From patchwork Thu Nov 3 13:04:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jinank Jain X-Patchwork-Id: 14863 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:6687:0:0:0:0:0 with SMTP id l7csp519919wru; Thu, 3 Nov 2022 06:09:42 -0700 (PDT) X-Google-Smtp-Source: AMsMyM6tUteQO7QxWNqEEubjctL4NUY9ky7K2Jj9Gm3jtkBvi/OMezSOWJOEqJBydmHq8rIh7YoX X-Received: by 2002:a63:f206:0:b0:446:eb31:47e0 with SMTP id v6-20020a63f206000000b00446eb3147e0mr26471937pgh.491.1667480982288; Thu, 03 Nov 2022 06:09:42 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1667480982; cv=none; d=google.com; s=arc-20160816; b=CReN+xRWmccQsmkCwWncSJ4haicDBSSGPCnlpGqRNw52WhZJy1Wycv9jZm4d1vq24w MpVnzj432mCjpGI3H0CWXmxHAwQ4RBozDKdQrxGuuJ+sacOHoqKLcm/QimWPNglAnNi7 qkgHNymaeb09zAj2HfsVCiHfAr9sGKYF1L0HJutzWw2yOuGCmQkNo8Zh6MiUNrgoaI+/ bZLgbPQGYLgKkdSrYDU5B8rciXDcATu17Ls9sSGv8zZOGQglwwgwUaFOpwuptP5LHfTy PLviVvAjCHkY7lSWqOzaj6CaHPTOMbXFBJkxUyQZAqHXgEKSYYCDUnGdIivLW/DLx1X4 txtg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:dkim-filter; bh=HLgBEfqnfR/pSo3ZddLSeTCBJ4DSAnSoOy6+9I7tDbg=; b=IcjvYlOJRgJGze6h2Uqm4QeqLSpHfxCy2iplGsQSdTt7qb+k21Mw3DZxPkMWUGo7Ku avzZ5OZS1Ai4JSfnx/Q+XaS3UYYi1IWdOhQ/1oo60HN7KfvFTEjqNgcjK6PRsjhDn7fM dS/RYq98yrcj8IU2bNu/CAFHuNG+UNnV3u21JupY9hfOpavQI+Gf4W7b/VAgw6raXRUd rqYJ0AarD/7putf2PgFj04ZAb3CaVfkfPi/iMj+fx5rzfU7GW0SnoRCJ6lKJ+uzBtnH1 LRPgXwmp7/mAtrps/jc6imX4oKy049MhpZwtkOaPOk6qMa13s9WIrLA7Tx2xKsyqzKDZ 3Mjw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linux.microsoft.com header.s=default header.b=tInIXzvZ; 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=NONE sp=NONE dis=NONE) header.from=linux.microsoft.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id lw3-20020a17090b180300b002131849ea4esi7378666pjb.140.2022.11.03.06.09.28; Thu, 03 Nov 2022 06:09:42 -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=@linux.microsoft.com header.s=default header.b=tInIXzvZ; 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=NONE sp=NONE dis=NONE) header.from=linux.microsoft.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231523AbiKCNFf (ORCPT + 99 others); Thu, 3 Nov 2022 09:05:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231226AbiKCNFL (ORCPT ); Thu, 3 Nov 2022 09:05:11 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F358417E32; Thu, 3 Nov 2022 06:04:17 -0700 (PDT) Received: from jinankjain-dranzer.zrrkmle5drku1h0apvxbr2u2ee.ix.internal.cloudapp.net (unknown [20.188.121.5]) by linux.microsoft.com (Postfix) with ESMTPSA id A0E09205DA2F; Thu, 3 Nov 2022 06:04:13 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com A0E09205DA2F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1667480657; bh=HLgBEfqnfR/pSo3ZddLSeTCBJ4DSAnSoOy6+9I7tDbg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tInIXzvZ5DLoKnJIuYBKNbwTa4rSOgbayfk53bVeJyTmK26j7jjfnGAuzBxv2YiR3 3bR2rI8U/yG2dnJxzMBLwr9g16xnc4PWetTLiDM7QG3jRbkJ74Y8vyLLuUnPG8a2Li Q6dVE3ZkxlJuz+jLcNIFgwtwwh1m1xPSVqTTNfPs= From: Jinank Jain To: jinankjain@microsoft.com Cc: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, arnd@arndb.de, peterz@infradead.org, jpoimboe@kernel.org, jinankjain@linux.microsoft.com, seanjc@google.com, kirill.shutemov@linux.intel.com, ak@linux.intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, anrayabh@linux.microsoft.com, mikelley@microsoft.com Subject: [PATCH v3 1/5] x86/hyperv: Add support for detecting nested hypervisor Date: Thu, 3 Nov 2022 13:04:03 +0000 Message-Id: <285b15b90ac6f29ef8ab6b6ececeeef7d7c6f380.1667480257.git.jinankjain@linux.microsoft.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-Spam-Status: No, score=-19.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,ENV_AND_HDR_SPF_MATCH,RCVD_IN_DNSWL_MED, SPF_HELO_PASS,SPF_PASS,USER_IN_DEF_DKIM_WL,USER_IN_DEF_SPF_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?1748480538366490741?= X-GMAIL-MSGID: =?utf-8?q?1748480538366490741?= When Linux runs as a root partition for Microsoft Hypervisor. It is possible to detect if it is running as nested hypervisor using hints exposed by mshv. While at it expose a new variable called hv_nested which can be used later for making decisions specific to nested use case. Signed-off-by: Jinank Jain Reviewed-by: --- arch/x86/include/asm/hyperv-tlfs.h | 3 +++ arch/x86/include/asm/mshyperv.h | 2 ++ arch/x86/kernel/cpu/mshyperv.c | 7 +++++++ drivers/hv/hv_common.c | 7 +++++-- 4 files changed, 17 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h index 3089ec352743..d9a611565859 100644 --- a/arch/x86/include/asm/hyperv-tlfs.h +++ b/arch/x86/include/asm/hyperv-tlfs.h @@ -114,6 +114,9 @@ /* Recommend using the newer ExProcessorMasks interface */ #define HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED BIT(11) +/* Indicates that the hypervisor is nested within a Hyper-V partition. */ +#define HV_X64_HYPERV_NESTED BIT(12) + /* Recommend using enlightened VMCS */ #define HV_X64_ENLIGHTENED_VMCS_RECOMMENDED BIT(14) diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index 61f0c206bff0..3c39923e5969 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -26,6 +26,8 @@ void hyperv_vector_handler(struct pt_regs *regs); #if IS_ENABLED(CONFIG_HYPERV) extern int hyperv_init_cpuhp; +extern bool hv_nested; + extern void *hv_hypercall_pg; extern u64 hv_current_partition_id; diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 831613959a92..9a4204139490 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -37,6 +37,8 @@ /* Is Linux running as the root partition? */ bool hv_root_partition; +/* Is Linux running on nested Microsoft Hypervisor */ +bool hv_nested; struct ms_hyperv_info ms_hyperv; #if IS_ENABLED(CONFIG_HYPERV) @@ -301,6 +303,11 @@ static void __init ms_hyperv_init_platform(void) pr_info("Hyper-V: running as root partition\n"); } + if (ms_hyperv.hints & HV_X64_HYPERV_NESTED) { + hv_nested = true; + pr_info("Hyper-V: running on a nested hypervisor\n"); + } + /* * Extract host information. */ diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c index ae68298c0dca..dcb336ce374f 100644 --- a/drivers/hv/hv_common.c +++ b/drivers/hv/hv_common.c @@ -25,8 +25,8 @@ #include /* - * hv_root_partition and ms_hyperv are defined here with other Hyper-V - * specific globals so they are shared across all architectures and are + * hv_root_partition, ms_hyperv and hv_nested are defined here with other + * Hyper-V specific globals so they are shared across all architectures and are * built only when CONFIG_HYPERV is defined. But on x86, * ms_hyperv_init_platform() is built even when CONFIG_HYPERV is not * defined, and it uses these two variables. So mark them as __weak @@ -36,6 +36,9 @@ bool __weak hv_root_partition; EXPORT_SYMBOL_GPL(hv_root_partition); +bool __weak hv_nested; +EXPORT_SYMBOL_GPL(hv_nested); + struct ms_hyperv_info __weak ms_hyperv; EXPORT_SYMBOL_GPL(ms_hyperv);