diff --git a/test_infra/src/lib.rs b/test_infra/src/lib.rs
index e1af41bc0..b6d7641f6 100644
--- a/test_infra/src/lib.rs
+++ b/test_infra/src/lib.rs
@@ -1694,7 +1694,7 @@ impl<'a> GuestCommand<'a> {
         self.args(["--net", self.guest.default_net_string().as_str()])
     }
 
-    pub fn default_kernel_cmdline(&mut self) -> &mut Self {
+    pub fn default_kernel_cmdline_with_platform(&mut self, platform: Option<&str>) -> &mut Self {
         if self.guest.vm_type == GuestVmType::Confidential {
             let console_str = if let Some(c) = &self.guest.console_type {
                 c.as_str()
@@ -1709,17 +1709,34 @@ impl<'a> GuestCommand<'a> {
             ]);
             self.command
                 .args(["--host-data", generate_host_data().as_str()]);
-            self.command.args(["--platform", "sev_snp=on"]);
+            self.command.args([
+                "--platform",
+                &format!(
+                    "{}sev_snp=on",
+                    if let Some(p) = platform {
+                        format!("{p},")
+                    } else {
+                        String::new()
+                    }
+                ),
+            ]);
         } else if let Some(kernel) = &self.guest.kernel_path {
             self.command.args(["--kernel", kernel.as_str()]);
             if let Some(cmdline) = &self.guest.kernel_cmdline {
                 self.command.args(["--cmdline", cmdline]);
             }
+            if let Some(platform_arg) = platform {
+                self.command.args(["--platform", platform_arg]);
+            }
         }
 
         self
     }
 
+    pub fn default_kernel_cmdline(&mut self) -> &mut Self {
+        self.default_kernel_cmdline_with_platform(None)
+    }
+
     pub fn default_cpus(&mut self) -> &mut Self {
         self.args(["--cpus", self.guest.default_cpus_string().as_str()])
     }