Re: [PATCH 1/3] selftests: kvm: s390: Add uc_map_unmap VM test case

Janosch Frank
2024-08-16T14:29:35Z

On 8/15/24 5:45 PM, Christoph Schlameuss wrote:
> Add a test case verifying basic running and interaction of ucontrol VMs.
> Fill the segment and page tables for allocated memory and map memory on
> first access.
>
> * uc_map_unmap
> Store and load data to mapped and unmapped memory and use pic segment
> translation handling to map memory on access.
>
> Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
> ---
> .../selftests/kvm/s390x/ucontrol_test.c | 120 +++++++++++++++++-
> 1 file changed, 119 insertions(+), 1 deletion(-)
>

> +static void uc_handle_exit_ucontrol(FIXTURE_DATA(uc_kvm) * self)
> +{
> + struct kvm_run *run = self->run;
> +
> + TEST_ASSERT_EQ(KVM_EXIT_S390_UCONTROL, run->exit_reason);
> + switch (run->s390_ucontrol.pgm_code) {
> + case PGM_SEGMENT_TRANSLATION:
> + pr_info("ucontrol pic segment translation 0x%llx\n",
> + run->s390_ucontrol.trans_exc_code);
> + /* map / make additional memory available */
> + struct kvm_s390_ucas_mapping map2 = {
> + .user_addr = (u64)gpa2hva(self, run->s390_ucontrol.trans_exc_code),
> + .vcpu_addr = run->s390_ucontrol.trans_exc_code,
> + .length = VM_MEM_EXT_SIZE,
> + };
> + pr_info("ucas map %p %p 0x%llx\n",
> + (void *)map2.user_addr, (void *)map2.vcpu_addr, map2.length);
> + TEST_ASSERT_EQ(0, ioctl(self->vcpu_fd, KVM_S390_UCAS_MAP, &map2));
> + break;

Why is this necessary if you fix up the mapping in the test?

[...]

>
> +TEST_F(uc_kvm, uc_map_unmap)
> +{
> + struct kvm_sync_regs *sync_regs = &self->run->s.regs;
> + struct kvm_run *run = self->run;
> + int rc;
> +
> + /* copy test_mem_asm to code_hva / code_gpa */
> + TH_LOG("copy code %p to vm mapped memory %p / %p",
> + &test_mem_asm, (void *)self->code_hva, (void *)self->code_gpa);
> + memcpy((void *)self->code_hva, &test_mem_asm, PAGE_SIZE);
> +
> + /* DAT disabled + 64 bit mode */
> + run->psw_mask = 0x0000000180000000ULL;
> + run->psw_addr = self->code_gpa;
> +
> + /* set register content for test_mem_asm to access not mapped memory*/
> + sync_regs->gprs[1] = 0x55;
> + sync_regs->gprs[5] = self->base_gpa;
> + sync_regs->gprs[6] = VM_MEM_SIZE;
> + run->kvm_dirty_regs |= KVM_SYNC_GPRS;
> +
> + /* run and expect to fail witch ucontrol pic segment translation */

s/witch/with/

> + ASSERT_EQ(0, uc_run_once(self));
> + ASSERT_EQ(1, sync_regs->gprs[0]);
> + ASSERT_EQ(KVM_EXIT_S390_UCONTROL, run->exit_reason);
> +
> + ASSERT_EQ(PGM_SEGMENT_TRANSLATION, run->s390_ucontrol.pgm_code);
> + ASSERT_EQ(self->base_gpa + VM_MEM_SIZE, run->s390_ucontrol.trans_exc_code);
> + /* map / make additional memory available */
> + struct kvm_s390_ucas_mapping map2 = {
> + .user_addr = (u64)gpa2hva(self, self->base_gpa + VM_MEM_SIZE),
> + .vcpu_addr = self->base_gpa + VM_MEM_SIZE,
> + .length = VM_MEM_EXT_SIZE,
> + };
> + TH_LOG("ucas map %p %p 0x%llx",
> + (void *)map2.user_addr, (void *)map2.vcpu_addr, map2.length);
> + rc = ioctl(self->vcpu_fd, KVM_S390_UCAS_MAP, &map2);
> + ASSERT_EQ(0, rc)
> + TH_LOG("ucas map result %d not expected, %s", rc, strerror(errno));
> + ASSERT_EQ(0, uc_run_once(self));
> + ASSERT_EQ(false, uc_handle_exit(self));
> + uc_assert_diag44(self);
> +
> + /* assert registers and memory are in expected state */
> + ASSERT_EQ(2, sync_regs->gprs[0]);
> + ASSERT_EQ(0x55, sync_regs->gprs[1]);
> + ASSERT_EQ(0x55, *(u32 *)gpa2hva(self, self->base_gpa + VM_MEM_SIZE));
> +
> + /* unmap and run loop again */
> + TH_LOG("ucas unmap %p %p 0x%llx",
> + (void *)map2.user_addr, (void *)map2.vcpu_addr, map2.length);
> + rc = ioctl(self->vcpu_fd, KVM_S390_UCAS_UNMAP, &map2);
> + ASSERT_EQ(0, rc)
> + TH_LOG("ucas map result %d not expected, %s", rc, strerror(errno));

s/map/unmap/

> + ASSERT_EQ(0, uc_run_once(self));
> + ASSERT_EQ(3, sync_regs->gprs[0]);
> + ASSERT_EQ(KVM_EXIT_S390_UCONTROL, run->exit_reason);
> + ASSERT_EQ(true, uc_handle_exit(self));
> +}
> +
> TEST_F(uc_kvm, uc_gprs)
> {
> struct kvm_sync_regs *sync_regs = &self->run->s.regs;