Re: [PATCH v14 15/22] KVM: selftests: Call KVM_TDX_INIT_VCPU when creating a new TDX vcpu

[Peter Fang <peter.fang@intel.com>]

On Fri, Aug 14, 2026 at 04:32:59PM +0800, Xiaoyao Li wrote:
> >   	}								\
> >   })
> > +#define __tdx_vcpu_ioctl(vcpu, cmd, _flags, arg)			\
> > +({									\
> > +	union {								\
> > +		struct kvm_tdx_cmd c;					\
> > +		unsigned long raw;					\
> > +	} tdx_cmd = { .c = {						\
> > +		.id = (cmd),						\
> > +		.flags = (u32)(_flags),					\
> > +		.data = (u64)(arg),					\
> > +	} };								\
> > +									\
> > +	__vcpu_ioctl(vcpu, KVM_MEMORY_ENCRYPT_OP, &tdx_cmd.raw);	\
> > +})
> > +
> > +#define tdx_vcpu_ioctl(vcpu, cmd, flags, arg)				\
> > +({									\
> > +	int ret = __tdx_vcpu_ioctl(vcpu, cmd, flags, arg);		\
> > +	TEST_ASSERT(!ret, "%s failed, errno: %d (%s)",			\
> > +		     #cmd, errno, strerror(errno));			\
> > +})
> 
> It doesn't handle the tdx_cmd.c.hw_error for vcpu ioctl, but handle it for
> vm ioctl, which looks inconsistent. This at least deserves a justification
> in the changelog.

Looks like this assymetry came from a v13 comment [1].

tdx_vcpu_ioctl() actually doesn't write back hw_error to userspace like
tdx_vm_ioctl() does, so hw_error is vCPU-scoped only right now. This is
a bit subtle so probably deserves to be called out.

[1] https://lore.kernel.org/all/bc8b458e-7893-4ad4-89a7-44568c227d32@linux.intel.com/

>