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

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;