[RFC V2 PATCH 5/8] selftests: kvm: Add implicit memory conversion tests

Vishal Annapurve
2022-05-11T00:09:26Z

Add tests to exercise implicit memory conversion path.

Signed-off-by: Vishal Annapurve <vannapurve@google.com>
---
tools/testing/selftests/kvm/priv_memfd_test.c | 384 +++++++++++++++++-
1 file changed, 383 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/priv_memfd_test.c b/tools/testing/selftests/kvm/priv_memfd_test.c
index 48bc4343e7b5..f6f6b064a101 100644
--- a/tools/testing/selftests/kvm/priv_memfd_test.c
+++ b/tools/testing/selftests/kvm/priv_memfd_test.c
@@ -211,6 +211,369 @@ static void pmsat_guest_code(void)
GUEST_DONE();
}

+/* Test to verify guest shared accesses on shared memory with following steps:
+ * 1) Upon entry, guest signals VMM that it has started.
+ * 2) VMM deallocates the backing private memory and populates the shared memory
+ * with known pattern and continues guest execution.
+ * 3) Guest reads shared gpa range in a shared fashion and verifies that it
+ * reads what VMM has written in step2.
+ * 3) Guest writes a different pattern on the shared memory and signals VMM
+ * that it has updated the shared memory.
+ * 4) VMM verifies shared memory contents to be same as the data populated
+ * in step 3 and continues guest execution.
+ */
+#define SMSAT_ID 2
+#define SMSAT_DESC "SharedMemorySharedAccessTest"
+
+#define SMSAT_GUEST_STARTED 0ULL
+#define SMSAT_GUEST_TEST_MEM_UPDATED 1ULL
+
+static bool smsat_handle_vm_stage(struct kvm_vm *vm,
+ void *test_info,
+ uint64_t stage)
+{
+ void *shared_mem = ((struct test_run_helper *)test_info)->shared_mem;
+ int priv_memfd = ((struct test_run_helper *)test_info)->priv_memfd;
+
+ switch (stage) {
+ case SMSAT_GUEST_STARTED: {
+ /* Remove the backing private memory storage */
+ int ret = fallocate(priv_memfd,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ 0, TEST_MEM_SIZE);
+ TEST_ASSERT(ret != -1,
+ "fallocate failed in smsat handling");
+ /* Initialize the contents of shared memory */
+ TEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE),
+ "Shared memory updated failed");
+ VM_STAGE_PROCESSED(SMSAT_GUEST_STARTED);
+ break;
+ }
+ case SMSAT_GUEST_TEST_MEM_UPDATED: {
+ /* verify data to be same as what guest wrote */
+ TEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE),
+ "Shared memory view mismatch");
+ VM_STAGE_PROCESSED(SMSAT_GUEST_TEST_MEM_UPDATED);
+ break;
+ }
+ default:
+ printf("Unhandled VM stage %ld\n", stage);
+ return false;
+ }
+
+ return true;
+}
+
+static void smsat_guest_code(void)
+{
+ void *shared_mem = (void *)TEST_MEM_GPA;
+
+ GUEST_SYNC(SMSAT_GUEST_STARTED);
+ GUEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE));
+
+ GUEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE));
+ GUEST_SYNC(SMSAT_GUEST_TEST_MEM_UPDATED);
+
+ GUEST_DONE();
+}
+
+/* Test to verify guest private accesses on shared memory with following steps:
+ * 1) Upon entry, guest signals VMM that it has started.
+ * 2) VMM deallocates the backing private memory and populates the shared memory
+ * with known pattern and continues guest execution.
+ * 3) Guest writes gpa range via private access and signals VMM.
+ * 4) VMM verifies shared memory contents to be same as the data populated
+ * in step 2 and continues guest execution.
+ * 5) Guest reads gpa range via private access and verifies that the contents
+ * are same as written in step 3.
+ */
+#define SMPAT_ID 3
+#define SMPAT_DESC "SharedMemoryPrivateAccessTest"
+
+#define SMPAT_GUEST_STARTED 0ULL
+#define SMPAT_GUEST_TEST_MEM_UPDATED 1ULL
+
+static bool smpat_handle_vm_stage(struct kvm_vm *vm,
+ void *test_info,
+ uint64_t stage)
+{
+ void *shared_mem = ((struct test_run_helper *)test_info)->shared_mem;
+ int priv_memfd = ((struct test_run_helper *)test_info)->priv_memfd;
+
+ switch (stage) {
+ case SMPAT_GUEST_STARTED: {
+ /* Remove the backing private memory storage */
+ int ret = fallocate(priv_memfd,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ 0, TEST_MEM_SIZE);
+ TEST_ASSERT(ret != -1,
+ "fallocate failed in smpat handling");
+ /* Initialize the contents of shared memory */
+ TEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE),
+ "Shared memory updated failed");
+ VM_STAGE_PROCESSED(SMPAT_GUEST_STARTED);
+ break;
+ }
+ case SMPAT_GUEST_TEST_MEM_UPDATED: {
+ /* verify data to be same as what vmm wrote earlier */
+ TEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE),
+ "Shared memory view mismatch");
+ VM_STAGE_PROCESSED(SMPAT_GUEST_TEST_MEM_UPDATED);
+ break;
+ }
+ default:
+ printf("Unhandled VM stage %ld\n", stage);
+ return false;
+ }
+
+ return true;
+}
+
+static void smpat_guest_code(void)
+{
+ void *shared_mem = (void *)TEST_MEM_GPA;
+ int ret;
+
+ GUEST_SYNC(SMPAT_GUEST_STARTED);
+
+ /* Mark the GPA range to be treated as always accessed privately */
+ ret = kvm_hypercall(KVM_HC_MAP_GPA_RANGE, TEST_MEM_GPA,
+ TEST_MEM_SIZE >> MIN_PAGE_SHIFT,
+ KVM_MARK_GPA_RANGE_ENC_ACCESS, 0);
+ GUEST_ASSERT_1(ret == 0, ret);
+
+ GUEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE));
+ GUEST_SYNC(SMPAT_GUEST_TEST_MEM_UPDATED);
+ GUEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE));
+
+ GUEST_DONE();
+}
+
+/* Test to verify guest shared and private accesses on memory with following
+ * steps:
+ * 1) Upon entry, guest signals VMM that it has started.
+ * 2) VMM populates the shared memory with known pattern and continues guest
+ * execution.
+ * 3) Guest writes shared gpa range in a private fashion and signals VMM
+ * 4) VMM verifies that shared memory still contains the pattern written in
+ * step 2 and continues guest execution.
+ * 5) Guest verifies private memory contents to be same as the data populated
+ * in step 3 and signals VMM.
+ * 6) VMM removes the private memory backing which should also clear out the
+ * second stage mappings for the VM
+ * 6) Guest does shared write access on shared memory and signals vmm
+ * 7) VMM reads the shared memory and verifies that the data is same as what
+ * guest wrote in step 6 and continues guest execution.
+ * 8) Guest reads the private memory and verifies that the data is same as
+ * written in step 6.
+ */
+#define PSAT_ID 4
+#define PSAT_DESC "PrivateSharedAccessTest"
+
+#define PSAT_GUEST_STARTED 0ULL
+#define PSAT_GUEST_PRIVATE_MEM_UPDATED 1ULL
+#define PSAT_GUEST_PRIVATE_MEM_VERIFIED 2ULL
+#define PSAT_GUEST_SHARED_MEM_UPDATED 3ULL
+
+static bool psat_handle_vm_stage(struct kvm_vm *vm,
+ void *test_info,
+ uint64_t stage)
+{
+ void *shared_mem = ((struct test_run_helper *)test_info)->shared_mem;
+ int priv_memfd = ((struct test_run_helper *)test_info)->priv_memfd;
+
+ switch (stage) {
+ case PSAT_GUEST_STARTED: {
+ /* Initialize the contents of shared memory */
+ TEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE),
+ "Shared memory update failed");
+ VM_STAGE_PROCESSED(PSAT_GUEST_STARTED);
+ break;
+ }
+ case PSAT_GUEST_PRIVATE_MEM_UPDATED: {
+ /* verify data to be same as what vmm wrote earlier */
+ TEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE),
+ "Shared memory view mismatch");
+ VM_STAGE_PROCESSED(PSAT_GUEST_PRIVATE_MEM_UPDATED);
+ break;
+ }
+ case PSAT_GUEST_PRIVATE_MEM_VERIFIED: {
+ /* Remove the backing private memory storage so that
+ * subsequent accesses from guest cause a second stage
+ * page fault
+ */
+ int ret = fallocate(priv_memfd,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ 0, TEST_MEM_SIZE);
+ TEST_ASSERT(ret != -1,
+ "fallocate failed in smpat handling");
+ VM_STAGE_PROCESSED(PSAT_GUEST_PRIVATE_MEM_VERIFIED);
+ break;
+ }
+ case PSAT_GUEST_SHARED_MEM_UPDATED: {
+ /* verify data to be same as what guest wrote */
+ TEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE),
+ "Shared memory view mismatch");
+ VM_STAGE_PROCESSED(PSAT_GUEST_SHARED_MEM_UPDATED);
+ break;
+ }
+ default:
+ printf("Unhandled VM stage %ld\n", stage);
+ return false;
+ }
+
+ return true;
+}
+
+static void psat_guest_code(void)
+{
+ void *shared_mem = (void *)TEST_MEM_GPA;
+ int ret;
+
+ GUEST_SYNC(PSAT_GUEST_STARTED);
+ /* Mark the GPA range to be treated as always accessed privately */
+ ret = kvm_hypercall(KVM_HC_MAP_GPA_RANGE, TEST_MEM_GPA,
+ TEST_MEM_SIZE >> MIN_PAGE_SHIFT,
+ KVM_MARK_GPA_RANGE_ENC_ACCESS, 0);
+ GUEST_ASSERT_1(ret == 0, ret);
+
+ GUEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE));
+ GUEST_SYNC(PSAT_GUEST_PRIVATE_MEM_UPDATED);
+ GUEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE));
+
+ GUEST_SYNC(PSAT_GUEST_PRIVATE_MEM_VERIFIED);
+
+ /* Mark no GPA range to be treated as accessed privately */
+ ret = kvm_hypercall(KVM_HC_MAP_GPA_RANGE, 0,
+ 0, KVM_MARK_GPA_RANGE_ENC_ACCESS, 0);
+ GUEST_ASSERT_1(ret == 0, ret);
+ GUEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE));
+ GUEST_SYNC(PSAT_GUEST_SHARED_MEM_UPDATED);
+ GUEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE));
+
+ GUEST_DONE();
+}
+
+/* Test to verify guest shared and private accesses on memory with following
+ * steps:
+ * 1) Upon entry, guest signals VMM that it has started.
+ * 2) VMM removes the private memory backing and populates the shared memory
+ * with known pattern and continues guest execution.
+ * 3) Guest reads shared gpa range in a shared fashion and verifies that it
+ * reads what VMM has written in step2.
+ * 4) Guest writes a different pattern on the shared memory and signals VMM
+ * that it has updated the shared memory.
+ * 5) VMM verifies shared memory contents to be same as the data populated
+ * in step 4 and installs private memory backing again to allow guest
+ * to do private access and invalidate second stage mappings.
+ * 6) Guest does private write access on shared memory and signals vmm
+ * 7) VMM reads the shared memory and verified that the data is still same
+ * as in step 4 and continues guest execution.
+ * 8) Guest reads the private memory and verifies that the data is same as
+ * written in step 6.
+ */
+#define SPAT_ID 5
+#define SPAT_DESC "SharedPrivateAccessTest"
+
+#define SPAT_GUEST_STARTED 0ULL
+#define SPAT_GUEST_SHARED_MEM_UPDATED 1ULL
+#define SPAT_GUEST_PRIVATE_MEM_UPDATED 2ULL
+
+static bool spat_handle_vm_stage(struct kvm_vm *vm,
+ void *test_info,
+ uint64_t stage)
+{
+ void *shared_mem = ((struct test_run_helper *)test_info)->shared_mem;
+ int priv_memfd = ((struct test_run_helper *)test_info)->priv_memfd;
+
+ switch (stage) {
+ case SPAT_GUEST_STARTED: {
+ /* Remove the backing private memory storage so that
+ * subsequent accesses from guest cause a second stage
+ * page fault
+ */
+ int ret = fallocate(priv_memfd,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ 0, TEST_MEM_SIZE);
+ TEST_ASSERT(ret != -1,
+ "fallocate failed in spat handling");
+
+ /* Initialize the contents of shared memory */
+ TEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE),
+ "Shared memory updated failed");
+ VM_STAGE_PROCESSED(SPAT_GUEST_STARTED);
+ break;
+ }
+ case SPAT_GUEST_SHARED_MEM_UPDATED: {
+ /* verify data to be same as what guest wrote earlier */
+ TEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE),
+ "Shared memory view mismatch");
+ /* Allocate memory for private backing store */
+ int ret = fallocate(priv_memfd,
+ 0, 0, TEST_MEM_SIZE);
+ TEST_ASSERT(ret != -1,
+ "fallocate failed in spat handling");
+ VM_STAGE_PROCESSED(SPAT_GUEST_SHARED_MEM_UPDATED);
+ break;
+ }
+ case SPAT_GUEST_PRIVATE_MEM_UPDATED: {
+ /* verify data to be same as what guest wrote earlier */
+ TEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE),
+ "Shared memory view mismatch");
+ VM_STAGE_PROCESSED(SPAT_GUEST_PRIVATE_MEM_UPDATED);
+ break;
+ }
+ default:
+ printf("Unhandled VM stage %ld\n", stage);
+ return false;
+ }
+
+ return true;
+}
+
+static void spat_guest_code(void)
+{
+ void *shared_mem = (void *)TEST_MEM_GPA;
+ int ret;
+
+ GUEST_SYNC(SPAT_GUEST_STARTED);
+ GUEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE));
+ GUEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT2, TEST_MEM_SIZE));
+ GUEST_SYNC(SPAT_GUEST_SHARED_MEM_UPDATED);
+ /* Mark the GPA range to be treated as always accessed privately */
+ ret = kvm_hypercall(KVM_HC_MAP_GPA_RANGE, TEST_MEM_GPA,
+ TEST_MEM_SIZE >> MIN_PAGE_SHIFT,
+ KVM_MARK_GPA_RANGE_ENC_ACCESS, 0);
+ GUEST_ASSERT_1(ret == 0, ret);
+
+ GUEST_ASSERT(do_mem_op(SET_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE));
+ GUEST_SYNC(PSAT_GUEST_PRIVATE_MEM_UPDATED);
+ GUEST_ASSERT(do_mem_op(VERIFY_PAT, shared_mem,
+ TEST_MEM_DATA_PAT1, TEST_MEM_SIZE));
+ GUEST_DONE();
+}
+
static struct test_run_helper priv_memfd_testsuite[] = {
[PMPAT_ID] = {
.test_desc = PMPAT_DESC,
@@ -222,6 +585,26 @@ static struct test_run_helper priv_memfd_testsuite[] = {
.vmst_handler = pmsat_handle_vm_stage,
.guest_fn = pmsat_guest_code,
},
+ [SMSAT_ID] = {
+ .test_desc = SMSAT_DESC,
+ .vmst_handler = smsat_handle_vm_stage,
+ .guest_fn = smsat_guest_code,
+ },
+ [SMPAT_ID] = {
+ .test_desc = SMPAT_DESC,
+ .vmst_handler = smpat_handle_vm_stage,
+ .guest_fn = smpat_guest_code,
+ },
+ [PSAT_ID] = {
+ .test_desc = PSAT_DESC,
+ .vmst_handler = psat_handle_vm_stage,
+ .guest_fn = psat_guest_code,
+ },
+ [SPAT_ID] = {
+ .test_desc = SPAT_DESC,
+ .vmst_handler = spat_handle_vm_stage,
+ .guest_fn = spat_guest_code,
+ },
};

static void handle_vm_exit_hypercall(struct kvm_run *run,
@@ -365,7 +748,6 @@ static void priv_memory_region_add(struct kvm_vm *vm, void *mem, uint32_t slot,
guest_addr);
}

-/* Do private access to the guest's private memory */
static void setup_and_execute_test(uint32_t test_id)
{
struct kvm_vm *vm;
--
2.36.0.550.gb090851708-goog