Re: [PATCH v2 2/9] crypto: ccp: Fix implicit SEV/SNP init and shutdown in ioctls

[Alexey Kardashevskiy <aik@amd.com>]

On 17/12/24 10:57, Ashish Kalra wrote:
> From: Ashish Kalra <ashish.kalra@amd.com>
> 
> Modify the behavior of implicit SEV initialization in some of the
> SEV ioctls to do both SEV initialization and shutdown and adds
> implicit SNP initialization and shutdown to some of the SNP ioctls
> so that the change of SEV/SNP platform initialization not being
> done during PSP driver probe time does not break userspace tools
> such as sevtool, etc.
> 
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
> ---
>   drivers/crypto/ccp/sev-dev.c | 149 +++++++++++++++++++++++++++++------
>   1 file changed, 125 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index 1c1c33d3ed9a..0ec2e8191583 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1454,7 +1454,8 @@ static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
>   static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool writable)
>   {
>   	struct sev_device *sev = psp_master->sev_data;
> -	int rc;
> +	bool shutdown_required = false;
> +	int rc, ret, error;
>   
>   	if (!writable)
>   		return -EPERM;
> @@ -1463,19 +1464,30 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp, bool wr
>   		rc = __sev_platform_init_locked(&argp->error);
>   		if (rc)
>   			return rc;
> +		shutdown_required = true;
> +	}
> +
> +	rc = __sev_do_cmd_locked(cmd, NULL, &argp->error);
> +
> +	if (shutdown_required) {
> +		ret = __sev_platform_shutdown_locked(&error);
> +		if (ret)
> +			dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
> +				error, ret);
>   	}
>   
> -	return __sev_do_cmd_locked(cmd, NULL, &argp->error);
> +	return rc;
>   }
>   
>   static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
>   {
>   	struct sev_device *sev = psp_master->sev_data;
>   	struct sev_user_data_pek_csr input;
> +	bool shutdown_required = false;
>   	struct sev_data_pek_csr data;
>   	void __user *input_address;
> +	int ret, rc, error;
>   	void *blob = NULL;
> -	int ret;
>   
>   	if (!writable)
>   		return -EPERM;
> @@ -1506,6 +1518,7 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
>   		ret = __sev_platform_init_locked(&argp->error);
>   		if (ret)
>   			goto e_free_blob;
> +		shutdown_required = true;
>   	}
>   
>   	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, &data, &argp->error);
> @@ -1524,6 +1537,13 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp, bool writable)
>   	}
>   
>   e_free_blob:
> +	if (shutdown_required) {
> +		rc = __sev_platform_shutdown_locked(&error);
> +		if (rc)
> +			dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
> +				error, rc);
> +	}
> +
>   	kfree(blob);
>   	return ret;
>   }
> @@ -1739,8 +1759,9 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
>   	struct sev_device *sev = psp_master->sev_data;
>   	struct sev_user_data_pek_cert_import input;
>   	struct sev_data_pek_cert_import data;
> +	bool shutdown_required = false;
>   	void *pek_blob, *oca_blob;
> -	int ret;
> +	int ret, rc, error;
>   
>   	if (!writable)
>   		return -EPERM;
> @@ -1772,11 +1793,19 @@ static int sev_ioctl_do_pek_import(struct sev_issue_cmd *argp, bool writable)
>   		ret = __sev_platform_init_locked(&argp->error);
>   		if (ret)
>   			goto e_free_oca;
> +		shutdown_required = true;
>   	}
>   
>   	ret = __sev_do_cmd_locked(SEV_CMD_PEK_CERT_IMPORT, &data, &argp->error);
>   
>   e_free_oca:
> +	if (shutdown_required) {
> +		rc = __sev_platform_shutdown_locked(&error);
> +		if (rc)
> +			dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
> +				error, rc);
> +	}
> +
>   	kfree(oca_blob);
>   e_free_pek:
>   	kfree(pek_blob);
> @@ -1893,17 +1922,8 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>   	struct sev_data_pdh_cert_export data;
>   	void __user *input_cert_chain_address;
>   	void __user *input_pdh_cert_address;
> -	int ret;
> -
> -	/* If platform is not in INIT state then transition it to INIT. */
> -	if (sev->state != SEV_STATE_INIT) {
> -		if (!writable)
> -			return -EPERM;
> -
> -		ret = __sev_platform_init_locked(&argp->error);
> -		if (ret)
> -			return ret;
> -	}
> +	bool shutdown_required = false;
> +	int ret, rc, error;
>   
>   	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
>   		return -EFAULT;
> @@ -1944,6 +1964,16 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>   	data.cert_chain_len = input.cert_chain_len;
>   
>   cmd:
> +	/* If platform is not in INIT state then transition it to INIT. */
> +	if (sev->state != SEV_STATE_INIT) {
> +		if (!writable)
> +			return -EPERM;

goto e_free_cert, not return, otherwise leaks memory.


> +		ret = __sev_platform_init_locked(&argp->error);
> +		if (ret)
> +			goto e_free_cert;
> +		shutdown_required = true;
> +	}
> +
>   	ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, &data, &argp->error);
>   
>   	/* If we query the length, FW responded with expected data. */
> @@ -1970,6 +2000,13 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>   	}
>   
>   e_free_cert:
> +	if (shutdown_required) {
> +		rc = __sev_platform_shutdown_locked(&error);
> +		if (rc)
> +			dev_err(sev->dev, "SEV: failed to SHUTDOWN error %#x, rc %d\n",
> +				error, rc);
> +	}
> +
>   	kfree(cert_blob);
>   e_free_pdh:
>   	kfree(pdh_blob);
> @@ -1979,12 +2016,13 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>   static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
>   {
>   	struct sev_device *sev = psp_master->sev_data;
> +	bool shutdown_required = false;
>   	struct sev_data_snp_addr buf;
>   	struct page *status_page;
> +	int ret, rc, error;
>   	void *data;
> -	int ret;
>   
> -	if (!sev->snp_initialized || !argp->data)
> +	if (!argp->data)
>   		return -EINVAL;
>   
>   	status_page = alloc_page(GFP_KERNEL_ACCOUNT);
> @@ -1993,6 +2031,13 @@ static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
>   
>   	data = page_address(status_page);
>   
> +	if (!sev->snp_initialized) {
> +		ret = __sev_snp_init_locked(&argp->error);
> +		if (ret)
> +			goto cleanup;
> +		shutdown_required = true;
> +	}
> +
>   	/*
>   	 * Firmware expects status page to be in firmware-owned state, otherwise
>   	 * it will report firmware error code INVALID_PAGE_STATE (0x1A).
> @@ -2021,6 +2066,13 @@ static int sev_ioctl_do_snp_platform_status(struct sev_issue_cmd *argp)
>   		ret = -EFAULT;
>   
>   cleanup:
> +	if (shutdown_required) {
> +		rc = __sev_snp_shutdown_locked(&error, false);
> +		if (rc)
> +			dev_err(sev->dev, "SEV-SNP: failed to SHUTDOWN error %#x, rc %d\n",
> +				error, rc);
> +	}
> +
>   	__free_pages(status_page, 0);
>   	return ret;
>   }
> @@ -2029,21 +2081,38 @@ static int sev_ioctl_do_snp_commit(struct sev_issue_cmd *argp)
>   {
>   	struct sev_device *sev = psp_master->sev_data;
>   	struct sev_data_snp_commit buf;
> +	bool shutdown_required = false;
> +	int ret, rc, error;
>   
> -	if (!sev->snp_initialized)
> -		return -EINVAL;
> +	if (!sev->snp_initialized) {
> +		ret = __sev_snp_init_locked(&argp->error);
> +		if (ret)
> +			return ret;
> +		shutdown_required = true;
> +	}
>   
>   	buf.len = sizeof(buf);
>   
> -	return __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
> +	ret = __sev_do_cmd_locked(SEV_CMD_SNP_COMMIT, &buf, &argp->error);
> +
> +	if (shutdown_required) {
> +		rc = __sev_snp_shutdown_locked(&error, false);
> +		if (rc)
> +			dev_err(sev->dev, "SEV-SNP: failed to SHUTDOWN error %#x, rc %d\n",
> +				error, rc);
> +	}
> +
> +	return ret;
>   }
>   
>   static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable)
>   {
>   	struct sev_device *sev = psp_master->sev_data;
>   	struct sev_user_data_snp_config config;
> +	bool shutdown_required = false;
> +	int ret, rc, error;
>   
> -	if (!sev->snp_initialized || !argp->data)
> +	if (!argp->data)
>   		return -EINVAL;
>   
>   	if (!writable)
> @@ -2052,17 +2121,34 @@ static int sev_ioctl_do_snp_set_config(struct sev_issue_cmd *argp, bool writable
>   	if (copy_from_user(&config, (void __user *)argp->data, sizeof(config)))
>   		return -EFAULT;
>   
> -	return __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
> +	if (!sev->snp_initialized) {
> +		ret = __sev_snp_init_locked(&argp->error);
> +		if (ret)
> +			return ret;
> +		shutdown_required = true;
> +	}
> +
> +	ret = __sev_do_cmd_locked(SEV_CMD_SNP_CONFIG, &config, &argp->error);
> +
> +	if (shutdown_required) {
> +		rc = __sev_snp_shutdown_locked(&error, false);
> +		if (rc)
> +			dev_err(sev->dev, "SEV-SNP: failed to SHUTDOWN error %#x, rc %d\n",
> +				error, rc);
> +	}
> +
> +	return ret;
>   }
>   
>   static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
>   {
>   	struct sev_device *sev = psp_master->sev_data;
>   	struct sev_user_data_snp_vlek_load input;
> +	bool shutdown_required = false;
> +	int ret, rc, error;
>   	void *blob;
> -	int ret;
>   
> -	if (!sev->snp_initialized || !argp->data)
> +	if (!argp->data)
>   		return -EINVAL;
>   
>   	if (!writable)
> @@ -2081,8 +2167,23 @@ static int sev_ioctl_do_snp_vlek_load(struct sev_issue_cmd *argp, bool writable)
>   
>   	input.vlek_wrapped_address = __psp_pa(blob);
>   
> +	if (!sev->snp_initialized) {
> +		ret = __sev_snp_init_locked(&argp->error);
> +		if (ret)
> +			goto cleanup;
> +		shutdown_required = true;
> +	}
> +
>   	ret = __sev_do_cmd_locked(SEV_CMD_SNP_VLEK_LOAD, &input, &argp->error);
>   
> +	if (shutdown_required) {
> +		rc = __sev_snp_shutdown_locked(&error, false);
> +		if (rc)
> +			dev_err(sev->dev, "SEV-SNP: failed to SHUTDOWN error %#x, rc %d\n",
> +				error, rc);
> +	}


It is the same template 8 times, I'd declare rc and error inside the "if 
(shutdown_required)" scope or even drop them and error messages as 
__sev_snp_shutdown_locked() prints dev_err() anyway.

if (shutdown_required)
	__sev_snp_shutdown_locked(&error, false);

and that's it. Thanks,

> +
> +cleanup:
>   	kfree(blob);
>   
>   	return ret;

-- 
Alexey