Re: [RFC PATCH v5 16/45] x86/virt/tdx: Add tdx_alloc/free_control_page() helpers

[Yan Zhao]

> +void tdx_quirk_reset_page(struct page *page);
Looks this change is unnecessary.

>  int tdx_guest_keyid_alloc(void);
>  u32 tdx_get_nr_guest_keyids(void);
>  void tdx_guest_keyid_free(unsigned int keyid);
>  
> -void tdx_quirk_reset_page(struct page *page);
> +struct page *__tdx_alloc_control_page(gfp_t gfp);
> +void __tdx_free_control_page(struct page *page);
> +
> +static inline unsigned long tdx_alloc_control_page(gfp_t gfp)
> +{
> +	struct page *page = __tdx_alloc_control_page(gfp);
> +
> +	if (!page)
> +		return 0;
> +
> +	return (unsigned long)page_address(page);
> +}
> +
> +static inline void tdx_free_control_page(unsigned long addr)
> +{
> +	if (!addr)
> +		return;
> +
> +	__tdx_free_control_page(virt_to_page(addr));
> +}
>  
>  struct tdx_td {
>  	/* TD root structure: */
> diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
> index f6e80aba5895..682c8a228b53 100644
> --- a/arch/x86/virt/vmx/tdx/tdx.c
> +++ b/arch/x86/virt/vmx/tdx/tdx.c
> @@ -1824,6 +1824,50 @@ u64 tdh_mng_rd(struct tdx_td *td, u64 field, u64 *data)
>  }
>  EXPORT_SYMBOL_FOR_KVM(tdh_mng_rd);
>  
> +/* Number PAMT pages to be provided to TDX module per 2M region of PA */
> +static int tdx_dpamt_entry_pages(void)
> +{
> +	if (!tdx_supports_dynamic_pamt(&tdx_sysinfo))
> +		return 0;
> +
This function is not invoked when !tdx_supports_dynamic_pamt().
So, probably we can just return the count below?

> +	return tdx_sysinfo.tdmr.pamt_4k_entry_size * PTRS_PER_PTE / PAGE_SIZE;
> +}
> +