<snip>
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c
index 0f16ba52ae62..a5e77893b2c0 100644
--- a/arch/x86/coco/tdx/tdx.c
+++ b/arch/x86/coco/tdx/tdx.c
@@ -51,13 +51,38 @@
#define TDREPORT_SUBTYPE_0 0
+/* Called from __tdx_hypercall() for unrecoverable failure */
+static noinstr void __tdx_hypercall_failed(void)
+{
+ instrumentation_begin();
+ panic("TDVMCALL failed. TDX module bug?");
+}
So what's the deal with this instrumentation here. The instruction is
noinstr, so you want to make just the panic call itself instrumentable?,
if so where's the instrumentation_end() cal;?No instrumentation_end()
call. Actually is this complexity really worth it for the failure case?
AFAICS there is a single call site for __tdx_hypercall_failed so why
noot call panic() directly ?
+
+static inline u64 __tdx_hypercall(struct tdx_module_args *args)
+{
+ u64 ret;
+
+ args->rcx = TDVMCALL_EXPOSE_REGS_MASK;
+ ret = __tdcall_saved_ret(TDG_VP_VMCALL, args);
+
+ /*
+ * RAX!=0 indicates a failure of the TDVMCALL mechanism itself and that
nit: Why mention the register explicitly, just say that if
__tdcall_saved_ret returns non-zero ....
+ * something has gone horribly wrong with the TDX module.
+ */
+ if (ret)
+ __tdx_hypercall_failed();
+
+ /* The return status of the hypercall itself is in R10. */
+ return args->r10;
+}
+
/*
- * Wrapper for standard use of __tdx_hypercall with no output aside from
- * return code.
+ * Wrapper for standard use of __tdx_hypercall() w/o needing any output
+ * register except the return code.
*/
static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15)
{
- struct tdx_hypercall_args args = {
+ struct tdx_module_args args = {
.r10 = TDX_HYPERCALL_STANDARD,
.r11 = fn,
.r12 = r12,
<snip>
