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[Part2,v7,18/38] crypto: ccp: Implement SEV_PEK_CSR ioctl command

Message ID 20171101211623.71496-19-brijesh.singh@amd.com (mailing list archive)
State Not Applicable
Delegated to: Herbert Xu
Headers show

Commit Message

Brijesh Singh Nov. 1, 2017, 9:16 p.m. UTC
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>
---
 drivers/crypto/ccp/psp-dev.c | 68 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)

Comments

Borislav Petkov Nov. 3, 2017, 7:42 p.m. UTC | #1
On Wed, Nov 01, 2017 at 04:16:03PM -0500, Brijesh Singh wrote:
> 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>
> ---
>  drivers/crypto/ccp/psp-dev.c | 68 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 68 insertions(+)
> 
> diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
> index 42991c2e9085..4e2f9d037f0a 100644
> --- a/drivers/crypto/ccp/psp-dev.c
> +++ b/drivers/crypto/ccp/psp-dev.c
> @@ -298,6 +298,71 @@ 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(psp_master->sev_init, &argp->error);

Right, you're passing psp_master->sev_init (or whatever you're going to
end up calling it) down but then in __sev_platform_init_locked() you end
up doing

        if (!data)
                data = &psp->cmd_buf;

which looks silly.

IOW, if not really required, __sev_platform_init_locked() could have
only one argument instead:

static int __sev_platform_init_locked(int *error)

unless some later patch needs to pass in a different command buffer. I
guess I need to keep on reviewing...
Brijesh Singh Nov. 3, 2017, 8:01 p.m. UTC | #2
On 11/3/17 2:42 PM, Borislav Petkov wrote:

...
>> +	if (psp_master->sev_state == SEV_STATE_UNINIT) {
>> +		ret = __sev_platform_init_locked(psp_master->sev_init, &argp->error);
> Right, you're passing psp_master->sev_init (or whatever you're going to
> end up calling it) down but then in __sev_platform_init_locked() you end
> up doing
>
>         if (!data)
>                 data = &psp->cmd_buf;
>
> which looks silly.
>
> IOW, if not really required, __sev_platform_init_locked() could have
> only one argument instead:
>
> static int __sev_platform_init_locked(int *error)

The cmd_buf argument can be remove. I am have not looked at SEV-ES but
it may be possible that during SEV-ES patches kvm driver may need to
call the sev_platform_init() with different cmd_buf to initialize SEV-ES
states. I can removed it in next version.


-Brijesh
diff mbox

Patch

diff --git a/drivers/crypto/ccp/psp-dev.c b/drivers/crypto/ccp/psp-dev.c
index 42991c2e9085..4e2f9d037f0a 100644
--- a/drivers/crypto/ccp/psp-dev.c
+++ b/drivers/crypto/ccp/psp-dev.c
@@ -298,6 +298,71 @@  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(psp_master->sev_init, &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;
@@ -332,6 +397,9 @@  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;