Re: [PATCH v12 05/22] x86/virt/tdx: Add SEAMCALL infrastructure

[Huang, Kai]

On Wed, 2023-06-28 at 11:09 +0800, Chao Gao wrote:
> > +/*
> > + * Wrapper of __seamcall() to convert SEAMCALL leaf function error code
> > + * to kernel error code.  @seamcall_ret and @out contain the SEAMCALL
> > + * leaf function return code and the additional output respectively if
> > + * not NULL.
> > + */
> > +static int __always_unused seamcall(u64 fn, u64 rcx, u64 rdx, u64 r8, u64
> > r9,
> > +				    u64 *seamcall_ret,
> > +				    struct tdx_module_output *out)
> > +{
> > +	u64 sret;
> > +	int cpu;
> > +
> > +	/* Need a stable CPU id for printing error message */
> > +	cpu = get_cpu();
> > +	sret = __seamcall(fn, rcx, rdx, r8, r9, out);
> > +	put_cpu();
> > +
> > +	/* Save SEAMCALL return code if the caller wants it */
> > +	if (seamcall_ret)
> > +		*seamcall_ret = sret;
> 
> Hi Kai,
> 
> All callers in this series pass NULL for seamcall_ret. I am no sure if
> you keep it intentionally.

In this series all the callers doesn't need seamcall_ret.

> 
> > +
> > +	switch (sret) {
> > +	case 0:
> > +		/* SEAMCALL was successful */
> 
> Nit: if you add
> 
> #define TDX_SUCCESS	0
> 
> and do
> 
> 	case TDX_SUCCESS:
> 		return 0;
> 
> then the code becomes self-explanatory. i.e., you can drop the comment.

If using this, I ended up with below:

--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -23,6 +23,8 @@
 #define TDX_SEAMCALL_GP                        (TDX_SW_ERROR | X86_TRAP_GP)
 #define TDX_SEAMCALL_UD                        (TDX_SW_ERROR | X86_TRAP_UD)
 
+#define TDX_SUCCESS           0
+

Hi Kirill/Dave/David,

Are you happy with this?