnSQvHU1iy+V4c7hOlY1N L70QAoDmwtXVfHYwaGd+gEfIo1Ij58gAp6pq0XAnVYUonunlszHdwl+yjhEP2I4CM6U4 NQsQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=edynv05y; 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 e18-20020a17090301d200b00186c41bebf1si20505649plh.76.2022.11.02.18.13.13; Wed, 02 Nov 2022 18:13:26 -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=edynv05y; 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 S230208AbiKCBKu (ORCPT + 99 others); Wed, 2 Nov 2022 21:10:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229561AbiKCBKr (ORCPT ); Wed, 2 Nov 2022 21:10:47 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A18755FBD for ; Wed, 2 Nov 2022 18:10:46 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id x11-20020a056a000bcb00b0056c6ec11eefso90431pfu.14 for ; Wed, 02 Nov 2022 18:10:46 -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=HyZsB0Vwzo7IzN1ked5Cd3Ddxr3Z9Vwhd+P65i1+rEk=; b=edynv05y2slAK4iCYIit3g9z2RR+Y6QMecSPtEGQR0+8ha7AuDLA97NGcz95GzONLO k0ANPukr5J2zLboMfgShqvPwiBp+n50l4D1AZYt6a+O27iPXVurz3lz38g4SOMYjDb2t RSNdECxviz+jT1YbNLiPZ1Yz6719zBOWazm1hTtTvdFVxJixV6bt2Gd9inbsgiveLJtZ /zobthD+X74SJbAgD3Fqd9qpxqVUmZlKjJ8k6omSGe7u0dcvWzfjDQvYIBXsubMKdFEa 1tzvKfQ7eCcwFVE3B6Uvd9mY4OqkUG0ICnCZshGigfbxQ4VlPvBN41W2GYcfOwZy53dW gUig== 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=HyZsB0Vwzo7IzN1ked5Cd3Ddxr3Z9Vwhd+P65i1+rEk=; b=aWvz7+JgBtcJfbf5resqzM0JlH+gIH9ePIKDu2Ws4i70IOVO2udShgAWH30M+y+bb1 meOXtTBpSI9RJeQaWel5aSDuNssIRji+bkIY/XLLczoPi19RZoPsfzFh8vQtEX2BkLiN tGLTKAUf4wZF6Im2sE91sRMgmJQKbYf0fzu+IPkhqGoAGba7eJwv4IQC0U/apEMAmJQf 7YelUvZfnPJykTuFRsrAoIqTZYh/83G9doakihHf1HnqLA/SfZnq1D+fqqk0aXrRiUwB aLP8zR/H6UA3PAKCg1nxViyk5lHM2syIHc//plVdikzzxbEheJ/P0p8Dk+WtFAWG3lO3 SjQQ== X-Gm-Message-State: ACrzQf0xL5DlXMt8Ny3x+N+xCCuq5NfvgvisgnkAB3vde4bTTIWv0pT0 J0w982NV0UWx8kPaTjLdGI0XBvhc60Z8JGVMjZqhsV++Z2WekAtpi0kE5VYs3XneXb+97nkOetq 7agSh8KzgRIam8hzpvxwvI75b+0B5dJIWzBnWB67T19lzXxAkNdW9lgQSz7l4+5ov4PkGcQ8e+q sGPyzFGp4= X-Received: from dionnaglaze.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2ee6]) (user=dionnaglaze job=sendgmr) by 2002:aa7:9212:0:b0:562:b5f6:f7d7 with SMTP id 18-20020aa79212000000b00562b5f6f7d7mr28251603pfo.70.1667437846061; Wed, 02 Nov 2022 18:10:46 -0700 (PDT) Date: Thu, 3 Nov 2022 01:10:35 +0000 In-Reply-To: <20221103011038.1542614-1-dionnaglaze@google.com> Mime-Version: 1.0 References: <20221103011038.1542614-1-dionnaglaze@google.com> X-Mailer: git-send-email 2.38.1.273.g43a17bfeac-goog Message-ID: <20221103011038.1542614-2-dionnaglaze@google.com> Subject: [PATCH v6 1/4] crypto: ccp - Name -1 return value as SEV_RET_NO_FW_CALL From: Dionna Glaze To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Peter Gonda , Thomas Lendacky , Paolo Bonzini , Joerg Roedel , Ingo Molnar , Andy Lutomirsky , John Allen , Herbert Xu , "David S. Miller" , Dionna Glaze 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?1748435474953823380?= X-GMAIL-MSGID: =?utf-8?q?1748435474953823380?= From: Peter Gonda The PSP can return a "firmware error" code of -1 in circumstances where the PSP is not actually called. To make this protocol unambiguous, we add a constant naming the return value. Cc: Thomas Lendacky Cc: Paolo Bonzini Cc: Joerg Roedel Cc: Ingo Molnar Cc: Andy Lutomirsky Cc: John Allen Cc: Herbert Xu Cc: "David S. Miller" Signed-off-by: Peter Gonda Signed-off-by: Dionna Glaze --- drivers/crypto/ccp/sev-dev.c | 2 +- include/uapi/linux/psp-sev.h | 7 +++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c index 06fc7156c04f..97eb3544ab36 100644 --- a/drivers/crypto/ccp/sev-dev.c +++ b/drivers/crypto/ccp/sev-dev.c @@ -444,7 +444,7 @@ static int __sev_platform_init_locked(int *error) { struct psp_device *psp = psp_master; struct sev_device *sev; - int rc = 0, psp_ret = -1; + int rc = 0, psp_ret = SEV_RET_NO_FW_CALL; int (*init_function)(int *error); if (!psp || !psp->sev_data) diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h index 91b4c63d5cbf..1ad7f0a7e328 100644 --- a/include/uapi/linux/psp-sev.h +++ b/include/uapi/linux/psp-sev.h @@ -36,6 +36,13 @@ enum { * SEV Firmware status code */ typedef enum { + /* + * This error code is not in the SEV spec but is added to convey that + * there was an error that prevented the SEV Firmware from being called. + * This is (u32)-1 since the firmware error code is represented as a + * 32-bit integer. + */ + SEV_RET_NO_FW_CALL = 0xffffffff, SEV_RET_SUCCESS = 0, SEV_RET_INVALID_PLATFORM_STATE, SEV_RET_INVALID_GUEST_STATE, From patchwork Thu Nov 3 01:10:36 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: 14575 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp245893wru; Wed, 2 Nov 2022 18:13:57 -0700 (PDT) X-Google-Smtp-Source: AMsMyM65YyLnesSsaahwcC/7FojwBPTRLXVTn4ibWWeEYH4ct8m4uID2UQmqu9ctD47uVxAaOI1U X-Received: by 2002:aa7:c389:0:b0:463:5926:7254 with SMTP id k9-20020aa7c389000000b0046359267254mr20096863edq.255.1667438037358; Wed, 02 Nov 2022 18:13:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667438037; cv=none; d=google.com; s=arc-20160816; b=ArGU5L7gelmfc5STIK625y0UEghJ9EsKaEshwugqEo7MUR6ucENjBmKEHlsA4Yu6Ik Bqhh/Etrs6OcecPzB73NWqi5eGj71yvpMbopOqfUIRpnTLmQl1qLvl2v3wQlZymziLbo 8fKpP5cfzrmFqheVc3vnbg1dbciyO5DCc3+RzA2qjq7+qPzdlHrZEhvIL/FkhOGecLZW nqS3AFlZi/fDU6fjl25t9mTkTtB7DvjKd1pWB8/xSXEtnrqDxbrOZjyhcyn6k1XbI1mF v9+MiSW8ARD6mknQ0g1PYeISTlZMIIloBw1HKMDaTvzwdepe6tPqjon2beXa/thBUbL3 EIWQ== 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=dOS13YU2U5T+1AmdnlWuqTgjd7kbK/oQZXyXRqKO1MM=; b=an2PSNv8ewMI6uuDxbuwhATh1xd7KHWxaKQ4nZlbL4k94Rwt2o20b25NwKWo66fQJR hp5dICsY2/e6wvEBcciRNlo6nYoaneeJ8XaF9LtoDhayRrieTOKGX6YMPQVKoCn3Rx2c B7lkiwCrO0+EdkiB8xoNxYY0eWUX4IjSD5gDroPU+vmAM0leuLNtuW2iL361sPnSnoDe Vs1rdbVe32DGSc8BPaH5lR3me0m8Ad01Up8xcG+gZ/IfY1WfI5UyqLbFuPf/ojmFcIzR mcyaZlN+LeuX//P6EOq+FKFBGUE91cmh0/THg6d0bjhJtGEZigheCCuOYz+78KlD0trJ 1phA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=iHkfIdFp; 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. 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Peter Anvin" , Venu Busireddy , Michael Roth , "Kirill A. Shutemov" , Michael Sterritt 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?1748435507433865207?= X-GMAIL-MSGID: =?utf-8?q?1748435507433865207?= The GHCB specification declares that the firmware error value for a guest request will be stored in the lower 32 bits of EXIT_INFO_2. The upper 32 bits are for the VMM's own error code. The fw_err argument is thus a misnomer, and callers will need access to all 64 bits. The type of unsigned long also causes problems, since sw_exit_info2 is u64 (unsigned long long) vs the argument's previous unsigned long*. The signature change requires the follow-up change to drivers/virt/coco/sev-guest to use the new expected type in order to compile. The firmware might not even be called, so we bookend the call with the no firmware call error and clearing the error. Cc: Tom Lendacky Cc: Paolo Bonzini Cc: Joerg Roedel Cc: Peter Gonda Cc: Thomas Gleixner Cc: Dave Hansen Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Cc: Venu Busireddy Cc: Michael Roth Cc: "Kirill A. Shutemov" Cc: Michael Sterritt Fixes: d5af44dde546 ("x86/sev: Provide support for SNP guest request NAEs") Signed-off-by: Dionna Glaze --- arch/x86/include/asm/sev.h | 4 ++-- arch/x86/kernel/sev.c | 10 ++++++---- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index ebc271bb6d8e..05de34d10d89 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -196,7 +196,7 @@ void snp_set_memory_private(unsigned long vaddr, unsigned int npages); void snp_set_wakeup_secondary_cpu(void); bool snp_init(struct boot_params *bp); void __init __noreturn snp_abort(void); -int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err); +int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, u64 *exitinfo2); #else static inline void sev_es_ist_enter(struct pt_regs *regs) { } static inline void sev_es_ist_exit(void) { } @@ -217,7 +217,7 @@ static inline void snp_set_wakeup_secondary_cpu(void) { } static inline bool snp_init(struct boot_params *bp) { return false; } static inline void snp_abort(void) { } static inline int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, - unsigned long *fw_err) + u64 *exitinfo2) { return -ENOTTY; } diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index a428c62330d3..148f17cb07b5 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -2175,7 +2176,7 @@ static int __init init_sev_config(char *str) } __setup("sev=", init_sev_config); -int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned long *fw_err) +int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, u64 *exitinfo2) { struct ghcb_state state; struct es_em_ctxt ctxt; @@ -2186,9 +2187,11 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP)) return -ENODEV; - if (!fw_err) + if (!exitinfo2) return -EINVAL; + *exitinfo2 = SEV_RET_NO_FW_CALL; + /* * __sev_get_ghcb() needs to run with IRQs disabled because it is using * a per-CPU GHCB. @@ -2212,14 +2215,13 @@ int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, unsigned if (ret) goto e_put; + *exitinfo2 = ghcb->save.sw_exit_info_2; if (ghcb->save.sw_exit_info_2) { /* Number of expected pages are returned in RBX */ if (exit_code == SVM_VMGEXIT_EXT_GUEST_REQUEST && ghcb->save.sw_exit_info_2 == SNP_GUEST_REQ_INVALID_LEN) input->data_npages = ghcb_get_rbx(ghcb); - *fw_err = ghcb->save.sw_exit_info_2; - ret = -EIO; } From patchwork Thu Nov 3 01:10:37 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: 14574 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp245873wru; Wed, 2 Nov 2022 18:13:55 -0700 (PDT) X-Google-Smtp-Source: AMsMyM60kWWu61y4ar+jHLjiZL7iW8sm9LcZFFEKICuvJGfSr44NChHw2S6wkKDLV10iB0G0w2m4 X-Received: by 2002:a17:902:db02:b0:187:4736:f783 with SMTP id m2-20020a170902db0200b001874736f783mr6430477plx.155.1667438035604; Wed, 02 Nov 2022 18:13:55 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667438035; cv=none; d=google.com; s=arc-20160816; b=ag8PuMxgwggQw8Ik3BhlMv2lMupMLBcZ/6+vY72vlMVhtB+8zYgESNr4kb5LzwHU6E sZt0/T/8g44ZGDo6TYSiHJMy0O8XGEQ2ExWUHTvUkYKkgFEU27sZ66HPyRyCWjbUlL0e wpI6id+sbltxemOA1qIqHo3za9+5zoA72yR4Kmsvw1FVKqCIgEZjP+SdSIRps2wxVXrT sbdeyja7q2ZesXnLXyTuUQYDPyKoGH6s+9o7CLXqEz5d2t2ju2ff/OYYMotHnoZqgyFH SuXhvPmkisZSX+ViAwWXGMivHNqCN8T3ZGDldzDX+HYKM6o7o2NNbURCcolnAbvr8nHc XZ9g== 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=/vy9fIPcvn2rwaNqM4HfeZWrqvTDpalnz2HwsiIC1NU=; b=MMYuPWqU3IOXlz6/mn3OhEvob+w3O3e1E+HhGrN7PxYsqgXkDekmLnPE45zNsmNzcV cvC/M99RxTGCy3PSm1GiSiT4lkL5ajIKAiRxweEzkVZmqeCrRKVfKBTiT2USrmHLo9ua N09bU9S8OiyHlwA52Fw1Gs8SVahHsu3XSoTw90XxysXqkRqJQB9DxYqGTl2/hV3jnJS+ EQAlECaBnXtzekb/vYLFeLrmC7tL6DhdLHU1grqfsy2JLxtKDI3JuwplIK5MZKY+cdKG 5lyjWKBGbB0INZ0ZNgxlicafaQDYdlsia8FOby9LXYbLisvpVIraP2qUoWhuZNLB+Ahl 3CFQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=aDP5nCCE; 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. 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This is undefined behavior, and currently returns uninitialized kernel stack memory to user space. The fw_err argument is better to just pass through to snp_issue_guest_request, so we do that. Since the issue_request's signature has changed fw_err to exitinfo2, we change the argument name here. Cc: Tom Lendacky Cc: Paolo Bonzini Cc: Joerg Roedel Cc: Peter Gonda Cc: Thomas Gleixner Cc: Dave Hansen Cc: Borislav Petkov Cc: Haowen Bai Cc: Liam Merwick Cc: Yang Yingliang Fixes: fce96cf04430 ("virt: Add SEV-SNP guest driver") Signed-off-by: Dionna Glaze --- drivers/virt/coco/sev-guest/sev-guest.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c index f422f9c58ba7..0508c2f46f6b 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -303,9 +303,8 @@ 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; u64 seqno; int rc; @@ -322,9 +321,7 @@ 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 (rc) return rc; From patchwork Thu Nov 3 01:10:38 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: 14576 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp246061wru; Wed, 2 Nov 2022 18:14:31 -0700 (PDT) X-Google-Smtp-Source: AMsMyM7nUgM20Qq4W88CvscDheztKXsD65Cl2gcd3qdDl2N+vDD/XqzECvt9n9ya+BmezNHkiofY X-Received: by 2002:a05:6a00:140f:b0:56e:1190:e731 with SMTP id l15-20020a056a00140f00b0056e1190e731mr6062209pfu.39.1667438070905; Wed, 02 Nov 2022 18:14:30 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667438070; cv=none; d=google.com; s=arc-20160816; b=IMV2fqE0HWh5HDd68QYE3ZyScc8tN8xg8WCfsmyD+I4M+GsjXn0ArSelOWVhbHMo1G 0dJFtXBJfDdJYWSgIB5yDo6M66ARaODfpQlKU8ZAo6tuHsuapnAIKTJdnUf7jod+rs5T DWapJvdh39LLtp6vSLwGRxX6JfkWrZ8dMa5mVOmoFKUkhK9lXCD36Z+ks6gQAP7XA+Uv tl97oeh19uglByjE85OBc9sQEWFG2xdKr+zmNWBapQ6ybCMSoHlh+QMKUwMGPgVHdkqy Z73rgZx0icP1zjlbEm7ufHvi8szfjvkWJRsp8zNmnVyhVsxoByRdWsVZFiaqYvkX/dC5 YhFA== 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=kYKgV9ZKdPHZZFBhdSWAVOyv34GIciO94ig2I8LrdA4=; b=UmGKl8NNjkh8bSdhz+vA76DWewmbGYOYekglisJ/DihIsEgxIV5cqiWwBbBTXBWGJw kmmcfMqxxNHj7fTCJiPwsAPMFMkDzWd8h2kg8FAzDcIW4bapvgB6b+LeD4xTMRv3uJL+ qq/dbj7fNYWjricEe7hBDFBjcxMw9hLvCqxCXFzHH5kvTx6OMSKPKLe3Yx9eq5SqqVUt QZPnNGcQb1tEWn03c0hIzB88Yhn5NaFAsTbi6WUBrx7TvSx4++HB2o0sxHabohk44dJw 7S2pPgIHB4oIpclvZSBrWzpAnIAnLhh1NNGdQohxi7n4Cilkm0Oa5QoNEVMrltVKcJpc nWQg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=ZR0RSLAa; 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. 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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. We can still interpret the upper 32 bits of exitinfo2 for the user anyway in case the request gets throttled. For safety, since the encryption algorithm in GHCBv2 is AES_GCM, we cannot return to user space without having completed the request with the current sequence number. If we were to return and the guest were to make another request but with different message contents, then that would be IV reuse. When throttled, the driver will reschedule itself and then try again after sleeping half its ratelimit time to avoid a big wait queue. The ioctl may block indefinitely, but that has always been the case when deferring these requests to the host. Cc: Tom Lendacky Cc: Peter Gonda Cc: Borislav Petkov Cc: Tom Lendacky Cc: Liam Merwick Cc: Yang Yingliang Cc: Haowen Bai Signed-off-by: Dionna Glaze --- drivers/virt/coco/sev-guest/sev-guest.c | 50 ++++++++++++++++++++++--- include/uapi/linux/sev-guest.h | 18 ++++++++- 2 files changed, 60 insertions(+), 8 deletions(-) diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c index 0508c2f46f6b..43e110ad4aa9 100644 --- a/drivers/virt/coco/sev-guest/sev-guest.c +++ b/drivers/virt/coco/sev-guest/sev-guest.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -48,12 +49,22 @@ struct snp_guest_dev { struct snp_req_data input; u32 *os_area_msg_seqno; u8 *vmpck; + + struct ratelimit_state rs; }; static u32 vmpck_id; module_param(vmpck_id, uint, 0444); MODULE_PARM_DESC(vmpck_id, "The VMPCK ID to use when communicating with the PSP."); +static int rate_hz = 2; +module_param(rate_hz, int, 0444); +MODULE_PARM_DESC(vmpck_id, "The rate limit frequency to limit requests to."); + +static int rate_burst = 1; +module_param(rate_burst, int, 0444); +MODULE_PARM_DESC(rate_burst, "The rate limit burst amount to limit requests to."); + /* Mutex to serialize the shared buffer access and command handling. */ static DEFINE_MUTEX(snp_cmd_mutex); @@ -305,6 +316,7 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in u8 type, void *req_buf, size_t req_sz, void *resp_buf, u32 resp_sz, __u64 *exitinfo2) { + unsigned int vmm_err; u64 seqno; int rc; @@ -320,9 +332,33 @@ static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_code, in if (rc) return rc; +retry: + /* + * Rate limit commands internally since the host can also throttle, and + * we don't want to create a tight request spin that could end up + * getting this VM throttled more heavily. + */ + if (!__ratelimit(&snp_dev->rs)) { + sleep_timeout_interruptible((rate_hz * HZ) / 2); + goto retry; + } /* Call firmware to process the request */ rc = snp_issue_guest_request(exit_code, &snp_dev->input, exitinfo2); + vmm_err = *exitinfo2 >> SNP_GUEST_VMM_ERR_SHIFT; + /* + * The host may return EBUSY if the request has been throttled. + * We retry in the driver to avoid returning and reusing the message + * sequence number on a different message. + */ + if (vmm_err == SNP_GUEST_VMM_ERR_BUSY) + goto retry; + + 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; @@ -375,7 +411,7 @@ 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; @@ -415,7 +451,7 @@ 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; @@ -477,10 +513,10 @@ 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))) @@ -515,7 +551,7 @@ 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 = SEV_RET_NO_FW_CALL; /* Message version must be non-zero */ if (!input.msg_version) @@ -546,7 +582,7 @@ 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; @@ -696,6 +732,8 @@ static int __init sev_guest_probe(struct platform_device *pdev) if (ret) goto e_free_cert_data; + ratelimit_state_init(&snp_dev->rs, rate_hz * HZ, rate_burst); + dev_info(dev, "Initialized SEV guest driver (using vmpck_id %d)\n", vmpck_id); return 0; diff --git a/include/uapi/linux/sev-guest.h b/include/uapi/linux/sev-guest.h index 256aaeff7e65..8e4144aa78c9 100644 --- a/include/uapi/linux/sev-guest.h +++ b/include/uapi/linux/sev-guest.h @@ -52,8 +52,15 @@ 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 +84,11 @@ 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) +/* Guest message request EXIT_INFO_2 constants */ +#define SNP_GUEST_FW_ERR_MASK GENMASK_ULL(31, 0) +#define SNP_GUEST_VMM_ERR_SHIFT 32 + +#define SNP_GUEST_VMM_ERR_INVALID_LEN 1 +#define SNP_GUEST_VMM_ERR_BUSY 2 + #endif /* __UAPI_LINUX_SEV_GUEST_H_ */