Re: [PATCH v2 7/8] crypto: ccp: Use the stack and common buffer for INIT command

2021-04-17 Thread Paolo Bonzini 

On 07/04/21 07:20, Christophe Leroy wrote:


+    struct sev_data_init data;


struct sev_data_init data = {0, 0, 0, 0};


Having to count the number of items is suboptimal.  The alternative 
could be {} (which however is technically not standard C), {0} (a bit 
mysterious, but it works) and memset.  I kept the latter to avoid 
touching the submitter's patch too much.


Paolo

Re: [PATCH v2 7/8] crypto: ccp: Use the stack and common buffer for INIT command

2021-04-06 Thread Christophe Leroy 




Le 07/04/2021 à 00:49, Sean Christopherson a écrit :

Drop the dedicated init_cmd_buf and instead use a local variable.  Now
that the low level helper uses an internal buffer for all commands,
using the stack for the upper layers is safe even when running with
CONFIG_VMAP_STACK=y.

Signed-off-by: Sean Christopherson 
---
  drivers/crypto/ccp/sev-dev.c | 10 ++
  drivers/crypto/ccp/sev-dev.h |  1 -
  2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index e54774b0d637..9ff28df03030 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -233,6 +233,7 @@ static int sev_do_cmd(int cmd, void *data, int *psp_ret)
  static int __sev_platform_init_locked(int *error)
  {
struct psp_device *psp = psp_master;
+   struct sev_data_init data;


struct sev_data_init data = {0, 0, 0, 0};


struct sev_device *sev;
int rc = 0;
  
@@ -244,6 +245,7 @@ static int __sev_platform_init_locked(int *error)

if (sev->state == SEV_STATE_INIT)
return 0;
  
+	memset(, 0, sizeof(data));


Not needed.


if (sev_es_tmr) {
u64 tmr_pa;
  
@@ -253,12 +255,12 @@ static int __sev_platform_init_locked(int *error)

 */
tmr_pa = __pa(sev_es_tmr);
  
-		sev->init_cmd_buf.flags |= SEV_INIT_FLAGS_SEV_ES;

-   sev->init_cmd_buf.tmr_address = tmr_pa;
-   sev->init_cmd_buf.tmr_len = SEV_ES_TMR_SIZE;
+   data.flags |= SEV_INIT_FLAGS_SEV_ES;
+   data.tmr_address = tmr_pa;
+   data.tmr_len = SEV_ES_TMR_SIZE;
}
  
-	rc = __sev_do_cmd_locked(SEV_CMD_INIT, >init_cmd_buf, error);

+   rc = __sev_do_cmd_locked(SEV_CMD_INIT, , error);
if (rc)
return rc;
  
diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h

index 0fd21433f627..666c21eb81ab 100644
--- a/drivers/crypto/ccp/sev-dev.h
+++ b/drivers/crypto/ccp/sev-dev.h
@@ -46,7 +46,6 @@ struct sev_device {
unsigned int int_rcvd;
wait_queue_head_t int_queue;
struct sev_misc_dev *misc;
-   struct sev_data_init init_cmd_buf;
  
  	u8 api_major;

u8 api_minor;

[PATCH v2 7/8] crypto: ccp: Use the stack and common buffer for INIT command

2021-04-06 Thread Sean Christopherson 
Drop the dedicated init_cmd_buf and instead use a local variable.  Now
that the low level helper uses an internal buffer for all commands,
using the stack for the upper layers is safe even when running with
CONFIG_VMAP_STACK=y.

Signed-off-by: Sean Christopherson 
---
 drivers/crypto/ccp/sev-dev.c | 10 ++
 drivers/crypto/ccp/sev-dev.h |  1 -
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
index e54774b0d637..9ff28df03030 100644
--- a/drivers/crypto/ccp/sev-dev.c
+++ b/drivers/crypto/ccp/sev-dev.c
@@ -233,6 +233,7 @@ static int sev_do_cmd(int cmd, void *data, int *psp_ret)
 static int __sev_platform_init_locked(int *error)
 {
struct psp_device *psp = psp_master;
+   struct sev_data_init data;
struct sev_device *sev;
int rc = 0;
 
@@ -244,6 +245,7 @@ static int __sev_platform_init_locked(int *error)
if (sev->state == SEV_STATE_INIT)
return 0;
 
+   memset(, 0, sizeof(data));
if (sev_es_tmr) {
u64 tmr_pa;
 
@@ -253,12 +255,12 @@ static int __sev_platform_init_locked(int *error)
 */
tmr_pa = __pa(sev_es_tmr);
 
-   sev->init_cmd_buf.flags |= SEV_INIT_FLAGS_SEV_ES;
-   sev->init_cmd_buf.tmr_address = tmr_pa;
-   sev->init_cmd_buf.tmr_len = SEV_ES_TMR_SIZE;
+   data.flags |= SEV_INIT_FLAGS_SEV_ES;
+   data.tmr_address = tmr_pa;
+   data.tmr_len = SEV_ES_TMR_SIZE;
}
 
-   rc = __sev_do_cmd_locked(SEV_CMD_INIT, >init_cmd_buf, error);
+   rc = __sev_do_cmd_locked(SEV_CMD_INIT, , error);
if (rc)
return rc;
 
diff --git a/drivers/crypto/ccp/sev-dev.h b/drivers/crypto/ccp/sev-dev.h
index 0fd21433f627..666c21eb81ab 100644
--- a/drivers/crypto/ccp/sev-dev.h
+++ b/drivers/crypto/ccp/sev-dev.h
@@ -46,7 +46,6 @@ struct sev_device {
unsigned int int_rcvd;
wait_queue_head_t int_queue;
struct sev_misc_dev *misc;
-   struct sev_data_init init_cmd_buf;
 
u8 api_major;
u8 api_minor;
-- 
2.31.0.208.g409f899ff0-goog