On Fri, Nov 5, 2021 at 11:54 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote:
>
> On Sat, Oct 30, 2021, Zixuan Wang wrote:
> > +efi_status_t setup_efi(efi_bootinfo_t *efi_bootinfo)
> > {
> > + efi_status_t status;
> > +
> > + status = setup_memory_allocator(efi_bootinfo);
> > + if (status != EFI_SUCCESS) {
> > + printf("Failed to set up memory allocator: ");
> > + switch (status) {
> > + case EFI_OUT_OF_RESOURCES:
> > + printf("No free memory region\n");
> > + break;
> > + default:
> > + printf("Unknown error\n");
> > + break;
> > + }
> > + return status;
> > + }
> > +
> > + status = setup_rsdp(efi_bootinfo);
> > + if (status != EFI_SUCCESS) {
> > + printf("Cannot find RSDP in EFI system table\n");
> > + return status;
> > + }
> > +
> > + status = setup_amd_sev();
> > + if (status != EFI_SUCCESS) {
> > + switch (status) {
> > + case EFI_UNSUPPORTED:
> > + /* Continue if AMD SEV is not supported */
> > + break;
> > + default:
> > + printf("Set up AMD SEV failed\n");
> > + return status;
> > + }
> > + }
>
> Looks like this is pre-existing behavior, but the switch is quite gratuituous,
> and arguably does the wrong thing for EFI_UNSUPPORTED here as attempting to setup
> SEV-ES without SEV is guaranteed to fail. And it'd be really nice if the printf()
> actually provided the error (below might be wrong, I don't know the type of
> efi_status-t).
>
> status = setup_amd_sev();
>
> /* Continue on if AMD SEV isn't supported, but skip SEV-ES setup. */
> if (status == EFI_UNSUPPORTED)
> goto continue_setup;
>
> if (status != EFI_SUCCESS) {
> printf("AMD SEV setup failed, error = %d\n", status);
> return status;
> }
>
> /* Same as above, lack of SEV-ES is not a fatal error. */
> status = setup_amd_sev_es();
> if (status != EFI_SUCCESS && status != EFI_UNSUPPORTED) {
> printf("AMD SEV-ES setup failed, error = %d\n", status);
> return status;
> }
>
> continue_setup:
>
I agree. The current setup_amd_sev_es() checks if SEV is available and
returns EFI_UNSUPPORTED if not, so it does no harm if called after
setup_amd_sev() fails. But I think we should not rely on these
underlying implementation details. I will include this part in the
next version.
Best regards,
Zixuan
