[Part2,v7,14/38] crypto: ccp: Implement SEV_FACTORY_RESET ioctl command

Commit Message

Brijesh Singh Nov. 1, 2017, 9:15 p.m. UTC

The SEV_FACTORY_RESET command can be used by the platform owner to
reset the non-volatile SEV related data. The command is defined in
SEV spec section 5.4

Cc: Paolo Bonzini <[e-mail]>
Cc: "Radim Krčmář" <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Herbert Xu <[e-mail]>
Cc: Gary Hook <[e-mail]>
Cc: Tom Lendacky <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Improvements-by: Borislav Petkov <[e-mail]>
Signed-off-by: Brijesh Singh <[e-mail]>
Acked-by: Gary R Hook <[e-mail]>
---
 drivers/crypto/ccp/psp-dev.c | 70 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

Comments

Borislav Petkov Nov. 3, 2017, 12:42 p.m. UTC | #1

On Wed, Nov 01, 2017 at 04:15:59PM -0500, Brijesh Singh wrote:
> The SEV_FACTORY_RESET command can be used by the platform owner to
> reset the non-volatile SEV related data. The command is defined in
> SEV spec section 5.4
> 
> Cc: Paolo Bonzini <[e-mail]>
> Cc: "Radim Krčmář" <[e-mail]>
> Cc: Borislav Petkov <[e-mail]>
> Cc: Herbert Xu <[e-mail]>
> Cc: Gary Hook <[e-mail]>
> Cc: Tom Lendacky <[e-mail]>
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: [e-mail]
> Improvements-by: Borislav Petkov <[e-mail]>
> Signed-off-by: Brijesh Singh <[e-mail]>
> Acked-by: Gary R Hook <[e-mail]>

Acked-by: needs to go away too if you send a new revision with
non-trivial changes. Same as with Reviewed-by: tags.

> ---
>  drivers/crypto/ccp/psp-dev.c | 70 +++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 69 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> index c61ca16096ca..a757bd1c34e8 100644
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -235,9 +235,77 @@ static int sev_platform_shutdown(int *error)
>  	return rc;
>  }
>  
> +static int sev_platform_state(int *state, int *error)

It needs a verb in the name: sev_get_platform_state()

> +{
> +	int rc;
> +
> +	rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS,
> +				 psp_master->sev_status, error);
> +	if (rc)
> +		return rc;
> +
> +	*state = psp_master->sev_status->state;
> +	return rc;
> +}
> +
> +static int sev_ioctl_do_reset(struct sev_issue_cmd *argp)
> +{
> +	int state, rc;
> +
> +	rc = sev_platform_state(&state, &argp->error);
> +	if (rc)
> +		return rc;
> +
> +	if (state == SEV_STATE_WORKING) {

You could write a short blurb somewhere in a comment around here, what
the logic now is going to be for the SEV device: If in working state,
reset is denied. All other states accept it, because... <reasons>.

> +		argp->error = SEV_RET_INVALID_PLATFORM_STATE;

If you're going to write enum psp_ret_code types into argp->error, then
it needs to be of enum psp_ret_code type and not an int.

> +		return -EBUSY;
> +	}
> +
> +	if (state == SEV_STATE_INIT) {
> +		rc = __sev_platform_shutdown_locked(&argp->error);
> +		if (rc)
> +			return rc;
> +	}
> +
> +	return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, 0, &argp->error);
> +}

Patch

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index c61ca16096ca..a757bd1c34e8 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -235,9 +235,77 @@  static int sev_platform_shutdown(int *error)
 	return rc;
 }
 
+static int sev_platform_state(int *state, int *error)
+{
+	int rc;
+
+	rc = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS,
+				 psp_master->sev_status, error);
+	if (rc)
+		return rc;
+
+	*state = psp_master->sev_status->state;
+	return rc;
+}
+
+static int sev_ioctl_do_reset(struct sev_issue_cmd *argp)
+{
+	int state, rc;
+
+	rc = sev_platform_state(&state, &argp->error);
+	if (rc)
+		return rc;
+
+	if (state == SEV_STATE_WORKING) {
+		argp->error = SEV_RET_INVALID_PLATFORM_STATE;
+		return -EBUSY;
+	}
+
+	if (state == SEV_STATE_INIT) {
+		rc = __sev_platform_shutdown_locked(&argp->error);
+		if (rc)
+			return rc;
+	}
+
+	return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, 0, &argp->error);
+}
+
 static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 {
-	return -ENOTTY;
+	void __user *argp = (void __user *)arg;
+	struct sev_issue_cmd input;
+	int ret = -EFAULT;
+
+	if (!psp_master)
+		return -ENODEV;
+
+	if (ioctl != SEV_ISSUE_CMD)
+		return -EINVAL;
+
+	if (copy_from_user(&input, argp, sizeof(struct sev_issue_cmd)))
+		return -EFAULT;
+
+	if (input.cmd > SEV_MAX)
+		return -EINVAL;
+
+	mutex_lock(&sev_cmd_mutex);
+
+	switch (input.cmd) {
+
+	case SEV_FACTORY_RESET:
+		ret = sev_ioctl_do_reset(&input);
+		break;
+	default:
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (copy_to_user(argp, &input, sizeof(struct sev_issue_cmd)))
+		ret = -EFAULT;
+out:
+	mutex_unlock(&sev_cmd_mutex);
+
+	return ret;
 }
 
 static const struct file_operations sev_fops = {