Re: [PATCH v5 08/14] x86/mm: Add generic guest initialization hook

Tom Lendacky
2023-10-30T19:19:45Z

On 10/30/23 01:36, Nikunj A Dadhania wrote:
> Add generic enc_init guest hook for performing any type of
> initialization that is vendor specific.

I think this commit message should be expanded on a bit... like when it is
intended to be called, etc.

Thanks,
Tom

>
> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
> ---
> arch/x86/include/asm/x86_init.h | 2 ++
> arch/x86/kernel/x86_init.c | 2 ++
> arch/x86/mm/mem_encrypt.c | 3 +++
> 3 files changed, 7 insertions(+)
>
> diff --git a/arch/x86/include/asm/x86_init.h b/arch/x86/include/asm/x86_init.h
> index 5240d88db52a..6a08dcd1f3c4 100644
> --- a/arch/x86/include/asm/x86_init.h
> +++ b/arch/x86/include/asm/x86_init.h
> @@ -148,12 +148,14 @@ struct x86_init_acpi {
> * @enc_status_change_finish Notify HV after the encryption status of a range is changed
> * @enc_tlb_flush_required Returns true if a TLB flush is needed before changing page encryption status
> * @enc_cache_flush_required Returns true if a cache flush is needed before changing page encryption status
> + * @enc_init Prepare and initialize encryption features
> */
> struct x86_guest {
> bool (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
> bool (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc);
> bool (*enc_tlb_flush_required)(bool enc);
> bool (*enc_cache_flush_required)(void);
> + void (*enc_init)(void);
> };
>
> /**
> diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
> index a37ebd3b4773..a07985a96ca5 100644
> --- a/arch/x86/kernel/x86_init.c
> +++ b/arch/x86/kernel/x86_init.c
> @@ -136,6 +136,7 @@ static bool enc_status_change_finish_noop(unsigned long vaddr, int npages, bool
> static bool enc_tlb_flush_required_noop(bool enc) { return false; }
> static bool enc_cache_flush_required_noop(void) { return false; }
> static bool is_private_mmio_noop(u64 addr) {return false; }
> +static void enc_init_noop(void) { }
>
> struct x86_platform_ops x86_platform __ro_after_init = {
> .calibrate_cpu = native_calibrate_cpu_early,
> @@ -158,6 +159,7 @@ struct x86_platform_ops x86_platform __ro_after_init = {
> .enc_status_change_finish = enc_status_change_finish_noop,
> .enc_tlb_flush_required = enc_tlb_flush_required_noop,
> .enc_cache_flush_required = enc_cache_flush_required_noop,
> + .enc_init = enc_init_noop,
> },
> };
>
> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
> index 9f27e14e185f..01abecc9a774 100644
> --- a/arch/x86/mm/mem_encrypt.c
> +++ b/arch/x86/mm/mem_encrypt.c
> @@ -84,5 +84,8 @@ void __init mem_encrypt_init(void)
> /* Call into SWIOTLB to update the SWIOTLB DMA buffers */
> swiotlb_update_mem_attributes();
>
> + if (x86_platform.guest.enc_init)
> + x86_platform.guest.enc_init();
> +
> print_mem_encrypt_feature_info();
> }