Commit 909e0aba authored by Wainer dos Santos Moschetta's avatar Wainer dos Santos Moschetta Committed by Paolo Bonzini
Browse files

selftests: kvm: Add testcase for creating max number of memslots 



This patch introduces test_add_max_memory_regions(), which checks
that a 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: default avatarWainer dos Santos Moschetta <wainersm@redhat.com>
Reviewed-by: default avatarAndrew Jones <drjones@redhat.com>
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200410231707.7128-11-sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 5b4f758f

tools/testing/selftests/kvm/set_memory_region_test.c

+61 −4
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <stdlib.h>

#include <string.h>

#include <sys/ioctl.h>

#include <sys/mman.h>



#include <linux/compiler.h>
@@ -18,14 +19,18 @@ 


#define VCPU_ID 0



/*

 * s390x needs at least 1MB alignment, and the x86_64 MOVE/DELETE tests need a

 * 2MB sized and aligned region so that the initial region corresponds to

 * exactly one large page.

 */

#define MEM_REGION_SIZE		0x200000



#ifdef __x86_64__

/*

 * Somewhat arbitrary location and slot, intended to not overlap anything.  The

 * location and size are specifically 2mb sized/aligned so that the initial

 * region corresponds to exactly one large page.

 * Somewhat arbitrary location and slot, intended to not overlap anything.

 */

#define MEM_REGION_GPA		0xc0000000

#define MEM_REGION_SIZE		0x200000

#define MEM_REGION_SLOT		10



static const uint64_t MMIO_VAL = 0xbeefull;
@@ -312,6 +317,54 @@ 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.

 */

static void test_add_max_memory_regions(void)

{

	int ret;

	struct kvm_vm *vm;

	uint32_t max_mem_slots;

	uint32_t slot;

	uint64_t guest_addr = 0x0;

	uint64_t mem_reg_npages;

	void *mem;



	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);



	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);

	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;

	}



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

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

		   MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

	TEST_ASSERT(mem != 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});

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

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



	munmap(mem, MEM_REGION_SIZE);

	kvm_vm_free(vm);

}



int main(int argc, char *argv[])

{

#ifdef __x86_64__
@@ -327,7 +380,11 @@ int main(int argc, char *argv[]) 
	 * KVM_RUN fails with ENOEXEC or EFAULT.

	 */

	test_zero_memory_regions();

#endif



	test_add_max_memory_regions();



#ifdef __x86_64__

	if (argc > 1)

		loops = atoi(argv[1]);

	else