From patchwork Wed Mar 30 17:46:21 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Gardon X-Patchwork-Id: 12796140 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 69CD7C433FE for ; Wed, 30 Mar 2022 17:47:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349522AbiC3Rsu (ORCPT ); Wed, 30 Mar 2022 13:48:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349454AbiC3Rsd (ORCPT ); Wed, 30 Mar 2022 13:48:33 -0400 Received: from mail-ot1-x349.google.com (mail-ot1-x349.google.com [IPv6:2607:f8b0:4864:20::349]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06F4410AF for ; Wed, 30 Mar 2022 10:46:47 -0700 (PDT) Received: by mail-ot1-x349.google.com with SMTP id v12-20020a05683018cc00b005cb5db35adaso11991144ote.22 for ; Wed, 30 Mar 2022 10:46:47 -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=zkLPtLgP4f8lahneFPhxB49cwHOmpmWMwYFdRQOyspU=; b=IPcnIrbSKblWsCyaVezhk5I+TW9O75I+DEC5RZc24jMakgquDmyiFouMKjDX0apCIq 8hPKImUPj5o1A31sI29jgiJ+8dIJe2GkG5HulJFj4SJv3eoXgBgG/dKaFol8hmfP64em giAiEgH5DeY3R3YsCczc2x3bxDlRakQ1UwffoiSvZE8dfrdIIoS+Hf60fvqRHdQ+4PPb yMwb6iWf/f9EFWLMcfXXfJezyBJF3bkaW9NVzE8o8gKWuNUWgTiZwduhh4spbYU3Gnp3 EFlU/2YLBWVbswX+BZCbiBotBeUgsTPlcug/QsbnfXvAub5gdcpuE7U+GNQpsWUpk/tL PuHw== 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=zkLPtLgP4f8lahneFPhxB49cwHOmpmWMwYFdRQOyspU=; b=XQTEgSoj9qbc4lh0Y3qqX7IyjkB2leYI2P4kVp3I/mzVmJWZgIA94ul/Lvow1ffa6I cujpYx0CD7RZ4nDYX0cHECMor/zlNqEXjUc4pe/TF6sRl4m5h4srJSFBbe8lYnLIElwR DkTFADLq1OrzkxRBOBLP4Ul0tpZoQpLjKo2SL7pZmv2TEhm1PsqULRbis2fs/sAcP6ax N0jpqMFeDT+9DdejDQb0GYmZ3RUSwjOpsVEaYfIwwKhhAhTtgQ8tSJjQudVo+FkHCqlD SDWC78A6g+tzTTzaDPGi31CDVTKs25TpOQXyxy+hfbodrw+eheNMoMChE2SWOzhBF/hH DfTg== X-Gm-Message-State: AOAM531nNZkAWFy2y15mp0nJw9Q0PqVJt5oeQXnvffU4lYzRWPQW8dIk zn1pi+BppT1NiGzjEOsAuov6zLdM0fNU X-Google-Smtp-Source: ABdhPJxtJpJ4jFm3lSuaP+2ohkBJNFPXeQidsiS1RT6z36hgKXeJ/VLQtRDxmvvtUH3OKGzhG8SLipTurDdx X-Received: from bgardon.sea.corp.google.com ([2620:15c:100:202:7c53:ec2f:bd26:b69c]) (user=bgardon job=sendgmr) by 2002:aca:f288:0:b0:2f4:6cb:4c84 with SMTP id q130-20020acaf288000000b002f406cb4c84mr456922oih.185.1648662406810; Wed, 30 Mar 2022 10:46:46 -0700 (PDT) Date: Wed, 30 Mar 2022 10:46:21 -0700 In-Reply-To: <20220330174621.1567317-1-bgardon@google.com> Message-Id: <20220330174621.1567317-12-bgardon@google.com> Mime-Version: 1.0 References: <20220330174621.1567317-1-bgardon@google.com> X-Mailer: git-send-email 2.35.1.1021.g381101b075-goog Subject: [PATCH v3 11/11] selftests: KVM: 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 Precedence: bulk List-ID: X-Mailing-List: kvm@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 | 7 ++ .../selftests/kvm/x86_64/nx_huge_pages_test.c | 67 ++++++++++++++++--- .../kvm/x86_64/nx_huge_pages_test.sh | 2 +- 4 files changed, 66 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 72163ba2f878..4db8251c3ce5 100644 --- a/tools/testing/selftests/kvm/include/kvm_util_base.h +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h @@ -411,4 +411,6 @@ uint64_t vm_get_single_stat(struct kvm_vm *vm, const char *stat_name); uint32_t guest_get_vcpuid(void); +void 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 9d72d1bb34fa..46a7fa08d3e0 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -2765,3 +2765,10 @@ uint64_t vm_get_single_stat(struct kvm_vm *vm, const char *stat_name) return value; } +void vm_disable_nx_huge_pages(struct kvm_vm *vm) +{ + struct kvm_enable_cap cap = { 0 }; + + cap.cap = KVM_CAP_VM_DISABLE_NX_HUGE_PAGES; + 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 2bcbe4efdc6a..a0c79f6ddc08 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" @@ -57,13 +59,56 @@ static void check_split_count(struct kvm_vm *vm, int expected_splits) expected_splits, actual_splits); } +static void help(void) +{ + puts(""); + printf("usage: nx_huge_pages_test.sh [-x]\n"); + puts(""); + printf(" -x: Allow executable huge pages on the VM.\n"); + puts(""); + exit(0); +} + int main(int argc, char **argv) { struct kvm_vm *vm; struct timespec ts; + bool disable_nx = false; + int opt; + int r; + + while ((opt = getopt(argc, argv, "x")) != -1) { + switch (opt) { + case 'x': + disable_nx = true; + break; + case 'h': + default: + help(); + break; + } + } vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR); + if (disable_nx) { + /* + * 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 == -EPERM) + return KSFT_SKIP; + TEST_ASSERT(r == -EINVAL, + "Reboot syscall should fail with -EINVAL"); + + vm_disable_nx_huge_pages(vm); + } + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS_HUGETLB, HPAGE_PADDR_START, HPAGE_SLOT, HPAGE_SLOT_NPAGES, 0); @@ -83,21 +128,21 @@ int main(int argc, char **argv) * at 2M. */ run_guest_code(vm, guest_code0); - check_2m_page_count(vm, 2); - check_split_count(vm, 2); + check_2m_page_count(vm, disable_nx ? 4 : 2); + check_split_count(vm, disable_nx ? 0 : 2); /* * guest_code1 is in the same huge page as data1, so it will cause * that huge page to be remapped at 4k. */ run_guest_code(vm, guest_code1); - check_2m_page_count(vm, 1); - check_split_count(vm, 3); + check_2m_page_count(vm, disable_nx ? 4 : 1); + check_split_count(vm, disable_nx ? 0 : 3); /* Run guest_code0 again to check that is has no effect. */ run_guest_code(vm, guest_code0); - check_2m_page_count(vm, 1); - check_split_count(vm, 3); + check_2m_page_count(vm, disable_nx ? 4 : 1); + check_split_count(vm, disable_nx ? 0 : 3); /* * Give recovery thread time to run. The wrapper script sets @@ -110,7 +155,7 @@ 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 ? 4 : 1); check_split_count(vm, 0); /* @@ -118,13 +163,13 @@ int main(int argc, char **argv) * again to check that pages are mapped at 2M again. */ run_guest_code(vm, guest_code0); - check_2m_page_count(vm, 2); - check_split_count(vm, 2); + check_2m_page_count(vm, disable_nx ? 4 : 2); + check_split_count(vm, disable_nx ? 0 : 2); /* Pages are once again split from running guest_code1. */ run_guest_code(vm, guest_code1); - check_2m_page_count(vm, 1); - check_split_count(vm, 3); + check_2m_page_count(vm, disable_nx ? 4 : 1); + check_split_count(vm, disable_nx ? 0 : 3); kvm_vm_free(vm); diff --git a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh index 19fc95723fcb..29f999f48848 100755 --- a/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh +++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh @@ -14,7 +14,7 @@ echo 1 > /sys/module/kvm/parameters/nx_huge_pages_recovery_ratio echo 100 > /sys/module/kvm/parameters/nx_huge_pages_recovery_period_ms echo 200 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages -./nx_huge_pages_test +./nx_huge_pages_test "${@}" RET=$? echo $NX_HUGE_PAGES > /sys/module/kvm/parameters/nx_huge_pages