dm: parse bootargs of vssram regions

1) With this patch, '--ssram' option is updated to enable
    vSSRAM feature support for ACRN user VMs.

   '--ssram' argument of Device Model shall follow below format:
	--ssram {Ln,vcpu=vcpu_set,size=nK|M;}
   example:
    --ssram L2,vcpu=0,1,size=4K;L2,vcpu=2,3,size=1M;L3,vcpu=all,size=2M

 2) define data structure and variable
    to store the configuration data for later processing.

 3) add new API to cleanup configuration data when VM shutdown.

Tracked-On: #7010
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>
Acked-by: Wang Yu1 <yu1.wang@intel.com>

devicemodel/core/main.c

@@ -67,6 +67,7 @@
 #include "pm_vuart.h"
 #include "log.h"
 #include "pci_util.h"
+#include "vssram.h"
 
 #define	VM_MAXCPU		16	/* maximum virtual cpus */
 
@@ -164,7 +165,7 @@ usage(int code)
 		"       -W: force virtio to use single-vector MSI\n"
 		"       --mac_seed: set a platform unique string as a seed for generate mac address\n"
 		"       --ovmf: ovmf file path\n"
-		"       --ssram: Enable Software SRAM passthrough\n"
+		"       --ssram: Congfiure Software SRAM parameters\n"
 		"       --cpu_affinity: list of pCPUs assigned to this VM\n"
 		"       --enable_trusty: enable trusty for guest\n"
 		"       --debugexit: enable debug exit function\n"
@@ -794,7 +795,7 @@ static struct option long_options[] = {
 	{"vtpm2",		required_argument,	0, CMD_OPT_VTPM2},
 	{"lapic_pt",		no_argument,		0, CMD_OPT_LAPIC_PT},
 	{"rtvm",		no_argument,		0, CMD_OPT_RTVM},
-	{"ssram",		no_argument,		0, CMD_OPT_SOFTWARE_SRAM},
+	{"ssram",		required_argument,	0, CMD_OPT_SOFTWARE_SRAM},
 	{"logger_setting",	required_argument,	0, CMD_OPT_LOGGER_SETTING},
 	{"pm_notify_channel",	required_argument,	0, CMD_OPT_PM_NOTIFY_CHANNEL},
 	{"pm_by_vuart",	required_argument,	0, CMD_OPT_PM_BY_VUART},
@@ -936,7 +937,8 @@ main(int argc, char *argv[])
 			is_rtvm = true;
 			break;
 		case CMD_OPT_SOFTWARE_SRAM:
-			/* TODO: we need to support parameter to specify Software SRAM size in the future */
+			if (parse_vssram_buf_params(optarg) != 0)
+				errx(EX_USAGE, "invalid vSSRAM buffer size param %s", optarg);
 			ssram = true;
 			break;
 		case CMD_OPT_ACPIDEV_PT:
@@ -1116,6 +1118,9 @@ main(int argc, char *argv[])
 
 vm_fail:
 	vm_deinit_vdevs(ctx);
+	if (ssram)
+		clean_vssram_configs();
+
 dev_fail:
 	mevent_deinit();
 mevent_fail:

devicemodel/hw/platform/vssram/vssram.c

@@ -16,10 +16,13 @@
 #include <string.h>
 #include <errno.h>
 #include <stdbool.h>
+#include <unistd.h>
+#include <ctype.h>
 
 #include "pci_core.h"
 #include "vmmapi.h"
 #include "acpi.h"
+#include "dm_string.h"
 #include "log.h"
 #include "vssram.h"
 
@@ -32,6 +35,18 @@
 		((uint64_t)e - (uint64_t)rtct) < rtct->length; \
 		e = (struct rtct_entry *)((uint64_t)e + e->size))
 
+#define L2_CACHE 2
+#define L3_CACHE 3
+#define INVALID_CACHE_ID (-1)
+#define INVALID_FD (-1)
+#define VSSRAM_VCPUMASK_ALL ((uint64_t)-1)
+#define MAX_VSSRAM_BUFFER_NUM (ACRN_PLATFORM_LAPIC_IDS_MAX << 1)
+
+struct vssram_buf_param {
+	int level;
+	uint32_t size;
+	uint64_t vcpumask;
+};
 static uint16_t guest_vcpu_num;
 static uint64_t guest_pcpumask;
 uint32_t guest_l2_cat_shift;
@@ -42,6 +57,8 @@ static uint64_t vssram_size;
 static uint64_t vssram_gpa_base;
 static struct acpi_table_hdr  *vrtct_table;
 
+static struct   vssram_buf_param *vssram_buf_params;
+
 uint8_t vrtct_checksum(uint8_t *vrtct, uint32_t length)
 {
 	uint8_t sum = 0;
@@ -212,3 +229,148 @@ int init_vssram(struct vmctx *ctx)
 
 	return 0;
 }
+/**
+ * @brief Cleanup vSSRAM configurations resource.
+ *
+ * @param  void
+ *
+ * @return void
+ */
+void clean_vssram_configs(void)
+{
+	if (vssram_buf_params) {
+		free(vssram_buf_params);
+		vssram_buf_params = NULL;
+	}
+}
+
+/**
+ * @brief Parse input args for software SRAM configurations.
+ *
+ * @param opt  Pointer input args string.
+ *
+ * @return 0 on success and non-zero on fail.
+ *
+ * @note  Format of args shall be: "--ssram {Ln,vcpu=vcpu_set,size=nK|M;}"
+ *        - "Ln,vcpu=vcpu_set,size=nK|M;" is used to configure one software SRAM region,
+ *               multiple regions can be configured by separating them with semicolons(;).
+ *        - Ln   Cache level of software region, "L2"/"l3" and "L3"/"l3" are valid values
+ *               for L2 and L3 cache respectively.
+ *        - vcpu vCPU set of software region, multiple vCPU IDs can be configured by
+ *               separating them with comma(,), "all"/"ALL" can be used to set all vCPUs.
+ *        - size Size of software SRAM region, suffix of "K"/"k" or "M"/"m" must be used
+ *               to indicate unit of Kilo bytes and Mega bytes respectively, this value
+ *               must be decimal and page size(4Kbytes) aligned.
+ *        - example: --ssram L2,vcpu=0,1,size=4K;L2,vcpu=2,3,size=1M;L3,vcpu=all,size=2M
+ */
+int parse_vssram_buf_params(const char *opt)
+{
+	size_t size;
+	uint32_t vcpu_id;
+	uint64_t vcpumask;
+	int level, shift, error = -1, index = 0;
+	struct vssram_buf_param *params;
+	char *cp_opt, *str, *elem, *s_elem, *level_str, *vcpu_str, *size_str, *endptr;
+
+	cp_opt = str = strdup(opt);
+	if (!str) {
+		fprintf(stderr, "%s: strdup returns NULL.\n", __func__);
+		return -1;
+	}
+
+	params = calloc(MAX_VSSRAM_BUFFER_NUM, sizeof(struct vssram_buf_param));
+	if (params == NULL) {
+		pr_err("%s malloc buffer.\n", __func__);
+		goto exit;
+	}
+
+	/* param example: --ssram L2,vcpu=0,1,size=4K;L2,vcpu=2,3,size=1M;L3,vcpu=all,size=2M */
+	for (elem = strsep(&str, ";"); elem != NULL; elem = strsep(&str, ";")) {
+		if (strlen(elem) == 0)
+			break;
+
+		level_str = strsep(&elem, ",");
+		if (!strcmp(level_str, "L2") || !strcmp(level_str, "l2"))
+			level = L2_CACHE;
+		else if (!strcmp(level_str, "L3") || !strcmp(level_str, "l3"))
+			level = L3_CACHE;
+		else {
+			pr_err("invalid SSRAM buffer level:%s.\n", level_str);
+			goto exit;
+		}
+
+		vcpu_str = strsep(&elem, "=");
+		if (strcmp(vcpu_str, "vcpu")) {
+			pr_err("%s is invalid, 'vcpu' must be specified.\n", vcpu_str);
+			goto exit;
+		}
+		size_str = strstr(elem, "size=");
+		if (size_str == NULL) {
+			pr_err("invalid size parameter: %s\n", elem);
+			goto exit;
+		}
+
+		/* split elem into vcpu ID list string and size string */
+		*(size_str - 1) = '\0';
+		vcpu_str = elem;
+		vcpumask = 0;
+		for (s_elem = strsep(&vcpu_str, ","); s_elem != NULL; s_elem = strsep(&vcpu_str, ",")) {
+			if (strlen(s_elem) == 0)
+				break;
+
+			if (!strcmp(s_elem, "all") || !strcmp(s_elem, "ALL")) {
+				vcpumask = VSSRAM_VCPUMASK_ALL;
+				break;
+			}
+
+			if (dm_strtoui(s_elem, &endptr, 10, &vcpu_id)) {
+				pr_err("invalid '%s' to specify vcpu ID.\n", s_elem);
+				goto exit;
+			}
+			vcpumask |= (1 << vcpu_id);
+		}
+		if (bitmap_weight(vcpumask) == 0) {
+			pr_err("vCPU bitmask of ssram region is not set.\n");
+			goto exit;
+		}
+
+		strsep(&size_str, "=");
+		if (strlen(size_str) == 0) {
+			pr_err("invalid size configuration.\n");
+			goto exit;
+		}
+		size = strtoul(size_str, &endptr, 0);
+		switch (tolower((unsigned char)*endptr)) {
+		case 'm':
+			shift = 20;
+			break;
+		case 'k':
+			shift = 10;
+			break;
+		default:
+			pr_err("invalid size of '%s', only 'K','k'(KB) or 'M','m'(MB) can be suffixed!\n", size_str);
+			goto exit;
+		}
+
+		size <<= shift;
+		if ((size == 0) || ((size & ~PAGE_MASK) != 0) || (size > VSSRAM_MAX_SIZE)) {
+			pr_err("size 0x%lx is invalid, 0 or not page-aligned, or too large.\n", size);
+			goto exit;
+		}
+
+		pr_info("config index[%d]: cache level:%d, size:%lx, vcpumask:%lx\n", index, level, size, vcpumask);
+		params[index].level = level;
+		params[index].size = size;
+		params[index].vcpumask = vcpumask;
+		index++;
+	}
+	vssram_buf_params = params;
+	error = 0;
+
+exit:
+	if (error) {
+		free(params);
+	}
+	free(cp_opt);
+	return error;
+}

devicemodel/include/vssram.h

@@ -44,6 +44,8 @@ struct rtct_entry_data_ssram_v2 {
 uint64_t get_vssram_gpa_base(void);
 uint64_t get_vssram_size(void);
 uint8_t *get_vssram_vrtct(void);
+void clean_vssram_configs(void);
 int init_vssram(struct vmctx *ctx);
+int parse_vssram_buf_params(const char *opt);
 
 #endif  /* RTCT_H */