[v2,02/11] virt: sev-guest: Move mutex to SNP guest device structure

Message ID 20230326144701.3039598-3-nikunj@amd.com
State New
Headers
Series Add Secure TSC support for SNP guests |

Commit Message

Nikunj A. Dadhania March 26, 2023, 2:46 p.m. UTC
  In preparation to provide new API for sending SNP guest message to the
sev-guest driver, move the SNP command mutex to the snp_guest_dev
structure.

Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
---
 drivers/virt/coco/sev-guest/sev-guest.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)
  

Comments

Tom Lendacky April 3, 2023, 7:13 p.m. UTC | #1
On 3/26/23 09:46, Nikunj A Dadhania wrote:
> In preparation to provide new API for sending SNP guest message to the
> sev-guest driver, move the SNP command mutex to the snp_guest_dev
> structure.

In preparation for providing a new API to the sev-guest driver for sending 
an SNP guest message, ...

> 
> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>

Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>

> ---
>   drivers/virt/coco/sev-guest/sev-guest.c | 21 +++++++++++----------
>   1 file changed, 11 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
> index 57af908bafba..6ae197b57644 100644
> --- a/drivers/virt/coco/sev-guest/sev-guest.c
> +++ b/drivers/virt/coco/sev-guest/sev-guest.c
> @@ -35,6 +35,9 @@ struct snp_guest_dev {
>   	struct device *dev;
>   	struct miscdevice misc;
>   
> +	/* Mutex to serialize the shared buffer access and command handling. */
> +	struct mutex cmd_mutex;
> +
>   	void *certs_data;
>   	struct aesgcm_ctx *ctx;
>   	struct snp_guest_msg *request, *response;
> @@ -48,9 +51,6 @@ static u32 vmpck_id;
>   module_param(vmpck_id, uint, 0444);
>   MODULE_PARM_DESC(vmpck_id, "The VMPCK ID to use when communicating with the PSP.");
>   
> -/* Mutex to serialize the shared buffer access and command handling. */
> -static DEFINE_MUTEX(snp_cmd_mutex);
> -
>   static inline unsigned int get_ctx_authsize(struct snp_guest_dev *snp_dev)
>   {
>   	if (snp_dev && snp_dev->ctx)
> @@ -99,7 +99,7 @@ static inline u64 __snp_get_msg_seqno(struct snp_guest_dev *snp_dev)
>   {
>   	u64 count;
>   
> -	lockdep_assert_held(&snp_cmd_mutex);
> +	lockdep_assert_held(&snp_dev->cmd_mutex);
>   
>   	/* Read the current message sequence counter from secrets pages */
>   	count = *snp_dev->os_area_msg_seqno;
> @@ -377,7 +377,7 @@ static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
>   	struct snp_report_req req;
>   	int rc, resp_len;
>   
> -	lockdep_assert_held(&snp_cmd_mutex);
> +	lockdep_assert_held(&snp_dev->cmd_mutex);
>   
>   	if (!arg->req_data || !arg->resp_data)
>   		return -EINVAL;
> @@ -417,7 +417,7 @@ static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
>   	/* Response data is 64 bytes and max authsize for GCM is 16 bytes. */
>   	u8 buf[64 + 16];
>   
> -	lockdep_assert_held(&snp_cmd_mutex);
> +	lockdep_assert_held(&snp_dev->cmd_mutex);
>   
>   	if (!arg->req_data || !arg->resp_data)
>   		return -EINVAL;
> @@ -456,7 +456,7 @@ static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
>   	struct snp_report_resp *resp;
>   	int ret, npages = 0, resp_len;
>   
> -	lockdep_assert_held(&snp_cmd_mutex);
> +	lockdep_assert_held(&snp_dev->cmd_mutex);
>   
>   	if (!arg->req_data || !arg->resp_data)
>   		return -EINVAL;
> @@ -541,12 +541,12 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
>   	if (!input.msg_version)
>   		return -EINVAL;
>   
> -	mutex_lock(&snp_cmd_mutex);
> +	mutex_lock(&snp_dev->cmd_mutex);
>   
>   	/* Check if the VMPCK is not empty */
>   	if (is_vmpck_empty(snp_dev)) {
>   		dev_err_ratelimited(snp_dev->dev, "VMPCK is disabled\n");
> -		mutex_unlock(&snp_cmd_mutex);
> +		mutex_unlock(&snp_dev->cmd_mutex);
>   		return -ENOTTY;
>   	}
>   
> @@ -564,7 +564,7 @@ static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
>   		break;
>   	}
>   
> -	mutex_unlock(&snp_cmd_mutex);
> +	mutex_unlock(&snp_dev->cmd_mutex);
>   
>   	if (input.fw_err && copy_to_user(argp, &input, sizeof(input)))
>   		return -EFAULT;
> @@ -683,6 +683,7 @@ static int __init sev_guest_probe(struct platform_device *pdev)
>   		goto e_unmap;
>   	}
>   
> +	mutex_init(&snp_dev->cmd_mutex);
>   	platform_set_drvdata(pdev, snp_dev);
>   	snp_dev->dev = dev;
>   	snp_dev->layout = layout;
  
Nikunj A. Dadhania April 5, 2023, 5:23 a.m. UTC | #2
On 4/4/2023 12:43 AM, Tom Lendacky wrote:
> On 3/26/23 09:46, Nikunj A Dadhania wrote:
>> In preparation to provide new API for sending SNP guest message to the
>> sev-guest driver, move the SNP command mutex to the snp_guest_dev
>> structure.
> 
> In preparation for providing a new API to the sev-guest driver for sending an SNP guest message, ...

Sure.

>>
>> Signed-off-by: Nikunj A Dadhania <nikunj@amd.com>
> 
> Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
> 

Regards
Nikunj
  

Patch

diff --git a/drivers/virt/coco/sev-guest/sev-guest.c b/drivers/virt/coco/sev-guest/sev-guest.c
index 57af908bafba..6ae197b57644 100644
--- a/drivers/virt/coco/sev-guest/sev-guest.c
+++ b/drivers/virt/coco/sev-guest/sev-guest.c
@@ -35,6 +35,9 @@  struct snp_guest_dev {
 	struct device *dev;
 	struct miscdevice misc;
 
+	/* Mutex to serialize the shared buffer access and command handling. */
+	struct mutex cmd_mutex;
+
 	void *certs_data;
 	struct aesgcm_ctx *ctx;
 	struct snp_guest_msg *request, *response;
@@ -48,9 +51,6 @@  static u32 vmpck_id;
 module_param(vmpck_id, uint, 0444);
 MODULE_PARM_DESC(vmpck_id, "The VMPCK ID to use when communicating with the PSP.");
 
-/* Mutex to serialize the shared buffer access and command handling. */
-static DEFINE_MUTEX(snp_cmd_mutex);
-
 static inline unsigned int get_ctx_authsize(struct snp_guest_dev *snp_dev)
 {
 	if (snp_dev && snp_dev->ctx)
@@ -99,7 +99,7 @@  static inline u64 __snp_get_msg_seqno(struct snp_guest_dev *snp_dev)
 {
 	u64 count;
 
-	lockdep_assert_held(&snp_cmd_mutex);
+	lockdep_assert_held(&snp_dev->cmd_mutex);
 
 	/* Read the current message sequence counter from secrets pages */
 	count = *snp_dev->os_area_msg_seqno;
@@ -377,7 +377,7 @@  static int get_report(struct snp_guest_dev *snp_dev, struct snp_guest_request_io
 	struct snp_report_req req;
 	int rc, resp_len;
 
-	lockdep_assert_held(&snp_cmd_mutex);
+	lockdep_assert_held(&snp_dev->cmd_mutex);
 
 	if (!arg->req_data || !arg->resp_data)
 		return -EINVAL;
@@ -417,7 +417,7 @@  static int get_derived_key(struct snp_guest_dev *snp_dev, struct snp_guest_reque
 	/* Response data is 64 bytes and max authsize for GCM is 16 bytes. */
 	u8 buf[64 + 16];
 
-	lockdep_assert_held(&snp_cmd_mutex);
+	lockdep_assert_held(&snp_dev->cmd_mutex);
 
 	if (!arg->req_data || !arg->resp_data)
 		return -EINVAL;
@@ -456,7 +456,7 @@  static int get_ext_report(struct snp_guest_dev *snp_dev, struct snp_guest_reques
 	struct snp_report_resp *resp;
 	int ret, npages = 0, resp_len;
 
-	lockdep_assert_held(&snp_cmd_mutex);
+	lockdep_assert_held(&snp_dev->cmd_mutex);
 
 	if (!arg->req_data || !arg->resp_data)
 		return -EINVAL;
@@ -541,12 +541,12 @@  static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
 	if (!input.msg_version)
 		return -EINVAL;
 
-	mutex_lock(&snp_cmd_mutex);
+	mutex_lock(&snp_dev->cmd_mutex);
 
 	/* Check if the VMPCK is not empty */
 	if (is_vmpck_empty(snp_dev)) {
 		dev_err_ratelimited(snp_dev->dev, "VMPCK is disabled\n");
-		mutex_unlock(&snp_cmd_mutex);
+		mutex_unlock(&snp_dev->cmd_mutex);
 		return -ENOTTY;
 	}
 
@@ -564,7 +564,7 @@  static long snp_guest_ioctl(struct file *file, unsigned int ioctl, unsigned long
 		break;
 	}
 
-	mutex_unlock(&snp_cmd_mutex);
+	mutex_unlock(&snp_dev->cmd_mutex);
 
 	if (input.fw_err && copy_to_user(argp, &input, sizeof(input)))
 		return -EFAULT;
@@ -683,6 +683,7 @@  static int __init sev_guest_probe(struct platform_device *pdev)
 		goto e_unmap;
 	}
 
+	mutex_init(&snp_dev->cmd_mutex);
 	platform_set_drvdata(pdev, snp_dev);
 	snp_dev->dev = dev;
 	snp_dev->layout = layout;