Re: [PATCH v5 3/3] x86/tdx: Add Quote generation support

[Kai Huang]

> +
> +	/* Get order for Quote buffer page allocation */
> +	order = get_order(quote_req.len);
> +
> +	/*
> +	 * Allocate buffer to get TD Quote from the VMM.
> +	 * Size needs to be 4KB aligned (which is already
> +	 * met in page allocation).
> +	 */
> +	tdquote = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
> +	if (!tdquote) {
> +		ret = -ENOMEM;
> +		goto quote_failed;
> +	}

You can use alloc_pages_exact().

> +
> +	/*
> +	 * Since this buffer will be shared with the VMM via GetQuote
> +	 * hypercall, decrypt it.
> +	 */
> +	ret = set_memory_decrypted((unsigned long)tdquote, 1UL << order);
> +	if (ret)
> +		goto quote_failed;


Again, Dave and Andi already commented you should use vmap() to avoid breaking
up the direct-mapping.  Please use vmap() instead.

https://lore.kernel.org/all/ce0feeec-a949-35f8-3010-b0d69acbbc2e@xxxxxxxxxxxxxxx/

Will review the rest later.


-- 
Thanks,
-Kai