From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CF314C47088 for ; Thu, 1 Dec 2022 00:09:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:Reply-To:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:Message-ID :References:Mime-Version:In-Reply-To:Date:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=WHb0+EPDjDJ+OT9rzdxuwLM+tVvVM1YTyBiNa1vN+PA=; b=mSnNRR68pNRfAs bKfr6T6xDBLMEclpwBeA0lmBeKDwhbu5YpaZvvOPaq8afn2MFtIk7PXo4Kd9V4nN1dEchSjiVg5JI zCrnJwIb75ONSqmUdIaz6yyShl/9iq+aX4W2O8HF9S7LFVrgY6N4KDH7vvnOjYmhMcWGRYxNTr0UD mOA18dfeceL7qPIk8rZgQVSnxHs77CkSw0rDcSXgudVhxV6yDC3bY7NJ3itBvkpHDs1vcapDis9zN +FBqechDCDlk+jrm9FxhDAGS0MDk2weyI+h26raZJ1cr91gdPNWicwEE7wDLJ6iNAz+hYA8LKc8WF BHC1esGsnvwy/71uKJUw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p0X7A-003V19-2A; Thu, 01 Dec 2022 00:07:46 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p0Wbk-003Gqn-RT for linux-arm-kernel@bombadil.infradead.org; Wed, 30 Nov 2022 23:35:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:Cc:To:From:Subject: Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To:Sender: Content-Transfer-Encoding:Content-ID:Content-Description; bh=GJ+yfhkspt7ZNo22OgQpawec1Ei4RCTiEbe5vknIrT0=; b=beMqsTk0nhwVs4DtrPTK0SfbDW u33UxJbS5t1N6zYFFKBvBLRTqudP/sZyo02tcHXq9CLQqWNRfQCFbgSXa3aiq897prpx7rmy5fXPm S4zsEqWEmsYX5CIwZJhk3v4rwLqM3/ZzIYY+4+4MRmSh1QFQZOkopVoV8+bKizeCL3dZZ8osPT0U4 BDzQw2ZtjWydkpB3OHWfdKrGhtGbLYiEWK+wLVWwdW9eNCHWahnhZ3fIe3YqxvyQFsMi8nAJ0R18M OEPMIt1lXDYOAlDhm7Vi/f0Ubq/g6WqNSvpiRgJ/9yDBJSc+XNAYNB1lNJcflSCa6VtpKhv7S7q4S z/ScvuEA==; Received: from mail-pf1-x449.google.com ([2607:f8b0:4864:20::449]) by casper.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p0WDM-00FPmW-RE for linux-arm-kernel@lists.infradead.org; Wed, 30 Nov 2022 23:10:07 +0000 Received: by mail-pf1-x449.google.com with SMTP id v23-20020aa78097000000b005748c087db1so207315pff.2 for ; Wed, 30 Nov 2022 15:09:56 -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=GJ+yfhkspt7ZNo22OgQpawec1Ei4RCTiEbe5vknIrT0=; b=B3425sD5ssEx57pTtG98b8HpTdxzwssCBDuFcB0njTKI/XsYVhIlUT7t8VxfTZyCaj rNNcjy7ZkLO7sRu1croI6V17oM3JUWZ66KJz3dPOFnS6ZNXt9vF/ufrGiEJRrVh1rawx jBIyIycJ1nYQ/Tln+uKRdhBxUMbn2zrY+g01yeSgTRVjheiz5bWBhhhmJyUaJsAkE6GE dL6EhA0QNU/VHGk45s0/jNhjn17XdiiiF1JWKkMNdSlcYBJTXiZUBYEqCsiTUua4xdbH Vsh2/Hg502nb0uGz/tvW1rhibXANnp+7b1r3Lx8wxi+xiH/bRTNX1OQgA8zn4Jd+xIMD ResQ== 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=GJ+yfhkspt7ZNo22OgQpawec1Ei4RCTiEbe5vknIrT0=; b=qhYdzLyzZc69ISfQxbAhnBQ4Skfm19yaa2mjzMpQd9BJcHWEVGVWr4nZLSWM9v0R2I FNXq4R+NY4EtQQF35g4dLfkf9i8LBeSuXbIJvEjC0zHzNCcycGOsPp7XfWvELyKLQLom loMO/ocn8nBaPKMU9oFZHfDxGvlVA6PYZsMxG4X2rQTx2wusaEgSPByjRRil/ccE4QyC 2lQoRZ4uqNY2cC+1ywsuWdtfGjnLrxJHL4KFR0JHt3W+p8tUWGterV5VXnFVsbhweuZ4 3jdTTPx+2T+NEa1wgNGGZphFKgHxRMT/RGiOh3ag8Lg7fipeCzMJZwG1KfciomDMQRLD Hf/Q== X-Gm-Message-State: ANoB5pmpDHzEswfnp7Ljm+F+oRydmuxs2ojN8P4+hZ9vCKwcqhSS7U6t 1byuLYjZ+SoJEM9iOU/tnTERGoIQErg= X-Google-Smtp-Source: AA0mqf7QiNOgWP00XAD7anVxRZ3dDrQeLQqiZYyRJhfOxzgfK7hENIJxdqXXKq1jBfur3SWcS0zGNy7/Bfo= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6a00:27ab:b0:56c:71a4:efe with SMTP id bd43-20020a056a0027ab00b0056c71a40efemr48704277pfb.84.1669849794774; Wed, 30 Nov 2022 15:09:54 -0800 (PST) Date: Wed, 30 Nov 2022 23:08:54 +0000 In-Reply-To: <20221130230934.1014142-1-seanjc@google.com> Mime-Version: 1.0 References: <20221130230934.1014142-1-seanjc@google.com> X-Mailer: git-send-email 2.38.1.584.g0f3c55d4c2-goog Message-ID: <20221130230934.1014142-11-seanjc@google.com> Subject: [PATCH v2 10/50] KVM: VMX: Reset eVMCS controls in VP assist page during hardware disabling From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Huacai Chen , Aleksandar Markovic , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Matthew Rosato , Eric Farman , Sean Christopherson , Vitaly Kuznetsov , David Woodhouse , Paul Durrant Cc: James Morse , Alexandru Elisei , Suzuki K Poulose , Oliver Upton , Atish Patra , David Hildenbrand , kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvmarm@lists.cs.columbia.edu, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, Yuan Yao , Cornelia Huck , Isaku Yamahata , "=?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?=" , Fabiano Rosas , Michael Ellerman , Kai Huang , Chao Gao , Thomas Gleixner X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221130_231004_938528_760F8A1D X-CRM114-Status: GOOD ( 16.96 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Sean Christopherson Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Reset the eVMCS controls in the per-CPU VP assist page during hardware disabling instead of waiting until kvm-intel's module exit. The controls are activated if and only if KVM creates a VM, i.e. don't need to be reset if hardware is never enabled. Doing the reset during hardware disabling will naturally fix a potential NULL pointer deref bug once KVM disables CPU hotplug while enabling and disabling hardware (which is necessary to fix a variety of bugs). If the kernel is running as the root partition, the VP assist page is unmapped during CPU hot unplug, and so KVM's clearing of the eVMCS controls needs to occur with CPU hot(un)plug disabled, otherwise KVM could attempt to write to a CPU's VP assist page after it's unmapped. Reported-by: Vitaly Kuznetsov Signed-off-by: Sean Christopherson --- arch/x86/kvm/vmx/vmx.c | 50 +++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 20 deletions(-) diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index cea8c07f5229..d85d175dca70 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -551,6 +551,33 @@ static int hv_enable_l2_tlb_flush(struct kvm_vcpu *vcpu) return 0; } +static void hv_reset_evmcs(void) +{ + struct hv_vp_assist_page *vp_ap; + + if (!static_branch_unlikely(&enable_evmcs)) + return; + + /* + * KVM should enable eVMCS if and only if all CPUs have a VP assist + * page, and should reject CPU onlining if eVMCS is enabled the CPU + * doesn't have a VP assist page allocated. + */ + vp_ap = hv_get_vp_assist_page(smp_processor_id()); + if (WARN_ON_ONCE(!vp_ap)) + return; + + /* + * Reset everything to support using non-enlightened VMCS access later + * (e.g. when we reload the module with enlightened_vmcs=0) + */ + vp_ap->nested_control.features.directhypercall = 0; + vp_ap->current_nested_vmcs = 0; + vp_ap->enlighten_vmentry = 0; +} + +#else /* IS_ENABLED(CONFIG_HYPERV) */ +static void hv_reset_evmcs(void) {} #endif /* IS_ENABLED(CONFIG_HYPERV) */ /* @@ -2496,6 +2523,8 @@ static void vmx_hardware_disable(void) if (cpu_vmxoff()) kvm_spurious_fault(); + hv_reset_evmcs(); + intel_pt_handle_vmx(0); } @@ -8462,27 +8491,8 @@ static void vmx_exit(void) kvm_exit(); #if IS_ENABLED(CONFIG_HYPERV) - if (static_branch_unlikely(&enable_evmcs)) { - int cpu; - struct hv_vp_assist_page *vp_ap; - /* - * Reset everything to support using non-enlightened VMCS - * access later (e.g. when we reload the module with - * enlightened_vmcs=0) - */ - for_each_online_cpu(cpu) { - vp_ap = hv_get_vp_assist_page(cpu); - - if (!vp_ap) - continue; - - vp_ap->nested_control.features.directhypercall = 0; - vp_ap->current_nested_vmcs = 0; - vp_ap->enlighten_vmentry = 0; - } - + if (static_branch_unlikely(&enable_evmcs)) static_branch_disable(&enable_evmcs); - } #endif vmx_cleanup_l1d_flush(); -- 2.38.1.584.g0f3c55d4c2-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel