From nobody Tue Apr 7 08:08:51 2026 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 31D5AC4332F for ; Thu, 13 Oct 2022 16:01:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229694AbiJMQBD (ORCPT ); Thu, 13 Oct 2022 12:01:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229513AbiJMQBA (ORCPT ); Thu, 13 Oct 2022 12:01:00 -0400 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5012EFE927 for ; Thu, 13 Oct 2022 09:00:59 -0700 (PDT) Received: by mail-pl1-x649.google.com with SMTP id o1-20020a170902d4c100b00177f59a9889so1549758plg.13 for ; Thu, 13 Oct 2022 09:00:59 -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=MFIZXP+0RvRDVkccAAekEgFLUK+lQGqw03T8y+VqePQ=; b=MAazyoS2V7THRiFDYYrrOq38Kf4Z8t7qlDLZXLyAdEelxB2juuPZPHrgmYaXI7/l09 cC9pivN4wW60IymPa9roTYnEkbv7Lw8k42QPDv6xI+aIwyoXgjCe5dchPx5XvtE5dazN NSeoxzxNxRSohb2VJoENXopTKZiZ3LGN95Cs8eRVA/feFNHmkJ547gOMu0aqiynUoAUs Ac6j35o9lmhM1rWlUuPtmqQhZwCD3UxlJotuiAOHxXsOY4QbNO2N6KlyXV0y9TDWZPJ1 eisp1tLqUa8QAjs1IxZSSXTTLY169aJPJPVdF+tor5cdtnZ6WHZRXvJ9zNZ6leYmjXao +u3w== 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=MFIZXP+0RvRDVkccAAekEgFLUK+lQGqw03T8y+VqePQ=; b=c4XQRTK3HT63HgGsw2MWquFpWxRh9Lr7TpETBOd4bgYTtjCVnn7K7OVxRlGWUizhYt O/TDnNAMs+/TVBP49J91yNV/4AvWOYeSSdgkqhnX4zLv4caRS8TKMs2OG+09ttcfGyCR IDWgQNgkBZsdyo3nErzHABWhBttIrEBrGrjpHaTbulWClduDlmkqGQI8zhMpRrEm+g7l HQA3GGjt03luBjUSJ8SryLyQUxx/7WAx3fDnP7gWZrabjhc0kxWTU7wLg2iX3PQIBbgL u7HL0rStmuDQgsnmc8+9pxN1Xm62So627MFpVJO+JjdruoFEq122YaHYejxrq2vpXdKM i78w== X-Gm-Message-State: ACrzQf2p8cDJ0/74ZcLW5O1437zxl0qvs6RlOT7ysubXiUrSH7leOPqb 1PbyvmCup9wXIwRfwTCCqcZTv8q6D+R2pDpi+ggp3ELrcKviacbCvm6yWpuxQlGG3InPgv+zPdh iCRg06vS47ayXjUsU/69Xw3Aj4Z7C3Sd1phFeF/kRfidxi2Kj0eFI2Bs0qqpL1qKELDx7TpJdAF HshHU7nm0= X-Google-Smtp-Source: AMsMyM4PUVo7Xol1CSaEtsAq0hrjEyv1xy8leks5fVsOnLmK8rlbfda9JnmQ+bNpX50kiCQTyT2R9J9WwcveH1r2nA== X-Received: from dionnaglaze.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:2ee6]) (user=dionnaglaze job=sendgmr) by 2002:a05:6a00:17a9:b0:563:3255:8601 with SMTP id s41-20020a056a0017a900b0056332558601mr288210pfg.12.1665676858718; Thu, 13 Oct 2022 09:00:58 -0700 (PDT) Date: Thu, 13 Oct 2022 16:00:39 +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: <20221013160040.2858732-2-dionnaglaze@google.com> Subject: [PATCH 1/2] x86/sev: Rename snp_guest_issue_request's fw_err 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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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. Cc: Tom Lendacky Cc: Paolo Bonzini Cc: Joerg Roedel Cc: Peter Gonda Cc: Thomas Gleixner Cc: Dave Hansen Signed-off-by: Dionna Glaze --- arch/x86/include/asm/sev.h | 4 ++-- arch/x86/kernel/sev.c | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index ebc271bb6d8e..4312d6be129f 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, unsign= ed 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, uns= igned long *fw_err); +int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, uns= igned long *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_da= ta *input, - unsigned long *fw_err) + unsigned long *exitinfo2) { return -ENOTTY; } diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index a428c62330d3..a4eca63e8b90 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -2175,7 +2175,7 @@ static int __init init_sev_config(char *str) } __setup("sev=3D", init_sev_config); =20 -int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, uns= igned long *fw_err) +int snp_issue_guest_request(u64 exit_code, struct snp_req_data *input, uns= igned long *exitinfo2) { struct ghcb_state state; struct es_em_ctxt ctxt; @@ -2186,7 +2186,7 @@ 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; =20 - if (!fw_err) + if (!exitinfo2) return -EINVAL; =20 /* @@ -2218,7 +2218,7 @@ int snp_issue_guest_request(u64 exit_code, struct snp= _req_data *input, unsigned ghcb->save.sw_exit_info_2 =3D=3D SNP_GUEST_REQ_INVALID_LEN) input->data_npages =3D ghcb_get_rbx(ghcb); =20 - *fw_err =3D ghcb->save.sw_exit_info_2; + *exitinfo2 =3D ghcb->save.sw_exit_info_2; =20 ret =3D -EIO; } --=20 2.38.0.rc1.362.ged0d419d3c-goog From nobody Tue Apr 7 08:08:51 2026 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 F22EBC4332F for ; Thu, 13 Oct 2022 16:01:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229722AbiJMQBH (ORCPT ); Thu, 13 Oct 2022 12:01:07 -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 ; 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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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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/se= v-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 =20 static int handle_guest_request(struct snp_guest_dev *snp_dev, u64 exit_co= de, 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 =3D 0; + unsigned int vmm_err; u64 seqno; int rc; =20 @@ -322,9 +323,20 @@ static int handle_guest_request(struct snp_guest_dev *= snp_dev, u64 exit_code, in return rc; =20 /* Call firmware to process the request */ - rc =3D snp_issue_guest_request(exit_code, &snp_dev->input, &err); - if (fw_err) - *fw_err =3D err; + rc =3D snp_issue_guest_request(exit_code, &snp_dev->input, &_exitinfo2); + if (exitinfo2) + *exitinfo2 =3D _exitinfo2; + + vmm_err =3D _exitinfo2 >> SNP_GUEST_VMM_ERR_SHIFT; + /* The host may return EBUSY if the request has been throttled. */ + if (vmm_err =3D=3D SNP_GUEST_VMM_ERR_BUSY) + return -EAGAIN; + + if (vmm_err && vmm_err !=3D SNP_GUEST_VMM_ERR_INVALID_LEN) { + pr_err("sev-guest: host returned unknown error code: %d\n", + vmm_err); + return -EINVAL; + } =20 if (rc) return rc; @@ -378,7 +390,7 @@ static int get_report(struct snp_guest_dev *snp_dev, st= ruct snp_guest_request_io =20 rc =3D 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; =20 @@ -418,7 +430,7 @@ static int get_derived_key(struct snp_guest_dev *snp_de= v, struct snp_guest_reque =20 rc =3D 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; =20 @@ -480,10 +492,10 @@ static int get_ext_report(struct snp_guest_dev *snp_d= ev, struct snp_guest_reques snp_dev->input.data_npages =3D npages; ret =3D 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); =20 /* If certs length is invalid then copy the returned length */ - if (arg->fw_err =3D=3D SNP_GUEST_REQ_INVALID_LEN) { + if (arg->vmm_error =3D=3D SNP_GUEST_VMM_ERR_INVALID_LEN) { req.certs_len =3D snp_dev->input.data_npages << PAGE_SHIFT; =20 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; =20 - input.fw_err =3D 0xff; + input.exitinfo2 =3D 0xff; =20 /* 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 =20 mutex_unlock(&snp_cmd_mutex); =20 - if (input.fw_err && copy_to_user(argp, &input, sizeof(input))) + if (input.exitinfo2 && copy_to_user(argp, &input, sizeof(input))) return -EFAULT; =20 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_ =20 +#include #include =20 struct snp_report_req { @@ -52,8 +53,15 @@ struct snp_guest_request_ioctl { __u64 req_data; __u64 resp_data; =20 - /* 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-s= ev.h) */ + union { + __u64 exitinfo2; + __u64 fw_err; /* Name deprecated in favor of others */ + struct { + __u32 fw_error; + __u32 vmm_error; + }; + }; }; =20 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_g= uest_request_ioctl) =20 + +#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_ */ --=20 2.38.0.rc1.362.ged0d419d3c-goog