x86/spec: do not print thunk option selection if not built-in

Since the thunk built-in enable is printed as part of the "Compiled-in
support:" line, avoid printing anything in "Xen settings:" if the thunk is
disabled at build time.

Note the BTI-Thunk option printing is also adjusted to print a colon in the
same way the other options on the line do.

Requested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 576528a2a742069af203e90c613c5c93e23c9755
master date: 2024-02-27 14:58:40 +0100

diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c
index 99ecfb3cba92d429c5782d22bcf4ad13e40f60ef..a965b6db28baec25c8363cbe6c0806cbfda2c33a 100644 (file)
--- a/xen/arch/x86/spec_ctrl.c
+++ b/xen/arch/x86/spec_ctrl.c
@@ -504,11 +504,12 @@ static void __init print_details(enum ind_thunk thunk)
                "\n");
 
     /* Settings for Xen's protection, irrespective of guests. */
-    printk("  Xen settings: BTI-Thunk %s, SPEC_CTRL: %s%s%s%s%s, Other:%s%s%s%s%s%s\n",
-           thunk == THUNK_NONE      ? "N/A" :
-           thunk == THUNK_RETPOLINE ? "RETPOLINE" :
-           thunk == THUNK_LFENCE    ? "LFENCE" :
-           thunk == THUNK_JMP       ? "JMP" : "?",
+    printk("  Xen settings: %s%sSPEC_CTRL: %s%s%s%s%s, Other:%s%s%s%s%s%s\n",
+           thunk != THUNK_NONE      ? "BTI-Thunk: " : "",
+           thunk == THUNK_NONE      ? "" :
+           thunk == THUNK_RETPOLINE ? "RETPOLINE, " :
+           thunk == THUNK_LFENCE    ? "LFENCE, " :
+           thunk == THUNK_JMP       ? "JMP, " : "?, ",
            (!boot_cpu_has(X86_FEATURE_IBRSB) &&
             !boot_cpu_has(X86_FEATURE_IBRS))         ? "No" :
            (default_xen_spec_ctrl & SPEC_CTRL_IBRS)  ? "IBRS+" :  "IBRS-",