Re: [PATCH v3 2/3] selftests: kvm: s390: Add uc_skey VM test case

On 9/13/24 1:52 PM, Christoph Schlameuss wrote:

Add a test case manipulating s390 storage keys from within the ucontrol VM.

Signed-off-by: Christoph Schlameuss schlameuss@linux.ibm.com

Except for the two nits: Reviewed-by: Janosch Frank frankja@linux.ibm.com

I'll think about what to do with the nits next week.

---

.../selftests/kvm/s390x/ucontrol_test.c | 89 ++++++++++++++++++- 1 file changed, 88 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/s390x/ucontrol_test.c b/tools/testing/selftests/kvm/s390x/ucontrol_test.c index 084cea02c2fa..f6e3a68f89a9 100644 --- a/tools/testing/selftests/kvm/s390x/ucontrol_test.c +++ b/tools/testing/selftests/kvm/s390x/ucontrol_test.c @@ -79,6 +79,33 @@ asm("test_mem_asm:\n" " j 0b\n" ); +/* Test program manipulating storage keys */ +extern char test_skey_asm[]; +asm("test_skey_asm:\n"

• "xgr %r0, %r0\n"
• "0:\n"
• " ahi %r0,1\n"
• " st %r1,0(%r5,%r6)\n"
• " iske %r1,%r6\n"
• " ahi %r0,1\n"
• " diag 0,0,0x44\n"
• " sske %r1,%r6\n"
• " xgr %r1,%r1\n"
• " iske %r1,%r6\n"
• " ahi %r0,1\n"
• " diag 0,0,0x44\n"
• " rrbe %r1,%r6\n"
• " iske %r1,%r6\n"
• " ahi %r0,1\n"
• " diag 0,0,0x44\n"
• " j 0b\n"

+);

• FIXTURE(uc_kvm) { struct kvm_s390_sie_block *sie_block;

@@ -299,8 +326,9 @@ static void uc_handle_exit_ucontrol(FIXTURE_DATA(uc_kvm) * self) } /* verify SIEIC exit

• • • reset stop requests

Argh, that made it in the patches that I've picked up.

• • • handle expected interception codes
  • • fail on codes not expected in the test cases
• • Returns if interception is handled / execution can be continued
  */ static bool uc_handle_sieic(FIXTURE_DATA(uc_kvm) * self) {

@@ -317,6 +345,10 @@ static bool uc_handle_sieic(FIXTURE_DATA(uc_kvm) * self) /* end execution in caller on intercepted instruction */ pr_info("sie instruction interception\n"); return false;

• case ICPT_KSS:

• /* disable KSS and continue; KVM would init the skeys here */
  

• sie_block->cpuflags &= ~CPUSTAT_KSS;
  

• return true;
  

  case ICPT_OPEREXC: /* operation exception */ TEST_FAIL("sie exception on %.4x%.8x", sie_block->ipa, sie_block->ipb);

@@ -473,4 +505,59 @@ TEST_F(uc_kvm, uc_gprs) ASSERT_EQ(1, sync_regs->gprs[0]); } +TEST_F(uc_kvm, uc_skey) +{

• u64 test_vaddr = VM_MEM_SIZE - (SZ_1M / 2);
• struct kvm_sync_regs *sync_regs = &self->run->s.regs;
• struct kvm_run *run = self->run;
• u8 skeyvalue = 0x34;
• /* copy test_skey_asm to code_hva / code_gpa */
• TH_LOG("copy code %p to vm mapped memory %p / %p",

•       &test_skey_asm, (void *)self->code_hva, (void *)self->code_gpa);
  

• memcpy((void *)self->code_hva, &test_skey_asm, PAGE_SIZE);
• /* set register content for test_skey_asm to access not mapped memory */
• sync_regs->gprs[1] = skeyvalue;
• sync_regs->gprs[5] = self->base_gpa;
• sync_regs->gprs[6] = test_vaddr;
• run->kvm_dirty_regs |= KVM_SYNC_GPRS;
• /* DAT disabled + 64 bit mode */
• run->psw_mask = 0x0000000180000000ULL;
• run->psw_addr = self->code_gpa;
• ASSERT_EQ(0, uc_run_once(self));
• ASSERT_EQ(true, uc_handle_exit(self));
• ASSERT_EQ(1, sync_regs->gprs[0]);
• /* ISKE */
• ASSERT_EQ(0, uc_run_once(self));
• ASSERT_EQ(false, uc_handle_exit(self));
• ASSERT_EQ(2, sync_regs->gprs[0]);
• /* assert initial skey (ACC = 0, R & C = 1) */
• ASSERT_EQ(0x06, sync_regs->gprs[1]);
• uc_assert_diag44(self);
• /* SSKE */
• sync_regs->gprs[1] = skeyvalue;
• run->kvm_dirty_regs |= KVM_SYNC_GPRS;
• ASSERT_EQ(0, uc_run_once(self));
• ASSERT_EQ(false, uc_handle_exit(self));
• ASSERT_EQ(3, sync_regs->gprs[0]);
• ASSERT_EQ(skeyvalue, sync_regs->gprs[1]);
• uc_assert_diag44(self);
• /* RRBE */
• sync_regs->gprs[1] = skeyvalue;
• run->kvm_dirty_regs |= KVM_SYNC_GPRS;
• ASSERT_EQ(0, uc_run_once(self));
• ASSERT_EQ(false, uc_handle_exit(self));
• ASSERT_EQ(4, sync_regs->gprs[0]);
• /* assert R reset but rest of skey unchanged*/

Missing space before "*"

• ASSERT_EQ(skeyvalue & 0xfa, sync_regs->gprs[1]);
• ASSERT_EQ(0x00, sync_regs->gprs[1] & 0x04);
• uc_assert_diag44(self);

+}

• TEST_HARNESS_MAIN