Received: by 2002:a05:6a10:3150:0:0:0:0 with SMTP id m16csp3146189pxc; Tue, 12 Apr 2022 14:53:12 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxMlHqQiQEQU22M2qDB7hNHDn32K19mtoJiUE/Wd/lPrnYQd8HyLWpwmJkXlrBh0W1a/4JW X-Received: by 2002:a17:902:6b0c:b0:158:9baa:795a with SMTP id o12-20020a1709026b0c00b001589baa795amr1515244plk.98.1649800391797; Tue, 12 Apr 2022 14:53:11 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1649800391; cv=none; d=google.com; s=arc-20160816; b=MMGpQGdBjeqTFsLYo1DCCzQjSygOlUoWxsT6j8q3P3t9epVe0CFs2dC7kaxqI+Zlm5 Lw6tH42hhzKuw0+rX2Ae0a+nXMzpBohV6frEnCb/96cIsz4SbN1BGzY4lZghbP2T6d4Z eHylOC90XsjFMnug1CllkR0HV1Dv2rE+DmXDig3oyLivFxgFViJig/yMKBleZ8adEy0D G5wmcT1AMZ9+GFmb2AcdhbH566Faw6msIA1zZz6xxYubvQDsn6BmLJz6GVESSL4uibkz fXdv7Q/za1tsdF6G4tE23p17E/WTNvx9KuAqjkHaH2cu8HrvSXYKp+JOiogsNH+eeP6E UQyA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:subject:message-id:date:from:in-reply-to :references:mime-version:dkim-signature; bh=PPBeyuq46va0noO+Dk67+HuZMeHjQWh17sfc1QaEgsU=; b=dvi1FDCcGDTs7sc5n9KJKGRBxDW3gwaDTaBzSlTteajyNrAMnA+Rim0nkycBLXb152 CSm+4BuEpXQyiwa5WJ9vv9X27/nh+bTd2A+h/EjJ+UsgV4R3rX95pl619qgfG0JQI7kr 6hHCPCgV/GQDqTxqpLGrZzgZoTwN+Lacf21dUIy9OhBQpYIC5XMDsI1D7BcB6EglIPWZ iKr+pNjTpAeiJcIr3mnZsp70TMOTDJPYQJ7NQoJupVhuahPiBm6UtNJhkEAhsRMClz+G P1J49vxORqRYj4z4eA/4w5v8VO4BY3dPWP++utb1LmXK9cq0p/wABrBM+3yFFp04YpRg Gsag== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=HnUdiJRJ; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Return-Path: Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net. [2620:137:e000::1:18]) by mx.google.com with ESMTPS id b5-20020a170902650500b00153dd942e08si12133821plk.407.2022.04.12.14.53.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 Apr 2022 14:53:11 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20210112 header.b=HnUdiJRJ; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 12B2C14B031; Tue, 12 Apr 2022 13:55:16 -0700 (PDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245262AbiDKWam (ORCPT + 99 others); Mon, 11 Apr 2022 18:30:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229451AbiDKWak (ORCPT ); Mon, 11 Apr 2022 18:30:40 -0400 Received: from mail-lj1-x229.google.com (mail-lj1-x229.google.com [IPv6:2a00:1450:4864:20::229]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E059B1EC77 for ; Mon, 11 Apr 2022 15:28:24 -0700 (PDT) Received: by mail-lj1-x229.google.com with SMTP id q189so5308637ljb.13 for ; Mon, 11 Apr 2022 15:28:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PPBeyuq46va0noO+Dk67+HuZMeHjQWh17sfc1QaEgsU=; b=HnUdiJRJ9ey1jrQcyl/iLWbuTi8tU3an1KV+AIuIC3T6C/zmKvMznd4E6l7o8JsOYb F62fwnHGxLCUIGFuyKsv65Ys0TrCoNdFFj4ADN9BAElPWTBWpqNk0mkobmrbYG0Q2MgO xkCm4HvESj6qKhnnSZrqqTKCSy5OtPhPAJ3oayGgINRDQ8ZjbwEUUm56klxQJQ7nYfnl RfB2W5Yq0F5REeIiQ64UxrTXoC+XYl8/XZcVc/lsGEqwu7YJ1FIs/TM0tJyCG0SH+iXT tpmES6v1gTF65d8ZFtgwEpd35sWNhkZA8yCef/xcZm1tkn5kiC/xK9QkfesbyXx80zYv U1kQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PPBeyuq46va0noO+Dk67+HuZMeHjQWh17sfc1QaEgsU=; b=HPJkUkii7tZMejp33xPntA0/GJZPZV/xpwUZM6NLArkMgaa3JrmRJaGOp2wQ0r5hjF DurI4A2C28Zph52xCiSKGY7E9zbF//PlgGVzUgPdW2OxlruWKGMXBU31D9RyraYnIHfA tkPBcbBrs8kgN5y7FjK7gffEBsyG2phCq8mxj8UtrzhcRKzS3xtmueiUjA0YDIk2I1oB XGlzG20JPlbAVcstwCU1eBypDJuYznwpKvM+Z5wW5fVt/Vw7uFnDP8+W4Q8IKXZyOR0k Z59yjZAMAqJCFn4fRO6QEYRcQKq+VBYkhzKwUl8IOvoCCsC/JoMMhRnV9CO4n7ZvnYZs c2Bw== X-Gm-Message-State: AOAM533mL6FeimUrktHkb+Kv+rWMKaeIXTqHtKmTTdUUhZEP101RRRwm a3WC0AxLFm7Rl92NJ3vESvywBeIo8DGg2MX/f9RoBQ== X-Received: by 2002:a05:651c:1792:b0:235:1df3:7b8e with SMTP id bn18-20020a05651c179200b002351df37b8emr21518331ljb.464.1649716102928; Mon, 11 Apr 2022 15:28:22 -0700 (PDT) MIME-Version: 1.0 References: <20220411211015.3091615-1-bgardon@google.com> <20220411211015.3091615-6-bgardon@google.com> In-Reply-To: <20220411211015.3091615-6-bgardon@google.com> From: David Matlack Date: Mon, 11 Apr 2022 15:27:56 -0700 Message-ID: Subject: Re: [PATCH v4 05/10] KVM: selftests: Add NX huge pages test To: Ben Gardon Cc: LKML , kvm list , Paolo Bonzini , Peter Xu , Sean Christopherson , Peter Shier , David Dunn , Junaid Shahid , Jim Mattson , Mingwei Zhang , Jing Zhang Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-9.5 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RDNS_NONE,SPF_HELO_NONE,T_SCC_BODY_TEXT_LINE, USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 11, 2022 at 2:10 PM Ben Gardon wrote: > > There's currently no test coverage of NX hugepages in KVM selftests, so > add a basic test to ensure that the feature works as intended. > > Signed-off-by: Ben Gardon > --- > tools/testing/selftests/kvm/Makefile | 10 ++ > .../selftests/kvm/include/kvm_util_base.h | 1 + > tools/testing/selftests/kvm/lib/kvm_util.c | 48 ++++++ > .../selftests/kvm/x86_64/nx_huge_pages_test.c | 163 ++++++++++++++++++ > .../kvm/x86_64/nx_huge_pages_test.sh | 25 +++ > 5 files changed, 247 insertions(+) > create mode 100644 tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c > create mode 100755 tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh > > diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile > index af582d168621..9bb9bce4df37 100644 > --- a/tools/testing/selftests/kvm/Makefile > +++ b/tools/testing/selftests/kvm/Makefile > @@ -43,6 +43,10 @@ LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c lib/aarch64/handler > LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c > LIBKVM_riscv = lib/riscv/processor.c lib/riscv/ucall.c > > +# Non-compiled test targets > +TEST_PROGS_x86_64 += x86_64/nx_huge_pages_test.sh > + > +# Compiled test targets > TEST_GEN_PROGS_x86_64 = x86_64/cpuid_test > TEST_GEN_PROGS_x86_64 += x86_64/cr4_cpuid_sync_test > TEST_GEN_PROGS_x86_64 += x86_64/get_msr_index_features > @@ -104,6 +108,9 @@ TEST_GEN_PROGS_x86_64 += steal_time > TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test > TEST_GEN_PROGS_x86_64 += system_counter_offset_test > > +# Compiled outputs used by test targets > +TEST_GEN_PROGS_EXTENDED_x86_64 += x86_64/nx_huge_pages_test > + > TEST_GEN_PROGS_aarch64 += aarch64/arch_timer > TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions > TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list > @@ -142,7 +149,9 @@ TEST_GEN_PROGS_riscv += kvm_page_table_test > TEST_GEN_PROGS_riscv += set_memory_region_test > TEST_GEN_PROGS_riscv += kvm_binary_stats_test > > +TEST_PROGS += $(TEST_PROGS_$(UNAME_M)) > TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M)) > +TEST_GEN_PROGS_EXTENDED += $(TEST_GEN_PROGS_EXTENDED_$(UNAME_M)) > LIBKVM += $(LIBKVM_$(UNAME_M)) > > INSTALL_HDR_PATH = $(top_srcdir)/usr > @@ -193,6 +202,7 @@ $(OUTPUT)/libkvm.a: $(LIBKVM_OBJS) > x := $(shell mkdir -p $(sort $(dir $(TEST_GEN_PROGS)))) > all: $(STATIC_LIBS) > $(TEST_GEN_PROGS): $(STATIC_LIBS) > +$(TEST_GEN_PROGS_EXTENDED): $(STATIC_LIBS) > > cscope: include_paths = $(LINUX_TOOL_INCLUDE) $(LINUX_HDR_PATH) include lib .. > cscope: > diff --git a/tools/testing/selftests/kvm/include/kvm_util_base.h b/tools/testing/selftests/kvm/include/kvm_util_base.h > index b2684cfc2cb1..f9c2ac0a5b97 100644 > --- a/tools/testing/selftests/kvm/include/kvm_util_base.h > +++ b/tools/testing/selftests/kvm/include/kvm_util_base.h > @@ -408,6 +408,7 @@ void read_vm_stats_desc(int stats_fd, struct kvm_stats_header *header, > int read_stat_data(int stats_fd, struct kvm_stats_header *header, > struct kvm_stats_desc *desc, uint64_t *data, > ssize_t max_elements); > +uint64_t vm_get_single_stat(struct kvm_vm *vm, const char *stat_name); > > uint32_t guest_get_vcpuid(void); > > diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c > index 64e2085f1129..833c7e63d62d 100644 > --- a/tools/testing/selftests/kvm/lib/kvm_util.c > +++ b/tools/testing/selftests/kvm/lib/kvm_util.c > @@ -2614,3 +2614,51 @@ int read_stat_data(int stats_fd, struct kvm_stats_header *header, > > return ret; > } > + > +static int vm_get_stat_data(struct kvm_vm *vm, const char *stat_name, > + uint64_t *data, ssize_t max_elements) > +{ > + struct kvm_stats_desc *stats_desc; > + struct kvm_stats_header header; > + struct kvm_stats_desc *desc; > + size_t size_desc; > + int stats_fd; > + int ret = -EINVAL; > + int i; > + > + stats_fd = vm_get_stats_fd(vm); > + > + read_vm_stats_header(stats_fd, &header); > + > + stats_desc = alloc_vm_stats_desc(stats_fd, &header); > + read_vm_stats_desc(stats_fd, &header, stats_desc); This is a fair bit of redundant work to do when reading every stat. Reading stats in selftests is probably not going to be performance-senstive, but it should be pretty easy to move everything above to VM initialization and storing the outputs in struct kvm_vm for access during this function. > + > + size_desc = sizeof(struct kvm_stats_desc) + header.name_size; > + > + /* Read kvm stats data one by one */ > + for (i = 0; i < header.num_desc; ++i) { > + desc = (void *)stats_desc + (i * size_desc); > + > + if (strcmp(desc->name, stat_name)) > + continue; > + > + ret = read_stat_data(stats_fd, &header, desc, data, > + max_elements); > + } > + > + free(stats_desc); > + close(stats_fd); > + return ret; > +} > + > +uint64_t vm_get_single_stat(struct kvm_vm *vm, const char *stat_name) nit: I'd prefer the simpler "vm_get_stat()". The function signature already makes it clear we're reading one stat value. And when we add more support for more complicated stats (e.g. vm_get_histogram_stat()), I think "vm_get_stat()" will still work for reading single value stats. > +{ > + uint64_t data; > + int ret; > + > + ret = vm_get_stat_data(vm, stat_name, &data, 1); > + TEST_ASSERT(ret == 1, > + "Stat %s expected to have 1 element, but %d returned", > + stat_name, ret); > + return data; > +} > 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 > new file mode 100644 > index 000000000000..3f21726b22c7 > --- /dev/null > +++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.c > @@ -0,0 +1,163 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * tools/testing/selftests/kvm/nx_huge_page_test.c > + * > + * Usage: to be run via nx_huge_page_test.sh, which does the necessary > + * environment setup and teardown > + * > + * Copyright (C) 2022, Google LLC. > + */ > + > +#define _GNU_SOURCE > + > +#include > +#include > +#include > + > +#include > +#include "kvm_util.h" > + > +#define HPAGE_SLOT 10 > +#define HPAGE_GVA (23*1024*1024) > +#define HPAGE_GPA (10*1024*1024) > +#define HPAGE_SLOT_NPAGES (512 * 3) > +#define PAGE_SIZE 4096 > + > +/* > + * When writing to guest memory, write the opcode for the `ret` instruction so > + * that subsequent iteractions can exercise instruction fetch by calling the > + * memory. I think this comment needs to be reworded to better fit this test. > + */ > +#define RETURN_OPCODE 0xC3 > + > +void guest_code(void) > +{ > + uint64_t hpage_1 = HPAGE_GVA; > + uint64_t hpage_2 = hpage_1 + (PAGE_SIZE * 512); > + uint64_t hpage_3 = hpage_2 + (PAGE_SIZE * 512); > + > + READ_ONCE(*(uint64_t *)hpage_1); > + GUEST_SYNC(1); > + > + READ_ONCE(*(uint64_t *)hpage_2); > + GUEST_SYNC(2); > + > + ((void (*)(void)) hpage_1)(); > + GUEST_SYNC(3); > + > + ((void (*)(void)) hpage_3)(); > + GUEST_SYNC(4); > + > + READ_ONCE(*(uint64_t *)hpage_1); > + GUEST_SYNC(5); > + > + READ_ONCE(*(uint64_t *)hpage_3); > + GUEST_SYNC(6); > +} > + > +static void check_2m_page_count(struct kvm_vm *vm, int expected_pages_2m) > +{ > + int actual_pages_2m; > + > + actual_pages_2m = vm_get_single_stat(vm, "pages_2m"); > + > + TEST_ASSERT(actual_pages_2m == expected_pages_2m, > + "Unexpected 2m page count. Expected %d, got %d", > + expected_pages_2m, actual_pages_2m); > +} > + > +static void check_split_count(struct kvm_vm *vm, int expected_splits) > +{ > + int actual_splits; > + > + actual_splits = vm_get_single_stat(vm, "nx_lpage_splits"); > + > + TEST_ASSERT(actual_splits == expected_splits, > + "Unexpected nx lpage split count. Expected %d, got %d", > + expected_splits, actual_splits); > +} > + > +int main(int argc, char **argv) > +{ > + struct kvm_vm *vm; > + struct timespec ts; > + void *hva; > + > + vm = vm_create_default(0, 0, guest_code); > + > + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS_HUGETLB, > + HPAGE_GPA, HPAGE_SLOT, > + HPAGE_SLOT_NPAGES, 0); > + > + virt_map(vm, HPAGE_GVA, HPAGE_GPA, HPAGE_SLOT_NPAGES); > + > + hva = addr_gpa2hva(vm, HPAGE_GPA); > + memset(hva, RETURN_OPCODE, HPAGE_SLOT_NPAGES * PAGE_SIZE); > + > + check_2m_page_count(vm, 0); > + check_split_count(vm, 0); > + > + /* > + * The guest code will first read from the first hugepage, resulting > + * in a huge page mapping being created. > + */ > + vcpu_run(vm, 0); > + check_2m_page_count(vm, 1); > + check_split_count(vm, 0); > + > + /* > + * Then the guest code will read from the second hugepage, resulting > + * in another huge page mapping being created. > + */ > + vcpu_run(vm, 0); > + check_2m_page_count(vm, 2); > + check_split_count(vm, 0); > + > + /* > + * Next, the guest will execute from the first huge page, causing it > + * to be remapped at 4k. > + */ > + vcpu_run(vm, 0); > + check_2m_page_count(vm, 1); > + check_split_count(vm, 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); > + > + /* 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); > + > + /* > + * Give recovery thread time to run. The wrapper script sets > + * recovery_period_ms to 100, so wait 5x that. > + */ > + ts.tv_sec = 0; > + ts.tv_nsec = 500000000; > + nanosleep(&ts, NULL); > + > + /* > + * Now that the reclaimer has run, all the split pages should be gone. > + */ > + check_2m_page_count(vm, 1); > + check_split_count(vm, 0); > + > + /* > + * The 4k mapping on hpage 3 should have been removed, so check that > + * reading from it causes a huge page mapping to be installed. > + */ > + vcpu_run(vm, 0); > + check_2m_page_count(vm, 2); > + check_split_count(vm, 0); > + > + kvm_vm_free(vm); > + > + return 0; > +} > + > 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 > new file mode 100755 > index 000000000000..19fc95723fcb > --- /dev/null > +++ b/tools/testing/selftests/kvm/x86_64/nx_huge_pages_test.sh > @@ -0,0 +1,25 @@ > +#!/bin/bash > +# SPDX-License-Identifier: GPL-2.0-only */ > + > +# tools/testing/selftests/kvm/nx_huge_page_test.sh > +# Copyright (C) 2022, Google LLC. > + > +NX_HUGE_PAGES=$(cat /sys/module/kvm/parameters/nx_huge_pages) > +NX_HUGE_PAGES_RECOVERY_RATIO=$(cat /sys/module/kvm/parameters/nx_huge_pages_recovery_ratio) > +NX_HUGE_PAGES_RECOVERY_PERIOD=$(cat /sys/module/kvm/parameters/nx_huge_pages_recovery_period_ms) > +HUGE_PAGES=$(cat /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages) > + > +echo 1 > /sys/module/kvm/parameters/nx_huge_pages > +echo 1 > /sys/module/kvm/parameters/nx_huge_pages_recovery_ratio > +echo 100 > /sys/module/kvm/parameters/nx_huge_pages_recovery_period_ms > +echo 200 > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages > + > +./nx_huge_pages_test > +RET=$? > + > +echo $NX_HUGE_PAGES > /sys/module/kvm/parameters/nx_huge_pages > +echo $NX_HUGE_PAGES_RECOVERY_RATIO > /sys/module/kvm/parameters/nx_huge_pages_recovery_ratio > +echo $NX_HUGE_PAGES_RECOVERY_PERIOD > /sys/module/kvm/parameters/nx_huge_pages_recovery_period_ms > +echo $HUGE_PAGES > /sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages > + > +exit $RET > -- > 2.35.1.1178.g4f1659d476-goog >