HV: parse seed from ABL

ABL pass seed_lists to HV through different interface/structures.
So, in this patch, add interface to retrieve seed from ABL and refactor
the seed parsing logic.

Tracked-On: #1488
Signed-off-by: Qi Yadong <yadong.qi@intel.com>
Acked-by: Zhu Bing <bing.zhu@intel.com>

hypervisor/boot/sbl/abl_seed_parse.c

@@ -0,0 +1,155 @@
+/*
+ * Copyright (C) 2018 Intel Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <hypervisor.h>
+#include <abl_seed_parse.h>
+
+#define ABL_SEED_LEN 32U
+struct abl_seed_info {
+	uint8_t svn;
+	uint8_t reserved[3];
+	uint8_t seed[ABL_SEED_LEN];
+};
+
+#define ABL_SEED_LIST_MAX 4U
+struct dev_sec_info {
+	uint32_t size_of_this_struct;
+	uint32_t version;
+	uint32_t num_seeds;
+	struct abl_seed_info seed_list[ABL_SEED_LIST_MAX];
+};
+
+static const char *dev_sec_info_arg= "dev_sec_info.param_addr=";
+
+static void parse_seed_list_abl(void *param_addr)
+{
+	uint32_t i;
+	uint32_t legacy_seed_index = 0U;
+	struct seed_info dseed_list[BOOTLOADER_SEED_MAX_ENTRIES];
+	struct dev_sec_info *sec_info = (struct dev_sec_info *)param_addr;
+
+	if (sec_info == NULL) {
+		goto fail;
+	}
+
+	if (sec_info->num_seeds < 2U ||
+			sec_info->num_seeds > ABL_SEED_LIST_MAX) {
+		goto fail;
+	}
+
+	/*
+	 * The seed_list from ABL contains several seeds which based on SVN
+	 * and one legacy seed which is not based on SVN. The legacy seed's
+	 * svn value is minimum in the seed list. And CSE ensures at least two
+	 * seeds will be generated which will contain the legacy seed.
+	 * Here find the legacy seed index first.
+	 */
+	for (i = 1U; i < sec_info->num_seeds; i++) {
+		if (sec_info->seed_list[i].svn <
+				sec_info->seed_list[legacy_seed_index].svn) {
+			legacy_seed_index = i;
+		}
+	}
+
+	/*
+	 * Copy out abl_seed for trusty and clear the original seed in memory.
+	 * The SOS requires the legacy seed to derive RPMB key. So skip the
+	 * legacy seed when clear original seed.
+	 */
+	(void)memset((void *)dseed_list, 0U, sizeof(dseed_list));
+	for (i = 0U; i < sec_info->num_seeds; i++) {
+		dseed_list[i].cse_svn = sec_info->seed_list[i].svn;
+		(void)memcpy_s((void *)dseed_list[i].seed,
+				sizeof(dseed_list[i].seed),
+				(void *)sec_info->seed_list[i].seed,
+				sizeof(sec_info->seed_list[i].seed));
+
+		if (i == legacy_seed_index) {
+			continue;
+		}
+
+		(void)memset((void *)sec_info->seed_list[i].seed, 0U,
+				sizeof(sec_info->seed_list[i].seed));
+	}
+
+	trusty_set_dseed((void *)dseed_list, (uint8_t)(sec_info->num_seeds));
+	(void)memset((void *)dseed_list, 0U, sizeof(dseed_list));
+	return;
+fail:
+	trusty_set_dseed(NULL, 0U);
+	(void)memset((void *)dseed_list, 0U, sizeof(dseed_list));
+}
+
+/*
+ * abl_seed_parse
+ *
+ * description:
+ *    This function parse dev_sec_info from cmdline. Mainly on
+ *    1. parse structure address from cmdline
+ *    2. call  parse_seed_list_abl to parse seed_list
+ *    3. convert address in the structure from HPA to SOS's GPA
+ *    4. clear original image_boot_params argument in cmdline since
+ *       original address is HPA.
+ *
+ * input:
+ *    vm            pointer to vm structure
+ *    cmdline       pointer to cmdline string
+ *    out_len       the max len of out_arg
+ *
+ * output:
+ *    out_arg       the argument with SOS's GPA
+ *
+ * return value:
+ *    true if parse successfully, otherwise false.
+ */
+bool abl_seed_parse(struct vm *vm, char *cmdline, char *out_arg, uint32_t out_len)
+{
+	char *arg, *arg_end;
+	char *param;
+	void *param_addr;
+	uint32_t len;
+
+	if (cmdline == NULL) {
+		goto fail;
+	}
+
+	len = strnlen_s(dev_sec_info_arg, MEM_1K);
+	arg = strstr_s(cmdline, MEM_2K, dev_sec_info_arg, len);
+
+	if (arg == NULL) {
+		goto fail;
+	}
+
+	param = arg + len;
+	param_addr = (void *)hpa2hva(strtoul_hex(param));
+	if (param_addr == NULL) {
+		goto fail;
+	}
+
+	parse_seed_list_abl(param_addr);
+
+	/*
+	 * Replace original arguments with spaces since SOS's GPA is not
+	 * identity mapped to HPA. The argument will be appended later when
+	 * compose cmdline for SOS.
+	 */
+	arg_end = strchr(arg, ' ');
+	len = (arg_end != NULL) ? (uint32_t)(arg_end - arg) :
+							strnlen_s(arg, MEM_2K);
+	(void)memset((void *)arg, ' ', len);
+
+	/* Convert the param_addr to SOS GPA and copy to caller */
+	if (out_arg) {
+		snprintf(out_arg, out_len, "%s0x%X ",
+			dev_sec_info_arg, hva2gpa(vm, param_addr));
+	}
+
+	return true;
+
+fail:
+	parse_seed_list_abl(NULL);
+	return false;
+}