crypto: ccp: Implement SEV_PEK_CSR ioctl command

The SEV_PEK_CSR command can be used to generate a PEK certificate
signing request. The command is defined in SEV spec section 5.7.

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 fd3daf0..c3906bb 100644 (file)
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -302,6 +302,69 @@ static int sev_ioctl_do_pek_pdh_gen(int cmd, struct sev_issue_cmd *argp)
        return __sev_do_cmd_locked(cmd, 0, &argp->error);
 }
 
+static int sev_ioctl_do_pek_csr(struct sev_issue_cmd *argp)
+{
+       struct sev_user_data_pek_csr input;
+       struct sev_data_pek_csr *data;
+       void *blob = NULL;
+       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 CSR length */
+       if (!input.address || !input.length)
+               goto cmd;
+
+       /* allocate a physically contiguous buffer to store the CSR blob */
+       if (!access_ok(VERIFY_WRITE, input.address, input.length) ||
+           input.length > SEV_FW_BLOB_MAX_SIZE) {
+               ret = -EFAULT;
+               goto e_free;
+       }
+
+       blob = kmalloc(input.length, GFP_KERNEL);
+       if (!blob) {
+               ret = -ENOMEM;
+               goto e_free;
+       }
+
+       data->address = __psp_pa(blob);
+       data->len = input.length;
+
+cmd:
+       if (psp_master->sev_state == SEV_STATE_UNINIT) {
+               ret = __sev_platform_init_locked(&argp->error);
+               if (ret)
+                       goto e_free_blob;
+       }
+
+       ret = __sev_do_cmd_locked(SEV_CMD_PEK_CSR, data, &argp->error);
+
+        /* If we query the CSR length, FW responded with expected data. */
+       input.length = data->len;
+
+       if (copy_to_user((void __user *)argp->data, &input, sizeof(input))) {
+               ret = -EFAULT;
+               goto e_free_blob;
+       }
+
+       if (blob) {
+               if (copy_to_user((void __user *)input.address, blob, input.length))
+                       ret = -EFAULT;
+       }
+
+e_free_blob:
+       kfree(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;
@@ -336,6 +399,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
        case SEV_PDH_GEN:
                ret = sev_ioctl_do_pek_pdh_gen(SEV_CMD_PDH_GEN, &input);
                break;
+       case SEV_PEK_CSR:
+               ret = sev_ioctl_do_pek_csr(&input);
+               break;
        default:
                ret = -EINVAL;
                goto out;