Merge tag 'kvm-s390-next-5.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: add kselftests

This is the initial implementation for KVM selftests on s390.

10 files changed, 494 insertions, 10 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 1be025959be9..debbb7b97c98 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8797,6 +8797,8 @@ F:	arch/s390/include/asm/gmap.h
 F:	arch/s390/include/asm/kvm*
 F:	arch/s390/kvm/
 F:	arch/s390/mm/gmap.c
+F:	tools/testing/selftests/kvm/s390x/
+F:	tools/testing/selftests/kvm/*/s390x/
 
 KERNEL VIRTUAL MACHINE FOR X86 (KVM/x86)
 M:	Paolo Bonzini <pbonzini@redhat.com>
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 62afd0b43074..ba7849751989 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -10,11 +10,11 @@ UNAME_M := $(shell uname -m)
 LIBKVM = lib/assert.c lib/elf.c lib/io.c lib/kvm_util.c lib/ucall.c lib/sparsebit.c
 LIBKVM_x86_64 = lib/x86_64/processor.c lib/x86_64/vmx.c
 LIBKVM_aarch64 = lib/aarch64/processor.c
+LIBKVM_s390x = lib/s390x/processor.c
 
 TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test
 TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test
 TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid
-TEST_GEN_PROGS_x86_64 += x86_64/kvm_create_max_vcpus
 TEST_GEN_PROGS_x86_64 += x86_64/mmio_warning_test
 TEST_GEN_PROGS_x86_64 += x86_64/platform_info_test
 TEST_GEN_PROGS_x86_64 += x86_64/set_sregs_test
@@ -26,9 +26,14 @@ TEST_GEN_PROGS_x86_64 += x86_64/vmx_set_nested_state_test
 TEST_GEN_PROGS_x86_64 += x86_64/vmx_tsc_adjust_test
 TEST_GEN_PROGS_x86_64 += clear_dirty_log_test
 TEST_GEN_PROGS_x86_64 += dirty_log_test
+TEST_GEN_PROGS_x86_64 += kvm_create_max_vcpus
 
 TEST_GEN_PROGS_aarch64 += clear_dirty_log_test
 TEST_GEN_PROGS_aarch64 += dirty_log_test
+TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
+
+TEST_GEN_PROGS_s390x += s390x/sync_regs_test
+TEST_GEN_PROGS_s390x += kvm_create_max_vcpus
 
 TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
 LIBKVM += $(LIBKVM_$(UNAME_M))
@@ -43,7 +48,12 @@ CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \
 no-pie-option := $(call try-run, echo 'int main() { return 0; }' | \
         $(CC) -Werror $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -no-pie -x c - -o "$$TMP", -no-pie)
 
-LDFLAGS += -pthread $(no-pie-option)
+# On s390, build the testcases KVM-enabled
+pgste-option = $(call try-run, echo 'int main() { return 0; }' | \
+	$(CC) -Werror -Wl$(comma)--s390-pgste -x c - -o "$$TMP",-Wl$(comma)--s390-pgste)
+
+
+LDFLAGS += -pthread $(no-pie-option) $(pgste-option)
 
 # After inclusion, $(OUTPUT) is defined and
 # $(TEST_GEN_PROGS) starts with $(OUTPUT)/
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 00235f5932f0..e0e66b115ef2 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -41,6 +41,12 @@ enum vm_guest_mode {
 	NUM_VM_MODES,
 };
 
+#ifdef __aarch64__
+#define VM_MODE_DEFAULT VM_MODE_P40V48_4K
+#else
+#define VM_MODE_DEFAULT VM_MODE_P52V48_4K
+#endif
+
 #define vm_guest_mode_string(m) vm_guest_mode_string[m]
 extern const char * const vm_guest_mode_string[];
 
@@ -111,10 +117,12 @@ void vcpu_sregs_set(struct kvm_vm *vm, uint32_t vcpuid,
 		    struct kvm_sregs *sregs);
 int _vcpu_sregs_set(struct kvm_vm *vm, uint32_t vcpuid,
 		    struct kvm_sregs *sregs);
+#ifdef __KVM_HAVE_VCPU_EVENTS
 void vcpu_events_get(struct kvm_vm *vm, uint32_t vcpuid,
 		     struct kvm_vcpu_events *events);
 void vcpu_events_set(struct kvm_vm *vm, uint32_t vcpuid,
 		     struct kvm_vcpu_events *events);
+#endif
 #ifdef __x86_64__
 void vcpu_nested_state_get(struct kvm_vm *vm, uint32_t vcpuid,
 			   struct kvm_nested_state *state);
diff --git a/tools/testing/selftests/kvm/include/s390x/processor.h b/tools/testing/selftests/kvm/include/s390x/processor.h
new file mode 100644
index 000000000000..e0e96a5f608c
--- /dev/null
+++ b/tools/testing/selftests/kvm/include/s390x/processor.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * s390x processor specific defines
+ */
+#ifndef SELFTEST_KVM_PROCESSOR_H
+#define SELFTEST_KVM_PROCESSOR_H
+
+/* Bits in the region/segment table entry */
+#define REGION_ENTRY_ORIGIN	~0xfffUL /* region/segment table origin	   */
+#define REGION_ENTRY_PROTECT	0x200	 /* region protection bit	   */
+#define REGION_ENTRY_NOEXEC	0x100	 /* region no-execute bit	   */
+#define REGION_ENTRY_OFFSET	0xc0	 /* region table offset		   */
+#define REGION_ENTRY_INVALID	0x20	 /* invalid region table entry	   */
+#define REGION_ENTRY_TYPE	0x0c	 /* region/segment table type mask */
+#define REGION_ENTRY_LENGTH	0x03	 /* region third length		   */
+
+/* Bits in the page table entry */
+#define PAGE_INVALID	0x400		/* HW invalid bit    */
+#define PAGE_PROTECT	0x200		/* HW read-only bit  */
+#define PAGE_NOEXEC	0x100		/* HW no-execute bit */
+
+#endif
diff --git a/tools/testing/selftests/kvm/x86_64/kvm_create_max_vcpus.c b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
index 429226bc6a92..231d79e57774 100644
--- a/tools/testing/selftests/kvm/x86_64/kvm_create_max_vcpus.c
+++ b/tools/testing/selftests/kvm/kvm_create_max_vcpus.c
@@ -27,7 +27,7 @@ void test_vcpu_creation(int first_vcpu_id, int num_vcpus)
 	printf("Testing creating %d vCPUs, with IDs %d...%d.\n",
 	       num_vcpus, first_vcpu_id, first_vcpu_id + num_vcpus - 1);
 
-	vm = vm_create(VM_MODE_P52V48_4K, DEFAULT_GUEST_PHY_PAGES, O_RDWR);
+	vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR);
 
 	for (i = 0; i < num_vcpus; i++) {
 		int vcpu_id = first_vcpu_id + i;
diff --git a/tools/testing/selftests/kvm/lib/aarch64/processor.c b/tools/testing/selftests/kvm/lib/aarch64/processor.c
index af2023d818a5..486400a97374 100644
--- a/tools/testing/selftests/kvm/lib/aarch64/processor.c
+++ b/tools/testing/selftests/kvm/lib/aarch64/processor.c
@@ -227,7 +227,7 @@ struct kvm_vm *vm_create_default(uint32_t vcpuid, uint64_t extra_mem_pages,
 	uint64_t extra_pg_pages = (extra_mem_pages / ptrs_per_4k_pte) * 2;
 	struct kvm_vm *vm;
 
-	vm = vm_create(VM_MODE_P40V48_4K, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);
+	vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);
 
 	kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
 	vm_vcpu_add_default(vm, vcpuid, guest_code);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 221e3fa46680..6e49bb039376 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -556,6 +556,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
 	int ret;
 	struct userspace_mem_region *region;
 	size_t huge_page_size = KVM_UTIL_PGS_PER_HUGEPG * vm->page_size;
+	size_t alignment;
 
 	TEST_ASSERT((guest_paddr % vm->page_size) == 0, "Guest physical "
 		"address not on a page boundary.\n"
@@ -605,9 +606,20 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
 	TEST_ASSERT(region != NULL, "Insufficient Memory");
 	region->mmap_size = npages * vm->page_size;
 
-	/* Enough memory to align up to a huge page. */
+#ifdef __s390x__
+	/* On s390x, the host address must be aligned to 1M (due to PGSTEs) */
+	alignment = 0x100000;
+#else
+	alignment = 1;
+#endif
+
 	if (src_type == VM_MEM_SRC_ANONYMOUS_THP)
-		region->mmap_size += huge_page_size;
+		alignment = max(huge_page_size, alignment);
+
+	/* Add enough memory to align up if necessary */
+	if (alignment > 1)
+		region->mmap_size += alignment;
+
 	region->mmap_start = mmap(NULL, region->mmap_size,
 				  PROT_READ | PROT_WRITE,
 				  MAP_PRIVATE | MAP_ANONYMOUS
@@ -617,9 +629,8 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm,
 		    "test_malloc failed, mmap_start: %p errno: %i",
 		    region->mmap_start, errno);
 
-	/* Align THP allocation up to start of a huge page. */
-	region->host_mem = align(region->mmap_start,
-				 src_type == VM_MEM_SRC_ANONYMOUS_THP ?  huge_page_size : 1);
+	/* Align host address */
+	region->host_mem = align(region->mmap_start, alignment);
 
 	/* As needed perform madvise */
 	if (src_type == VM_MEM_SRC_ANONYMOUS || src_type == VM_MEM_SRC_ANONYMOUS_THP) {
@@ -1218,6 +1229,7 @@ void vcpu_regs_set(struct kvm_vm *vm, uint32_t vcpuid, struct kvm_regs *regs)
 		ret, errno);
 }
 
+#ifdef __KVM_HAVE_VCPU_EVENTS
 void vcpu_events_get(struct kvm_vm *vm, uint32_t vcpuid,
 		     struct kvm_vcpu_events *events)
 {
@@ -1243,6 +1255,7 @@ void vcpu_events_set(struct kvm_vm *vm, uint32_t vcpuid,
 	TEST_ASSERT(ret == 0, "KVM_SET_VCPU_EVENTS, failed, rc: %i errno: %i",
 		ret, errno);
 }
+#endif
 
 #ifdef __x86_64__
 void vcpu_nested_state_get(struct kvm_vm *vm, uint32_t vcpuid,
diff --git a/tools/testing/selftests/kvm/lib/s390x/processor.c b/tools/testing/selftests/kvm/lib/s390x/processor.c
new file mode 100644
index 000000000000..32a02360b1eb
--- /dev/null
+++ b/tools/testing/selftests/kvm/lib/s390x/processor.c
@@ -0,0 +1,278 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KVM selftest s390x library code - CPU-related functions (page tables...)
+ *
+ * Copyright (C) 2019, Red Hat, Inc.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_name */
+
+#include "processor.h"
+#include "kvm_util.h"
+#include "../kvm_util_internal.h"
+
+#define KVM_GUEST_PAGE_TABLE_MIN_PADDR		0x180000
+
+#define PAGES_PER_REGION 4
+
+void virt_pgd_alloc(struct kvm_vm *vm, uint32_t memslot)
+{
+	vm_paddr_t paddr;
+
+	TEST_ASSERT(vm->page_size == 4096, "Unsupported page size: 0x%x",
+		    vm->page_size);
+
+	if (vm->pgd_created)
+		return;
+
+	paddr = vm_phy_pages_alloc(vm, PAGES_PER_REGION,
+				   KVM_GUEST_PAGE_TABLE_MIN_PADDR, memslot);
+	memset(addr_gpa2hva(vm, paddr), 0xff, PAGES_PER_REGION * vm->page_size);
+
+	vm->pgd = paddr;
+	vm->pgd_created = true;
+}
+
+/*
+ * Allocate 4 pages for a region/segment table (ri < 4), or one page for
+ * a page table (ri == 4). Returns a suitable region/segment table entry
+ * which points to the freshly allocated pages.
+ */
+static uint64_t virt_alloc_region(struct kvm_vm *vm, int ri, uint32_t memslot)
+{
+	uint64_t taddr;
+
+	taddr = vm_phy_pages_alloc(vm,  ri < 4 ? PAGES_PER_REGION : 1,
+				   KVM_GUEST_PAGE_TABLE_MIN_PADDR, memslot);
+	memset(addr_gpa2hva(vm, taddr), 0xff, PAGES_PER_REGION * vm->page_size);
+
+	return (taddr & REGION_ENTRY_ORIGIN)
+		| (((4 - ri) << 2) & REGION_ENTRY_TYPE)
+		| ((ri < 4 ? (PAGES_PER_REGION - 1) : 0) & REGION_ENTRY_LENGTH);
+}
+
+/*
+ * VM Virtual Page Map
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   gva - VM Virtual Address
+ *   gpa - VM Physical Address
+ *   memslot - Memory region slot for new virtual translation tables
+ *
+ * Output Args: None
+ *
+ * Return: None
+ *
+ * Within the VM given by vm, creates a virtual translation for the page
+ * starting at vaddr to the page starting at paddr.
+ */
+void virt_pg_map(struct kvm_vm *vm, uint64_t gva, uint64_t gpa,
+		 uint32_t memslot)
+{
+	int ri, idx;
+	uint64_t *entry;
+
+	TEST_ASSERT((gva % vm->page_size) == 0,
+		"Virtual address not on page boundary,\n"
+		"  vaddr: 0x%lx vm->page_size: 0x%x",
+		gva, vm->page_size);
+	TEST_ASSERT(sparsebit_is_set(vm->vpages_valid,
+		(gva >> vm->page_shift)),
+		"Invalid virtual address, vaddr: 0x%lx",
+		gva);
+	TEST_ASSERT((gpa % vm->page_size) == 0,
+		"Physical address not on page boundary,\n"
+		"  paddr: 0x%lx vm->page_size: 0x%x",
+		gva, vm->page_size);
+	TEST_ASSERT((gpa >> vm->page_shift) <= vm->max_gfn,
+		"Physical address beyond beyond maximum supported,\n"
+		"  paddr: 0x%lx vm->max_gfn: 0x%lx vm->page_size: 0x%x",
+		gva, vm->max_gfn, vm->page_size);
+
+	/* Walk through region and segment tables */
+	entry = addr_gpa2hva(vm, vm->pgd);
+	for (ri = 1; ri <= 4; ri++) {
+		idx = (gva >> (64 - 11 * ri)) & 0x7ffu;
+		if (entry[idx] & REGION_ENTRY_INVALID)
+			entry[idx] = virt_alloc_region(vm, ri, memslot);
+		entry = addr_gpa2hva(vm, entry[idx] & REGION_ENTRY_ORIGIN);
+	}
+
+	/* Fill in page table entry */
+	idx = (gva >> 12) & 0x0ffu;		/* page index */
+	if (!(entry[idx] & PAGE_INVALID))
+		fprintf(stderr,
+			"WARNING: PTE for gpa=0x%"PRIx64" already set!\n", gpa);
+	entry[idx] = gpa;
+}
+
+/*
+ * Address Guest Virtual to Guest Physical
+ *
+ * Input Args:
+ *   vm - Virtual Machine
+ *   gpa - VM virtual address
+ *
+ * Output Args: None
+ *
+ * Return:
+ *   Equivalent VM physical address
+ *
+ * Translates the VM virtual address given by gva to a VM physical
+ * address and then locates the memory region containing the VM
+ * physical address, within the VM given by vm.  When found, the host
+ * virtual address providing the memory to the vm physical address is
+ * returned.
+ * A TEST_ASSERT failure occurs if no region containing translated
+ * VM virtual address exists.
+ */
+vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva)
+{
+	int ri, idx;
+	uint64_t *entry;
+
+	TEST_ASSERT(vm->page_size == 4096, "Unsupported page size: 0x%x",
+		    vm->page_size);
+
+	entry = addr_gpa2hva(vm, vm->pgd);
+	for (ri = 1; ri <= 4; ri++) {
+		idx = (gva >> (64 - 11 * ri)) & 0x7ffu;
+		TEST_ASSERT(!(entry[idx] & REGION_ENTRY_INVALID),
+			    "No region mapping for vm virtual address 0x%lx",
+			    gva);
+		entry = addr_gpa2hva(vm, entry[idx] & REGION_ENTRY_ORIGIN);
+	}
+
+	idx = (gva >> 12) & 0x0ffu;		/* page index */
+
+	TEST_ASSERT(!(entry[idx] & PAGE_INVALID),
+		    "No page mapping for vm virtual address 0x%lx", gva);
+
+	return (entry[idx] & ~0xffful) + (gva & 0xffful);
+}
+
+static void virt_dump_ptes(FILE *stream, struct kvm_vm *vm, uint8_t indent,
+			   uint64_t ptea_start)
+{
+	uint64_t *pte, ptea;
+
+	for (ptea = ptea_start; ptea < ptea_start + 0x100 * 8; ptea += 8) {
+		pte = addr_gpa2hva(vm, ptea);
+		if (*pte & PAGE_INVALID)
+			continue;
+		fprintf(stream, "%*spte @ 0x%lx: 0x%016lx\n",
+			indent, "", ptea, *pte);
+	}
+}
+
+static void virt_dump_region(FILE *stream, struct kvm_vm *vm, uint8_t indent,
+			     uint64_t reg_tab_addr)
+{
+	uint64_t addr, *entry;
+
+	for (addr = reg_tab_addr; addr < reg_tab_addr + 0x400 * 8; addr += 8) {
+		entry = addr_gpa2hva(vm, addr);
+		if (*entry & REGION_ENTRY_INVALID)
+			continue;
+		fprintf(stream, "%*srt%lde @ 0x%lx: 0x%016lx\n",
+			indent, "", 4 - ((*entry & REGION_ENTRY_TYPE) >> 2),
+			addr, *entry);
+		if (*entry & REGION_ENTRY_TYPE) {
+			virt_dump_region(stream, vm, indent + 2,
+					 *entry & REGION_ENTRY_ORIGIN);
+		} else {
+			virt_dump_ptes(stream, vm, indent + 2,
+				       *entry & REGION_ENTRY_ORIGIN);
+		}
+	}
+}
+
+void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent)
+{
+	if (!vm->pgd_created)
+		return;
+
+	virt_dump_region(stream, vm, indent, vm->pgd);
+}
+
+/*
+ * Create a VM with reasonable defaults
+ *
+ * Input Args:
+ *   vcpuid - The id of the single VCPU to add to the VM.
+ *   extra_mem_pages - The size of extra memories to add (this will
+ *                     decide how much extra space we will need to
+ *                     setup the page tables using mem slot 0)
+ *   guest_code - The vCPU's entry point
+ *
+ * Output Args: None
+ *
+ * Return:
+ *   Pointer to opaque structure that describes the created VM.
+ */
+struct kvm_vm *vm_create_default(uint32_t vcpuid, uint64_t extra_mem_pages,
+				 void *guest_code)
+{
+	/*
+	 * The additional amount of pages required for the page tables is:
+	 * 1 * n / 256 + 4 * (n / 256) / 2048 + 4 * (n / 256) / 2048^2 + ...
+	 * which is definitely smaller than (n / 256) * 2.
+	 */
+	uint64_t extra_pg_pages = extra_mem_pages / 256 * 2;
+	struct kvm_vm *vm;
+
+	vm = vm_create(VM_MODE_DEFAULT,
+		       DEFAULT_GUEST_PHY_PAGES + extra_pg_pages, O_RDWR);
+
+	kvm_vm_elf_load(vm, program_invocation_name, 0, 0);
+	vm_vcpu_add_default(vm, vcpuid, guest_code);
+
+	return vm;
+}
+
+/*
+ * Adds a vCPU with reasonable defaults (i.e. a stack and initial PSW)
+ *
+ * Input Args:
+ *   vcpuid - The id of the VCPU to add to the VM.
+ *   guest_code - The vCPU's entry point
+ */
+void vm_vcpu_add_default(struct kvm_vm *vm, uint32_t vcpuid, void *guest_code)
+{
+	size_t stack_size =  DEFAULT_STACK_PGS * getpagesize();
+	uint64_t stack_vaddr;
+	struct kvm_regs regs;
+	struct kvm_sregs sregs;
+	struct kvm_run *run;
+
+	TEST_ASSERT(vm->page_size == 4096, "Unsupported page size: 0x%x",
+		    vm->page_size);
+
+	stack_vaddr = vm_vaddr_alloc(vm, stack_size,
+				     DEFAULT_GUEST_STACK_VADDR_MIN, 0, 0);
+
+	vm_vcpu_add(vm, vcpuid);
+
+	/* Setup guest registers */
+	vcpu_regs_get(vm, vcpuid, &regs);
+	regs.gprs[15] = stack_vaddr + (DEFAULT_STACK_PGS * getpagesize()) - 160;
+	vcpu_regs_set(vm, vcpuid, &regs);
+
+	vcpu_sregs_get(vm, vcpuid, &sregs);
+	sregs.crs[0] |= 0x00040000;		/* Enable floating point regs */
+	sregs.crs[1] = vm->pgd | 0xf;		/* Primary region table */
+	vcpu_sregs_set(vm, vcpuid, &sregs);
+
+	run = vcpu_state(vm, vcpuid);
+	run->psw_mask = 0x0400000180000000ULL;  /* DAT enabled + 64 bit mode */
+	run->psw_addr = (uintptr_t)guest_code;
+}
+
+void vcpu_dump(FILE *stream, struct kvm_vm *vm, uint32_t vcpuid, uint8_t indent)
+{
+	struct vcpu *vcpu = vm->vcpu_head;
+
+	fprintf(stream, "%*spstate: psw: 0x%.16llx:0x%.16llx\n",
+		indent, "", vcpu->state->psw_mask, vcpu->state->psw_addr);
+}
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c
index b430f962e323..6cb34a0fa200 100644
--- a/tools/testing/selftests/kvm/lib/x86_64/processor.c
+++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c
@@ -821,7 +821,7 @@ struct kvm_vm *vm_create_default(uint32_t vcpuid, uint64_t extra_mem_pages,
 	uint64_t extra_pg_pages = extra_mem_pages / 512 * 2;
 
 	/* Create VM */
-	vm = vm_create(VM_MODE_P52V48_4K,
+	vm = vm_create(VM_MODE_DEFAULT,
 		       DEFAULT_GUEST_PHY_PAGES + extra_pg_pages,
 		       O_RDWR);
 
diff --git a/tools/testing/selftests/kvm/s390x/sync_regs_test.c b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
new file mode 100644
index 000000000000..e85ff0d69548
--- /dev/null
+++ b/tools/testing/selftests/kvm/s390x/sync_regs_test.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Test for s390x KVM_CAP_SYNC_REGS
+ *
+ * Based on the same test for x86:
+ * Copyright (C) 2018, Google LLC.
+ *
+ * Adaptions for s390x:
+ * Copyright (C) 2019, Red Hat, Inc.
+ *
+ * Test expected behavior of the KVM_CAP_SYNC_REGS functionality.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+
+#include "test_util.h"
+#include "kvm_util.h"
+
+#define VCPU_ID 5
+
+static void guest_code(void)
+{
+	for (;;) {
+		asm volatile ("diag 0,0,0x501");
+		asm volatile ("ahi 11,1");
+	}
+}
+
+#define REG_COMPARE(reg) \
+	TEST_ASSERT(left->reg == right->reg, \
+		    "Register " #reg \
+		    " values did not match: 0x%llx, 0x%llx\n", \
+		    left->reg, right->reg)
+
+static void compare_regs(struct kvm_regs *left, struct kvm_sync_regs *right)
+{
+	int i;
+
+	for (i = 0; i < 16; i++)
+		REG_COMPARE(gprs[i]);
+}
+
+static void compare_sregs(struct kvm_sregs *left, struct kvm_sync_regs *right)
+{
+	int i;
+
+	for (i = 0; i < 16; i++)
+		REG_COMPARE(acrs[i]);
+
+	for (i = 0; i < 16; i++)
+		REG_COMPARE(crs[i]);
+}
+
+#undef REG_COMPARE
+
+#define TEST_SYNC_FIELDS   (KVM_SYNC_GPRS|KVM_SYNC_ACRS|KVM_SYNC_CRS)
+#define INVALID_SYNC_FIELD 0x80000000
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vm *vm;
+	struct kvm_run *run;
+	struct kvm_regs regs;
+	struct kvm_sregs sregs;
+	int rv, cap;
+
+	/* Tell stdout not to buffer its content */
+	setbuf(stdout, NULL);
+
+	cap = kvm_check_cap(KVM_CAP_SYNC_REGS);
+	if (!cap) {
+		fprintf(stderr, "CAP_SYNC_REGS not supported, skipping test\n");
+		exit(KSFT_SKIP);
+	}
+
+	/* Create VM */
+	vm = vm_create_default(VCPU_ID, 0, guest_code);
+
+	run = vcpu_state(vm, VCPU_ID);
+
+	/* Request and verify all valid register sets. */
+	run->kvm_valid_regs = TEST_SYNC_FIELDS;
+	rv = _vcpu_run(vm, VCPU_ID);
+	TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
+	TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
+		    "Unexpected exit reason: %u (%s)\n",
+		    run->exit_reason,
+		    exit_reason_str(run->exit_reason));
+	TEST_ASSERT(run->s390_sieic.icptcode == 4 &&
+		    (run->s390_sieic.ipa >> 8) == 0x83 &&
+		    (run->s390_sieic.ipb >> 16) == 0x501,
+		    "Unexpected interception code: ic=%u, ipa=0x%x, ipb=0x%x\n",
+		    run->s390_sieic.icptcode, run->s390_sieic.ipa,
+		    run->s390_sieic.ipb);
+
+	vcpu_regs_get(vm, VCPU_ID, &regs);
+	compare_regs(&regs, &run->s.regs);
+
+	vcpu_sregs_get(vm, VCPU_ID, &sregs);
+	compare_sregs(&sregs, &run->s.regs);
+
+	/* Set and verify various register values */
+	run->s.regs.gprs[11] = 0xBAD1DEA;
+	run->s.regs.acrs[0] = 1 << 11;
+
+	run->kvm_valid_regs = TEST_SYNC_FIELDS;
+	run->kvm_dirty_regs = KVM_SYNC_GPRS | KVM_SYNC_ACRS;
+	rv = _vcpu_run(vm, VCPU_ID);
+	TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
+	TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
+		    "Unexpected exit reason: %u (%s)\n",
+		    run->exit_reason,
+		    exit_reason_str(run->exit_reason));
+	TEST_ASSERT(run->s.regs.gprs[11] == 0xBAD1DEA + 1,
+		    "r11 sync regs value incorrect 0x%llx.",
+		    run->s.regs.gprs[11]);
+	TEST_ASSERT(run->s.regs.acrs[0]  == 1 << 11,
+		    "acr0 sync regs value incorrect 0x%llx.",
+		    run->s.regs.acrs[0]);
+
+	vcpu_regs_get(vm, VCPU_ID, &regs);
+	compare_regs(&regs, &run->s.regs);
+
+	vcpu_sregs_get(vm, VCPU_ID, &sregs);
+	compare_sregs(&sregs, &run->s.regs);
+
+	/* Clear kvm_dirty_regs bits, verify new s.regs values are
+	 * overwritten with existing guest values.
+	 */
+	run->kvm_valid_regs = TEST_SYNC_FIELDS;
+	run->kvm_dirty_regs = 0;
+	run->s.regs.gprs[11] = 0xDEADBEEF;
+	rv = _vcpu_run(vm, VCPU_ID);
+	TEST_ASSERT(rv == 0, "vcpu_run failed: %d\n", rv);
+	TEST_ASSERT(run->exit_reason == KVM_EXIT_S390_SIEIC,
+		    "Unexpected exit reason: %u (%s)\n",
+		    run->exit_reason,
+		    exit_reason_str(run->exit_reason));
+	TEST_ASSERT(run->s.regs.gprs[11] != 0xDEADBEEF,
+		    "r11 sync regs value incorrect 0x%llx.",
+		    run->s.regs.gprs[11]);
+
+	kvm_vm_free(vm);
+
+	return 0;
+}