[PATCH v9 6/6] selftests: tdx: Test GetQuote TDX attestation feature

[Kuppuswamy Sathyanarayanan]

In TDX guest, the second stage of the attestation process is Quote
generation. This process is required to convert the locally generated
TDREPORT into a remotely verifiable Quote. It involves sending the
TDREPORT data to a Quoting Enclave (QE) which will verify the
integerity of the TDREPORT and sign it with an attestation key.

Intel's TDX attestation driver exposes TDX_CMD_GET_QUOTE IOCTL to
allow user agent get the TD Quote.

Add a kernel selftest module to verify the Quote generation feature.

TD Quote generation involves following steps:

* Get the TDREPORT data using TDX_CMD_GET_REPORT IOCTL.
* Embed the TDREPORT data in quote buffer and request for quote
  generation via TDX_CMD_GET_QUOTE IOCTL request.
* Upon completion of the GetQuote request, check for non zero value
  in the status field of Quote header to make sure the generated
  quote is valid.

Reviewed-by: Tony Luck <tony.luck@xxxxxxxxx>
Reviewed-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
---
 tools/testing/selftests/tdx/tdx_attest_test.c | 74 ++++++++++++++++---
 1 file changed, 64 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/tdx/tdx_attest_test.c b/tools/testing/selftests/tdx/tdx_attest_test.c
index 7155cc751eaa..14125b97e308 100644
--- a/tools/testing/selftests/tdx/tdx_attest_test.c
+++ b/tools/testing/selftests/tdx/tdx_attest_test.c
@@ -23,6 +23,7 @@
 
 #define devname         "/dev/tdx-guest"
 #define HEX_DUMP_SIZE	8
+#define QUOTE_SIZE	8192
 
 /*
  * struct td_info - It contains the measurements and initial configuration of
@@ -114,17 +115,11 @@ static void print_array_hex(const char *title, const char *prefix_str,
 }
 #endif
 
-TEST(verify_report)
+/* Helper function to get TDREPORT */
+long get_tdreport(int devfd, __u8 *reportdata, __u8 *tdreport)
 {
-	__u8 reportdata[TDX_REPORTDATA_LEN];
-	struct tdreport_data *tdr_data;
-	__u8 tdreport[TDX_REPORT_LEN];
 	struct tdx_report_req req;
-	int devfd, i;
-
-	devfd = open(devname, O_RDWR | O_SYNC);
-
-	ASSERT_LT(0, devfd);
+	int i;
 
 	/* Generate sample report data */
 	for (i = 0; i < TDX_REPORTDATA_LEN; i++)
@@ -137,8 +132,22 @@ TEST(verify_report)
 	req.tdreport    = (__u64)tdreport;
 	req.tdr_len     = TDX_REPORT_LEN;
 
+	return ioctl(devfd, TDX_CMD_GET_REPORT, &req);
+}
+
+TEST(verify_report)
+{
+	__u8 reportdata[TDX_REPORTDATA_LEN];
+	struct tdreport_data *tdr_data;
+	__u8 tdreport[TDX_REPORT_LEN];
+	int devfd;
+
+	devfd = open(devname, O_RDWR | O_SYNC);
+
+	ASSERT_LT(0, devfd);
+
 	/* Get TDREPORT */
-	ASSERT_EQ(0, ioctl(devfd, TDX_CMD_GET_REPORT, &req));
+	ASSERT_EQ(0, get_tdreport(devfd, reportdata, tdreport));
 
 	tdr_data = (struct tdreport_data *)tdreport;
 
@@ -157,4 +166,49 @@ TEST(verify_report)
 	ASSERT_EQ(0, close(devfd));
 }
 
+TEST(verify_quote)
+{
+	__u8 reportdata[TDX_REPORTDATA_LEN];
+	struct tdx_quote_hdr *quote_hdr;
+	struct tdx_quote_req quote_req;
+	__u8 *quote_buf = NULL;
+	__u64 quote_buf_size;
+	int devfd;
+
+	/* Open attestation device */
+	devfd = open(devname, O_RDWR | O_SYNC);
+
+	ASSERT_LT(0, devfd);
+
+	/* Add size for quote header */
+	quote_buf_size = sizeof(*quote_hdr) + QUOTE_SIZE;
+
+	/* Allocate quote buffer */
+	quote_buf = malloc(quote_buf_size);
+	ASSERT_NE(NULL, quote_buf);
+
+	quote_hdr = (struct tdx_quote_hdr *)quote_buf;
+
+	/* Initialize GetQuote header */
+	quote_hdr->version = 1;
+	quote_hdr->status  = GET_QUOTE_SUCCESS;
+	quote_hdr->in_len  = TDX_REPORT_LEN;
+	quote_hdr->out_len = 0;
+
+	/* Get TDREPORT data */
+	ASSERT_EQ(0, get_tdreport(devfd, reportdata,
+				(__u8 *)&quote_hdr->data));
+
+	/* Fill GetQuote request */
+	quote_req.buf	  = (__u64)quote_buf;
+	quote_req.len	  = quote_buf_size;
+
+	ASSERT_EQ(0, ioctl(devfd, TDX_CMD_GET_QUOTE, &quote_req));
+
+	/* Check whether GetQuote request is successful */
+	EXPECT_EQ(0, quote_hdr->status);
+
+	free(quote_buf);
+}
+
 TEST_HARNESS_MAIN
-- 
2.25.1