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 X-Spam-Level: X-Spam-Status: No, score=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61605C4707A for ; Fri, 21 May 2021 17:38:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 334E1611AB for ; Fri, 21 May 2021 17:38:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238242AbhEURj6 (ORCPT ); Fri, 21 May 2021 13:39:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56382 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234956AbhEURjz (ORCPT ); Fri, 21 May 2021 13:39:55 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C030BC061574 for ; Fri, 21 May 2021 10:38:31 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id s5-20020aa78d450000b02902ace63a7e93so12884709pfe.8 for ; Fri, 21 May 2021 10:38:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=xdGv0OCyISv0+o0WfZ9E36lugmUmFkFPCE+9HuHmiFo=; b=tws0Kf7f5L/2Gwcun3oTIPiZ6BcC7MezDjAMMISE3AGuhML7tnmgye1zNnqOnpoFvo 32RR3qJonuAxF/3slmxzRx0lZr5DEfTDXyUen7mh2jxb6U1lVUIWj//jzL2l5eMfNUFm Nw48qW6T13fs+JmWnHUdQ3wkGPyyMjk0XCzocrT+eGnjHRcnQi5U0eKqlMl/vuXwzCvi cpuCZSuDIbN0FZFXMO7X5//wdCe9n9xFQu8Lj0hkDeUvIgilg0+jLnUpijD2urVsS9DP g/iujR+uEYiPHQs1QDqfeY1PmdPhpDAosPk0Ce3TrHB0PgqP+3wxqp+0ETBTfGzo3mTf L/iw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=xdGv0OCyISv0+o0WfZ9E36lugmUmFkFPCE+9HuHmiFo=; b=aNjBI58CdGFWAq9p8GVGdJnWMiGwg0NlUFikryafJJi23S3jZvlKQCYEHzVaSMHejr 29H5qqTP4o3+dkST+QIbtoSGaVvhBoMVHOxhF4BATYSWxhE6QLnxtiRst8530YxAJj5t R/z1AurrSWLqx/B11Jm51ETXe5mouK/ihIZlZR/KCm7RNUu0dCZbXmRIWdtU+bA4MdDP PknkEhk0QQLVETV/Wg3SUO4BHdsPxGQH/UwZhV/f7ZkcOwHFV1PqBpnJgkPe6ZBhg2jG SCDsN1bBkCjXTB4QeqQuGQhRSWLkqwXZOUFwscaHJFxiCSjPZasGeD4gHWGcOYL3TJYG Nn5g== X-Gm-Message-State: AOAM531fksSG3lUg+1M67OcdFe+Vq24QUhlHHbGo5TNJ1pynOvGrHvyV phiIw8rka+3vNJuW9SC878s7c6dtJKNMDLe26VQaxBigS0be2ILUBLaAbqGHM2ZuZh/IA/sQoef 94ifV3k22Jz39b7PC00GhKjosOTMkY7sZyVQG3LI3gA4TtEaOUXq4zvMiUPr26AE= X-Google-Smtp-Source: ABdhPJxnpsTU8PnjyyNFBMud+YBLmfmd78OkBsf1wTmW8Bt2hM19YVd9RD1SPyQmoDp5xS/DCbe55NZmBUxQpw== X-Received: from dmatlack-heavy.c.googlers.com ([fda3:e722:ac3:10:7f:e700:c0a8:19cd]) (user=dmatlack job=sendgmr) by 2002:a17:90a:29c4:: with SMTP id h62mr12331562pjd.177.1621618711076; Fri, 21 May 2021 10:38:31 -0700 (PDT) Date: Fri, 21 May 2021 17:38:28 +0000 Message-Id: <20210521173828.1180619-1-dmatlack@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.31.1.818.g46aad6cb9e-goog Subject: [PATCH v2] KVM: selftests: Fix 32-bit truncation of vm_get_max_gfn() From: David Matlack To: kvm@vger.kernel.org, Venkatesh Srinivas Cc: Paolo Bonzini , Andrew Jones , Ben Gardon , Peter Xu , David Matlack Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org vm_get_max_gfn() casts vm->max_gfn from a uint64_t to an unsigned int, which causes the upper 32-bits of the max_gfn to get truncated. Nobody noticed until now likely because vm_get_max_gfn() is only used as a mechanism to create a memslot in an unused region of the guest physical address space (the top), and the top of the 32-bit physical address space was always good enough. This fix reveals a bug in memslot_modification_stress_test which was trying to create a dummy memslot past the end of guest physical memory. Fix that by moving the dummy memslot lower. Fixes: 52200d0d944e ("KVM: selftests: Remove duplicate guest mode handling") Reviewed-by: Venkatesh Srinivas Signed-off-by: David Matlack --- v1 -> v2: - Added Venkatesh's R-b line. - Used PRIx64 to print uint64_t instead of %lx. tools/testing/selftests/kvm/include/kvm_util.h | 2 +- tools/testing/selftests/kvm/lib/kvm_util.c | 2 +- .../testing/selftests/kvm/lib/perf_test_util.c | 4 +++- .../kvm/memslot_modification_stress_test.c | 18 +++++++++++------- 4 files changed, 16 insertions(+), 10 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index 84982eb02b29..5d9b35d09251 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -303,7 +303,7 @@ bool vm_is_unrestricted_guest(struct kvm_vm *vm); unsigned int vm_get_page_size(struct kvm_vm *vm); unsigned int vm_get_page_shift(struct kvm_vm *vm); -unsigned int vm_get_max_gfn(struct kvm_vm *vm); +uint64_t vm_get_max_gfn(struct kvm_vm *vm); int vm_get_fd(struct kvm_vm *vm); unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size); diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 1af1009254c4..aeffbb1e7c7d 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -2058,7 +2058,7 @@ unsigned int vm_get_page_shift(struct kvm_vm *vm) return vm->page_shift; } -unsigned int vm_get_max_gfn(struct kvm_vm *vm) +uint64_t vm_get_max_gfn(struct kvm_vm *vm) { return vm->max_gfn; } diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c index 81490b9b4e32..abf381800a59 100644 --- a/tools/testing/selftests/kvm/lib/perf_test_util.c +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c @@ -2,6 +2,7 @@ /* * Copyright (C) 2020, Google LLC. */ +#include #include "kvm_util.h" #include "perf_test_util.h" @@ -80,7 +81,8 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, */ TEST_ASSERT(guest_num_pages < vm_get_max_gfn(vm), "Requested more guest memory than address space allows.\n" - " guest pages: %lx max gfn: %x vcpus: %d wss: %lx]\n", + " guest pages: %" PRIx64 " max gfn: %" PRIx64 + " vcpus: %d wss: %" PRIx64 "]\n", guest_num_pages, vm_get_max_gfn(vm), vcpus, vcpu_memory_bytes); diff --git a/tools/testing/selftests/kvm/memslot_modification_stress_test.c b/tools/testing/selftests/kvm/memslot_modification_stress_test.c index 6096bf0a5b34..98351ba0933c 100644 --- a/tools/testing/selftests/kvm/memslot_modification_stress_test.c +++ b/tools/testing/selftests/kvm/memslot_modification_stress_test.c @@ -71,14 +71,22 @@ struct memslot_antagonist_args { }; static void add_remove_memslot(struct kvm_vm *vm, useconds_t delay, - uint64_t nr_modifications, uint64_t gpa) + uint64_t nr_modifications) { + const uint64_t pages = 1; + uint64_t gpa; int i; + /* + * Add the dummy memslot just below the perf_test_util memslot, which is + * at the top of the guest physical address space. + */ + gpa = guest_test_phys_mem - pages * vm_get_page_size(vm); + for (i = 0; i < nr_modifications; i++) { usleep(delay); vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, gpa, - DUMMY_MEMSLOT_INDEX, 1, 0); + DUMMY_MEMSLOT_INDEX, pages, 0); vm_mem_region_delete(vm, DUMMY_MEMSLOT_INDEX); } @@ -120,11 +128,7 @@ static void run_test(enum vm_guest_mode mode, void *arg) pr_info("Started all vCPUs\n"); add_remove_memslot(vm, p->memslot_modification_delay, - p->nr_memslot_modifications, - guest_test_phys_mem + - (guest_percpu_mem_size * nr_vcpus) + - perf_test_args.host_page_size + - perf_test_args.guest_page_size); + p->nr_memslot_modifications); run_vcpus = false; -- 2.31.1.818.g46aad6cb9e-goog