Re: [PATCH v4 09/34] KVM: selftests: Add a selftest for guest prints and formatted asserts
From: Andrew Jones
Date: Mon Jul 31 2023 - 12:32:16 EST
On Fri, Jul 28, 2023 at 05:36:18PM -0700, Sean Christopherson wrote:
> From: Aaron Lewis <aaronlewis@xxxxxxxxxx>
>
> Add a test to exercise the various features in KVM selftest's local
> snprintf() and compare them to LIBC's snprintf() to ensure they behave
> the same.
>
> This is not an exhaustive test. KVM's local snprintf() does not
> implement all the features LIBC does, e.g. KVM's local snprintf() does
> not support floats or doubles, so testing for those features were
> excluded.
>
> Testing was added for the features that are expected to work to
> support a minimal version of printf() in the guest.
>
> Signed-off-by: Aaron Lewis <aaronlewis@xxxxxxxxxx>
> Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/Makefile | 1 +
> .../testing/selftests/kvm/guest_print_test.c | 223 ++++++++++++++++++
> 2 files changed, 224 insertions(+)
> create mode 100644 tools/testing/selftests/kvm/guest_print_test.c
I added this diff to this patch
diff --git a/tools/testing/selftests/kvm/guest_print_test.c b/tools/testing/selftests/kvm/guest_print_test.c
index 3a9a5db9794e..602a23ea9f01 100644
--- a/tools/testing/selftests/kvm/guest_print_test.c
+++ b/tools/testing/selftests/kvm/guest_print_test.c
@@ -115,7 +115,7 @@ static void run_test(struct kvm_vcpu *vcpu, const char *expected_printf,
while (1) {
vcpu_run(vcpu);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+ TEST_ASSERT(run->exit_reason == UCALL_EXIT_REASON,
"Unexpected exit reason: %u (%s),\n",
run->exit_reason,
exit_reason_str(run->exit_reason));
@@ -161,7 +161,7 @@ static void test_limits(void)
run = vcpu->run;
vcpu_run(vcpu);
- TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
+ TEST_ASSERT(run->exit_reason == UCALL_EXIT_REASON,
"Unexpected exit reason: %u (%s),\n",
run->exit_reason,
exit_reason_str(run->exit_reason));
diff --git a/tools/testing/selftests/kvm/include/ucall_common.h b/tools/testing/selftests/kvm/include/ucall_common.h
index 4cf69fa8bfba..4adf526dc378 100644
--- a/tools/testing/selftests/kvm/include/ucall_common.h
+++ b/tools/testing/selftests/kvm/include/ucall_common.h
@@ -6,8 +6,19 @@
*/
#ifndef SELFTEST_KVM_UCALL_COMMON_H
#define SELFTEST_KVM_UCALL_COMMON_H
+#include <linux/kvm.h>
#include "test_util.h"
+#if defined(__aarch64__)
+#define UCALL_EXIT_REASON KVM_EXIT_MMIO
+#elif defined(__x86_64__)
+#define UCALL_EXIT_REASON KVM_EXIT_IO
+#elif defined(__s390x__)
+#define UCALL_EXIT_REASON KVM_EXIT_S390_SIEIC
+#elif defined(__riscv)
+#define UCALL_EXIT_REASON KVM_EXIT_RISCV_SBI
+#endif
+
/* Common ucalls */
enum {
UCALL_NONE,
and then compiled the test for riscv and it passed. I also ran all other
riscv tests successfully.
Thanks,
drew
>
> diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
> index f65889f5a083..f2a8b3262f17 100644
> --- a/tools/testing/selftests/kvm/Makefile
> +++ b/tools/testing/selftests/kvm/Makefile
> @@ -123,6 +123,7 @@ TEST_GEN_PROGS_x86_64 += access_tracking_perf_test
> TEST_GEN_PROGS_x86_64 += demand_paging_test
> TEST_GEN_PROGS_x86_64 += dirty_log_test
> TEST_GEN_PROGS_x86_64 += dirty_log_perf_test
> +TEST_GEN_PROGS_x86_64 += guest_print_test
> TEST_GEN_PROGS_x86_64 += hardware_disable_test
> TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
> TEST_GEN_PROGS_x86_64 += kvm_page_table_test
> diff --git a/tools/testing/selftests/kvm/guest_print_test.c b/tools/testing/selftests/kvm/guest_print_test.c
> new file mode 100644
> index 000000000000..777838d42427
> --- /dev/null
> +++ b/tools/testing/selftests/kvm/guest_print_test.c
> @@ -0,0 +1,223 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * A test for GUEST_PRINTF
> + *
> + * Copyright 2022, Google, Inc. and/or its affiliates.
> + */
> +#define USE_GUEST_ASSERT_PRINTF 1
> +
> +#include <fcntl.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <sys/ioctl.h>
> +
> +#include "test_util.h"
> +#include "kvm_util.h"
> +#include "processor.h"
> +
> +struct guest_vals {
> + uint64_t a;
> + uint64_t b;
> + uint64_t type;
> +};
> +
> +static struct guest_vals vals;
> +
> +/* GUEST_PRINTF()/GUEST_ASSERT_FMT() does not support float or double. */
> +#define TYPE_LIST \
> +TYPE(test_type_i64, I64, "%ld", int64_t) \
> +TYPE(test_type_u64, U64u, "%lu", uint64_t) \
> +TYPE(test_type_x64, U64x, "0x%lx", uint64_t) \
> +TYPE(test_type_X64, U64X, "0x%lX", uint64_t) \
> +TYPE(test_type_u32, U32u, "%u", uint32_t) \
> +TYPE(test_type_x32, U32x, "0x%x", uint32_t) \
> +TYPE(test_type_X32, U32X, "0x%X", uint32_t) \
> +TYPE(test_type_int, INT, "%d", int) \
> +TYPE(test_type_char, CHAR, "%c", char) \
> +TYPE(test_type_str, STR, "'%s'", const char *) \
> +TYPE(test_type_ptr, PTR, "%p", uintptr_t)
> +
> +enum args_type {
> +#define TYPE(fn, ext, fmt_t, T) TYPE_##ext,
> + TYPE_LIST
> +#undef TYPE
> +};
> +
> +static void run_test(struct kvm_vcpu *vcpu, const char *expected_printf,
> + const char *expected_assert);
> +
> +#define BUILD_TYPE_STRINGS_AND_HELPER(fn, ext, fmt_t, T) \
> +const char *PRINTF_FMT_##ext = "Got params a = " fmt_t " and b = " fmt_t; \
> +const char *ASSERT_FMT_##ext = "Expected " fmt_t ", got " fmt_t " instead"; \
> +static void fn(struct kvm_vcpu *vcpu, T a, T b) \
> +{ \
> + char expected_printf[UCALL_BUFFER_LEN]; \
> + char expected_assert[UCALL_BUFFER_LEN]; \
> + \
> + snprintf(expected_printf, UCALL_BUFFER_LEN, PRINTF_FMT_##ext, a, b); \
> + snprintf(expected_assert, UCALL_BUFFER_LEN, ASSERT_FMT_##ext, a, b); \
> + vals = (struct guest_vals){ (uint64_t)a, (uint64_t)b, TYPE_##ext }; \
> + sync_global_to_guest(vcpu->vm, vals); \
> + run_test(vcpu, expected_printf, expected_assert); \
> +}
> +
> +#define TYPE(fn, ext, fmt_t, T) \
> + BUILD_TYPE_STRINGS_AND_HELPER(fn, ext, fmt_t, T)
> + TYPE_LIST
> +#undef TYPE
> +
> +static void guest_code(void)
> +{
> + while (1) {
> + switch (vals.type) {
> +#define TYPE(fn, ext, fmt_t, T) \
> + case TYPE_##ext: \
> + GUEST_PRINTF(PRINTF_FMT_##ext, vals.a, vals.b); \
> + __GUEST_ASSERT(vals.a == vals.b, \
> + ASSERT_FMT_##ext, vals.a, vals.b); \
> + break;
> + TYPE_LIST
> +#undef TYPE
> + default:
> + GUEST_SYNC(vals.type);
> + }
> +
> + GUEST_DONE();
> + }
> +}
> +
> +/*
> + * Unfortunately this gets a little messy because 'assert_msg' doesn't
> + * just contains the matching string, it also contains additional assert
> + * info. Fortunately the part that matches should be at the very end of
> + * 'assert_msg'.
> + */
> +static void ucall_abort(const char *assert_msg, const char *expected_assert_msg)
> +{
> + int len_str = strlen(assert_msg);
> + int len_substr = strlen(expected_assert_msg);
> + int offset = len_str - len_substr;
> +
> + TEST_ASSERT(len_substr <= len_str,
> + "Expected '%s' to be a substring of '%s'\n",
> + assert_msg, expected_assert_msg);
> +
> + TEST_ASSERT(strcmp(&assert_msg[offset], expected_assert_msg) == 0,
> + "Unexpected mismatch. Expected: '%s', got: '%s'",
> + expected_assert_msg, &assert_msg[offset]);
> +}
> +
> +static void run_test(struct kvm_vcpu *vcpu, const char *expected_printf,
> + const char *expected_assert)
> +{
> + struct kvm_run *run = vcpu->run;
> + struct ucall uc;
> +
> + while (1) {
> + vcpu_run(vcpu);
> +
> + TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
> + "Unexpected exit reason: %u (%s),\n",
> + run->exit_reason,
> + exit_reason_str(run->exit_reason));
> +
> + switch (get_ucall(vcpu, &uc)) {
> + case UCALL_SYNC:
> + TEST_FAIL("Unknown 'args_type' = %lu", uc.args[1]);
> + break;
> + case UCALL_PRINTF:
> + TEST_ASSERT(strcmp(uc.buffer, expected_printf) == 0,
> + "Unexpected mismatch. Expected: '%s', got: '%s'",
> + expected_printf, uc.buffer);
> + break;
> + case UCALL_ABORT:
> + ucall_abort(uc.buffer, expected_assert);
> + break;
> + case UCALL_DONE:
> + return;
> + default:
> + TEST_FAIL("Unknown ucall %lu", uc.cmd);
> + }
> + }
> +}
> +
> +static void guest_code_limits(void)
> +{
> + char test_str[UCALL_BUFFER_LEN + 10];
> +
> + memset(test_str, 'a', sizeof(test_str));
> + test_str[sizeof(test_str) - 1] = 0;
> +
> + GUEST_PRINTF("%s", test_str);
> +}
> +
> +static void test_limits(void)
> +{
> + struct kvm_vcpu *vcpu;
> + struct kvm_run *run;
> + struct kvm_vm *vm;
> + struct ucall uc;
> +
> + vm = vm_create_with_one_vcpu(&vcpu, guest_code_limits);
> + run = vcpu->run;
> + vcpu_run(vcpu);
> +
> + TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
> + "Unexpected exit reason: %u (%s),\n",
> + run->exit_reason,
> + exit_reason_str(run->exit_reason));
> +
> + TEST_ASSERT(get_ucall(vcpu, &uc) == UCALL_ABORT,
> + "Unexpected ucall command: %lu, Expected: %u (UCALL_ABORT)\n",
> + uc.cmd, UCALL_ABORT);
> +
> + kvm_vm_free(vm);
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + struct kvm_vcpu *vcpu;
> + struct kvm_vm *vm;
> +
> + vm = vm_create_with_one_vcpu(&vcpu, guest_code);
> +
> + test_type_i64(vcpu, -1, -1);
> + test_type_i64(vcpu, -1, 1);
> + test_type_i64(vcpu, 0x1234567890abcdef, 0x1234567890abcdef);
> + test_type_i64(vcpu, 0x1234567890abcdef, 0x1234567890abcdee);
> +
> + test_type_u64(vcpu, 0x1234567890abcdef, 0x1234567890abcdef);
> + test_type_u64(vcpu, 0x1234567890abcdef, 0x1234567890abcdee);
> + test_type_x64(vcpu, 0x1234567890abcdef, 0x1234567890abcdef);
> + test_type_x64(vcpu, 0x1234567890abcdef, 0x1234567890abcdee);
> + test_type_X64(vcpu, 0x1234567890abcdef, 0x1234567890abcdef);
> + test_type_X64(vcpu, 0x1234567890abcdef, 0x1234567890abcdee);
> +
> + test_type_u32(vcpu, 0x90abcdef, 0x90abcdef);
> + test_type_u32(vcpu, 0x90abcdef, 0x90abcdee);
> + test_type_x32(vcpu, 0x90abcdef, 0x90abcdef);
> + test_type_x32(vcpu, 0x90abcdef, 0x90abcdee);
> + test_type_X32(vcpu, 0x90abcdef, 0x90abcdef);
> + test_type_X32(vcpu, 0x90abcdef, 0x90abcdee);
> +
> + test_type_int(vcpu, -1, -1);
> + test_type_int(vcpu, -1, 1);
> + test_type_int(vcpu, 1, 1);
> +
> + test_type_char(vcpu, 'a', 'a');
> + test_type_char(vcpu, 'a', 'A');
> + test_type_char(vcpu, 'a', 'b');
> +
> + test_type_str(vcpu, "foo", "foo");
> + test_type_str(vcpu, "foo", "bar");
> +
> + test_type_ptr(vcpu, 0x1234567890abcdef, 0x1234567890abcdef);
> + test_type_ptr(vcpu, 0x1234567890abcdef, 0x1234567890abcdee);
> +
> + kvm_vm_free(vm);
> +
> + test_limits();
> +
> + return 0;
> +}
> --
> 2.41.0.487.g6d72f3e995-goog
>