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 91F4DC25B72 for ; Fri, 27 Oct 2023 19:31:03 +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=uOTV9dWubo9OUpTKWXzm274J8HPw9dEXPKLPGYXZ1wQ=; b=kmxdW+/ukZW33/ QqhIJO/begJhXy9OINdU24qcHon+TjCAoGYTJOFgTYXnltsxi35Qn9XcItiBK4UAM6GK5qiyHL4NJ dt0ZH3hFS14dBS3zgg8E+udSfxo/oc9M+/ixiFCNDMySvE4CyNY57h4G9zKZMaqTvgf9tEjUNLIBs IKeiCI2NjCFZEhMsRDlrRExgQcNcPeawwHYSqcabV8UNT87orAJ1FxDESkbpwVMxQqSNmGgQuquF1 QZeH4PMLVzPfHC5/73sw6WTLzyMxDxpSOuURoqe5D7nOsm6m76Nxw9GKCBRRQ5N+McCHzDBjXFSH1 f3QR9PaQJMWLqtai0t5A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qwSXq-00H5LP-0w; Fri, 27 Oct 2023 19:30:58 +0000 Received: from mail-yw1-x114a.google.com ([2607:f8b0:4864:20::114a]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qwRTh-00Gwn6-12 for linux-arm-kernel@lists.infradead.org; Fri, 27 Oct 2023 18:22:42 +0000 Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-5af9ad9341fso10343347b3.2 for ; Fri, 27 Oct 2023 11:22:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1698430953; x=1699035753; darn=lists.infradead.org; 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=QjG+iTAl+MysAoCDX0shLrWGCG7e9aCGlo9+qs2tVnE=; b=dxOVMbCDl9g25wVioTBYtDL97jXaioqbdrQIr7skwbQExg5gSOdbOmhzDoV5W/k2S1 61JBb87xFvbSEkOIefRAfu34pLGs2lWJBQVzmporomI5srS9sgMNF7cesAehjs2vzmNZ nBnpmQYwOlHPI0sJ9fsixobbOGWE7s1Jffv7aQijZrf7QZWA0F1A/tZ5cKspPgyxM5J8 TJIya2UhjxEVnH+rCbx0hu40xebOWyDeLhB2f0Z2ze27gvJu2E/A1cVkrCN4q2q28aW2 sAT59SGFS7blpdhun+nW3HOc/wr2QXuemiwKFALjUrfLFQvOIkPtgGek4bozKjQhKhDb YNNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1698430953; x=1699035753; 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=QjG+iTAl+MysAoCDX0shLrWGCG7e9aCGlo9+qs2tVnE=; b=Qni8yVn0sifoH3PZcNCnXRoiIBNjPS0ol8zyuKpco/jVE7Ek97F7QrWlp1tqsmzlap nqtIOwYf4AX7RFUC1wa34iNAZit7k6gYpKik06ug41RiV6+cao0CJCxQIOoMba97sUkf W6XkR1Ky6HsS7Alk5SU4v9s3UB6Zz6eQw1v0SxGS8MCBJPe2Zad2ydLOTeE2EjE35Non 2w+06yHADWUfugFZG1X4ynMRkkV5Ts2m75+ffisF/oiqzCPxT8cM77CuKC0x5VotwD/O lyjdm/dC8xCY/XsGZoOBHfSMzXEB6JyAy/ysuxTBKEWPpO7bP7Qk97DvEmcJpDaTE1wm dWgw== X-Gm-Message-State: AOJu0Yz2GkRnElNcrJWOabca1/SvF2hlZMQapZasrANdCrcR3XJSZfWJ NDXUy0Pmf0tekvpVAH2JOxvxO1Rcr2Q= X-Google-Smtp-Source: AGHT+IFjdgmBdyxBQ0zr6Phdzdc3NhfRHFKE/+Wea1IZiVOT7T4IBQHOPkTpo2hU6PU86u42a7hH74NJYwo= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a05:6902:1083:b0:da0:567d:f819 with SMTP id v3-20020a056902108300b00da0567df819mr78680ybu.10.1698430953673; Fri, 27 Oct 2023 11:22:33 -0700 (PDT) Date: Fri, 27 Oct 2023 11:21:46 -0700 In-Reply-To: <20231027182217.3615211-1-seanjc@google.com> Mime-Version: 1.0 References: <20231027182217.3615211-1-seanjc@google.com> X-Mailer: git-send-email 2.42.0.820.g83a721a137-goog Message-ID: <20231027182217.3615211-5-seanjc@google.com> Subject: [PATCH v13 04/35] KVM: WARN if there are dangling MMU invalidations at VM destruction From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Huacai Chen , Michael Ellerman , Anup Patel , Paul Walmsley , Palmer Dabbelt , Albert Ou , Sean Christopherson , Alexander Viro , Christian Brauner , "Matthew Wilcox (Oracle)" , Andrew Morton Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Xiaoyao Li , Xu Yilun , Chao Peng , Fuad Tabba , Jarkko Sakkinen , Anish Moorthy , David Matlack , Yu Zhang , Isaku Yamahata , "=?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?=" , Vlastimil Babka , Vishal Annapurve , Ackerley Tng , Maciej Szmigiero , David Hildenbrand , Quentin Perret , Michael Roth , Wang , Liam Merwick , Isaku Yamahata , "Kirill A . Shutemov" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231027_112237_396467_8767BD4A X-CRM114-Status: GOOD ( 13.09 ) 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 Add an assertion that there are no in-progress MMU invalidations when a VM is being destroyed, with the exception of the scenario where KVM unregisters its MMU notifier between an .invalidate_range_start() call and the corresponding .invalidate_range_end(). KVM can't detect unpaired calls from the mmu_notifier due to the above exception waiver, but the assertion can detect KVM bugs, e.g. such as the bug that *almost* escaped initial guest_memfd development. Link: https://lore.kernel.org/all/e397d30c-c6af-e68f-d18e-b4e3739c5389@linux.intel.com Signed-off-by: Sean Christopherson --- virt/kvm/kvm_main.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 1a577a25de47..4dba682586ee 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1356,9 +1356,16 @@ static void kvm_destroy_vm(struct kvm *kvm) * No threads can be waiting in kvm_swap_active_memslots() as the * last reference on KVM has been dropped, but freeing * memslots would deadlock without this manual intervention. + * + * If the count isn't unbalanced, i.e. KVM did NOT unregister its MMU + * notifier between a start() and end(), then there shouldn't be any + * in-progress invalidations. */ WARN_ON(rcuwait_active(&kvm->mn_memslots_update_rcuwait)); - kvm->mn_active_invalidate_count = 0; + if (kvm->mn_active_invalidate_count) + kvm->mn_active_invalidate_count = 0; + else + WARN_ON(kvm->mmu_invalidate_in_progress); #else kvm_flush_shadow_all(kvm); #endif -- 2.42.0.820.g83a721a137-goog _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel