Commit c071ff41 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: selftests: Expose align() helpers to tests 



Refactor align() to work with non-pointers and split into separate
helpers for aligning up vs. down. Add align_ptr_up() for use with
pointers. Expose all helpers so that they can be used by tests and/or
other utilities.  The align_down() helper in particular will be used to
ensure gpa alignment for hugepages.

No functional change intended.

[Added sepearate up/down helpers and replaced open-coded alignment
 bit math throughout the KVM selftests.]

Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarDavid Matlack <dmatlack@google.com>
Reviewed-by: default avatarBen Gardon <bgardon@google.com>
Message-Id: <20211111000310.1435032-3-dmatlack@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 531ca3d6

tools/testing/selftests/kvm/dirty_log_test.c

+3 −3
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ static void guest_code(void) 
			addr = guest_test_virt_mem;

			addr += (READ_ONCE(random_array[i]) % guest_num_pages)

				* guest_page_size;

			addr &= ~(host_page_size - 1);

			addr = align_down(addr, host_page_size);

			*(uint64_t *)addr = READ_ONCE(iteration);

		}
@@ -737,14 +737,14 @@ static void run_test(enum vm_guest_mode mode, void *arg) 
	if (!p->phys_offset) {

		guest_test_phys_mem = (vm_get_max_gfn(vm) -

				       guest_num_pages) * guest_page_size;

		guest_test_phys_mem &= ~(host_page_size - 1);

		guest_test_phys_mem = align_down(guest_test_phys_mem, host_page_size);

	} else {

		guest_test_phys_mem = p->phys_offset;

	}



#ifdef __s390x__

	/* Align to 1M (segment size) */

	guest_test_phys_mem &= ~((1 << 20) - 1);

	guest_test_phys_mem = align_down(guest_test_phys_mem, 1 << 20);

#endif



	pr_info("guest physical test memory offset: 0x%lx\n", guest_test_phys_mem);

tools/testing/selftests/kvm/include/test_util.h

+25 −0
Original line number Diff line number Diff line
@@ -117,4 +117,29 @@ static inline bool backing_src_is_shared(enum vm_mem_backing_src_type t) 
	return vm_mem_backing_src_alias(t)->flag & MAP_SHARED;

}



/* Aligns x up to the next multiple of size. Size must be a power of 2. */

static inline uint64_t align_up(uint64_t x, uint64_t size)

{

	uint64_t mask = size - 1;



	TEST_ASSERT(size != 0 && !(size & (size - 1)),

		    "size not a power of 2: %lu", size);

	return ((x + mask) & ~mask);

}



static inline uint64_t align_down(uint64_t x, uint64_t size)

{

	uint64_t x_aligned_up = align_up(x, size);



	if (x == x_aligned_up)

		return x;

	else

		return x_aligned_up - size;

}



static inline void *align_ptr_up(void *x, size_t size)

{

	return (void *)align_up((unsigned long)x, size);

}



#endif /* SELFTEST_KVM_TEST_UTIL_H */

tools/testing/selftests/kvm/kvm_page_table_test.c

+1 −1
Original line number Diff line number Diff line
@@ -280,7 +280,7 @@ static struct kvm_vm *pre_init_before_test(enum vm_guest_mode mode, void *arg) 
#ifdef __s390x__

	alignment = max(0x100000, alignment);

#endif

	guest_test_phys_mem &= ~(alignment - 1);

	guest_test_phys_mem = align_down(guest_test_virt_mem, alignment);



	/* Set up the shared data structure test_args */

	test_args.vm = vm;

tools/testing/selftests/kvm/lib/elf.c

+1 −2
Original line number Diff line number Diff line
@@ -157,8 +157,7 @@ void kvm_vm_elf_load(struct kvm_vm *vm, const char *filename) 
			"memsize of 0,\n"

			"  phdr index: %u p_memsz: 0x%" PRIx64,

			n1, (uint64_t) phdr.p_memsz);

		vm_vaddr_t seg_vstart = phdr.p_vaddr;

		seg_vstart &= ~(vm_vaddr_t)(vm->page_size - 1);

		vm_vaddr_t seg_vstart = align_down(phdr.p_vaddr, vm->page_size);

		vm_vaddr_t seg_vend = phdr.p_vaddr + phdr.p_memsz - 1;

		seg_vend |= vm->page_size - 1;

		size_t seg_size = seg_vend - seg_vstart + 1;

tools/testing/selftests/kvm/lib/kvm_util.c

+2 −11
Original line number Diff line number Diff line
@@ -22,15 +22,6 @@ 


static int vcpu_mmap_sz(void);



/* Aligns x up to the next multiple of size. Size must be a power of 2. */

static void *align(void *x, size_t size)

{

	size_t mask = size - 1;

	TEST_ASSERT(size != 0 && !(size & (size - 1)),

		    "size not a power of 2: %lu", size);

	return (void *) (((size_t) x + mask) & ~mask);

}



/*

 * Open KVM_DEV_PATH if available, otherwise exit the entire program.

 *
@@ -911,7 +902,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, 
		    region->mmap_start, errno);



	/* Align host address */

	region->host_mem = align(region->mmap_start, alignment);

	region->host_mem = align_ptr_up(region->mmap_start, alignment);



	/* As needed perform madvise */

	if ((src_type == VM_MEM_SRC_ANONYMOUS ||
@@ -954,7 +945,7 @@ void vm_userspace_mem_region_add(struct kvm_vm *vm, 
			    "mmap of alias failed, errno: %i", errno);



		/* Align host alias address */

		region->host_alias = align(region->mmap_alias, alignment);

		region->host_alias = align_ptr_up(region->mmap_alias, alignment);

	}

}