[kvm-unit-tests PATCH v4 5/5] s390x: uv-guest: Add attestation tests

Steffen Eiden
2022-04-21T09:45:56Z

Adds several tests to verify correct error paths of attestation.

Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
lib/s390x/asm/uv.h | 5 +-
s390x/Makefile | 1 +
s390x/pv-attest.c | 225 +++++++++++++++++++++++++++++++++++++++++++++
s390x/uv-guest.c | 13 ++-
4 files changed, 240 insertions(+), 4 deletions(-)
create mode 100644 s390x/pv-attest.c

diff --git a/lib/s390x/asm/uv.h b/lib/s390x/asm/uv.h
index 7c8c399d..38920461 100644
--- a/lib/s390x/asm/uv.h
+++ b/lib/s390x/asm/uv.h
@@ -108,7 +108,10 @@ struct uv_cb_qui {
u8 reserved88[158 - 136]; /* 0x0088 */
uint16_t max_guest_cpus; /* 0x009e */
u64 uv_feature_indications; /* 0x00a0 */
- u8 reserveda8[200 - 168]; /* 0x00a8 */
+ uint8_t reserveda8[224 - 168]; /* 0x00a8 */
+ uint64_t supp_att_hdr_ver; /* 0x00e0 */
+ uint64_t supp_paf; /* 0x00e8 */
+ uint8_t reservedf0[256 - 240]; /* 0x00f0 */
} __attribute__((packed)) __attribute__((aligned(8)));

struct uv_cb_cgc {
diff --git a/s390x/Makefile b/s390x/Makefile
index 8ff84db5..5a49d1e7 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -29,6 +29,7 @@ tests += $(TEST_DIR)/mvpg-sie.elf
tests += $(TEST_DIR)/spec_ex-sie.elf
tests += $(TEST_DIR)/firq.elf
tests += $(TEST_DIR)/epsw.elf
+tests += $(TEST_DIR)/pv-attest.elf

pv-tests += $(TEST_DIR)/pv-diags.elf

diff --git a/s390x/pv-attest.c b/s390x/pv-attest.c
new file mode 100644
index 00000000..e31780a3
--- /dev/null
+++ b/s390x/pv-attest.c
@@ -0,0 +1,225 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Retrieve Attestation Measurement Utravisor Call tests
+ *
+ * Copyright IBM Corp. 2022
+ *
+ * Authors:
+ * Steffen Eiden <seiden@linux.ibm.com>
+ */
+
+#include <libcflat.h>
+#include <alloc_page.h>
+#include <asm/page.h>
+#include <asm/facility.h>
+#include <asm/uv.h>
+#include <sclp.h>
+#include <uv.h>
+
+#define ARCB_VERSION_NONE 0
+#define ARCB_VERSION_1 0x0100
+#define ARCB_MEAS_NONE 0
+#define ARCB_MEAS_HMAC_SHA512 1
+#define MEASUREMENT_SIZE_HMAC_SHA512 64
+#define PAF_PHKH_ATT (1ULL << 61)
+#define ADDITIONAL_SIZE_PAF_PHKH_ATT 32
+/* arcb with one key slot and no nonce */
+struct uv_arcb_v1 {
+ uint64_t reserved0; /* 0x0000 */
+ uint32_t req_ver; /* 0x0008 */
+ uint32_t req_len; /* 0x000c */
+ uint8_t iv[12]; /* 0x0010 */
+ uint32_t reserved1c; /* 0x001c */
+ uint8_t reserved20[7]; /* 0x0020 */
+ uint8_t nks; /* 0x0027 */
+ int32_t reserved28; /* 0x0028 */
+ uint32_t sea; /* 0x002c */
+ uint64_t plaint_att_flags; /* 0x0030 */
+ uint32_t meas_alg_id; /* 0x0038 */
+ uint32_t reserved3c; /* 0x003c */
+ uint8_t cpk[160]; /* 0x0040 */
+ uint8_t key_slot[80]; /* 0x00e0 */
+ uint8_t meas_key[64]; /* 0x0130 */
+ uint8_t tag[16]; /* 0x0170 */
+} __attribute__((packed));
+
+struct attest_request_v1 {
+ struct uv_arcb_v1 arcb;
+ uint8_t measurement[MEASUREMENT_SIZE_HMAC_SHA512];
+ uint8_t additional[ADDITIONAL_SIZE_PAF_PHKH_ATT];
+};
+
+static void test_attest_v1(uint64_t page)
+{
+ struct uv_cb_attest uvcb = {
+ .header.cmd = UVC_CMD_ATTESTATION,
+ .header.len = sizeof(uvcb),
+ };
+ const struct uv_cb_qui *uvcb_qui = uv_get_query_data();
+ struct attest_request_v1 *attest_req = (void *)page;
+ struct uv_arcb_v1 *arcb = &attest_req->arcb;
+ int cc;
+
+ report_prefix_push("v1");
+ if (!test_bit_inv(0, &uvcb_qui->supp_att_hdr_ver)) {
+ report_skip("Attestation version 1 not supported");
+ goto done;
+ }
+
+ memset((void *)page, 0, PAGE_SIZE);
+
+ /*
+ * Create a minimal arcb/uvcb such that FW has everything to start
+ * unsealing the request. However, this unsealing will fail as the
+ * kvm-unit-test framework provides no cryptography functions that
+ * would be needed to seal such requests.
+ */
+ arcb->req_ver = ARCB_VERSION_1;
+ arcb->req_len = sizeof(*arcb);
+ arcb->nks = 1;
+ arcb->sea = sizeof(arcb->meas_key);
+ arcb->plaint_att_flags = PAF_PHKH_ATT;
+ arcb->meas_alg_id = ARCB_MEAS_HMAC_SHA512;
+ uvcb.arcb_addr = (uint64_t)&attest_req->arcb;
+ uvcb.measurement_address = (uint64_t)attest_req->measurement;
+ uvcb.measurement_length = sizeof(attest_req->measurement);
+ uvcb.add_data_address = (uint64_t)attest_req->additional;
+ uvcb.add_data_length = sizeof(attest_req->additional);
+
+ uvcb.continuation_token = 0xff;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0101, "invalid continuation token");
+ uvcb.continuation_token = 0;
+
+ uvcb.user_data_length = sizeof(uvcb.user_data) + 1;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0102, "invalid user data size");
+ uvcb.user_data_length = 0;
+
+ uvcb.arcb_addr = get_ram_size() + PAGE_SIZE;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0103, "invalid address arcb");
+ uvcb.arcb_addr = page;
+
+ /* 0104 - 0105 need an unseal-able request */
+
+ arcb->req_ver = ARCB_VERSION_NONE;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0106, "unsupported version");
+ arcb->req_ver = ARCB_VERSION_1;
+
+ arcb->req_len += 1;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0107, "arcb too big");
+ arcb->req_len -= 1;
+
+ /*
+ * The arcb needs to grow as well if number of key slots (nks)
+ * is increased. However, this is not the case and there is no explicit
+ * 'too many/less nks for that arcb size' error code -> expect 0x0107
+ */
+ arcb->nks = 2;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0107, "too many nks for arcb");
+ arcb->nks = 1;
+
+ arcb->nks = 0;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0108, "invalid num key slots");
+ arcb->nks = 1;
+
+ /*
+ * Possible valid size (when using nonce).
+ * However, req_len too small to host a nonce
+ */
+ arcb->sea = 80;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0109, "encrypted size too big");
+ arcb->sea = 17;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x0109, "encrypted size too small");
+ arcb->sea = 64;
+
+ arcb->plaint_att_flags = uvcb_qui->supp_paf ^ GENMASK_ULL(63, 0);
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x010a, "invalid flag");
+ arcb->plaint_att_flags = PAF_PHKH_ATT;
+
+ arcb->meas_alg_id = ARCB_MEAS_NONE;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x010b, "invalid measurement algorithm");
+ arcb->meas_alg_id = ARCB_MEAS_HMAC_SHA512;
+
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x010c, "unable unseal");
+
+ uvcb.measurement_length = 0;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x010d, "invalid measurement size");
+ uvcb.measurement_length = sizeof(attest_req->measurement);
+
+ uvcb.add_data_length = 0;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc == 1 && uvcb.header.rc == 0x010e, "invalid additional size");
+ uvcb.add_data_length = sizeof(attest_req->additional);
+
+done:
+ report_prefix_pop();
+}
+
+static void test_attest(uint64_t page)
+{
+ struct uv_cb_attest uvcb = {
+ .header.cmd = UVC_CMD_ATTESTATION,
+ .header.len = sizeof(uvcb),
+ };
+ const struct uv_cb_qui *uvcb_qui = uv_get_query_data();
+ int cc;
+
+ /* Verify that the UV supports at least one header version */
+ report(uvcb_qui->supp_att_hdr_ver, "has hdr support");
+
+ memset((void *)page, 0, PAGE_SIZE);
+
+ uvcb.header.len -= 1;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc && uvcb.header.rc == UVC_RC_INV_LEN, "uvcb too small");
+ uvcb.header.len += 1;
+
+ uvcb.header.len += 1;
+ cc = uv_call(0, (uint64_t)&uvcb);
+ report(cc && uvcb.header.rc == UVC_RC_INV_LEN, "uvcb too large");
+ uvcb.header.len -= 1;
+}
+
+int main(void)
+{
+ bool has_uvc = test_facility(158);
+ uint64_t page;
+
+
+ report_prefix_push("attestation");
+ if (!has_uvc) {
+ report_skip("Ultravisor call facility is not available");
+ goto done;
+ }
+
+ if (!uv_os_is_guest()) {
+ report_skip("Not a protected guest");
+ goto done;
+ }
+
+ if (!uv_query_test_call(BIT_UVC_CMD_ATTESTATION)) {
+ report_skip("Attestation not supported.");
+ goto done;
+ }
+
+ page = (uint64_t)alloc_page();
+ /* The privilege check is done in uv-guest.c */
+ test_attest(page);
+ test_attest_v1(page);
+ free_page((void *)page);
+done:
+ report_prefix_pop();
+ return report_summary();
+}
diff --git a/s390x/uv-guest.c b/s390x/uv-guest.c
index 77057bd2..c3a90614 100644
--- a/s390x/uv-guest.c
+++ b/s390x/uv-guest.c
@@ -2,7 +2,7 @@
/*
* Guest Ultravisor Call tests
*
- * Copyright (c) 2020 IBM Corp
+ * Copyright IBM Corp. 2020, 2022
*
* Authors:
* Janosch Frank <frankja@linux.ibm.com>
@@ -53,6 +53,15 @@ static void test_priv(void)
check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
report_prefix_pop();

+ report_prefix_push("attest");
+ uvcb.cmd = UVC_CMD_ATTESTATION;
+ uvcb.len = sizeof(struct uv_cb_attest);
+ expect_pgm_int();
+ enter_pstate();
+ uv_call_once(0, (uint64_t)&uvcb);
+ check_pgm_int_code(PGM_INT_CODE_PRIVILEGED_OPERATION);
+ report_prefix_pop();
+
report_prefix_pop();
}

@@ -111,8 +120,6 @@ static void test_sharing(void)
cc = uv_call(0, (u64)&uvcb);
report(cc == 0 && uvcb.header.rc == UVC_RC_EXECUTED, "unshare");
report_prefix_pop();
-
- report_prefix_pop();
}

static struct {
--
2.30.2