crypto: ccp: Implement SEV_PDH_CERT_EXPORT ioctl command

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 <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>
Acked-by: Gary R Hook <gary.hook@amd.com>

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 9d1c460..fcfa5b1 100644 (file)
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -443,6 +443,100 @@ e_free:
        return ret;
 }
 
+static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp)
+{
+       struct sev_user_data_pdh_cert_export input;
+       void *pdh_blob = NULL, *cert_blob = NULL;
+       struct sev_data_pdh_cert_export *data;
+       int ret;
+
+       if (copy_from_user(&input, (void __user *)argp->data, sizeof(input)))
+               return -EFAULT;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       /* Userspace wants to query the certificate length. */
+       if (!input.pdh_cert_address ||
+           !input.pdh_cert_len ||
+           !input.cert_chain_address)
+               goto cmd;
+
+       /* Allocate a physically contiguous buffer to store the PDH blob. */
+       if ((input.pdh_cert_len > SEV_FW_BLOB_MAX_SIZE) ||
+           !access_ok(VERIFY_WRITE, input.pdh_cert_address, input.pdh_cert_len)) {
+               ret = -EFAULT;
+               goto e_free;
+       }
+
+       /* Allocate a physically contiguous buffer to store the cert chain blob. */
+       if ((input.cert_chain_len > SEV_FW_BLOB_MAX_SIZE) ||
+           !access_ok(VERIFY_WRITE, input.cert_chain_address, input.cert_chain_len)) {
+               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 = 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;
+
+cmd:
+       /* If platform is not in INIT state then transition it to INIT. */
+       if (psp_master->sev_state != SEV_STATE_INIT) {
+               ret = __sev_platform_init_locked(&argp->error);
+               if (ret)
+                       goto e_free_cert;
+       }
+
+       ret = __sev_do_cmd_locked(SEV_CMD_PDH_CERT_EXPORT, data, &argp->error);
+
+       /* If we query the length, FW responded with expected data. */
+       input.cert_chain_len = data->cert_chain_len;
+       input.pdh_cert_len = data->pdh_cert_len;
+
+       if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
+               ret = -EFAULT;
+               goto e_free_cert;
+       }
+
+       if (pdh_blob) {
+               if (copy_to_user((void __user *)input.pdh_cert_address,
+                                pdh_blob, input.pdh_cert_len)) {
+                       ret = -EFAULT;
+                       goto e_free_cert;
+               }
+       }
+
+       if (cert_blob) {
+               if (copy_to_user((void __user *)input.cert_chain_address,
+                                cert_blob, input.cert_chain_len))
+                       ret = -EFAULT;
+       }
+
+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;
@@ -483,6 +577,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
        case SEV_PEK_CERT_IMPORT:
                ret = sev_ioctl_do_pek_import(&input);
                break;
+       case SEV_PDH_CERT_EXPORT:
+               ret = sev_ioctl_do_pdh_export(&input);
+               break;
        default:
                ret = -EINVAL;
                goto out;