Attempt to provide a more helpful error message when the user attempts to set
spec-ctrl=bti-thunk option but the support is build-time disabled.
Reported-by: Andrew Cooper <andrew.coop...@citrix.com>
Signed-off-by: Roger Pau Monné <roger....@citrix.com>
---
Changes since v1:
- New in this version.
---
xen/arch/x86/spec_ctrl.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c
index 4ce8a7a0b8ef..f3432f1a6c80 100644
--- a/xen/arch/x86/spec_ctrl.c
+++ b/xen/arch/x86/spec_ctrl.c
@@ -239,6 +239,7 @@ static int __init cf_check parse_spec_ctrl(const char *s)
/* Xen's speculative sidechannel mitigation settings. */
else if ( !strncmp(s, "bti-thunk=", 10) )
{
+#ifdef CONFIG_INDIRECT_THUNK
s += 10;
if ( !cmdline_strcmp(s, "retpoline") )
@@ -249,6 +250,10 @@ static int __init cf_check parse_spec_ctrl(const char *s)
opt_thunk = THUNK_JMP;
else
rc = -EINVAL;
+#else
+ no_config_param("INDIRECT_THUNK", "spec-ctrl", s, ss);
+ rc = -EINVAL;
+#endif
}
/* Bits in MSR_SPEC_CTRL. */
--
2.43.0
