[PATCH v2 5/5] KVM: s390: selftests: Add error memop tests

Janis Schoetterl-Glausch
2022-02-25T15:53:28Z

Test that errors occur if key protection disallows access, including
tests for storage and fetch protection override. Perform tests for both
logical vcpu and absolute vm ioctls.
Also extend the existing tests to the vm ioctl.

Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com>
---
tools/testing/selftests/kvm/s390x/memop.c | 136 +++++++++++++++++++---
1 file changed, 123 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/kvm/s390x/memop.c b/tools/testing/selftests/kvm/s390x/memop.c
index 088d1cc61709..55048bfecdcb 100644
--- a/tools/testing/selftests/kvm/s390x/memop.c
+++ b/tools/testing/selftests/kvm/s390x/memop.c
@@ -422,6 +422,46 @@ static void test_copy_key_fetch_prot(void)
kvm_vm_free(t.kvm_vm);
}

+#define ERR_PROT_MOP(...) \
+({ \
+ int rv; \
+ \
+ rv = ERR_MOP(__VA_ARGS__); \
+ TEST_ASSERT(rv == 4, "Should result in protection exception"); \
+})
+
+static void test_errors_key(void)
+{
+ struct test_default t = test_default_init(guest_copy_key_fetch_prot);
+
+ HOST_SYNC(t.vcpu, STAGE_INITED);
+ HOST_SYNC(t.vcpu, STAGE_SKEYS_SET);
+
+ /* vm/vcpu, mismatching keys, fetch protection in effect */
+ CHECK_N_DO(ERR_PROT_MOP, t.vcpu, LOGICAL, WRITE, mem1, t.size, GADDR_V(mem1), KEY(2));
+ CHECK_N_DO(ERR_PROT_MOP, t.vcpu, LOGICAL, READ, mem2, t.size, GADDR_V(mem2), KEY(2));
+ CHECK_N_DO(ERR_PROT_MOP, t.vm, ABSOLUTE, WRITE, mem1, t.size, GADDR_V(mem1), KEY(2));
+ CHECK_N_DO(ERR_PROT_MOP, t.vm, ABSOLUTE, READ, mem2, t.size, GADDR_V(mem2), KEY(2));
+
+ kvm_vm_free(t.kvm_vm);
+}
+
+static void test_errors_key_storage_prot_override(void)
+{
+ struct test_default t = test_default_init(guest_copy_key_fetch_prot);
+
+ HOST_SYNC(t.vcpu, STAGE_INITED);
+ t.run->s.regs.crs[0] |= CR0_STORAGE_PROTECTION_OVERRIDE;
+ t.run->kvm_dirty_regs = KVM_SYNC_CRS;
+ HOST_SYNC(t.vcpu, STAGE_SKEYS_SET);
+
+ /* vm, mismatching keys, storage protection override not applicable to vm */
+ CHECK_N_DO(ERR_PROT_MOP, t.vm, ABSOLUTE, WRITE, mem1, t.size, GADDR_V(mem1), KEY(2));
+ CHECK_N_DO(ERR_PROT_MOP, t.vm, ABSOLUTE, READ, mem2, t.size, GADDR_V(mem2), KEY(2));
+
+ kvm_vm_free(t.kvm_vm);
+}
+
const uint64_t last_page_addr = -PAGE_SIZE;

static void guest_copy_key_fetch_prot_override(void)
@@ -481,6 +521,57 @@ static void test_copy_key_fetch_prot_override(void)
kvm_vm_free(t.kvm_vm);
}

+static void test_errors_key_fetch_prot_override_not_enabled(void)
+{
+ struct test_default t = test_default_init(guest_copy_key_fetch_prot_override);
+ vm_vaddr_t guest_0_page, guest_last_page;
+
+ guest_0_page = vm_vaddr_alloc(t.kvm_vm, PAGE_SIZE, 0);
+ guest_last_page = vm_vaddr_alloc(t.kvm_vm, PAGE_SIZE, last_page_addr);
+ if (guest_0_page != 0 || guest_last_page != last_page_addr) {
+ print_skip("did not allocate guest pages at required positions");
+ goto out;
+ }
+ HOST_SYNC(t.vcpu, STAGE_INITED);
+ HOST_SYNC(t.vcpu, STAGE_SKEYS_SET);
+
+ /* vcpu, mismatching keys on fetch, fetch protection override not enabled */
+ CHECK_N_DO(ERR_PROT_MOP, t.vcpu, LOGICAL, READ, mem2, 2048, GADDR_V(0), KEY(2));
+
+out:
+ kvm_vm_free(t.kvm_vm);
+}
+
+static void test_errors_key_fetch_prot_override_enabled(void)
+{
+ struct test_default t = test_default_init(guest_copy_key_fetch_prot_override);
+ vm_vaddr_t guest_0_page, guest_last_page;
+
+ guest_0_page = vm_vaddr_alloc(t.kvm_vm, PAGE_SIZE, 0);
+ guest_last_page = vm_vaddr_alloc(t.kvm_vm, PAGE_SIZE, last_page_addr);
+ if (guest_0_page != 0 || guest_last_page != last_page_addr) {
+ print_skip("did not allocate guest pages at required positions");
+ goto out;
+ }
+ HOST_SYNC(t.vcpu, STAGE_INITED);
+ t.run->s.regs.crs[0] |= CR0_FETCH_PROTECTION_OVERRIDE;
+ t.run->kvm_dirty_regs = KVM_SYNC_CRS;
+ HOST_SYNC(t.vcpu, STAGE_SKEYS_SET);
+
+ /*
+ * vcpu, mismatching keys on fetch,
+ * fetch protection override does not apply because memory range acceeded
+ */
+ CHECK_N_DO(ERR_PROT_MOP, t.vcpu, LOGICAL, READ, mem2, 2048 + 1, GADDR_V(0), KEY(2));
+ CHECK_N_DO(ERR_PROT_MOP, t.vcpu, LOGICAL, READ, mem2, PAGE_SIZE + 2048 + 1,
+ GADDR_V(guest_last_page), KEY(2));
+ CHECK_N_DO(ERR_PROT_MOP, t.vm, ABSOLUTE, READ, mem2, 2048, GADDR(0), KEY(2));
+ CHECK_N_DO(ERR_PROT_MOP, t.vm, ABSOLUTE, READ, mem2, 2048, GADDR_V(guest_0_page), KEY(2));
+
+out:
+ kvm_vm_free(t.kvm_vm);
+}
+
static void guest_idle(void)
{
GUEST_SYNC(STAGE_INITED); /* for consistencies sake */
@@ -488,39 +579,54 @@ static void guest_idle(void)
GUEST_SYNC(STAGE_IDLED);
}

-static void test_errors(void)
+static void _test_errors_common(struct test_vcpu vcpu, enum mop_target target, int size)
{
- struct test_default t = test_default_init(guest_idle);
int rv;

- HOST_SYNC(t.vcpu, STAGE_INITED);
-
/* Bad size: */
- rv = ERR_MOP(t.vcpu, LOGICAL, WRITE, mem1, -1, GADDR_V(mem1));
+ rv = ERR_MOP(vcpu, target, WRITE, mem1, -1, GADDR_V(mem1));
TEST_ASSERT(rv == -1 && errno == E2BIG, "ioctl allows insane sizes");

/* Zero size: */
- rv = ERR_MOP(t.vcpu, LOGICAL, WRITE, mem1, 0, GADDR_V(mem1));
+ rv = ERR_MOP(vcpu, target, WRITE, mem1, 0, GADDR_V(mem1));
TEST_ASSERT(rv == -1 && (errno == EINVAL || errno == ENOMEM),
"ioctl allows 0 as size");

/* Bad flags: */
- rv = ERR_MOP(t.vcpu, LOGICAL, WRITE, mem1, t.size, GADDR_V(mem1), SET_FLAGS(-1));
+ rv = ERR_MOP(vcpu, target, WRITE, mem1, size, GADDR_V(mem1), SET_FLAGS(-1));
TEST_ASSERT(rv == -1 && errno == EINVAL, "ioctl allows all flags");

- /* Bad operation: */
- rv = ERR_MOP(t.vcpu, INVALID, WRITE, mem1, t.size, GADDR_V(mem1));
- TEST_ASSERT(rv == -1 && errno == EINVAL, "ioctl allows bad operations");
-
/* Bad guest address: */
- rv = ERR_MOP(t.vcpu, LOGICAL, WRITE, mem1, t.size, GADDR((void *)~0xfffUL), CHECK_ONLY);
+ rv = ERR_MOP(vcpu, target, WRITE, mem1, size, GADDR((void *)~0xfffUL), CHECK_ONLY);
TEST_ASSERT(rv > 0, "ioctl does not report bad guest memory access");

/* Bad host address: */
- rv = ERR_MOP(t.vcpu, LOGICAL, WRITE, 0, t.size, GADDR_V(mem1));
+ rv = ERR_MOP(vcpu, target, WRITE, 0, size, GADDR_V(mem1));
TEST_ASSERT(rv == -1 && errno == EFAULT,
"ioctl does not report bad host memory address");

+ /* Bad key: */
+ rv = ERR_MOP(vcpu, target, WRITE, mem1, size, GADDR_V(mem1), KEY(17));
+ TEST_ASSERT(rv == -1 && errno == EINVAL, "ioctl allows invalid key");
+}
+
+static void test_errors(void)
+{
+ struct test_default t = test_default_init(guest_idle);
+ int rv;
+
+ HOST_SYNC(t.vcpu, STAGE_INITED);
+
+ _test_errors_common(t.vcpu, LOGICAL, t.size);
+ _test_errors_common(t.vm, ABSOLUTE, t.size);
+
+ /* Bad operation: */
+ rv = ERR_MOP(t.vcpu, INVALID, WRITE, mem1, t.size, GADDR_V(mem1));
+ TEST_ASSERT(rv == -1 && errno == EINVAL, "ioctl allows bad operations");
+ /* virtual addresses are not translated when passing INVALID */
+ rv = ERR_MOP(t.vm, INVALID, WRITE, mem1, PAGE_SIZE, GADDR(0));
+ TEST_ASSERT(rv == -1 && errno == EINVAL, "ioctl allows bad operations");
+
/* Bad access register: */
t.run->psw_mask &= ~(3UL << (63 - 17));
t.run->psw_mask |= 1UL << (63 - 17); /* Enable AR mode */
@@ -560,6 +666,10 @@ int main(int argc, char *argv[])
test_copy_key_storage_prot_override();
test_copy_key_fetch_prot();
test_copy_key_fetch_prot_override();
+ test_errors_key();
+ test_errors_key_storage_prot_override();
+ test_errors_key_fetch_prot_override_not_enabled();
+ test_errors_key_fetch_prot_override_enabled();
} else {
print_skip("storage key memop extension not supported");
}
--
2.32.0