Re: [RFC PATCH v1 38/38] coco: guest: arm64: Add support for fetching device info

[Eric Biggers]

On Mon, Jul 28, 2025 at 07:22:15PM +0530, Aneesh Kumar K.V (Arm) wrote:
> @@ -5,6 +5,8 @@ config ARM_CCA_GUEST
>  	tristate "Arm CCA Guest driver"
>  	depends on ARM64
>  	depends on PCI_TSM
> +	select CRYPTO_SHA256
> +	select CRYPTO_SHA512
>  	select TSM_REPORTS
>  	select TSM

CRYPTO_LIB_SHA256 and CRYPTO_LIB_SHA512

> +	if (dsm->dev_info.hash_algo == RSI_HASH_SHA_256) {
> +		hash_alg_name = "sha256";
> +		digest_size = SHA256_DIGEST_SIZE;
> +	} else if (dsm->dev_info.hash_algo == RSI_HASH_SHA_512) {
> +		hash_alg_name = "sha512";
> +		digest_size = SHA512_DIGEST_SIZE;
> +	} else {
> +		pci_err(pdev, "unknown realm hash algorithm!\n");
> +		ret = -EINVAL;
> +		goto err_out;
> +	}
> +
> +	alg = crypto_alloc_shash(hash_alg_name, 0, 0);
> +	if (IS_ERR(alg)) {
> +		pci_err(pdev, "cannot allocate %s\n", hash_alg_name);
> +		return PTR_ERR(alg);
> +	}
> +
> +	sdesc_size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
> +	shash = kzalloc(sdesc_size, GFP_KERNEL);
> +	if (!shash) {
> +		pci_err(pdev, "cannot allocate sdesc\n");
> +		ret = -ENOMEM;
> +		goto err_free_shash;
> +	}
> +	shash->tfm = alg;
> +
> +	for (i = 0; i < ARRAY_SIZE(reports); i++) {
> +		ret = crypto_shash_digest(shash, reports[i].report,
> +					  reports[i].size, digest);
> +		if (ret) {
> +			pci_err(pdev, "failed to compute digest, %d\n", ret);
> +			goto err_free_sdesc;
> +		}

Use sha256() and sha512().

- Eric