From patchwork Mon Oct 17 19:58:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ricardo Koller X-Patchwork-Id: 13009408 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 22201C43219 for ; Mon, 17 Oct 2022 19:59:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229780AbiJQT7K (ORCPT ); Mon, 17 Oct 2022 15:59:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35110 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230494AbiJQT7G (ORCPT ); Mon, 17 Oct 2022 15:59:06 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D288479693 for ; Mon, 17 Oct 2022 12:58:56 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-348608c1cd3so121020107b3.10 for ; Mon, 17 Oct 2022 12:58:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=7ywyGD3FA1hbVSym0RQa+qQ9FZvJPbhq7Dc897jXRx8=; b=KBD+KHR6M95TrR+gIhM5YBDCeF/vs37j7IGCBcAXQ1NgaweOOsKWR+CjaXmR1odEyO cJ7QsLC1Q30dOnhaeDiEo7ErzFHxUwnq/G5SDo+npbBdlRl2H6XxCcWD5bz6BO7ww73e HRqucUd2ycfjdcD1ezEdySLh73NhtU7FDaeo0GNX5FxOJ8ckR7lC2lsCowvb2GlX4roP gqkD2iJKzeoc/1NKWEVcS2bYZLmF6yqroAI0h1IdDnDd6UCEBzKV4NbPq5T2aN0b+SC6 GB6KHperNEyPt/gB8iyFIUp2aODiNeRHyhPzvHDHGgXhXrDVUDxI8WPspZHflEjOnqMH 4Rrw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7ywyGD3FA1hbVSym0RQa+qQ9FZvJPbhq7Dc897jXRx8=; b=eFPsAz34h3roOLQs8QJOG0l1dG1T7SYGYwJRJDrC1Oxp9q0Mief0mYervYJypnvPlS vxT6QApclYXTNr7N+gH39aLrnABzoLg3cujkRdkj1nqwX8UH3r9sLgeHgUACm6eu2/h6 nAqZkcq9ofocj4mZZmrZZZ/Qim4RfJQk2IRk8cyVsJzAYJRzA6h6gjokAOkoknI1Wgwu Efm4YFJVL8ZEdHjinzZpRK+s7hOCHgvVvTOq5vsYw8TG7MQcgtUVjRzavgPdDO5efV4x kA51wCey4ZKpG3JbiIRE6MIRJbS4VPV9qyxB7E6hx1jEY9LNipLfVc23fHLF9hSfIcMy qJlA== X-Gm-Message-State: ACrzQf1aXraPTQWvlRNeEjwaWToq86Ye55EBebl02OgeAqxcM3gOYilK O1+Z7XVL711wKhKm3kJKYCjvske+3p1s+eNRzueTih6sPmExSLDA0dAIcVM89nnfr50CY2sFdM4 gbO+LRiX9LWFHgzKJKeMbdjWWQI0srAURB2KzKD8cbWm3whZl6Bi0ClhyIJS/fTI= X-Google-Smtp-Source: AMsMyM7s9+QJiqJ8E88WQaCW4OZFi8nRljdz6kWxSvHX55a1ltVrup8oPpK6J1++/HUOjcXFDTwPgrLvz7UIiw== X-Received: from ricarkol4.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:1248]) (user=ricarkol job=sendgmr) by 2002:a05:6902:709:b0:6bf:e5cc:343c with SMTP id k9-20020a056902070900b006bfe5cc343cmr10733833ybt.590.1666036735289; Mon, 17 Oct 2022 12:58:55 -0700 (PDT) Date: Mon, 17 Oct 2022 19:58:31 +0000 In-Reply-To: <20221017195834.2295901-1-ricarkol@google.com> Mime-Version: 1.0 References: <20221017195834.2295901-1-ricarkol@google.com> X-Mailer: git-send-email 2.38.0.413.g74048e4d9e-goog Message-ID: <20221017195834.2295901-12-ricarkol@google.com> Subject: [PATCH v10 11/14] KVM: selftests: aarch64: Add userfaultfd tests into page_fault_test From: Ricardo Koller To: kvm@vger.kernel.org, kvmarm@lists.linux.dev, kvmarm@lists.cs.columbia.edu, andrew.jones@linux.dev Cc: pbonzini@redhat.com, maz@kernel.org, seanjc@google.com, alexandru.elisei@arm.com, eric.auger@redhat.com, oupton@google.com, reijiw@google.com, rananta@google.com, bgardon@google.com, dmatlack@google.com, axelrasmussen@google.com, Ricardo Koller Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Add some userfaultfd tests into page_fault_test. Punch holes into the data and/or page-table memslots, perform some accesses, and check that the faults are taken (or not taken) when expected. Signed-off-by: Ricardo Koller --- .../selftests/kvm/aarch64/page_fault_test.c | 187 ++++++++++++++++++ 1 file changed, 187 insertions(+) diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c index 28859a96053f..8ecc2ac8c476 100644 --- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c +++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c @@ -35,6 +35,12 @@ static uint64_t *guest_test_memory = (uint64_t *)TEST_GVA; #define PREPARE_FN_NR 10 #define CHECK_FN_NR 10 +static struct event_cnt { + int uffd_faults; + /* uffd_faults is incremented from multiple threads. */ + pthread_mutex_t uffd_faults_mutex; +} events; + struct test_desc { const char *name; uint64_t mem_mark_cmd; @@ -42,11 +48,14 @@ struct test_desc { bool (*guest_prepare[PREPARE_FN_NR])(void); void (*guest_test)(void); void (*guest_test_check[CHECK_FN_NR])(void); + uffd_handler_t uffd_pt_handler; + uffd_handler_t uffd_data_handler; void (*dabt_handler)(struct ex_regs *regs); void (*iabt_handler)(struct ex_regs *regs); uint32_t pt_memslot_flags; uint32_t data_memslot_flags; bool skip; + struct event_cnt expected_events; }; struct test_params { @@ -263,7 +272,110 @@ static void no_iabt_handler(struct ex_regs *regs) GUEST_ASSERT_1(false, regs->pc); } +static struct uffd_args { + char *copy; + void *hva; + uint64_t paging_size; +} pt_args, data_args; + /* Returns true to continue the test, and false if it should be skipped. */ +static int uffd_generic_handler(int uffd_mode, int uffd, struct uffd_msg *msg, + struct uffd_args *args, bool expect_write) +{ + uint64_t addr = msg->arg.pagefault.address; + uint64_t flags = msg->arg.pagefault.flags; + struct uffdio_copy copy; + int ret; + + TEST_ASSERT(uffd_mode == UFFDIO_REGISTER_MODE_MISSING, + "The only expected UFFD mode is MISSING"); + ASSERT_EQ(!!(flags & UFFD_PAGEFAULT_FLAG_WRITE), expect_write); + ASSERT_EQ(addr, (uint64_t)args->hva); + + pr_debug("uffd fault: addr=%p write=%d\n", + (void *)addr, !!(flags & UFFD_PAGEFAULT_FLAG_WRITE)); + + copy.src = (uint64_t)args->copy; + copy.dst = addr; + copy.len = args->paging_size; + copy.mode = 0; + + ret = ioctl(uffd, UFFDIO_COPY, ©); + if (ret == -1) { + pr_info("Failed UFFDIO_COPY in 0x%lx with errno: %d\n", + addr, errno); + return ret; + } + + pthread_mutex_lock(&events.uffd_faults_mutex); + events.uffd_faults += 1; + pthread_mutex_unlock(&events.uffd_faults_mutex); + return 0; +} + +static int uffd_pt_write_handler(int mode, int uffd, struct uffd_msg *msg) +{ + return uffd_generic_handler(mode, uffd, msg, &pt_args, true); +} + +static int uffd_data_write_handler(int mode, int uffd, struct uffd_msg *msg) +{ + return uffd_generic_handler(mode, uffd, msg, &data_args, true); +} + +static int uffd_data_read_handler(int mode, int uffd, struct uffd_msg *msg) +{ + return uffd_generic_handler(mode, uffd, msg, &data_args, false); +} + +static void setup_uffd_args(struct userspace_mem_region *region, + struct uffd_args *args) +{ + args->hva = (void *)region->region.userspace_addr; + args->paging_size = region->region.memory_size; + + args->copy = malloc(args->paging_size); + TEST_ASSERT(args->copy, "Failed to allocate data copy."); + memcpy(args->copy, args->hva, args->paging_size); +} + +static void setup_uffd(struct kvm_vm *vm, struct test_params *p, + struct uffd_desc **pt_uffd, struct uffd_desc **data_uffd) +{ + struct test_desc *test = p->test_desc; + int uffd_mode = UFFDIO_REGISTER_MODE_MISSING; + + setup_uffd_args(vm_get_mem_region(vm, MEM_REGION_PT), &pt_args); + setup_uffd_args(vm_get_mem_region(vm, MEM_REGION_TEST_DATA), &data_args); + + *pt_uffd = NULL; + if (test->uffd_pt_handler) + *pt_uffd = uffd_setup_demand_paging(uffd_mode, 0, + pt_args.hva, + pt_args.paging_size, + test->uffd_pt_handler); + + *data_uffd = NULL; + if (test->uffd_data_handler) + *data_uffd = uffd_setup_demand_paging(uffd_mode, 0, + data_args.hva, + data_args.paging_size, + test->uffd_data_handler); +} + +static void free_uffd(struct test_desc *test, struct uffd_desc *pt_uffd, + struct uffd_desc *data_uffd) +{ + if (test->uffd_pt_handler) + uffd_stop_demand_paging(pt_uffd); + if (test->uffd_data_handler) + uffd_stop_demand_paging(data_uffd); + + free(pt_args.copy); + free(data_args.copy); +} + +/* Returns false if the test should be skipped. */ static bool punch_hole_in_backing_store(struct kvm_vm *vm, struct userspace_mem_region *region) { @@ -404,6 +516,11 @@ static void setup_memslots(struct kvm_vm *vm, struct test_params *p) vm->memslots[MEM_REGION_TEST_DATA] = TEST_DATA_MEMSLOT; } +static void check_event_counts(struct test_desc *test) +{ + ASSERT_EQ(test->expected_events.uffd_faults, events.uffd_faults); +} + static void print_test_banner(enum vm_guest_mode mode, struct test_params *p) { struct test_desc *test = p->test_desc; @@ -414,6 +531,11 @@ static void print_test_banner(enum vm_guest_mode mode, struct test_params *p) vm_mem_backing_src_alias(p->src_type)->name); } +static void reset_event_counts(void) +{ + memset(&events, 0, sizeof(events)); +} + /* * This function either succeeds, skips the test (after setting test->skip), or * fails with a TEST_FAIL that aborts all tests. @@ -453,6 +575,7 @@ static void run_test(enum vm_guest_mode mode, void *arg) struct test_desc *test = p->test_desc; struct kvm_vm *vm; struct kvm_vcpu *vcpu; + struct uffd_desc *pt_uffd, *data_uffd; print_test_banner(mode, p); @@ -465,7 +588,16 @@ static void run_test(enum vm_guest_mode mode, void *arg) ucall_init(vm, NULL); + reset_event_counts(); + + /* + * Set some code in the data memslot for the guest to execute (only + * applicable to the EXEC tests). This has to be done before + * setup_uffd() as that function copies the memslot data for the uffd + * handler. + */ load_exec_code_for_test(vm); + setup_uffd(vm, p, &pt_uffd, &data_uffd); setup_abort_handlers(vm, vcpu, test); vcpu_args_set(vcpu, 1, test); @@ -473,6 +605,14 @@ static void run_test(enum vm_guest_mode mode, void *arg) ucall_uninit(vm); kvm_vm_free(vm); + free_uffd(test, pt_uffd, data_uffd); + + /* + * Make sure we check the events after the uffd threads have exited, + * which means they updated their respective event counters. + */ + if (!test->skip) + check_event_counts(test); } static void help(char *name) @@ -488,6 +628,7 @@ static void help(char *name) #define SNAME(s) #s #define SCAT2(a, b) SNAME(a ## _ ## b) #define SCAT3(a, b, c) SCAT2(a, SCAT2(b, c)) +#define SCAT4(a, b, c, d) SCAT2(a, SCAT3(b, c, d)) #define _CHECK(_test) _CHECK_##_test #define _PREPARE(_test) _PREPARE_##_test @@ -515,6 +656,21 @@ static void help(char *name) .mem_mark_cmd = _mark_cmd, \ .guest_test = _access, \ .guest_test_check = { _CHECK(_with_af) }, \ + .expected_events = { 0 }, \ +} + +#define TEST_UFFD(_access, _with_af, _mark_cmd, \ + _uffd_data_handler, _uffd_pt_handler, _uffd_faults) \ +{ \ + .name = SCAT4(uffd, _access, _with_af, #_mark_cmd), \ + .guest_prepare = { _PREPARE(_with_af), \ + _PREPARE(_access) }, \ + .guest_test = _access, \ + .mem_mark_cmd = _mark_cmd, \ + .guest_test_check = { _CHECK(_with_af) }, \ + .uffd_data_handler = _uffd_data_handler, \ + .uffd_pt_handler = _uffd_pt_handler, \ + .expected_events = { .uffd_faults = _uffd_faults, }, \ } static struct test_desc tests[] = { @@ -545,6 +701,37 @@ static struct test_desc tests[] = { TEST_ACCESS(guest_at, no_af, CMD_HOLE_DATA), TEST_ACCESS(guest_dc_zva, no_af, CMD_HOLE_DATA), + /* + * Punch holes in the data and PT backing stores and mark them for + * userfaultfd handling. This should result in 2 faults: the access + * on the data backing store, and its respective S1 page table walk + * (S1PTW). + */ + TEST_UFFD(guest_read64, with_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_read_handler, uffd_pt_write_handler, 2), + /* no_af should also lead to a PT write. */ + TEST_UFFD(guest_read64, no_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_read_handler, uffd_pt_write_handler, 2), + /* Note how that cas invokes the read handler. */ + TEST_UFFD(guest_cas, with_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_read_handler, uffd_pt_write_handler, 2), + /* + * Can't test guest_at with_af as it's IMPDEF whether the AF is set. + * The S1PTW fault should still be marked as a write. + */ + TEST_UFFD(guest_at, no_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_read_handler, uffd_pt_write_handler, 1), + TEST_UFFD(guest_ld_preidx, with_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_read_handler, uffd_pt_write_handler, 2), + TEST_UFFD(guest_write64, with_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_write_handler, uffd_pt_write_handler, 2), + TEST_UFFD(guest_dc_zva, with_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_write_handler, uffd_pt_write_handler, 2), + TEST_UFFD(guest_st_preidx, with_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_write_handler, uffd_pt_write_handler, 2), + TEST_UFFD(guest_exec, with_af, CMD_HOLE_DATA | CMD_HOLE_PT, + uffd_data_read_handler, uffd_pt_write_handler, 2), + { 0 } };