This patch introduces the mem_slot_test test which checks an VM can have added memory slots up to the limit defined in KVM_CAP_NR_MEMSLOTS. Then attempt to add one more slot to verify it fails as expected.
Signed-off-by: Wainer dos Santos Moschetta wainersm@redhat.com --- tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 3 + tools/testing/selftests/kvm/mem_slot_test.c | 92 +++++++++++++++++++++ 3 files changed, 96 insertions(+) create mode 100644 tools/testing/selftests/kvm/mem_slot_test.c
diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index 30072c3f52fb..b1b94d50f6a2 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -17,3 +17,4 @@ /clear_dirty_log_test /dirty_log_test /kvm_create_max_vcpus +/mem_slot_test diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index d91c53b726e6..070133349403 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -30,16 +30,19 @@ TEST_GEN_PROGS_x86_64 += x86_64/svm_vmcall_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_x86_64 += mem_slot_test
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_aarch64 += mem_slot_test
TEST_GEN_PROGS_s390x = s390x/memop TEST_GEN_PROGS_s390x += s390x/sync_regs_test TEST_GEN_PROGS_s390x += s390x/resets TEST_GEN_PROGS_s390x += dirty_log_test TEST_GEN_PROGS_s390x += kvm_create_max_vcpus +TEST_GEN_PROGS_s390x += mem_slot_test
TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M)) LIBKVM += $(LIBKVM_$(UNAME_M)) diff --git a/tools/testing/selftests/kvm/mem_slot_test.c b/tools/testing/selftests/kvm/mem_slot_test.c new file mode 100644 index 000000000000..75d2bbd71642 --- /dev/null +++ b/tools/testing/selftests/kvm/mem_slot_test.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * mem_slot_test + * + * Copyright (C) 2020, Red Hat, Inc. + * + * Test it can be added memory slots up to KVM_CAP_NR_MEMSLOTS, then any + * tentative to add further slots should fail. + */ +#define _GNU_SOURCE /* for program_invocation_short_name */ +#include <linux/kvm.h> +#include <sys/mman.h> +#include <unistd.h> + +#include "test_util.h" +#include "kvm_util.h" + +/* Memory region flags */ +#define MEM_REG_FLAGS KVM_MEM_LOG_DIRTY_PAGES + +/* Guest VM mode */ +#define GUEST_VM_MODE VM_MODE_DEFAULT + +int main(int argc, char *argv[]) +{ + struct kvm_vm *vm; + /* Maximum allowed number of memory slots */ + uint32_t max_mem_slots; + /* Slot number */ + uint32_t slot; + /* Number of pages in a memory region */ + uint64_t mem_reg_npages; + /* Memory region size */ + uint64_t mem_reg_size; + /* Guest physical memory guest_address */ + uint64_t guest_addr; + /* VM page size */ + uint64_t vm_page_size; + int ret; + + max_mem_slots = kvm_check_cap(KVM_CAP_NR_MEMSLOTS); + TEST_ASSERT(max_mem_slots > 0, + "KVM_CAP_NR_MEMSLOTS should be greater than 0"); + DEBUG("Allowed number of memory slots: %i\n", max_mem_slots); + + vm = vm_create(GUEST_VM_MODE, 0, O_RDWR); + + /* Determine the minimal number of pages as possible per region. */ + vm_page_size = vm_get_page_size(vm); +#ifdef __s390x__ + mem_reg_size = 0x100000; +#else + uint64_t host_page_size = sysconf(_SC_PAGESIZE); + + mem_reg_size = (host_page_size > vm_page_size) ? host_page_size : + vm_page_size; +#endif + mem_reg_npages = mem_reg_size / vm_page_size; + guest_addr = 0x0; + + /* Check it can be added memory slots up to the maximum allowed */ + DEBUG("Adding slots 0..%i, each memory region with %ldK size\n", + (max_mem_slots - 1), mem_reg_size >> 10); + for (slot = 0; slot < max_mem_slots; slot++) { + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + guest_addr, slot, mem_reg_npages, + MEM_REG_FLAGS); + guest_addr += mem_reg_size; + } + + /* Check it cannot be added memory slots beyond the limit */ + guest_addr += mem_reg_size; + void *mem = mmap(NULL, mem_reg_size, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + TEST_ASSERT(mem != NULL, "Failed to mmap() host"); + + struct kvm_userspace_memory_region kvm_region = { + .slot = slot, + .flags = MEM_REG_FLAGS, + .guest_phys_addr = guest_addr, + .memory_size = mem_reg_size, + .userspace_addr = (uint64_t) mem, + }; + + ret = ioctl(vm_get_fd(vm), KVM_SET_USER_MEMORY_REGION, &kvm_region); + TEST_ASSERT(ret == -1, "Adding one more memory slot should fail"); + + munmap(mem, mem_reg_size); + kvm_vm_free(vm); + + return 0; +}