On Fri, 2023-05-26 at 01:58 +0300, Kirill A. Shutemov wrote:
> TDX code is going to provide guest.enc_status_change_prepare() that is
> able to fail.
>
> Add a way to return an error from the callback.
>
> While there, fix enc_status_change_finish_noop(). It is defined as
> always-fail now which doesn't make sense for noop.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> arch/x86/include/asm/x86_init.h | 2 +-
> arch/x86/kernel/x86_init.c | 4 ++--
> arch/x86/mm/mem_encrypt_amd.c | 4 +++-
> arch/x86/mm/pat/set_memory.c | 3 ++-
> 4 files changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
> index 88085f369ff6..1ca9701917c5 100644
> --- a/arch/x86/include/asm/x86_init.h
> +++ b/arch/x86/include/asm/x86_init.h
> @@ -150,7 +150,7 @@ struct x86_init_acpi {
> * @enc_cache_flush_required Returns true if a cache flush is needed before changing page encryption status
> */
> struct x86_guest {
> - void (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
> + bool (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
>
[...]
> @@ -2151,7 +2151,8 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
> cpa_flush(&cpa, x86_platform.guest.enc_cache_flush_required());
>
> /* Notify hypervisor that we are about to set/clr encryption attribute. */
> - x86_platform.guest.enc_status_change_prepare(addr, numpages, enc);
> + if (!x86_platform.guest.enc_status_change_prepare(addr, numpages, enc))
> + return -EIO;
The name "enc_status_change_prepare()" sounds like an action, but not some
true/false condition check. I think it's more reasonable to make it return
'int', and returning 0 means successful?
