Commit 3bf0fcd7 authored by Vitaly Kuznetsov's avatar Vitaly Kuznetsov Committed by Paolo Bonzini
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KVM: selftests: Speed up set_memory_region_test 



After commit 4fc096a9 ("KVM: Raise the maximum number of user memslots")
set_memory_region_test may take too long, reports are that the default
timeout value we have (120s) may not be enough even on a physical host.

Speed things up a bit by throwing away vm_userspace_mem_region_add() usage
from test_add_max_memory_regions(), we don't really need to do the majority
of the stuff it does for the sake of this test.

On my AMD EPYC 7401P, # time ./set_memory_region_test
pre-patch:
 Testing KVM_RUN with zero added memory regions
 Allowed number of memory slots: 32764
 Adding slots 0..32763, each memory region with 2048K size
 Testing MOVE of in-use region, 10 loops
 Testing DELETE of in-use region, 10 loops

 real	0m44.917s
 user	0m7.416s
 sys	0m34.601s

post-patch:
 Testing KVM_RUN with zero added memory regions
 Allowed number of memory slots: 32764
 Adding slots 0..32763, each memory region with 2048K size
 Testing MOVE of in-use region, 10 loops
 Testing DELETE of in-use region, 10 loops

 real	0m20.714s
 user	0m0.109s
 sys	0m18.359s

Reported-by: default avatarkernel test robot <oliver.sang@intel.com>
Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210426130121.758229-1-vkuznets@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent d4787579

tools/testing/selftests/kvm/set_memory_region_test.c

+45 −16
Original line number Diff line number Diff line
@@ -329,6 +329,22 @@ static void test_zero_memory_regions(void) 
}

#endif /* __x86_64__ */



static int test_memory_region_add(struct kvm_vm *vm, void *mem, uint32_t slot,

				   uint32_t size, uint64_t guest_addr)

{

	struct kvm_userspace_memory_region region;

	int ret;



	region.slot = slot;

	region.flags = 0;

	region.guest_phys_addr = guest_addr;

	region.memory_size = size;

	region.userspace_addr = (uintptr_t) mem;

	ret = ioctl(vm_get_fd(vm), KVM_SET_USER_MEMORY_REGION, &region);



	return ret;

}



/*

 * Test it can be added memory slots up to KVM_CAP_NR_MEMSLOTS, then any

 * tentative to add further slots should fail.
@@ -339,9 +355,15 @@ static void test_add_max_memory_regions(void) 
	struct kvm_vm *vm;

	uint32_t max_mem_slots;

	uint32_t slot;

	uint64_t guest_addr = 0x0;

	uint64_t mem_reg_npages;

	void *mem;

	void *mem, *mem_aligned, *mem_extra;

	size_t alignment;



#ifdef __s390x__

	/* On s390x, the host address must be aligned to 1M (due to PGSTEs) */

	alignment = 0x100000;

#else

	alignment = 1;

#endif



	max_mem_slots = kvm_check_cap(KVM_CAP_NR_MEMSLOTS);

	TEST_ASSERT(max_mem_slots > 0,
@@ -350,30 +372,37 @@ static void test_add_max_memory_regions(void) 


	vm = vm_create(VM_MODE_DEFAULT, 0, O_RDWR);



	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 */

	pr_info("Adding slots 0..%i, each memory region with %dK size\n",

		(max_mem_slots - 1), MEM_REGION_SIZE >> 10);



	mem = mmap(NULL, MEM_REGION_SIZE * max_mem_slots + alignment,

		   PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

	TEST_ASSERT(mem != MAP_FAILED, "Failed to mmap() host");

	mem_aligned = (void *)(((size_t) mem + alignment - 1) & ~(alignment - 1));



	for (slot = 0; slot < max_mem_slots; slot++) {

		vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,

					    guest_addr, slot, mem_reg_npages,

					    0);

		guest_addr += MEM_REGION_SIZE;

		ret = test_memory_region_add(vm, mem_aligned +

					     ((uint64_t)slot * MEM_REGION_SIZE),

					     slot, MEM_REGION_SIZE,

					     (uint64_t)slot * MEM_REGION_SIZE);

		TEST_ASSERT(ret == 0, "KVM_SET_USER_MEMORY_REGION IOCTL failed,\n"

			    "  rc: %i errno: %i slot: %i\n",

			    ret, errno, slot);

	}



	/* Check it cannot be added memory slots beyond the limit */

	mem = mmap(NULL, MEM_REGION_SIZE, PROT_READ | PROT_WRITE,

	mem_extra = mmap(NULL, MEM_REGION_SIZE, PROT_READ | PROT_WRITE,

			 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

	TEST_ASSERT(mem != MAP_FAILED, "Failed to mmap() host");

	TEST_ASSERT(mem_extra != MAP_FAILED, "Failed to mmap() host");



	ret = ioctl(vm_get_fd(vm), KVM_SET_USER_MEMORY_REGION,

		    &(struct kvm_userspace_memory_region) {slot, 0, guest_addr,

		    MEM_REGION_SIZE, (uint64_t) mem});

	ret = test_memory_region_add(vm, mem_extra, max_mem_slots, MEM_REGION_SIZE,

				     (uint64_t)max_mem_slots * MEM_REGION_SIZE);

	TEST_ASSERT(ret == -1 && errno == EINVAL,

		    "Adding one more memory slot should fail with EINVAL");



	munmap(mem, MEM_REGION_SIZE);

	munmap(mem, MEM_REGION_SIZE * max_mem_slots + alignment);

	munmap(mem_extra, MEM_REGION_SIZE);

	kvm_vm_free(vm);

}