selftests: kvm: s390: Add test fixture and simple VM setup tests

Add a uc_kvm fixture to create and destroy a ucontrol VM.

* uc_sie_assertions asserts basic settings in the SIE as setup by the
  kernel.
* uc_attr_mem_limit asserts the memory limit is max value and cannot be
  set (not supported).
* uc_no_dirty_log asserts dirty log is not supported.

Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Link: https://lore.kernel.org/r/20240807154512.316936-5-schlameuss@linux.ibm.com
Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Message-ID: <20240807154512.316936-5-schlameuss@linux.ibm.com>

tools/testing/selftests/kvm/s390x/ucontrol_test.c

@@ -9,10 +9,14 @@
  */
 #include "kselftest_harness.h"
 #include "kvm_util.h"
+#include "processor.h"
+#include "sie.h"
 
 #include <linux/capability.h>
 #include <linux/sizes.h>
 
+#define VM_MEM_SIZE (4 * SZ_1M)
+
 /* so directly declare capget to check caps without libcap */
 int capget(cap_user_header_t header, cap_user_data_t data);
 
@@ -36,6 +40,133 @@ void require_ucontrol_admin(void)
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_S390_UCONTROL));
 }
 
+FIXTURE(uc_kvm)
+{
+	struct kvm_s390_sie_block *sie_block;
+	struct kvm_run *run;
+	uintptr_t base_gpa;
+	uintptr_t code_gpa;
+	uintptr_t base_hva;
+	uintptr_t code_hva;
+	int kvm_run_size;
+	void *vm_mem;
+	int vcpu_fd;
+	int kvm_fd;
+	int vm_fd;
+};
+
+/**
+ * create VM with single vcpu, map kvm_run and SIE control block for easy access
+ */
+FIXTURE_SETUP(uc_kvm)
+{
+	struct kvm_s390_vm_cpu_processor info;
+	int rc;
+
+	require_ucontrol_admin();
+
+	self->kvm_fd = open_kvm_dev_path_or_exit();
+	self->vm_fd = ioctl(self->kvm_fd, KVM_CREATE_VM, KVM_VM_S390_UCONTROL);
+	ASSERT_GE(self->vm_fd, 0);
+
+	kvm_device_attr_get(self->vm_fd, KVM_S390_VM_CPU_MODEL,
+			    KVM_S390_VM_CPU_PROCESSOR, &info);
+	TH_LOG("create VM 0x%llx", info.cpuid);
+
+	self->vcpu_fd = ioctl(self->vm_fd, KVM_CREATE_VCPU, 0);
+	ASSERT_GE(self->vcpu_fd, 0);
+
+	self->kvm_run_size = ioctl(self->kvm_fd, KVM_GET_VCPU_MMAP_SIZE, NULL);
+	ASSERT_GE(self->kvm_run_size, sizeof(struct kvm_run))
+		  TH_LOG(KVM_IOCTL_ERROR(KVM_GET_VCPU_MMAP_SIZE, self->kvm_run_size));
+	self->run = (struct kvm_run *)mmap(NULL, self->kvm_run_size,
+		    PROT_READ | PROT_WRITE, MAP_SHARED, self->vcpu_fd, 0);
+	ASSERT_NE(self->run, MAP_FAILED);
+	/**
+	 * For virtual cpus that have been created with S390 user controlled
+	 * virtual machines, the resulting vcpu fd can be memory mapped at page
+	 * offset KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of
+	 * the virtual cpu's hardware control block.
+	 */
+	self->sie_block = (struct kvm_s390_sie_block *)mmap(NULL, PAGE_SIZE,
+			  PROT_READ | PROT_WRITE, MAP_SHARED,
+			  self->vcpu_fd, KVM_S390_SIE_PAGE_OFFSET << PAGE_SHIFT);
+	ASSERT_NE(self->sie_block, MAP_FAILED);
+
+	TH_LOG("VM created %p %p", self->run, self->sie_block);
+
+	self->base_gpa = 0;
+	self->code_gpa = self->base_gpa + (3 * SZ_1M);
+
+	self->vm_mem = aligned_alloc(SZ_1M, VM_MEM_SIZE);
+	ASSERT_NE(NULL, self->vm_mem) TH_LOG("malloc failed %u", errno);
+	self->base_hva = (uintptr_t)self->vm_mem;
+	self->code_hva = self->base_hva - self->base_gpa + self->code_gpa;
+	struct kvm_s390_ucas_mapping map = {
+		.user_addr = self->base_hva,
+		.vcpu_addr = self->base_gpa,
+		.length = VM_MEM_SIZE,
+	};
+	TH_LOG("ucas map %p %p 0x%llx",
+	       (void *)map.user_addr, (void *)map.vcpu_addr, map.length);
+	rc = ioctl(self->vcpu_fd, KVM_S390_UCAS_MAP, &map);
+	ASSERT_EQ(0, rc) TH_LOG("ucas map result %d not expected, %s",
+				rc, strerror(errno));
+
+	TH_LOG("page in %p", (void *)self->base_gpa);
+	rc = ioctl(self->vcpu_fd, KVM_S390_VCPU_FAULT, self->base_gpa);
+	ASSERT_EQ(0, rc) TH_LOG("vcpu fault (%p) result %d not expected, %s",
+				(void *)self->base_hva, rc, strerror(errno));
+
+	self->sie_block->cpuflags &= ~CPUSTAT_STOPPED;
+}
+
+FIXTURE_TEARDOWN(uc_kvm)
+{
+	munmap(self->sie_block, PAGE_SIZE);
+	munmap(self->run, self->kvm_run_size);
+	close(self->vcpu_fd);
+	close(self->vm_fd);
+	close(self->kvm_fd);
+	free(self->vm_mem);
+}
+
+TEST_F(uc_kvm, uc_sie_assertions)
+{
+	/* assert interception of Code 08 (Program Interruption) is set */
+	EXPECT_EQ(0, self->sie_block->ecb & ECB_SPECI);
+}
+
+TEST_F(uc_kvm, uc_attr_mem_limit)
+{
+	u64 limit;
+	struct kvm_device_attr attr = {
+		.group = KVM_S390_VM_MEM_CTRL,
+		.attr = KVM_S390_VM_MEM_LIMIT_SIZE,
+		.addr = (unsigned long)&limit,
+	};
+	int rc;
+
+	rc = ioctl(self->vm_fd, KVM_GET_DEVICE_ATTR, &attr);
+	EXPECT_EQ(0, rc);
+	EXPECT_EQ(~0UL, limit);
+
+	/* assert set not supported */
+	rc = ioctl(self->vm_fd, KVM_SET_DEVICE_ATTR, &attr);
+	EXPECT_EQ(-1, rc);
+	EXPECT_EQ(EINVAL, errno);
+}
+
+TEST_F(uc_kvm, uc_no_dirty_log)
+{
+	struct kvm_dirty_log dlog;
+	int rc;
+
+	rc = ioctl(self->vm_fd, KVM_GET_DIRTY_LOG, &dlog);
+	EXPECT_EQ(-1, rc);
+	EXPECT_EQ(EINVAL, errno);
+}
+
 /**
  * Assert HPAGE CAP cannot be enabled on UCONTROL VM
  */