| Message ID | 20210406224952.4177376-8-seanjc@google.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | ccp: KVM: SVM: Use stack for SEV command buffers | expand |
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 <seanjc@google.com> > --- > 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(&data, 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, &sev->init_cmd_buf, error); > + rc = __sev_do_cmd_locked(SEV_CMD_INIT, &data, 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; >
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
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(&data, 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, &sev->init_cmd_buf, error); + rc = __sev_do_cmd_locked(SEV_CMD_INIT, &data, 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;
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 <seanjc@google.com> --- drivers/crypto/ccp/sev-dev.c | 10 ++++++---- drivers/crypto/ccp/sev-dev.h | 1 - 2 files changed, 6 insertions(+), 5 deletions(-)