[Part2 PATCH v6.1 19/38] crypto: ccp: Implement SEV_PEK_CERT_IMPORT ioctl command

[Brijesh Singh <brijesh.singh@amd.com>]

The SEV_PEK_CERT_IMPORT command can be used to import the signed PEK
certificate. The command is defined in SEV spec section 5.8.

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
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---

Changes since v6:
 * when sev_do_cmd() and sev_platform_shutdown() fails then propogate
   the error status code from sev_do_cmd() because it can give us
   much better reason for the failure.

 drivers/crypto/ccp/psp-dev.c | 92 ++++++++++++++++++++++++++++++++++++++++++++
 include/linux/psp-sev.h      |  4 ++
 2 files changed, 96 insertions(+)

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index aaf1c5cf821d..108fc06bcdb3 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -301,6 +301,95 @@ static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp)
 	return ret;
 }
 
+void *psp_copy_user_blob(u64 __user uaddr, u32 len)
+{
+	void *data;
+
+	if (!uaddr || !len)
+		return ERR_PTR(-EINVAL);
+
+	/* verify that blob length does not exceed our limit */
+	if (len > SEV_FW_BLOB_MAX_SIZE)
+		return ERR_PTR(-EINVAL);
+
+	data = kmalloc(len, GFP_KERNEL);
+	if (!data)
+		return ERR_PTR(-ENOMEM);
+
+	if (copy_from_user(data, (void __user *)(uintptr_t)uaddr, len))
+		goto e_free;
+
+	return data;
+
+e_free:
+	kfree(data);
+	return ERR_PTR(-EFAULT);
+}
+EXPORT_SYMBOL_GPL(psp_copy_user_blob);
+
+static int sev_ioctl_do_pek_cert_import(struct sev_issue_cmd *argp)
+{
+	struct sev_user_data_pek_cert_import input;
+	struct sev_data_pek_cert_import *data;
+	void *pek_blob, *oca_blob;
+	int ret, err;
+
+	if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
+		return -EFAULT;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	/* copy PEK certificate blobs from userspace */
+	pek_blob = psp_copy_user_blob(input.pek_cert_address, input.pek_cert_len);
+	if (IS_ERR(pek_blob)) {
+		ret = PTR_ERR(pek_blob);
+		goto e_free;
+	}
+
+	data->pek_cert_address = __psp_pa(pek_blob);
+	data->pek_cert_len = input.pek_cert_len;
+
+	/* copy PEK certificate blobs from userspace */
+	oca_blob = psp_copy_user_blob(input.oca_cert_address, input.oca_cert_len);
+	if (IS_ERR(oca_blob)) {
+		ret = PTR_ERR(oca_blob);
+		goto e_free_pek;
+	}
+
+	data->oca_cert_address = __psp_pa(oca_blob);
+	data->oca_cert_len = input.oca_cert_len;
+
+	ret = sev_platform_init(NULL, &argp->error);
+	if (ret)
+		goto e_free_oca;
+
+	ret = sev_do_cmd(SEV_CMD_PEK_CERT_IMPORT, data, &argp->error);
+
+	if (sev_platform_shutdown(&err)) {
+		/*
+		 * If both sev_do_cmd() and sev_platform_shutdown() commands
+		 * failed then propogate the error code from the sev_do_cmd()
+		 * because it contains a useful status code for the command
+		 * failure.
+		 */
+		if (ret)
+			goto e_free_oca;
+
+		ret = -EIO;
+		argp->error = err;
+	}
+
+e_free_oca:
+	kfree(oca_blob);
+e_free_pek:
+	kfree(pek_blob);
+e_free:
+	kfree(data);
+	return ret;
+}
+
 static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
@@ -333,6 +422,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 	case SEV_PEK_CSR:
 		ret = sev_ioctl_do_pek_csr(&input);
 		break;
+	case SEV_PEK_CERT_IMPORT:
+		ret = sev_ioctl_do_pek_cert_import(&input);
+		break;
 	default:
 		ret = -EINVAL;
 		goto out;
diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
index eac850a97610..d535153ca82d 100644
--- a/include/linux/psp-sev.h
+++ b/include/linux/psp-sev.h
@@ -620,6 +620,8 @@ int sev_guest_df_flush(int *error);
  */
 int sev_guest_decommission(struct sev_data_decommission *data, int *error);
 
+void *psp_copy_user_blob(u64 __user uaddr, u32 len);
+
 #else	/* !CONFIG_CRYPTO_DEV_SP_PSP */
 
 static inline int
@@ -648,6 +650,8 @@ sev_issue_cmd_external_user(struct file *filep,
 	return -ENODEV;
 }
 
+static inline void *psp_copy_user_blob(u64 __user uaddr, u32 len) { return ERR_PTR(-EINVAL); }
+
 #endif	/* CONFIG_CRYPTO_DEV_SP_PSP */
 
 #endif	/* __PSP_SEV_H__ */
-- 
2.9.5