From patchwork Tue May 17 19:05:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Matlack X-Patchwork-Id: 12852905 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 D38EBC433FE for ; Tue, 17 May 2022 19:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351442AbiEQTFr (ORCPT ); Tue, 17 May 2022 15:05:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42320 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1352516AbiEQTFo (ORCPT ); Tue, 17 May 2022 15:05:44 -0400 Received: from mail-pf1-x449.google.com (mail-pf1-x449.google.com [IPv6:2607:f8b0:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 64896E8 for ; Tue, 17 May 2022 12:05:42 -0700 (PDT) Received: by mail-pf1-x449.google.com with SMTP id p18-20020aa78612000000b0050d1c170018so8107803pfn.15 for ; Tue, 17 May 2022 12:05:42 -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=GHdmigCWoJn3h4Ms4W+5m3/D0YUe4bVjbE0mjuDmz4c=; b=LBJ5sDo39urAAyFbQznRrEIDfZqGo9Dc1xuE9faD1aR1ha6Xf2o2146NiI8CeYtU+R 29U2uKKZ95LgRHdAnv7qz9eTHNKUVP1jsGWZ3Bo2gFkYzv2JhbpfKGw8srmzZjvEYw0e wx9EvArrvIwCPEtkAyh9FFkwCGSQUq2qRGQN3HJRzGmyin/BlRai+cZDoJv+r6VN2o3m j9RgPYYsOhNxeQVMTU/iZff7D92wfjHrQTJEFBnHqhqb+KWVT/0ZNIL9jyjnT/EEaraY 5CwZRuAe2mpIVe0hiUDFbGCv1INpF0HQX/IUTjyie/vRgenvqpYL6kKN3EWQgaIV5Nhl I8aQ== 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=GHdmigCWoJn3h4Ms4W+5m3/D0YUe4bVjbE0mjuDmz4c=; b=Xyp9tdRkcz2gRDslBhCUQcyeTRTTW7XKeSisdeLi7x0EzdnlT6QdnH9inNTVcKa0H3 7en2I97YWcpbykDzhyfcdxWldtwjNxuWTNc+BrHwVahhdz5/02aO1I94DfTD19lOdGeO kN6q/apdu0x9VAILa3nmcvqO6Bae4R6ETpkGu+OK94NN2PGLDjy8PaLs/hL15J57KKyu ljqoXMF8UzcbXb2HW2HvRIJ+IHXy3dfe9fTCM/zW2UsEh/yn9rO2r3RNUjnCZ42GVD8+ VjLgDGxazk74Zm8wm9WOD7a+3dBUpxhePHW2jCuT6Weso64F6x+kbde3lRD/lRg2xMzp xn+w== X-Gm-Message-State: AOAM5309efIq3JTgD4ei1t7QXYpoBdyU2SXuMVnkr7RsZAGKF6DVJ6G8 vX1NjuzCG15eiTE6zfrVfdgqRtLt3aegDw== X-Google-Smtp-Source: ABdhPJw/FK+Fd3N51diYnp8p8PGn0SqQOGLLFv/Egk451j9l/GMqByWbwhBhSoKvj/dox+aNmy1zNXT9E3Ejvg== X-Received: from dmatlack-heavy.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:19cd]) (user=dmatlack job=sendgmr) by 2002:a65:5bcc:0:b0:3c5:fff8:a6a6 with SMTP id o12-20020a655bcc000000b003c5fff8a6a6mr20979273pgr.48.1652814341850; Tue, 17 May 2022 12:05:41 -0700 (PDT) Date: Tue, 17 May 2022 19:05:24 +0000 In-Reply-To: <20220517190524.2202762-1-dmatlack@google.com> Message-Id: <20220517190524.2202762-11-dmatlack@google.com> Mime-Version: 1.0 References: <20220517190524.2202762-1-dmatlack@google.com> X-Mailer: git-send-email 2.36.0.550.gb090851708-goog Subject: [PATCH v2 10/10] KVM: selftests: Add option to run dirty_log_perf_test vCPUs in L2 From: David Matlack To: Paolo Bonzini Cc: Ben Gardon , Sean Christopherson , Oliver Upton , Peter Xu , Vitaly Kuznetsov , Andrew Jones , "open list:KERNEL VIRTUAL MACHINE (KVM)" , David Matlack Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Add an option to dirty_log_perf_test that configures the vCPUs to run in L2 instead of L1. This makes it possible to benchmark the dirty logging performance of nested virtualization, which is particularly interesting because KVM must shadow L1's EPT/NPT tables. For now this support only works on x86_64 CPUs with VMX. Otherwise passing -n results in the test being skipped. Signed-off-by: David Matlack --- tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/dirty_log_perf_test.c | 10 +- .../selftests/kvm/include/perf_test_util.h | 7 ++ .../selftests/kvm/include/x86_64/vmx.h | 3 + .../selftests/kvm/lib/perf_test_util.c | 29 +++++- .../selftests/kvm/lib/x86_64/perf_test_util.c | 98 +++++++++++++++++++ tools/testing/selftests/kvm/lib/x86_64/vmx.c | 13 +++ 7 files changed, 154 insertions(+), 7 deletions(-) create mode 100644 tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 83b9ffa456ea..42cb904f6e54 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -49,6 +49,7 @@ LIBKVM += lib/test_util.c LIBKVM_x86_64 += lib/x86_64/apic.c LIBKVM_x86_64 += lib/x86_64/handlers.S +LIBKVM_x86_64 += lib/x86_64/perf_test_util.c LIBKVM_x86_64 += lib/x86_64/processor.c LIBKVM_x86_64 += lib/x86_64/svm.c LIBKVM_x86_64 += lib/x86_64/ucall.c diff --git a/tools/testing/selftests/kvm/dirty_log_perf_test.c b/tools/testing/selftests/kvm/dirty_log_perf_test.c index 7b47ae4f952e..d60a34cdfaee 100644 --- a/tools/testing/selftests/kvm/dirty_log_perf_test.c +++ b/tools/testing/selftests/kvm/dirty_log_perf_test.c @@ -336,8 +336,8 @@ static void run_test(enum vm_guest_mode mode, void *arg) static void help(char *name) { puts(""); - printf("usage: %s [-h] [-i iterations] [-p offset] [-g]" - "[-m mode] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" + printf("usage: %s [-h] [-i iterations] [-p offset] [-g] " + "[-m mode] [-n] [-b vcpu bytes] [-v vcpus] [-o] [-s mem type]" "[-x memslots]\n", name); puts(""); printf(" -i: specify iteration counts (default: %"PRIu64")\n", @@ -351,6 +351,7 @@ static void help(char *name) printf(" -p: specify guest physical test memory offset\n" " Warning: a low offset can conflict with the loaded test code.\n"); guest_modes_help(); + printf(" -n: Run the vCPUs in nested mode (L2)\n"); printf(" -b: specify the size of the memory region which should be\n" " dirtied by each vCPU. e.g. 10M or 3G.\n" " (default: 1G)\n"); @@ -387,7 +388,7 @@ int main(int argc, char *argv[]) guest_modes_append_default(); - while ((opt = getopt(argc, argv, "ghi:p:m:b:f:v:os:x:")) != -1) { + while ((opt = getopt(argc, argv, "ghi:p:m:nb:f:v:os:x:")) != -1) { switch (opt) { case 'g': dirty_log_manual_caps = 0; @@ -401,6 +402,9 @@ int main(int argc, char *argv[]) case 'm': guest_modes_cmdline(optarg); break; + case 'n': + perf_test_args.nested = true; + break; case 'b': guest_percpu_mem_size = parse_size(optarg); break; diff --git a/tools/testing/selftests/kvm/include/perf_test_util.h b/tools/testing/selftests/kvm/include/perf_test_util.h index a86f953d8d36..b6c1770ab831 100644 --- a/tools/testing/selftests/kvm/include/perf_test_util.h +++ b/tools/testing/selftests/kvm/include/perf_test_util.h @@ -34,6 +34,9 @@ struct perf_test_args { uint64_t guest_page_size; int wr_fract; + /* Run vCPUs in L2 instead of L1, if the architecture supports it. */ + bool nested; + struct perf_test_vcpu_args vcpu_args[KVM_MAX_VCPUS]; }; @@ -49,5 +52,9 @@ void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract); void perf_test_start_vcpu_threads(int vcpus, void (*vcpu_fn)(struct perf_test_vcpu_args *)); void perf_test_join_vcpu_threads(int vcpus); +void perf_test_guest_code(uint32_t vcpu_id); + +uint64_t perf_test_nested_pages(int nr_vcpus); +void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus); #endif /* SELFTEST_KVM_PERF_TEST_UTIL_H */ diff --git a/tools/testing/selftests/kvm/include/x86_64/vmx.h b/tools/testing/selftests/kvm/include/x86_64/vmx.h index 3b1794baa97c..17d712503a36 100644 --- a/tools/testing/selftests/kvm/include/x86_64/vmx.h +++ b/tools/testing/selftests/kvm/include/x86_64/vmx.h @@ -96,6 +96,7 @@ #define VMX_MISC_PREEMPTION_TIMER_RATE_MASK 0x0000001f #define VMX_MISC_SAVE_EFER_LMA 0x00000020 +#define VMX_EPT_VPID_CAP_1G_PAGES 0x00020000 #define VMX_EPT_VPID_CAP_AD_BITS 0x00200000 #define EXIT_REASON_FAILED_VMENTRY 0x80000000 @@ -608,6 +609,7 @@ bool load_vmcs(struct vmx_pages *vmx); bool nested_vmx_supported(void); void nested_vmx_check_supported(void); +bool ept_1g_pages_supported(void); void nested_pg_map(struct vmx_pages *vmx, struct kvm_vm *vm, uint64_t nested_paddr, uint64_t paddr); @@ -615,6 +617,7 @@ void nested_map(struct vmx_pages *vmx, struct kvm_vm *vm, uint64_t nested_paddr, uint64_t paddr, uint64_t size); void nested_map_memslot(struct vmx_pages *vmx, struct kvm_vm *vm, uint32_t memslot); +void nested_map_all_1g(struct vmx_pages *vmx, struct kvm_vm *vm); void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm, uint32_t eptp_memslot); void prepare_virtualize_apic_accesses(struct vmx_pages *vmx, struct kvm_vm *vm); diff --git a/tools/testing/selftests/kvm/lib/perf_test_util.c b/tools/testing/selftests/kvm/lib/perf_test_util.c index 722df3a28791..530be01706d5 100644 --- a/tools/testing/selftests/kvm/lib/perf_test_util.c +++ b/tools/testing/selftests/kvm/lib/perf_test_util.c @@ -40,7 +40,7 @@ static bool all_vcpu_threads_running; * Continuously write to the first 8 bytes of each page in the * specified region. */ -static void guest_code(uint32_t vcpu_id) +void perf_test_guest_code(uint32_t vcpu_id) { struct perf_test_args *pta = &perf_test_args; struct perf_test_vcpu_args *vcpu_args = &pta->vcpu_args[vcpu_id]; @@ -108,7 +108,7 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, { struct perf_test_args *pta = &perf_test_args; struct kvm_vm *vm; - uint64_t guest_num_pages; + uint64_t guest_num_pages, slot0_pages = DEFAULT_GUEST_PHY_PAGES; uint64_t backing_src_pagesz = get_backing_src_pagesz(backing_src); int i; @@ -134,13 +134,20 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, "Guest memory cannot be evenly divided into %d slots.", slots); + /* + * If using nested, allocate extra pages for the nested page tables and + * in-memory data structures. + */ + if (pta->nested) + slot0_pages += perf_test_nested_pages(vcpus); + /* * Pass guest_num_pages to populate the page tables for test memory. * The memory is also added to memslot 0, but that's a benign side * effect as KVM allows aliasing HVAs in meslots. */ - vm = vm_create_with_vcpus(mode, vcpus, DEFAULT_GUEST_PHY_PAGES, - guest_num_pages, 0, guest_code, NULL); + vm = vm_create_with_vcpus(mode, vcpus, slot0_pages, guest_num_pages, 0, + perf_test_guest_code, NULL); pta->vm = vm; @@ -178,6 +185,9 @@ struct kvm_vm *perf_test_create_vm(enum vm_guest_mode mode, int vcpus, perf_test_setup_vcpus(vm, vcpus, vcpu_memory_bytes, partition_vcpu_memory_access); + if (pta->nested) + perf_test_setup_nested(vm, vcpus); + ucall_init(vm, NULL); /* Export the shared variables to the guest. */ @@ -198,6 +208,17 @@ void perf_test_set_wr_fract(struct kvm_vm *vm, int wr_fract) sync_global_to_guest(vm, perf_test_args); } +uint64_t __weak perf_test_nested_pages(int nr_vcpus) +{ + return 0; +} + +void __weak perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus) +{ + pr_info("%s() not support on this architecture, skipping.\n", __func__); + exit(KSFT_SKIP); +} + static void *vcpu_thread_main(void *data) { struct vcpu_thread *vcpu = data; diff --git a/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c b/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c new file mode 100644 index 000000000000..472e7d5a182b --- /dev/null +++ b/tools/testing/selftests/kvm/lib/x86_64/perf_test_util.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * x86_64-specific extensions to perf_test_util.c. + * + * Copyright (C) 2022, Google, Inc. + */ +#include +#include +#include +#include + +#include "test_util.h" +#include "kvm_util.h" +#include "perf_test_util.h" +#include "../kvm_util_internal.h" +#include "processor.h" +#include "vmx.h" + +void perf_test_l2_guest_code(uint64_t vcpu_id) +{ + perf_test_guest_code(vcpu_id); + vmcall(); +} + +extern char perf_test_l2_guest_entry[]; +__asm__( +"perf_test_l2_guest_entry:" +" mov (%rsp), %rdi;" +" call perf_test_l2_guest_code;" +" ud2;" +); + +static void perf_test_l1_guest_code(struct vmx_pages *vmx, uint64_t vcpu_id) +{ +#define L2_GUEST_STACK_SIZE 64 + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; + unsigned long *rsp; + + GUEST_ASSERT(vmx->vmcs_gpa); + GUEST_ASSERT(prepare_for_vmx_operation(vmx)); + GUEST_ASSERT(load_vmcs(vmx)); + GUEST_ASSERT(ept_1g_pages_supported()); + + rsp = &l2_guest_stack[L2_GUEST_STACK_SIZE - 1]; + *rsp = vcpu_id; + prepare_vmcs(vmx, perf_test_l2_guest_entry, rsp); + + GUEST_ASSERT(!vmlaunch()); + GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL); + GUEST_DONE(); +} + +uint64_t perf_test_nested_pages(int nr_vcpus) +{ + /* + * 513 page tables to identity-map the L2 with 1G pages, plus a few + * pages per-vCPU for data structures such as the VMCS. + */ + return 513 + 10 * nr_vcpus; +} + +void perf_test_setup_nested(struct kvm_vm *vm, int nr_vcpus) +{ + struct vmx_pages *vmx, *vmx0 = NULL; + struct kvm_regs regs; + vm_vaddr_t vmx_gva; + int vcpu_id; + + nested_vmx_check_supported(); + + for (vcpu_id = 0; vcpu_id < nr_vcpus; vcpu_id++) { + vmx = vcpu_alloc_vmx(vm, &vmx_gva); + + if (vcpu_id == 0) { + prepare_eptp(vmx, vm, 0); + /* + * Identity map L2 with 1G pages so that KVM can shadow + * the EPT12 with huge pages. + */ + nested_map_all_1g(vmx, vm); + vmx0 = vmx; + } else { + /* Share the same EPT table across all vCPUs. */ + vmx->eptp = vmx0->eptp; + vmx->eptp_hva = vmx0->eptp_hva; + vmx->eptp_gpa = vmx0->eptp_gpa; + } + + /* + * Override the vCPU to run perf_test_l1_guest_code() which will + * bounce it into L2 before calling perf_test_guest_code(). + */ + vcpu_regs_get(vm, vcpu_id, ®s); + regs.rip = (unsigned long) perf_test_l1_guest_code; + vcpu_regs_set(vm, vcpu_id, ®s); + vcpu_args_set(vm, vcpu_id, 2, vmx_gva, vcpu_id); + } +} diff --git a/tools/testing/selftests/kvm/lib/x86_64/vmx.c b/tools/testing/selftests/kvm/lib/x86_64/vmx.c index 5bf169179455..9858e56370cb 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/vmx.c +++ b/tools/testing/selftests/kvm/lib/x86_64/vmx.c @@ -203,6 +203,11 @@ static bool ept_vpid_cap_supported(uint64_t mask) return rdmsr(MSR_IA32_VMX_EPT_VPID_CAP) & mask; } +bool ept_1g_pages_supported(void) +{ + return ept_vpid_cap_supported(VMX_EPT_VPID_CAP_1G_PAGES); +} + /* * Initialize the control fields to the most basic settings possible. */ @@ -547,6 +552,14 @@ void nested_map_memslot(struct vmx_pages *vmx, struct kvm_vm *vm, } } +/* Identity map the entire guest physical address space with 1GiB Pages. */ +void nested_map_all_1g(struct vmx_pages *vmx, struct kvm_vm *vm) +{ + uint64_t gpa_size = (vm->max_gfn + 1) << vm->page_shift; + + __nested_map(vmx, vm, 0, 0, gpa_size, PG_LEVEL_1G); +} + void prepare_eptp(struct vmx_pages *vmx, struct kvm_vm *vm, uint32_t eptp_memslot) {