On Fri Aug 16, 2024 at 4:36 PM CEST, Janosch Frank wrote:
On 8/15/24 5:45 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
.../selftests/kvm/s390x/ucontrol_test.c | 76 +++++++++++++++++++ 1 file changed, 76 insertions(+)
diff --git a/tools/testing/selftests/kvm/s390x/ucontrol_test.c b/tools/testing/selftests/kvm/s390x/ucontrol_test.c index 41306bb52f29..5f8815a80544 100644 --- a/tools/testing/selftests/kvm/s390x/ucontrol_test.c +++ b/tools/testing/selftests/kvm/s390x/ucontrol_test.c @@ -79,6 +79,32 @@ 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"
Might want to add a xgr here so you're sure that you're not reading your own values if iske fails.
Good point. Will change the r1 value here.
- " 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;
@@ -345,6 +371,56 @@ static void uc_assert_diag44(FIXTURE_DATA(uc_kvm) * self) TEST_ASSERT_EQ(0x440000, sie_block->ipb); } +TEST_F(uc_kvm, uc_skey) +{
- u64 test_vaddr = self->base_gpa + 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;
- self->sie_block->ictl |= ICTL_OPEREXC | ICTL_PINT;
- self->sie_block->cpuflags &= ~CPUSTAT_KSS;
So you don't want KVM to initialize skeys? Or am I missing a ucontrol skey interaction?
What about the ICTLs if KSS is not available on the machine?
This is explicitly disabling KSS, not enabling it. Doing that explicitly might not strictly be necessary but I thought this does provide some clarity about the state.