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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE2F1C433F5 for ; Wed, 13 Apr 2022 18:01:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234950AbiDMSD3 (ORCPT ); Wed, 13 Apr 2022 14:03:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237609AbiDMSC3 (ORCPT ); Wed, 13 Apr 2022 14:02:29 -0400 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B484141F9D for ; Wed, 13 Apr 2022 11:00:06 -0700 (PDT) Received: by mail-pj1-x1049.google.com with SMTP id y3-20020a17090a8b0300b001cb4831a8fbso4108977pjn.1 for ; Wed, 13 Apr 2022 11:00:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Gy/3X4u6MXYQtgeHNH5kjdgpJgGkBIMGxlSxtIk71CY=; b=jeGlCKN9OtluiB/5f/mJ9LQLzPoIDA1Wo+ibNZbKfTzUBIfygIxTfP4/+r2jKj+CP8 sHxurmH0mY3yJKOKlNTH+0RoAMkUitaxWjrqDItdQ8HCkNO9wFU5kl944VOmC4Lvlo3X r2HpwlzwF6RnQ/Tfv7u6VF/GTdN8H4GGtWRExbNtz2clbV3GLugVjcADcv+pCUVZdkrw K+0yVf6TK7pTD7kbO+s+2ZV8D1h6oEb3bGTwVwYKdD4l2A9xUSoTnCF3pbXMxpy0gILc hKKFOAP4IeC7EJtvsikgfNdxnSetjqRxOfjbQ1nQyYifBugi0k5an28llAE9HQUgS2Ws eDZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Gy/3X4u6MXYQtgeHNH5kjdgpJgGkBIMGxlSxtIk71CY=; b=cvX6aRKgNHLDPtp0jIJyJzVwvCT7p6c8Xde+DeMe2exrjohVj1grXFwZSOy4zzd3kr Y09aXuyTgH2aIpsI0elLuLHOrsbAmzeUgkgUx/9/8/TC85RKjpvQQC/pdeXWUbBFGYjP y0Be8xNoECnK3IUdbLxA7d43sHBnFk8vIlAntgYyVtli/RALOuWwnRreLDhwO9EQHZPb PRPWmfc3/yPV5k9QpGyxjeeq2+Ko1Flhy0ORz/bKLeMr21s+YmOU4eQ9iQ7LirMbG1BW XM+bML361UreWupZFbIRCuH2ubNDyLX2fN9PEW7u3vQlMcuGnw572sVDsyhMHxSkHDk9 e86A== X-Gm-Message-State: AOAM532kO5gUnw6W7vPRk+8m/pl6/RospZRatF5NFZty49DFkRGMYSXk 35mwbaWti5lCEamGvTWF3KiScw+h8NwK3dtxtMlD7UFq8hbZFnNTGkk+/iFg8F2AQl8bTftYzYX VxJm6u6sJ71ad2lmma4DsAemqUhTsw7WDUS8xlw0i47+llLmFu6dusgFZJ0QduetiKrkfdd2X X-Google-Smtp-Source: ABdhPJwdQGF6KfkCW4KBWs4LWsNAoyhQDkcsu5V93bneH+RboPTeqdazql3ja8rt6ulHljKweQjRBB7F9n2e X-Received: from bgardon.sea.corp.google.com ([2620:15c:100:202:c087:f2f2:f5f0:f73]) (user=bgardon job=sendgmr) by 2002:a05:6a00:3406:b0:505:7a1c:c553 with SMTP id cn6-20020a056a00340600b005057a1cc553mr30393pfb.2.1649872806122; Wed, 13 Apr 2022 11:00:06 -0700 (PDT) Date: Wed, 13 Apr 2022 10:59:44 -0700 In-Reply-To: <20220413175944.71705-1-bgardon@google.com> Message-Id: <20220413175944.71705-11-bgardon@google.com> Mime-Version: 1.0 References: <20220413175944.71705-1-bgardon@google.com> X-Mailer: git-send-email 2.35.1.1178.g4f1659d476-goog Subject: [PATCH v5 10/10] KVM: selftests: Test disabling NX hugepages on a VM From: Ben Gardon To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Peter Xu , Sean Christopherson , David Matlack , Jim Mattson , David Dunn , Jing Zhang , Junaid Shahid , Ben Gardon Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add an argument to the NX huge pages test to test disabling the feature on a VM using the new capability. Signed-off-by: Ben Gardon --- .../selftests/kvm/include/kvm_util_base.h | 2 + tools/testing/selftests/kvm/lib/kvm_util.c | 16 ++++- .../selftests/kvm/x86_64/nx_huge_pages_test.c | 62 +++++++++++++++---- 3 files changed, 68 insertions(+), 12 deletions(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h index 1dac3c6607f1..8f6aad253392 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -414,4 +414,6 @@ uint64_t vm_get_stat(struct kvm_vm *vm, const char *stat_name); uint32_t guest_get_vcpuid(void); +int vm_disable_nx_huge_pages(struct kvm_vm *vm); + #endif /* SELFTEST_KVM_UTIL_BASE_H */ diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index 5ffed44ab328..ef01858745e9 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -112,6 +112,11 @@ int vm_check_cap(struct kvm_vm *vm, long cap) return ret; } +static int __vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap) +{ + return ioctl(vm->fd, KVM_ENABLE_CAP, cap); +} + /* VM Enable Capability * * Input Args: @@ -128,7 +133,7 @@ int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap) { int ret; - ret = ioctl(vm->fd, KVM_ENABLE_CAP, cap); + ret = __vm_enable_cap(vm, cap); TEST_ASSERT(ret == 0, "KVM_ENABLE_CAP IOCTL failed,\n" " rc: %i errno: %i", ret, errno); @@ -2740,3 +2745,12 @@ uint64_t vm_get_stat(struct kvm_vm *vm, const char *stat_name) stat_name, ret); return data; } + +int vm_disable_nx_huge_pages(struct kvm_vm *vm) +{ + struct kvm_enable_cap cap = { 0 }; + + cap.cap = KVM_CAP_VM_DISABLE_NX_HUGE_PAGES; + cap.args[0] = 0; + return __vm_enable_cap(vm, &cap); +} diff --git a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c index 7f80e48781fd..21c31e1d567e 100644 --- a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c +++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c @@ -13,6 +13,8 @@ #include #include #include +#include +#include #include #include "kvm_util.h" @@ -80,13 +82,45 @@ static void check_split_count(struct kvm_vm *vm, int expected_splits) expected_splits, actual_splits); } -int main(int argc, char **argv) +void run_test(bool disable_nx) { struct kvm_vm *vm; struct timespec ts; + uint64_t pages; void *hva; - - vm = vm_create_default(0, 0, guest_code); + int r; + + pages = vm_pages_needed(VM_MODE_DEFAULT, 1, DEFAULT_GUEST_PHY_PAGES, + 0, 0); + vm = vm_create_without_vcpus(VM_MODE_DEFAULT, pages); + + if (disable_nx) { + kvm_check_cap(KVM_CAP_VM_DISABLE_NX_HUGE_PAGES); + + /* + * Check if this process has the reboot permissions needed to + * disable NX huge pages on a VM. + * + * The reboot call below will never have any effect because + * the magic values are not set correctly, however the + * permission check is done before the magic value check. + */ + r = syscall(SYS_reboot, 0, 0, 0, NULL); + if (r && errno == EPERM) { + r = vm_disable_nx_huge_pages(vm); + TEST_ASSERT(r == EPERM, + "This process should not have permission to disable NX huge pages"); + return; + } + + TEST_ASSERT(r && errno == EINVAL, + "Reboot syscall should fail with -EINVAL"); + + r = vm_disable_nx_huge_pages(vm); + TEST_ASSERT(!r, "Disabling NX huge pages should succeed if process has reboot permissions"); + } + + vm_vcpu_add_default(vm, 0, guest_code); vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS_HUGETLB, HPAGE_GPA, HPAGE_SLOT, @@ -121,21 +155,21 @@ int main(int argc, char **argv) * to be remapped at 4k. */ vcpu_run(vm, 0); - check_2m_page_count(vm, 1); - check_split_count(vm, 1); + check_2m_page_count(vm, disable_nx ? 2 : 1); + check_split_count(vm, disable_nx ? 0 : 1); /* * Executing from the third huge page (previously unaccessed) will * cause part to be mapped at 4k. */ vcpu_run(vm, 0); - check_2m_page_count(vm, 1); - check_split_count(vm, 2); + check_2m_page_count(vm, disable_nx ? 3 : 1); + check_split_count(vm, disable_nx ? 0 : 2); /* Reading from the first huge page again should have no effect. */ vcpu_run(vm, 0); - check_2m_page_count(vm, 1); - check_split_count(vm, 2); + check_2m_page_count(vm, disable_nx ? 3 : 1); + check_split_count(vm, disable_nx ? 0 : 2); /* * Give recovery thread time to run. The wrapper script sets @@ -148,7 +182,7 @@ int main(int argc, char **argv) /* * Now that the reclaimer has run, all the split pages should be gone. */ - check_2m_page_count(vm, 1); + check_2m_page_count(vm, disable_nx ? 3 : 1); check_split_count(vm, 0); /* @@ -156,10 +190,16 @@ int main(int argc, char **argv) * reading from it causes a huge page mapping to be installed. */ vcpu_run(vm, 0); - check_2m_page_count(vm, 2); + check_2m_page_count(vm, disable_nx ? 3 : 2); check_split_count(vm, 0); kvm_vm_free(vm); +} + +int main(int argc, char **argv) +{ + run_test(false); + run_test(true); return 0; } -- 2.35.1.1178.g4f1659d476-goog