diff mbox series

[v4,09/34] KVM: selftests: Add a selftest for guest prints and formatted asserts

Message ID 20230729003643.1053367-10-seanjc@google.com (mailing list archive)
State New, archived
Headers show
Series KVM: selftests: Guest printf and asserts overhaul | expand

Commit Message

Sean Christopherson July 29, 2023, 12:36 a.m. UTC
From: Aaron Lewis <aaronlewis@google.com>

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@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 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

Comments

Andrew Jones July 31, 2023, 4:32 p.m. UTC | #1
On Fri, Jul 28, 2023 at 05:36:18PM -0700, Sean Christopherson wrote:
> From: Aaron Lewis <aaronlewis@google.com>
> 
> 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@google.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
>  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
>
Sean Christopherson July 31, 2023, 5:04 p.m. UTC | #2
On Mon, Jul 31, 2023, Andrew Jones wrote:
> On Fri, Jul 28, 2023 at 05:36:18PM -0700, Sean Christopherson wrote:
> > From: Aaron Lewis <aaronlewis@google.com>
> > 
> > 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@google.com>
> > Signed-off-by: Sean Christopherson <seanjc@google.com>
> > ---
> >  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.

Can I have your SoB for the ucall_common.h patch?  I'll write a changelog and fold
in a separate prep patch for that change.

> > 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

Argh, this is why ARM didn't fail for me, the test was only built for x86.  I'll
double check that ARM works with the above, and also enable the test for all
architectures.  If the printf stuff doesn't work on s390, then we definitely want
to know before this is fully merged.

Thanks Drew!
Sean Christopherson July 31, 2023, 5:19 p.m. UTC | #3
On Mon, Jul 31, 2023, Sean Christopherson wrote:
> On Mon, Jul 31, 2023, Andrew Jones wrote:
> > 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.
> 
> Can I have your SoB for the ucall_common.h patch?  I'll write a changelog and fold
> in a separate prep patch for that change.

On second thought, I take that back.  I think it makes more sense to add a ucall.h
for each arch and #define the exit type there.  All then move all of the
ucall_arch_do_ucall() implementations to ucall.h (except maybe x86 while it has
the horrific save/restore GPRs hack...).  That way the #define is colocated with
the code that generates the exit reason.
Andrew Jones July 31, 2023, 6:22 p.m. UTC | #4
On Mon, Jul 31, 2023 at 10:19:47AM -0700, Sean Christopherson wrote:
> On Mon, Jul 31, 2023, Sean Christopherson wrote:
> > On Mon, Jul 31, 2023, Andrew Jones wrote:
> > > 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.
> > 
> > Can I have your SoB for the ucall_common.h patch?  I'll write a changelog and fold
> > in a separate prep patch for that change.
> 
> On second thought, I take that back.  I think it makes more sense to add a ucall.h
> for each arch and #define the exit type there.  All then move all of the
> ucall_arch_do_ucall() implementations to ucall.h (except maybe x86 while it has
> the horrific save/restore GPRs hack...).  That way the #define is colocated with
> the code that generates the exit reason.

Yup, feel free to just take the above as inspiration and create a
different patch. If you decide you want an s-o-b for the above, though,
then here's one

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>

Thanks,
drew
diff mbox series

Patch

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;
+}