diff mbox series

[v10,19/50] crypto: ccp: Add the SNP_PLATFORM_STATUS command

Message ID 20231016132819.1002933-20-michael.roth@amd.com
State Superseded
Headers show
Series Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support | expand

Commit Message

Michael Roth Oct. 16, 2023, 1:27 p.m. UTC 
From: Brijesh Singh <brijesh.singh@amd.com>

The command can be used by the userspace to query the SNP platform status
report. See the SEV-SNP spec for more details.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
---
 Documentation/virt/coco/sev-guest.rst | 27 ++++++++++++++++
 drivers/crypto/ccp/sev-dev.c          | 45 +++++++++++++++++++++++++++
 include/uapi/linux/psp-sev.h          |  1 +
 3 files changed, 73 insertions(+)

Comments

Borislav Petkov Dec. 12, 2023, 4:45 p.m. UTC | #1 
On Mon, Oct 16, 2023 at 08:27:48AM -0500, Michael Roth wrote:
> From: Brijesh Singh <brijesh.singh@amd.com>
> 
> The command can be used by the userspace to query the SNP platform status

s/by the userspace //

> report. See the SEV-SNP spec for more details.
> 
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>

Mike, this doesn't have your SOB at the end. The whole set should have
it if you're sending it. Please go through the whole thing.

> ---
>  Documentation/virt/coco/sev-guest.rst | 27 ++++++++++++++++
>  drivers/crypto/ccp/sev-dev.c          | 45 +++++++++++++++++++++++++++
>  include/uapi/linux/psp-sev.h          |  1 +
>  3 files changed, 73 insertions(+)
> 
> diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst
> index 68b0d2363af8..e828c5326936 100644
> --- a/Documentation/virt/coco/sev-guest.rst
> +++ b/Documentation/virt/coco/sev-guest.rst
> @@ -67,6 +67,22 @@ counter (e.g. counter overflow), then -EIO will be returned.
>                  };
>          };
>  
> +The host ioctl should be called to /dev/sev device. The ioctl accepts commanda

"... should be sent to the... "

> +id and command input structure.
> +
> +::
> +        struct sev_issue_cmd {
> +                /* Command ID */
> +                __u32 cmd;
> +
> +                /* Command request structure */
> +                __u64 data;
> +
> +                /* firmware error code on failure (see psp-sev.h) */
> +                __u32 error;
> +        };
> +
> +
>  2.1 SNP_GET_REPORT
>  ------------------
>  
> @@ -124,6 +140,17 @@ be updated with the expected value.
>  
>  See GHCB specification for further detail on how to parse the certificate blob.
>  
> +2.4 SNP_PLATFORM_STATUS
> +-----------------------
> +:Technology: sev-snp
> +:Type: hypervisor ioctl cmd
> +:Parameters (in): struct sev_data_snp_platform_status
> +:Returns (out): 0 on success, -negative on error
> +
> +The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The
> +status includes API major, minor version and more. See the SEV-SNP
> +specification for further details.
> +
>  3. SEV-SNP CPUID Enforcement
>  ============================
>  
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index b574b0ef2b1f..679b8d6fc09a 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1772,6 +1772,48 @@ static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
>  	return ret;
>  }
>  
> +static int sev_ioctl_snp_platform_status(struct sev_issue_cmd *argp)

sev_ioctl_do_snp_platform_status like the others.

> +{
> +	struct sev_device *sev = psp_master->sev_data;
> +	struct sev_data_snp_addr buf;
> +	struct page *status_page;
> +	void *data;
> +	int ret;
> +
> +	if (!sev->snp_initialized || !argp->data)
> +		return -EINVAL;
> +
> +	status_page = alloc_page(GFP_KERNEL_ACCOUNT);
> +	if (!status_page)
> +		return -ENOMEM;
> +
> +	data = page_address(status_page);
> +	if (rmp_mark_pages_firmware(__pa(data), 1, true)) {
> +		__free_pages(status_page, 0);
> +		return -EFAULT;

		ret = -EFAULT;
		goto cleanup;

instead.

...
diff mbox series

Patch

diff --git a/Documentation/virt/coco/sev-guest.rst b/Documentation/virt/coco/sev-guest.rst
index 68b0d2363af8..e828c5326936 100644
--- a/Documentation/virt/coco/sev-guest.rst
+++ b/Documentation/virt/coco/sev-guest.rst
@@ -67,6 +67,22 @@  counter (e.g. counter overflow), then -EIO will be returned.
                 };
         };
 
+The host ioctl should be called to /dev/sev device. The ioctl accepts command
+id and command input structure.
+
+::
+        struct sev_issue_cmd {
+                /* Command ID */
+                __u32 cmd;
+
+                /* Command request structure */
+                __u64 data;
+
+                /* firmware error code on failure (see psp-sev.h) */
+                __u32 error;
+        };
+
+
 2.1 SNP_GET_REPORT
 ------------------
 
@@ -124,6 +140,17 @@  be updated with the expected value.
 
 See GHCB specification for further detail on how to parse the certificate blob.
 
+2.4 SNP_PLATFORM_STATUS
+-----------------------
+:Technology: sev-snp
+:Type: hypervisor ioctl cmd
+:Parameters (in): struct sev_data_snp_platform_status
+:Returns (out): 0 on success, -negative on error
+
+The SNP_PLATFORM_STATUS command is used to query the SNP platform status. The
+status includes API major, minor version and more. See the SEV-SNP
+specification for further details.
+
 3. SEV-SNP CPUID Enforcement
 ============================
 
diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index b574b0ef2b1f..679b8d6fc09a 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -1772,6 +1772,48 @@  static int sev_ioctl_do_pdh_export(struct sev_issue_cmd *argp, bool writable)
 	return ret;
 }
 
+static int sev_ioctl_snp_platform_status(struct sev_issue_cmd *argp)
+{
+	struct sev_device *sev = psp_master->sev_data;
+	struct sev_data_snp_addr buf;
+	struct page *status_page;
+	void *data;
+	int ret;
+
+	if (!sev->snp_initialized || !argp->data)
+		return -EINVAL;
+
+	status_page = alloc_page(GFP_KERNEL_ACCOUNT);
+	if (!status_page)
+		return -ENOMEM;
+
+	data = page_address(status_page);
+	if (rmp_mark_pages_firmware(__pa(data), 1, true)) {
+		__free_pages(status_page, 0);
+		return -EFAULT;
+	}
+
+	buf.gctx_paddr = __psp_pa(data);
+	ret = __sev_do_cmd_locked(SEV_CMD_SNP_PLATFORM_STATUS, &buf, &argp->error);
+
+	/* Change the page state before accessing it */
+	if (snp_reclaim_pages(__pa(data), 1, true)) {
+		snp_leak_pages(__pa(data) >> PAGE_SHIFT, 1);
+		return -EFAULT;
+	}
+
+	if (ret)
+		goto cleanup;
+
+	if (copy_to_user((void __user *)argp->data, data,
+			 sizeof(struct sev_user_data_snp_status)))
+		ret = -EFAULT;
+
+cleanup:
+	__free_pages(status_page, 0);
+	return ret;
+}
+
 static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
@@ -1823,6 +1865,9 @@  static long sev_ioctl(struct file *file, unsigned int ioctl, unsigned long arg)
 	case SEV_GET_ID2:
 		ret = sev_ioctl_do_get_id2(&input);
 		break;
+	case SNP_PLATFORM_STATUS:
+		ret = sev_ioctl_snp_platform_status(&input);
+		break;
 	default:
 		ret = -EINVAL;
 		goto out;
diff --git a/include/uapi/linux/psp-sev.h b/include/uapi/linux/psp-sev.h
index 48e3ef91559c..b94b3687edbb 100644
--- a/include/uapi/linux/psp-sev.h
+++ b/include/uapi/linux/psp-sev.h
@@ -28,6 +28,7 @@  enum {
 	SEV_PEK_CERT_IMPORT,
 	SEV_GET_ID,	/* This command is deprecated, use SEV_GET_ID2 */
 	SEV_GET_ID2,
+	SNP_PLATFORM_STATUS,
 
 	SEV_MAX,
 };