[PATCH v4 06/10] selftests: kvm: s390: Add VM run test case

Christoph Schlameuss
2024-08-02T15:59:59Z

Add test case running code interacting with registers within a
ucontrol VM.

* Add uc_gprs test case

The test uses the same VM setup using the fixture and debug macros
introduced in earlier patches in this series.

Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
---
.../selftests/kvm/s390x/ucontrol_test.c | 126 ++++++++++++++++++
1 file changed, 126 insertions(+)

diff --git a/tools/testing/selftests/kvm/s390x/ucontrol_test.c b/tools/testing/selftests/kvm/s390x/ucontrol_test.c
index d103a92e7495..030c59010fe1 100644
--- a/tools/testing/selftests/kvm/s390x/ucontrol_test.c
+++ b/tools/testing/selftests/kvm/s390x/ucontrol_test.c
@@ -7,6 +7,7 @@
* Authors:
* Christoph Schlameuss <schlameuss@linux.ibm.com>
*/
+#include "debug_print.h"
#include "kselftest_harness.h"
#include "kvm_util.h"
#include "processor.h"
@@ -40,6 +41,23 @@ void require_ucontrol_admin(void)
TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_UCONTROL));
}

+/* Test program setting some registers and looping */
+extern char test_gprs_asm[];
+asm("test_gprs_asm:\n"
+ "xgr %r0, %r0\n"
+ "lgfi %r1,1\n"
+ "lgfi %r2,2\n"
+ "lgfi %r3,3\n"
+ "lgfi %r4,4\n"
+ "lgfi %r5,5\n"
+ "lgfi %r6,6\n"
+ "lgfi %r7,7\n"
+ "0:\n"
+ " diag 0,0,0x44\n"
+ " ahi %r0,1\n"
+ " j 0b\n"
+);
+
FIXTURE(uc_kvm)
{
struct kvm_s390_sie_block *sie_block;
@@ -204,4 +222,112 @@ TEST(uc_cap_hpage)
close(kvm_fd);
}

+/* verify SIEIC exit
+ * * reset stop requests
+ * * fail on codes not expected in the test cases
+ */
+static bool uc_handle_sieic(FIXTURE_DATA(uc_kvm) * self)
+{
+ struct kvm_s390_sie_block *sie_block = self->sie_block;
+ struct kvm_run *run = self->run;
+
+ /* check SIE interception code */
+ pr_info("sieic: 0x%.2x 0x%.4x 0x%.4x\n",
+ run->s390_sieic.icptcode,
+ run->s390_sieic.ipa,
+ run->s390_sieic.ipb);
+ switch (run->s390_sieic.icptcode) {
+ case ICPT_INST:
+ /* end execution in caller on intercepted instruction */
+ pr_info("sie instruction interception\n");
+ return false;
+ case ICPT_OPEREXC:
+ /* operation exception */
+ TEST_FAIL("sie exception on %.4x%.8x", sie_block->ipa, sie_block->ipb);
+ default:
+ TEST_FAIL("UNEXPECTED SIEIC CODE %d", run->s390_sieic.icptcode);
+ }
+ return true;
+}
+
+/* verify VM state on exit */
+static bool uc_handle_exit(FIXTURE_DATA(uc_kvm) * self)
+{
+ struct kvm_run *run = self->run;
+
+ switch (run->exit_reason) {
+ case KVM_EXIT_S390_SIEIC:
+ return uc_handle_sieic(self);
+ default:
+ pr_info("exit_reason %2d not handled\n", run->exit_reason);
+ }
+ return true;
+}
+
+/* run the VM until interrupted */
+static int uc_run_once(FIXTURE_DATA(uc_kvm) * self)
+{
+ int rc;
+
+ rc = ioctl(self->vcpu_fd, KVM_RUN, NULL);
+ print_run(self->run, self->sie_block);
+ print_regs(self->run);
+ pr_debug("run %d / %d %s\n", rc, errno, strerror(errno));
+ return rc;
+}
+
+static void uc_assert_diag44(FIXTURE_DATA(uc_kvm) * self)
+{
+ struct kvm_s390_sie_block *sie_block = self->sie_block;
+
+ /* assert vm was interrupted by diag 0x0044 */
+ TEST_ASSERT_EQ(KVM_EXIT_S390_SIEIC, self->run->exit_reason);
+ TEST_ASSERT_EQ(ICPT_INST, sie_block->icptcode);
+ TEST_ASSERT_EQ(0x8300, sie_block->ipa);
+ TEST_ASSERT_EQ(0x440000, sie_block->ipb);
+}
+
+TEST_F(uc_kvm, uc_gprs)
+{
+ struct kvm_sync_regs *sync_regs = &self->run->s.regs;
+ struct kvm_run *run = self->run;
+ struct kvm_regs regs = {};
+
+ /* Set registers to values that are different from the ones that we expect below */
+ for (int i = 0; i < 8; i++)
+ sync_regs->gprs[i] = 8;
+ run->kvm_dirty_regs |= KVM_SYNC_GPRS;
+
+ /* copy test_gprs_asm to code_hva / code_gpa */
+ TH_LOG("copy code %p to vm mapped memory %p / %p",
+ &test_gprs_asm, (void *)self->code_hva, (void *)self->code_gpa);
+ memcpy((void *)self->code_hva, &test_gprs_asm, PAGE_SIZE);
+
+ /* DAT disabled + 64 bit mode */
+ run->psw_mask = 0x0000000180000000ULL;
+ run->psw_addr = self->code_gpa;
+
+ /* run and expect interception of diag 44 */
+ ASSERT_EQ(0, uc_run_once(self));
+ ASSERT_EQ(false, uc_handle_exit(self));
+ uc_assert_diag44(self);
+
+ /* Retrieve and check guest register values */
+ ASSERT_EQ(0, ioctl(self->vcpu_fd, KVM_GET_REGS, &regs));
+ for (int i = 0; i < 8; i++) {
+ ASSERT_EQ(i, regs.gprs[i]);
+ ASSERT_EQ(i, sync_regs->gprs[i]);
+ }
+
+ /* run and expect interception of diag 44 again */
+ ASSERT_EQ(0, uc_run_once(self));
+ ASSERT_EQ(false, uc_handle_exit(self));
+ uc_assert_diag44(self);
+
+ /* check continued increment of register 0 value */
+ ASSERT_EQ(0, ioctl(self->vcpu_fd, KVM_GET_REGS, &regs));
+ ASSERT_EQ(1, regs.gprs[0]);
+ ASSERT_EQ(1, sync_regs->gprs[0]);
+}
+
TEST_HARNESS_MAIN
--
2.45.2