crypto: ccp: Implement SEV_PLATFORM_STATUS ioctl command

The SEV_PLATFORM_STATUS command can be used by the platform owner to
get the current status of the platform. The command is defined in
SEV spec section 5.5.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-crypto@vger.kernel.org
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Improvements-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Acked-by: Gary R Hook <gary.hook@amd.com>

drivers/crypto/ccp/psp-dev.c

@@ -274,6 +274,21 @@ static int sev_ioctl_do_reset(struct sev_issue_cmd *argp)
 	return __sev_do_cmd_locked(SEV_CMD_FACTORY_RESET, 0, &argp->error);
 }
 
+static int sev_ioctl_do_platform_status(struct sev_issue_cmd *argp)
+{
+	struct sev_user_data_status *data = &psp_master->status_cmd_buf;
+	int ret;
+
+	ret = __sev_do_cmd_locked(SEV_CMD_PLATFORM_STATUS, data, &argp->error);
+	if (ret)
+		return ret;
+
+	if (copy_to_user((void __user *)argp->data, data, sizeof(*data)))
+		ret = -EFAULT;
+
+	return ret;
+}
+
 static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
@@ -299,6 +314,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 	case SEV_FACTORY_RESET:
 		ret = sev_ioctl_do_reset(&input);
 		break;
+	case SEV_PLATFORM_STATUS:
+		ret = sev_ioctl_do_platform_status(&input);
+		break;
 	default:
 		ret = -EINVAL;
 		goto out;