[PATCH v2 4/7] KVM: selftests: x86: Use TAP interface in the sync_regs test

Thomas Huth
2023-10-05T15:00:09Z

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 / kvm_test_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 new
KVM_ONE_VCPU_TEST() 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@google.com>
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
.../selftests/kvm/x86_64/sync_regs_test.c | 110 +++++++++++++-----
1 file changed, 84 insertions(+), 26 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 1cd19dfa0046c..c857244762bb2 100644
--- a/tools/testing/selftests/kvm/x86_64/sync_regs_test.c
+++ b/tools/testing/selftests/kvm/x86_64/sync_regs_test.c
@@ -17,6 +17,7 @@
#include <sys/ioctl.h>
#include <pthread.h>

+#include "kvm_test_harness.h"
#include "test_util.h"
#include "kvm_util.h"
#include "processor.h"
@@ -41,6 +42,8 @@ void guest_code(void)
: "rax", "rbx");
}

+KVM_ONE_VCPU_TEST_SUITE(sync_regs_test, guest_code);
+
static void compare_regs(struct kvm_regs *left, struct kvm_regs *right)
{
#define REG_COMPARE(reg) \
@@ -152,18 +155,15 @@ static noinline void *race_sregs_cr4(void *arg)
return NULL;
}

-static void race_sync_regs(void *racer)
+static void race_sync_regs(struct kvm_vcpu *vcpu, void *racer)
{
const time_t TIMEOUT = 2; /* seconds, roughly */
struct kvm_x86_state *state;
struct kvm_translation tr;
- struct kvm_vcpu *vcpu;
struct kvm_run *run;
- struct kvm_vm *vm;
pthread_t thread;
time_t t;

- vm = vm_create_with_one_vcpu(&vcpu, guest_code);
run = vcpu->run;

run->kvm_valid_regs = KVM_SYNC_X86_SREGS;
@@ -205,26 +205,12 @@ static void race_sync_regs(void *racer)
TEST_ASSERT_EQ(pthread_join(thread, NULL), 0);

kvm_x86_state_cleanup(state);
- kvm_vm_free(vm);
}

-int main(int argc, char *argv[])
+KVM_ONE_VCPU_TEST(sync_regs_test, read_invalid)
{
- struct kvm_vcpu *vcpu;
- struct kvm_vm *vm;
- struct kvm_run *run;
- struct kvm_regs regs;
- struct kvm_sregs sregs;
- struct kvm_vcpu_events events;
- int rv, cap;
-
- cap = kvm_check_cap(KVM_CAP_SYNC_REGS);
- TEST_REQUIRE((cap & TEST_SYNC_FIELDS) == TEST_SYNC_FIELDS);
- TEST_REQUIRE(!(cap & INVALID_SYNC_FIELD));
-
- vm = vm_create_with_one_vcpu(&vcpu, guest_code);
-
- run = vcpu->run;
+ struct kvm_run *run = vcpu->run;
+ int rv;

/* Request reading invalid register set from VCPU. */
run->kvm_valid_regs = INVALID_SYNC_FIELD;
@@ -240,6 +226,12 @@ 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;
+}
+
+KVM_ONE_VCPU_TEST(sync_regs_test, set_invalid)
+{
+ struct kvm_run *run = vcpu->run;
+ int rv;

/* Request setting invalid register set into VCPU. */
run->kvm_dirty_regs = INVALID_SYNC_FIELD;
@@ -255,6 +247,14 @@ 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;
+}
+
+KVM_ONE_VCPU_TEST(sync_regs_test, req_and_verify_all_valid)
+{
+ struct kvm_run *run = vcpu->run;
+ struct kvm_vcpu_events events;
+ struct kvm_sregs sregs;
+ struct kvm_regs regs;

/* Request and verify all valid register sets. */
/* TODO: BUILD TIME CHECK: TEST_ASSERT(KVM_SYNC_X86_NUM_FIELDS != 3); */
@@ -270,6 +270,19 @@ int main(int argc, char *argv[])

vcpu_events_get(vcpu, &events);
compare_vcpu_events(&events, &run->s.regs.events);
+}
+
+KVM_ONE_VCPU_TEST(sync_regs_test, set_and_verify_various)
+{
+ struct kvm_run *run = vcpu->run;
+ struct kvm_vcpu_events events;
+ struct kvm_sregs sregs;
+ struct kvm_regs regs;
+
+ /* Run once to get register set */
+ run->kvm_valid_regs = TEST_SYNC_FIELDS;
+ vcpu_run(vcpu);
+ TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO);

/* Set and verify various register values. */
run->s.regs.regs.rbx = 0xBAD1DEA;
@@ -295,6 +308,11 @@ int main(int argc, char *argv[])

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

/* Clear kvm_dirty_regs bits, verify new s.regs values are
* overwritten with existing guest values.
@@ -307,6 +325,17 @@ int main(int argc, char *argv[])
TEST_ASSERT(run->s.regs.regs.rbx != 0xDEADBEEF,
"rbx sync regs value incorrect 0x%llx.",
run->s.regs.regs.rbx);
+}
+
+KVM_ONE_VCPU_TEST(sync_regs_test, clear_kvm_valid_and_dirty_regs)
+{
+ struct kvm_run *run = vcpu->run;
+ struct kvm_regs regs;
+
+ /* Run once to get register set */
+ run->kvm_valid_regs = TEST_SYNC_FIELDS;
+ vcpu_run(vcpu);
+ 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
@@ -327,6 +356,17 @@ int main(int argc, char *argv[])
TEST_ASSERT(regs.rbx == 0xBAC0 + 1,
"rbx guest value incorrect 0x%llx.",
regs.rbx);
+}
+
+KVM_ONE_VCPU_TEST(sync_regs_test, clear_kvm_valid_regs_bits)
+{
+ struct kvm_run *run = vcpu->run;
+ struct kvm_regs regs;
+
+ /* Run once to get register set */
+ run->kvm_valid_regs = TEST_SYNC_FIELDS;
+ vcpu_run(vcpu);
+ 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
@@ -344,12 +384,30 @@ int main(int argc, char *argv[])
TEST_ASSERT(regs.rbx == 0xBBBB + 1,
"rbx guest value incorrect 0x%llx.",
regs.rbx);
+}
+
+KVM_ONE_VCPU_TEST(sync_regs_test, race_cr4)
+{
+ race_sync_regs(vcpu, race_sregs_cr4);
+}
+
+KVM_ONE_VCPU_TEST(sync_regs_test, race_exc)
+{
+ race_sync_regs(vcpu, race_events_exc);
+}

- kvm_vm_free(vm);
+KVM_ONE_VCPU_TEST(sync_regs_test, race_inj_pen)
+{
+ race_sync_regs(vcpu, race_events_inj_pen);
+}
+
+int main(int argc, char *argv[])
+{
+ int cap;

- race_sync_regs(race_sregs_cr4);
- race_sync_regs(race_events_exc);
- race_sync_regs(race_events_inj_pen);
+ 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);
}
--
2.41.0