The SEV_PDH_CERT_EXPORT command can be used to export the PDH and its
certificate chain. The command is defined in SEV spec section 5.10.

Cc: Paolo Bonzini <pbonz...@redhat.com>
Cc: "Radim Krčmář" <rkrc...@redhat.com>
Cc: Borislav Petkov <b...@suse.de>
Cc: Herbert Xu <herb...@gondor.apana.org.au>
Cc: Gary Hook <gary.h...@amd.com>
Cc: Tom Lendacky <thomas.lenda...@amd.com>
Cc: linux-cry...@vger.kernel.org
Cc: k...@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
---
 drivers/crypto/ccp/psp-dev.c | 110 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 861c44bf2910..0a069e3c7b8c 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -473,6 +473,112 @@ static int sev_ioctl_pek_cert_import(struct sev_issue_cmd 
*argp)
        return ret;
 }
 
+static int sev_ioctl_pdh_cert_export(struct sev_issue_cmd *argp)
+{
+       struct sev_user_data_pdh_cert_export input;
+       struct sev_data_pdh_cert_export *data;
+       int ret, state, need_shutdown = 0;
+       void *pdh_blob, *cert_blob;
+
+       if (copy_from_user(&input, (void __user *)(uintptr_t)argp->data,
+                          sizeof(struct sev_user_data_pdh_cert_export)))
+               return -EFAULT;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       pdh_blob = NULL;
+       if (input.pdh_cert_address) {
+               if (!access_ok(VERIFY_WRITE, input.pdh_cert_address, 
input.pdh_cert_len) ||
+                    (input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE)) {
+                       ret = -EFAULT;
+                       goto e_free;
+               }
+
+               pdh_blob = kmalloc(input.pdh_cert_len, GFP_KERNEL);
+               if (!pdh_blob) {
+                       ret = -ENOMEM;
+                       goto e_free;
+               }
+
+               data->pdh_cert_address = __psp_pa(pdh_blob);
+               data->pdh_cert_len = input.pdh_cert_len;
+       }
+
+       cert_blob = NULL;
+       if (input.cert_chain_address) {
+               if (!access_ok(VERIFY_WRITE, input.cert_chain_address, 
input.cert_chain_len) ||
+                   (input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE)) {
+                       ret = -EFAULT;
+                       goto e_free_pdh;
+               }
+
+               cert_blob = kmalloc(input.cert_chain_len, GFP_KERNEL);
+               if (!cert_blob) {
+                       ret = -ENOMEM;
+                       goto e_free_pdh;
+               }
+
+               data->cert_chain_address = __psp_pa(cert_blob);
+               data->cert_chain_len = input.cert_chain_len;
+       }
+
+       ret = sev_platform_get_state(&state, &argp->error);
+       if (ret)
+               goto e_free_cert;
+
+       /*
+        * CERT_EXPORT command can be issued in INIT or WORKING state.
+        * If we are in UNINIT state then transition to INIT.
+        */
+       if (state == SEV_STATE_UNINIT) {
+               ret = sev_firmware_init(&argp->error);
+               if (ret)
+                       goto e_free_cert;
+
+               need_shutdown = 1;
+       }
+
+       ret = sev_handle_cmd(SEV_CMD_PDH_CERT_EXPORT, data, &argp->error);
+
+       input.cert_chain_len = data->cert_chain_len;
+       input.pdh_cert_len = data->pdh_cert_len;
+
+       /* copy certificate length to userspace */
+       if (copy_to_user((void __user *)(uintptr_t)argp->data, &input,
+                        sizeof(struct sev_user_data_pdh_cert_export)))
+               ret = -EFAULT;
+
+       if (ret)
+               goto e_shutdown;
+
+       /* copy PDH certificate to userspace */
+       if (pdh_blob &&
+           copy_to_user((void __user *)(uintptr_t)input.pdh_cert_address,
+                        pdh_blob, input.pdh_cert_len)) {
+               ret = -EFAULT;
+               goto e_shutdown;
+       }
+
+       /* copy certificate chain to userspace */
+       if (cert_blob &&
+           copy_to_user((void __user *)(uintptr_t)input.cert_chain_address,
+                        cert_blob, input.cert_chain_len))
+               ret = -EFAULT;
+
+e_shutdown:
+       if (need_shutdown)
+               sev_handle_cmd(SEV_CMD_SHUTDOWN, 0, NULL);
+e_free_cert:
+       kfree(cert_blob);
+e_free_pdh:
+       kfree(pdh_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;
@@ -514,6 +620,10 @@ static long sev_ioctl(struct file *file, unsigned int 
ioctl, unsigned long arg)
                ret = sev_ioctl_pek_cert_import(&input);
                break;
        }
+       case SEV_PDH_CERT_EXPORT: {
+               ret = sev_ioctl_pdh_cert_export(&input);
+               break;
+       }
        default:
                ret = -EINVAL;
                break;
-- 
2.9.5

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