[PATCH 2/4] KVM: selftests: x86: Use TAP interface in the sync_regs test

From: Thomas Huth
Date: Wed Jul 12 2023 - 04:00:16 EST

The sync_regs test currently does not have any output (unless one
of the TEST_ASSERT statement fails), so it's hard to say for a user
whether a certain new sub-test has been included in the binary or
not. Let's make this a little bit more user-friendly and include
some TAP output via the kselftest_harness.h interface.
To be able to use the interface, we have to break up the huge main()
function here in more fine grained parts - then we can use the
TEST_F() macro to define the individual tests. Since these are run
with a separate VM now, we have also to make sure to create the
expected state at the beginning of each test, so some parts grow
a little bit - which should be OK considering that the individual
tests are more self-contained now.

Suggested-by: David Matlack <dmatlack@xxxxxxxxxx>
Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx>
---
.../selftests/kvm/x86_64/sync_regs_test.c | 113 +++++++++++++++---
1 file changed, 98 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c
index 2da89fdc2471a..e1359a4a07fea 100644
--- a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c
@@ -16,6 +16,7 @@
#include <string.h>
#include <sys/ioctl.h>

+#include "kselftest_harness.h"
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
@@ -80,23 +81,24 @@ static void compare_vcpu_events(struct kvm_vcpu_events *left,
#define TEST_SYNC_FIELDS (KVM_SYNC_X86_REGS|KVM_SYNC_X86_SREGS|KVM_SYNC_X86_EVENTS)
#define INVALID_SYNC_FIELD 0x80000000

-int main(int argc, char *argv[])
-{
- struct kvm_vcpu *vcpu;
+FIXTURE(sync_regs_test) {
struct kvm_vm *vm;
- struct kvm_run *run;
- struct kvm_regs regs;
- struct kvm_sregs sregs;
- struct kvm_vcpu_events events;
- int rv, cap;
+ struct kvm_vcpu *vcpu;
+};

- cap = kvm_check_cap(KVM_CAP_SYNC_REGS);
- TEST_REQUIRE((cap & TEST_SYNC_FIELDS) == TEST_SYNC_FIELDS);
- TEST_REQUIRE(!(cap & INVALID_SYNC_FIELD));
+FIXTURE_SETUP(sync_regs_test) {
+ self->vm = vm_create_with_one_vcpu(&self->vcpu, guest_code);
+}

- vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+FIXTURE_TEARDOWN(sync_regs_test) {
+ kvm_vm_free(self->vm);
+}

- run = vcpu->run;
+TEST_F(sync_regs_test, read_invalid)
+{
+ struct kvm_vcpu *vcpu = self->vcpu;
+ struct kvm_run *run = vcpu->run;
+ int rv;

/* Request reading invalid register set from VCPU. */
run->kvm_valid_regs = INVALID_SYNC_FIELD;
@@ -112,6 +114,13 @@ int main(int argc, char *argv[])
"Invalid kvm_valid_regs did not cause expected KVM_RUN error: %d\n",
rv);
run->kvm_valid_regs = 0;
+}
+
+TEST_F(sync_regs_test, set_invalid)
+{
+ struct kvm_vcpu *vcpu = self->vcpu;
+ struct kvm_run *run = vcpu->run;
+ int rv;

/* Request setting invalid register set into VCPU. */
run->kvm_dirty_regs = INVALID_SYNC_FIELD;
@@ -127,11 +136,22 @@ int main(int argc, char *argv[])
"Invalid kvm_dirty_regs did not cause expected KVM_RUN error: %d\n",
rv);
run->kvm_dirty_regs = 0;
+}
+
+TEST_F(sync_regs_test, req_and_verify_all_valid)
+{
+ struct kvm_vcpu *vcpu = self->vcpu;
+ struct kvm_run *run = vcpu->run;
+ struct kvm_vcpu_events events;
+ struct kvm_sregs sregs;
+ struct kvm_regs regs;
+ int rv;

/* Request and verify all valid register sets. */
/* TODO: BUILD TIME CHECK: TEST_ASSERT(KVM_SYNC_X86_NUM_FIELDS != 3); */
run->kvm_valid_regs = TEST_SYNC_FIELDS;
rv = _vcpu_run(vcpu);
+ TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);

vcpu_regs_get(vcpu, &regs);
@@ -142,6 +162,22 @@ int main(int argc, char *argv[])

vcpu_events_get(vcpu, &events);
compare_vcpu_events(&events, &run->s.regs.events);
+}
+
+TEST_F(sync_regs_test, set_and_verify_various)
+{
+ struct kvm_vcpu *vcpu = self->vcpu;
+ struct kvm_run *run = vcpu->run;
+ struct kvm_vcpu_events events;
+ struct kvm_sregs sregs;
+ struct kvm_regs regs;
+ int rv;
+
+ /* Run once to get register set */
+ run->kvm_valid_regs = TEST_SYNC_FIELDS;
+ rv = _vcpu_run(vcpu);
+ TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
+ TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);

/* Set and verify various register values. */
run->s.regs.regs.rbx = 0xBAD1DEA;
@@ -151,6 +187,7 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = TEST_SYNC_FIELDS;
run->kvm_dirty_regs = KVM_SYNC_X86_REGS | KVM_SYNC_X86_SREGS;
rv = _vcpu_run(vcpu);
+ TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
TEST_ASSERT(run->s.regs.regs.rbx == 0xBAD1DEA + 1,
"rbx sync regs value incorrect 0x%llx.",
@@ -167,6 +204,13 @@ int main(int argc, char *argv[])

vcpu_events_get(vcpu, &events);
compare_vcpu_events(&events, &run->s.regs.events);
+}
+
+TEST_F(sync_regs_test, clear_kvm_dirty_regs_bits)
+{
+ struct kvm_vcpu *vcpu = self->vcpu;
+ struct kvm_run *run = vcpu->run;
+ int rv;

/* Clear kvm_dirty_regs bits, verify new s.regs values are
* overwritten with existing guest values.
@@ -175,10 +219,25 @@ int main(int argc, char *argv[])
run->kvm_dirty_regs = 0;
run->s.regs.regs.rbx = 0xDEADBEEF;
rv = _vcpu_run(vcpu);
+ TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
TEST_ASSERT(run->s.regs.regs.rbx != 0xDEADBEEF,
"rbx sync regs value incorrect 0x%llx.",
run->s.regs.regs.rbx);
+}
+
+TEST_F(sync_regs_test, clear_kvm_valid_and_dirty_regs)
+{
+ struct kvm_vcpu *vcpu = self->vcpu;
+ struct kvm_run *run = vcpu->run;
+ struct kvm_regs regs;
+ int rv;
+
+ /* Run once to get register set */
+ run->kvm_valid_regs = TEST_SYNC_FIELDS;
+ rv = _vcpu_run(vcpu);
+ TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
+ TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);

/* Clear kvm_valid_regs bits and kvm_dirty_bits.
* Verify s.regs values are not overwritten with existing guest values
@@ -187,9 +246,11 @@ int main(int argc, char *argv[])
run->kvm_valid_regs = 0;
run->kvm_dirty_regs = 0;
run->s.regs.regs.rbx = 0xAAAA;
+ vcpu_regs_get(vcpu, &regs);
regs.rbx = 0xBAC0;
vcpu_regs_set(vcpu, &regs);
rv = _vcpu_run(vcpu);
+ TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
TEST_ASSERT(run->s.regs.regs.rbx == 0xAAAA,
"rbx sync regs value incorrect 0x%llx.",
@@ -198,6 +259,20 @@ int main(int argc, char *argv[])
TEST_ASSERT(regs.rbx == 0xBAC0 + 1,
"rbx guest value incorrect 0x%llx.",
regs.rbx);
+}
+
+TEST_F(sync_regs_test, clear_kvm_valid_regs_bits)
+{
+ struct kvm_vcpu *vcpu = self->vcpu;
+ struct kvm_run *run = vcpu->run;
+ struct kvm_regs regs;
+ int rv;
+
+ /* Run once to get register set */
+ run->kvm_valid_regs = TEST_SYNC_FIELDS;
+ rv = _vcpu_run(vcpu);
+ TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
+ TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);

/* Clear kvm_valid_regs bits. Verify s.regs values are not overwritten
* with existing guest values but that guest values are overwritten
@@ -207,6 +282,7 @@ int main(int argc, char *argv[])
run->kvm_dirty_regs = TEST_SYNC_FIELDS;
run->s.regs.regs.rbx = 0xBBBB;
rv = _vcpu_run(vcpu);
+ TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);
TEST_ASSERT(run->s.regs.regs.rbx == 0xBBBB,
"rbx sync regs value incorrect 0x%llx.",
@@ -215,8 +291,15 @@ int main(int argc, char *argv[])
TEST_ASSERT(regs.rbx == 0xBBBB + 1,
"rbx guest value incorrect 0x%llx.",
regs.rbx);
+}
+
+int main(int argc, char *argv[])
+{
+ int cap;

- kvm_vm_free(vm);
+ cap = kvm_check_cap(KVM_CAP_SYNC_REGS);
+ TEST_REQUIRE((cap & TEST_SYNC_FIELDS) == TEST_SYNC_FIELDS);
+ TEST_REQUIRE(!(cap & INVALID_SYNC_FIELD));

- return 0;
+ return test_harness_run(argc, argv);
}
--
2.39.3