From patchwork Wed Nov 30 23:36:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 28084 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:f944:0:0:0:0:0 with SMTP id q4csp1215267wrr; Wed, 30 Nov 2022 15:59:56 -0800 (PST) X-Google-Smtp-Source: AA0mqf42gmdM9Q+IWXxVF4DhFNzJN4uZapqHyqW9UFph7esd4Op0+odY2lzX/CNiCvs0HGE0AFwh X-Received: by 2002:a17:906:6403:b0:7b2:9667:241e with SMTP id d3-20020a170906640300b007b29667241emr54800828ejm.115.1669852796246; Wed, 30 Nov 2022 15:59:56 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1669852796; cv=none; d=google.com; s=arc-20160816; b=po2PAlYYIqXzrvvd1GmnnAs7yZq5auN5lzXOevLSTPp4BL/LJP2jaWkfwXcGGDunoQ P6RQd/7aY6QYMCbje5WzaQ8HFuOHpW2IlompLy4k3aqAlDx9cMlenG9huxxA9xKxGH0B 9YxLCgRz4sCO6xFSFLog5epLXoLzqi99tCsKuA6c0KNMYCZPxo2VE2pJDtoWJyQkSa3b 9n81mJ3BLjxAmPTW4N35AkzsxhvksrswGOdMLeeq7IEkTZg5grloyqYinMP1rB4I5mUA RGOubMJUMmSRXwAzfg8Zl/BTDA/s6ALQ138ijQPrfKbxeeG2PSKeDep5nkFj+hLxZjJJ 30gg== 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:reply-to:dkim-signature; bh=KY6cgH0FoQgBjJK6cWHlNWc/cuNwA3rTkcmq/FIE/W0=; b=HHIO8KQQBUI2qnuMox/ziwgZwZHYceOOM2U76hvVXf3ucd0zQlLDxfrtJZxgelcrAk vmnbzbOn68xhE1tDesqE3KtPvgi+lcQNmZx+SjSzvaW0Nb8X6vf2srSGxXZmvzsn8YTk FovvTdfWTTeux36In3pxm9oEs3Y/vGw2c+4yVnWJ9GciqksM+XOqCVeK63Dsr4UqbFkC deqCeVq6yEbPDZGEZybXXSeu9jPkSyTJ/rIxtg6xV49kJsDPAFNxfcgRjRcyMTUX5E71 6mhSQVUyBCvQxazr3dg2yXdYNQHQE4Etl+/S+P3QkQVL+/JZXc4ettsJcxW3Kqo2Kky2 4jaQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=O5Kmt+7v; 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 nb38-20020a1709071ca600b00791a67e4c00si2783939ejc.835.2022.11.30.15.59.33; Wed, 30 Nov 2022 15:59:56 -0800 (PST) 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=O5Kmt+7v; 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 S230028AbiK3XhG (ORCPT + 99 others); Wed, 30 Nov 2022 18:37:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229668AbiK3Xg5 (ORCPT ); Wed, 30 Nov 2022 18:36:57 -0500 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 90E571128 for ; Wed, 30 Nov 2022 15:36:56 -0800 (PST) Received: by mail-pf1-x449.google.com with SMTP id 145-20020a621497000000b00574fab7294dso227737pfu.13 for ; Wed, 30 Nov 2022 15:36:56 -0800 (PST) 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:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=KY6cgH0FoQgBjJK6cWHlNWc/cuNwA3rTkcmq/FIE/W0=; b=O5Kmt+7v3RpSCb0+VWEK9EqPSVW4nD/fCUmVYybP1v3f7uc0CVBZQJ6Mp82SSuZjF7 zmqc3E+bxzy+4Uq3+UDL+eohoq6ah6TrTNoVMvZHg4n+blU3QqemmrwiIawxne5qaD2T UConf3WriIgOVVFc0wl6okzHI4t82xGt4irFaBr3xR+F+tKQt3rl2uMUicSZ4RLGB9mZ L4lQxltIQF790VaPnhEgv3TVdq11vbEFZWepOygqrqfyQCJT5q3mxBQgc0290BBpcxCj r6Ta1DMsMNlerxvpH+yMMUmLS6f5AjQRavMBZ2mZ/a/ok3WETdkul8QghZxRpHT3AW/f vCcg== 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:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=KY6cgH0FoQgBjJK6cWHlNWc/cuNwA3rTkcmq/FIE/W0=; b=kJpX0xRPYYtITTix7Ybn79Zji4JU7QkVIEmQXhWUb739+X0QFIHJFiOQaHF4BQneRW 8uDV0Dxv4eg5oF51n2JBISyyMYYSgk5YqYD9XyRiEoYzMrxkmxn6q2mLiMW7mqRx+K+D mxy2DsbZMLzB5L9rNmqjpr26ShWvMG/ocFBET3WKaYGvFG5O8o+x2SujnuE/GjFm25a1 7KUgyE9FVOZptQ56RWj/R3GbtgFRETHmBQ2fTmtb1aOXLlc9vOX5Wz6FWfxPuixMKumb 9PuNWzoPONl1Mv3sfc8psahckh3f/evLnLvA8dC0kXuarxFa8SxxlgZgval0Y/qHa8Sb SlaQ== X-Gm-Message-State: ANoB5pnfTIVD2OF5jQEYy6YrTKJawWRNqiREYkrg/UU5aSFVB8IWWGya zWyBiAYpXALSbXD5GNunnaW1lcvmJto= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:903:1206:b0:186:a2ef:7a74 with SMTP id l6-20020a170903120600b00186a2ef7a74mr48409099plh.148.1669851416008; Wed, 30 Nov 2022 15:36:56 -0800 (PST) Reply-To: Sean Christopherson Date: Wed, 30 Nov 2022 23:36:48 +0000 In-Reply-To: <20221130233650.1404148-1-seanjc@google.com> Mime-Version: 1.0 References: <20221130233650.1404148-1-seanjc@google.com> X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog Message-ID: <20221130233650.1404148-3-seanjc@google.com> Subject: [PATCH v4 2/4] x86/virt: Force GIF=1 prior to disabling SVM (for reboot flows) From: Sean Christopherson To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org Cc: "H. Peter Anvin" , linux-kernel@vger.kernel.org, "Guilherme G . Piccoli" , Vitaly Kuznetsov , Paolo Bonzini , Sean Christopherson , Andrew Cooper , Tom Lendacky , stable@vger.kernel 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?1750967565403241723?= X-GMAIL-MSGID: =?utf-8?q?1750967565403241723?= Set GIF=1 prior to disabling SVM to ensure that INIT is recognized if the kernel is disabling SVM in an emergency, e.g. if the kernel is about to jump into a crash kernel or may reboot without doing a full CPU RESET. If GIF is left cleared, the new kernel (or firmware) will be unabled to awaken APs. Eat faults on STGI (due to EFER.SVME=0) as it's possible that SVM could be disabled via NMI shootdown between reading EFER.SVME and executing STGI. Link: https://lore.kernel.org/all/cbcb6f35-e5d7-c1c9-4db9-fe5cc4de579a@amd.com Cc: stable@vger.kernel.org Cc: Andrew Cooper Cc: Tom Lendacky Signed-off-by: Sean Christopherson --- arch/x86/include/asm/virtext.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/x86/include/asm/virtext.h b/arch/x86/include/asm/virtext.h index 8757078d4442..0acb14806a74 100644 --- a/arch/x86/include/asm/virtext.h +++ b/arch/x86/include/asm/virtext.h @@ -126,7 +126,18 @@ static inline void cpu_svm_disable(void) wrmsrl(MSR_VM_HSAVE_PA, 0); rdmsrl(MSR_EFER, efer); - wrmsrl(MSR_EFER, efer & ~EFER_SVME); + if (efer & EFER_SVME) { + /* + * Force GIF=1 prior to disabling SVM, e.g. to ensure INIT and + * NMI aren't blocked. Eat faults on STGI, as it #UDs if SVM + * isn't enabled and SVM can be disabled by an NMI callback. + */ + asm_volatile_goto("1: stgi\n\t" + _ASM_EXTABLE(1b, %l[fault]) + ::: "memory" : fault); +fault: + wrmsrl(MSR_EFER, efer & ~EFER_SVME); + } } /** Makes sure SVM is disabled, if it is supported on the CPU