[kvmtool,10/10] riscv: Allow including extensions in the min CPU type using command-line

Commit Message

Anup Patel March 26, 2025, 6:56 a.m. UTC

It is useful to allow including extensions in the min CPU type on need
basis via command-line. To achieve this, parse extension names as comma
separated values appended to the "min" CPU type using command-line.

For example, to include Sstc and Ssaia in the min CPU type use
"--cpu-type min,sstc,ssaia" command-line option.

Signed-off-by: Anup Patel <[e-mail]>
---
 riscv/fdt.c | 41 +++++++++++++++++++++++++++++++++++++++--
 1 file changed, 39 insertions(+), 2 deletions(-)

Patch

diff --git a/riscv/fdt.c b/riscv/fdt.c
index 4c018c8..9cefd2f 100644
--- a/riscv/fdt.c
+++ b/riscv/fdt.c
@@ -108,6 +108,20 @@  static bool __isa_ext_warn_disable_failure(struct kvm *kvm, struct isa_ext_info
 	return true;
 }
 
+static void __min_cpu_include(const char *ext, size_t ext_len)
+{
+	struct isa_ext_info *info;
+	unsigned long i;
+
+	for (i = 0; i < ARRAY_SIZE(isa_info_arr); i++) {
+		info = &isa_info_arr[i];
+		if (strlen(info->name) != ext_len)
+			continue;
+		if (!strncmp(ext, info->name, ext_len))
+			info->min_cpu_included = true;
+	}
+}
+
 bool riscv__isa_extension_disabled(struct kvm *kvm, unsigned long isa_ext_id)
 {
 	struct isa_ext_info *info = NULL;
@@ -128,16 +142,39 @@  bool riscv__isa_extension_disabled(struct kvm *kvm, unsigned long isa_ext_id)
 int riscv__cpu_type_parser(const struct option *opt, const char *arg, int unset)
 {
 	struct kvm *kvm = opt->ptr;
+	const char *str, *nstr;
+	int len;
 
-	if ((strncmp(arg, "min", 3) && strncmp(arg, "max", 3)) || strlen(arg) != 3)
+	if ((strncmp(arg, "min", 3) || strlen(arg) < 3) &&
+	    (strncmp(arg, "max", 3) || strlen(arg) != 3))
 		die("Invalid CPU type %s\n", arg);
 
 	if (!strncmp(arg, "max", 3))
 		kvm->cfg.arch.cpu_type = "max";
 
-	if (!strncmp(arg, "min", 3))
+	if (!strncmp(arg, "min", 3)) {
 		kvm->cfg.arch.cpu_type = "min";
 
+		str = arg;
+		str += 3;
+		while (*str) {
+			if (*str == ',') {
+				str++;
+				continue;
+			}
+
+			nstr = strchr(str, ',');
+			if (!nstr)
+				nstr = str + strlen(str);
+
+			len = nstr - str;
+			if (len) {
+				__min_cpu_include(str, len);
+				str += len;
+			}
+		}
+	}
+
 	return 0;
 }