The number of user memslots can now be limited with KVM_CAP_MEMSLOTS_LIMIT
and, when limited, per-VM KVM_CHECK_EXTENSION(KVM_CAP_NR_MEMSLOTS) should
return the updated value.
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
.../testing/selftests/kvm/include/kvm_util.h | 1 +
tools/testing/selftests/kvm/lib/kvm_util.c | 30 ++++++++++++-
.../selftests/kvm/set_memory_region_test.c | 43 ++++++++++++++++---
3 files changed, 67 insertions(+), 7 deletions(-)
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 5cbb861525ed..eb759a54dfc6 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -86,6 +86,7 @@ enum vm_mem_backing_src_type {
};
int kvm_check_cap(long cap);
+int vm_check_cap(struct kvm_vm *vm, long cap);
int vm_enable_cap(struct kvm_vm *vm, struct kvm_enable_cap *cap);
int vcpu_enable_cap(struct kvm_vm *vm, uint32_t vcpu_id,
struct kvm_enable_cap *cap);
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index fa5a90e6c6f0..115947b77808 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -31,7 +31,7 @@ static void *align(void *x, size_t size)
}
/*
- * Capability
+ * Check a global capability
*
* Input Args:
* cap - Capability
@@ -64,6 +64,34 @@ int kvm_check_cap(long cap)
return ret;
}
+/*
+ * Check a per-VM capability
+ *
+ * Input Args:
+ * vm - Virtual Machine
+ * cap - Capability
+ *
+ * Output Args: None
+ *
+ * Return:
+ * On success, the Value corresponding to the capability (KVM_CAP_*)
+ * specified by the value of cap. On failure a TEST_ASSERT failure
+ * is produced.
+ *
+ * Looks up and returns the value corresponding to the capability
+ * (KVM_CAP_*) given by cap.
+ */
+int vm_check_cap(struct kvm_vm *vm, long cap)
+{
+ int ret;
+
+ ret = ioctl(vm->fd, KVM_CHECK_EXTENSION, cap);
+ TEST_ASSERT(ret != -1, "KVM_CHECK_EXTENSION IOCTL failed,\n"
+ " rc: %i errno: %i", ret, errno);
+
+ return ret;
+}
+
/* VM Enable Capability
*
* Input Args:
diff --git a/tools/testing/selftests/kvm/set_memory_region_test.c b/tools/testing/selftests/kvm/set_memory_region_test.c
index f127ed31dba7..66ed011f26f3 100644
--- a/tools/testing/selftests/kvm/set_memory_region_test.c
+++ b/tools/testing/selftests/kvm/set_memory_region_test.c
@@ -330,14 +330,14 @@ static void test_zero_memory_regions(void)
#endif /* __x86_64__ */
/*
- * Test it can be added memory slots up to KVM_CAP_NR_MEMSLOTS, then any
- * tentative to add further slots should fail.
+ * Test it can be added memory slots up to KVM_CAP_NR_MEMSLOTS/given limit,
+ * then any tentative to add further slots should fail.
*/
-static void test_add_max_memory_regions(void)
+static void test_add_max_memory_regions(int limit)
{
int ret;
struct kvm_vm *vm;
- uint32_t max_mem_slots;
+ uint32_t max_mem_slots, vm_mem_slots;
uint32_t slot;
uint64_t guest_addr = 0x0;
uint64_t mem_reg_npages;
@@ -346,10 +346,38 @@ static void test_add_max_memory_regions(void)
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");
- pr_info("Allowed number of memory slots: %i\n", max_mem_slots);
+
+ if (!limit)
+ pr_info("Allowed number of memory slots: %i\n", max_mem_slots);
vm = vm_create(VM_MODE_DEFAULT, 0, O_RDWR);
+ if (limit) {
+ struct kvm_enable_cap cap = {
+ .cap = KVM_CAP_MEMSLOTS_LIMIT,
+ .args[0] = limit
+ };
+
+ pr_info("Default max number of memory slots: %i\n", max_mem_slots);
+
+ vm_mem_slots = vm_check_cap(vm, KVM_CAP_NR_MEMSLOTS);
+ TEST_ASSERT(vm_mem_slots == max_mem_slots,
+ "KVM_CAP_NR_MEMSLOTS for a newly created VM: %d"
+ " should equal to the global limit: %d",
+ vm_mem_slots, max_mem_slots);
+
+ pr_info("Limiting the number of memory slots to: %i\n", limit);
+
+ vm_enable_cap(vm, &cap);
+ vm_mem_slots = vm_check_cap(vm, KVM_CAP_NR_MEMSLOTS);
+ TEST_ASSERT(vm_mem_slots == limit,
+ "KVM_CAP_NR_MEMSLOTS was limited to: %d"
+ " but is currently set to %d instead",
+ limit, vm_mem_slots);
+
+ max_mem_slots = vm_mem_slots;
+ }
+
mem_reg_npages = vm_calc_num_guest_pages(VM_MODE_DEFAULT, MEM_REGION_SIZE);
/* Check it can be added memory slots up to the maximum allowed */
@@ -394,7 +422,10 @@ int main(int argc, char *argv[])
test_zero_memory_regions();
#endif
- test_add_max_memory_regions();
+ test_add_max_memory_regions(0);
+
+ test_add_max_memory_regions(10);
+
#ifdef __x86_64__
if (argc > 1)
--
2.29.2
