Re: [PATCH v4 08/10] selftests: kvm: s390: Add uc_skey VM test case

Christoph Schlameuss
2024-08-07T11:02:40Z

On Tue, 6 Aug 2024 15:39:44 +0200
Janosch Frank <frankja@linux.ibm.com> wrote:

> On 8/2/24 5:59 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 | 78 +++++++++++++++++++
> > 1 file changed, 78 insertions(+)
> >
>
> [...]
>
> > +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;
> > +
> > + init_st_pt(self);
> > +
> > + /* 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;
> > +
> > + run->kvm_dirty_regs |= KVM_SYNC_CRS;
> > + TH_LOG("set CR0 to 0x%llx", sync_regs->crs[0]);
>
> You haven't touched any CRs here or am I missing something?
>

No I am not. Removing that.

> > +
> > + self->sie_block->ictl |= ICTL_OPEREXC | ICTL_PINT;
> > + self->sie_block->cpuflags &= ~CPUSTAT_KSS;
> > + /* DAT enabled + 64 bit mode */
> > + run->psw_mask = 0x0400000180000000ULL;
> > + run->psw_addr = self->code_gpa;
> > +
> > + ASSERT_EQ(0, uc_run_once(self));
> > + ASSERT_EQ(false, uc_handle_exit(self));
> > + ASSERT_EQ(2, sync_regs->gprs[0]);
> > + ASSERT_EQ(0x06, sync_regs->gprs[1]);
>
> /* ACC = 0, F & R = 1 */
>

I will sprinkle in some comments here to make it more clear what is
tested in the different blocks.

> > + uc_assert_diag44(self);
> > +
> > + 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);
>
> Rest LGTM
>