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    Subject[Part2 PATCH v6.1 20/38] crypto: ccp: Implement SEV_PDH_CERT_EXPORT ioctl command
    Date
    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
    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 | 110 +++++++++++++++++++++++++++++++++++++++++++
    1 file changed, 110 insertions(+)

    diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
    index 108fc06bcdb3..b9f594cb10c1 100644
    --- a/drivers/crypto/ccp/psp-dev.c
    +++ b/drivers/crypto/ccp/psp-dev.c
    @@ -390,6 +390,113 @@ static int sev_ioctl_do_pek_cert_import(struct sev_issue_cmd *argp)
    return ret;
    }

    +static int sev_ioctl_do_pdh_cert_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, err;
    +
    + 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 || !input.cert_chain_address)
    + goto cmd;
    +
    + /* allocate a physically contiguous buffer to store the PDH blob */
    + 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;
    +
    + /* allocate a physically contiguous buffer to store the cert chain blob */
    + 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;
    +
    +cmd:
    + ret = sev_platform_init(NULL, &argp->error);
    + if (ret)
    + goto e_free_cert;
    +
    + ret = sev_do_cmd(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 (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_cert;
    +
    + ret = -EIO;
    + argp->error = err;
    + goto e_free_cert;
    + }
    +
    + 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;
    @@ -425,6 +532,9 @@ static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
    case SEV_PEK_CERT_IMPORT:
    ret = sev_ioctl_do_pek_cert_import(&input);
    break;
    + case SEV_PDH_CERT_EXPORT:
    + ret = sev_ioctl_do_pdh_cert_export(&input);
    + break;
    default:
    ret = -EINVAL;
    goto out;
    --
    2.9.5
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