From nobody Wed Sep 17 05:54:26 2025 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 C5187EB64DD for ; Sat, 29 Jul 2023 01:38:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231829AbjG2Bie (ORCPT ); Fri, 28 Jul 2023 21:38:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237641AbjG2Bh6 (ORCPT ); Fri, 28 Jul 2023 21:37:58 -0400 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CF9C14ED4 for ; Fri, 28 Jul 2023 18:37:21 -0700 (PDT) Received: by mail-pg1-x54a.google.com with SMTP id 41be03b00d2f7-563fc38db94so1629858a12.0 for ; Fri, 28 Jul 2023 18:37:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1690594591; x=1691199391; 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=Cv+DsoDLVKC7M6FclOb2McPWSddb97LBT0B8H7opNaY=; b=T6dKn0Eqxyz2hq1pOTYEfIvzKdLREMUo3Eg9TGB/irJNqcwSL7N1U8s/qojB7Pomtd HajhioTnMF465M8X+PS/k6ettCzrCZomyoVuYFcv0Nz/JHAeLUu/JPrCRJs3IRY4Y3P+ eY9C/JWu5kka2BzL4yTJsR+VP98afzcS2VbBYuLg7mbrhHcmSMJx1oQVVjfUUM65NxJw Mvmqplu8i0P/4ILWu1S78NWKp6Vz9QSIw7BZHTBZ/agXrwenZ/YSKCT1i4aZb6EvG3Tk CZIs+U82m251j7gMDbv/bLGUnBY17cIc3FNda3lpZHZWXsEku3CBzTn6AiLAuJCQM8Ro L+gw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1690594591; x=1691199391; 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=Cv+DsoDLVKC7M6FclOb2McPWSddb97LBT0B8H7opNaY=; b=RyA0KjInkZlRruZBweIY+uP59TpPBZB5N01KhChKZMZPYdQxuZ9QtXdhbHC0LjRBOL gNe3OMXQq538n2GZ1Ek2pXDSQQ5EUyp8o3mwfm+dlFX7KBM+0OkcvZktI1ilRuzIoSR+ 9hp5wl85KHsrFKJWvaj7TH+KboaYEe6t6UntB+wXD++EwYGk1XJMxaWsUQkaqJdmFSiL 6RP61QfcUzFdm4wqBWo1djkaWNqSVvaqXyMMi5JQSLmYS0Jo0mLRyL9zGP3EaudDX14H LGQxGG1Sh4Yb8wRhpzpSzhRaQ4LJqsQpP3hOObyTwXgDbaZGnWsyBTqPkMtSQuENHfBO kImg== X-Gm-Message-State: ABy/qLbS4jW8eLTOoTg5mlrxe9ANHFqsW2vvFa7YG9TPE/gLVWnwdyhY UPP59K59DLG7td9apaEcHc8jyjKMyUg= X-Google-Smtp-Source: APBJJlHqtoyrZzkA1RBEZPijpbgeZu0MncV0t8E8AkPf499XEff/G9cn4OJ6eavuvETRp4yMIx/pcoD/6Lk= X-Received: from zagreus.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5c37]) (user=seanjc job=sendgmr) by 2002:a17:902:d489:b0:1bb:83ec:841 with SMTP id c9-20020a170902d48900b001bb83ec0841mr12572plg.6.1690594591600; Fri, 28 Jul 2023 18:36:31 -0700 (PDT) Reply-To: Sean Christopherson Date: Fri, 28 Jul 2023 18:35:31 -0700 In-Reply-To: <20230729013535.1070024-1-seanjc@google.com> Mime-Version: 1.0 References: <20230729013535.1070024-1-seanjc@google.com> X-Mailer: git-send-email 2.41.0.487.g6d72f3e995-goog Message-ID: <20230729013535.1070024-26-seanjc@google.com> Subject: [PATCH v4 25/29] KVM: x86/mmu: Assert that correct locks are held for page write-tracking From: Sean Christopherson To: Sean Christopherson , Paolo Bonzini , Zhenyu Wang , Zhi Wang Cc: kvm@vger.kernel.org, intel-gvt-dev@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, Yan Zhao , Yongwei Ma , Ben Gardon Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When adding/removing gfns to/from write-tracking, assert that mmu_lock is held for write, and that either slots_lock or kvm->srcu is held. mmu_lock must be held for write to protect gfn_write_track's refcount, and SRCU or slots_lock must be held to protect the memslot itself. Tested-by: Yan Zhao Tested-by: Yongwei Ma Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/page_track.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index b835ba7f325c..29ae61f1e303 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -12,6 +12,7 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt =20 +#include #include #include =20 @@ -77,9 +78,6 @@ static void update_gfn_write_track(struct kvm_memory_slot= *slot, gfn_t gfn, * add guest page to the tracking pool so that corresponding access on that * page will be intercepted. * - * It should be called under the protection both of mmu-lock and kvm->srcu - * or kvm->slots_lock. - * * @kvm: the guest instance we are interested in. * @slot: the @gfn belongs to. * @gfn: the guest page. @@ -87,6 +85,11 @@ static void update_gfn_write_track(struct kvm_memory_slo= t *slot, gfn_t gfn, void kvm_write_track_add_gfn(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn) { + lockdep_assert_held_write(&kvm->mmu_lock); + + lockdep_assert_once(lockdep_is_held(&kvm->slots_lock) || + srcu_read_lock_held(&kvm->srcu)); + if (WARN_ON(!kvm_page_track_write_tracking_enabled(kvm))) return; =20 @@ -107,9 +110,6 @@ EXPORT_SYMBOL_GPL(kvm_write_track_add_gfn); * remove the guest page from the tracking pool which stops the intercepti= on * of corresponding access on that page. * - * It should be called under the protection both of mmu-lock and kvm->srcu - * or kvm->slots_lock. - * * @kvm: the guest instance we are interested in. * @slot: the @gfn belongs to. * @gfn: the guest page. @@ -117,6 +117,11 @@ EXPORT_SYMBOL_GPL(kvm_write_track_add_gfn); void kvm_write_track_remove_gfn(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn) { + lockdep_assert_held_write(&kvm->mmu_lock); + + lockdep_assert_once(lockdep_is_held(&kvm->slots_lock) || + srcu_read_lock_held(&kvm->srcu)); + if (WARN_ON(!kvm_page_track_write_tracking_enabled(kvm))) return; =20 --=20 2.41.0.487.g6d72f3e995-goog