[PATCH v7 11/13] KVM: selftests: aarch64: Add dirty logging tests into page_fault_test

Ricardo Koller
2022-09-20T04:26:30Z

Add some dirty logging tests into page_fault_test. Mark the data and/or
page-table memslots for dirty logging, perform some accesses, and check
that the dirty log bits are set or clean when expected.

Signed-off-by: Ricardo Koller <ricarkol@google.com>
---
.../selftests/kvm/aarch64/page_fault_test.c | 75 +++++++++++++++++++
1 file changed, 75 insertions(+)

diff --git a/tools/testing/selftests/kvm/aarch64/page_fault_test.c b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
index f0cdd4e99dd0..51b2ac260db5 100644
--- a/tools/testing/selftests/kvm/aarch64/page_fault_test.c
+++ b/tools/testing/selftests/kvm/aarch64/page_fault_test.c
@@ -31,6 +31,11 @@ static uint64_t *guest_test_memory = (uint64_t *)TEST_GVA;
#define CMD_SKIP_TEST (1ULL << 1)
#define CMD_HOLE_PT (1ULL << 2)
#define CMD_HOLE_DATA (1ULL << 3)
+#define CMD_CHECK_WRITE_IN_DIRTY_LOG (1ULL << 4)
+#define CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG (1ULL << 5)
+#define CMD_CHECK_NO_WRITE_IN_DIRTY_LOG (1ULL << 6)
+#define CMD_CHECK_NO_S1PTW_WR_IN_DIRTY_LOG (1ULL << 7)
+#define CMD_SET_PTE_AF (1ULL << 8)

#define PREPARE_FN_NR 10
#define CHECK_FN_NR 10
@@ -213,6 +218,21 @@ static void guest_check_pte_af(void)
GUEST_ASSERT_EQ(*((uint64_t *)TEST_PTE_GVA) & PTE_AF, PTE_AF);
}

+static void guest_check_write_in_dirty_log(void)
+{
+ GUEST_SYNC(CMD_CHECK_WRITE_IN_DIRTY_LOG);
+}
+
+static void guest_check_no_write_in_dirty_log(void)
+{
+ GUEST_SYNC(CMD_CHECK_NO_WRITE_IN_DIRTY_LOG);
+}
+
+static void guest_check_s1ptw_wr_in_dirty_log(void)
+{
+ GUEST_SYNC(CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG);
+}
+
static void guest_exec(void)
{
int (*code)(void) = (int (*)(void))TEST_EXEC_GVA;
@@ -398,6 +418,21 @@ static bool punch_hole_in_memslot(struct kvm_vm *vm,
return true;
}

+static bool check_write_in_dirty_log(struct kvm_vm *vm,
+ struct userspace_mem_region *region, uint64_t host_pg_nr)
+{
+ unsigned long *bmap;
+ bool first_page_dirty;
+ uint64_t size = region->region.memory_size;
+
+ /* getpage_size() is not always equal to vm->page_size */
+ bmap = bitmap_zalloc(size / getpagesize());
+ kvm_vm_get_dirty_log(vm, region->region.slot, bmap);
+ first_page_dirty = test_bit(host_pg_nr, bmap);
+ free(bmap);
+ return first_page_dirty;
+}
+
/* Returns true to continue the test, and false if it should be skipped. */
static bool handle_cmd(struct kvm_vm *vm, int cmd)
{
@@ -414,6 +449,18 @@ static bool handle_cmd(struct kvm_vm *vm, int cmd)
continue_test = punch_hole_in_memslot(vm, pt_region);
if (cmd & CMD_HOLE_DATA)
continue_test = punch_hole_in_memslot(vm, data_region);
+ if (cmd & CMD_CHECK_WRITE_IN_DIRTY_LOG)
+ TEST_ASSERT(check_write_in_dirty_log(vm, data_region, 0),
+ "Missing write in dirty log");
+ if (cmd & CMD_CHECK_S1PTW_WR_IN_DIRTY_LOG)
+ TEST_ASSERT(check_write_in_dirty_log(vm, pt_region, 0),
+ "Missing s1ptw write in dirty log");
+ if (cmd & CMD_CHECK_NO_WRITE_IN_DIRTY_LOG)
+ TEST_ASSERT(!check_write_in_dirty_log(vm, data_region, 0),
+ "Unexpected write in dirty log");
+ if (cmd & CMD_CHECK_NO_S1PTW_WR_IN_DIRTY_LOG)
+ TEST_ASSERT(!check_write_in_dirty_log(vm, pt_region, 0),
+ "Unexpected s1ptw write in dirty log");

return continue_test;
}
@@ -681,6 +728,19 @@ static void help(char *name)
.expected_events = { .uffd_faults = _uffd_faults, }, \
}

+#define TEST_DIRTY_LOG(_access, _with_af, _test_check) \
+{ \
+ .name = SCAT3(dirty_log, _access, _with_af), \
+ .data_memslot_flags = KVM_MEM_LOG_DIRTY_PAGES, \
+ .pt_memslot_flags = KVM_MEM_LOG_DIRTY_PAGES, \
+ .guest_prepare = { _PREPARE(_with_af), \
+ _PREPARE(_access) }, \
+ .guest_test = _access, \
+ .guest_test_check = { _CHECK(_with_af), _test_check, \
+ guest_check_s1ptw_wr_in_dirty_log}, \
+ .expected_events = { 0 }, \
+}
+
static struct test_desc tests[] = {

/* Check that HW is setting the Access Flag (AF) (sanity checks). */
@@ -734,6 +794,21 @@ static struct test_desc tests[] = {
TEST_UFFD(guest_exec, with_af, CMD_HOLE_DATA | CMD_HOLE_PT,
uffd_data_read_handler, uffd_pt_write_handler, 2),

+ /*
+ * Try accesses when the data and PT memslots are both tracked for
+ * dirty logging.
+ */
+ TEST_DIRTY_LOG(guest_read64, with_af, guest_check_no_write_in_dirty_log),
+ /* no_af should also lead to a PT write. */
+ TEST_DIRTY_LOG(guest_read64, no_af, guest_check_no_write_in_dirty_log),
+ TEST_DIRTY_LOG(guest_ld_preidx, with_af, guest_check_no_write_in_dirty_log),
+ TEST_DIRTY_LOG(guest_at, no_af, guest_check_no_write_in_dirty_log),
+ TEST_DIRTY_LOG(guest_exec, with_af, guest_check_no_write_in_dirty_log),
+ TEST_DIRTY_LOG(guest_write64, with_af, guest_check_write_in_dirty_log),
+ TEST_DIRTY_LOG(guest_cas, with_af, guest_check_write_in_dirty_log),
+ TEST_DIRTY_LOG(guest_dc_zva, with_af, guest_check_write_in_dirty_log),
+ TEST_DIRTY_LOG(guest_st_preidx, with_af, guest_check_write_in_dirty_log),
+
{ 0 }
};

--
2.37.3.968.ga6b4b080e4-goog