| Message ID | 20200605063719.456277-1-david@gibson.dropbear.id.au (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | tpm: ibmvtpm: Wait for ready buffer before probing for TPM2 attributes | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (787e1419e6c96ab8641adb4391b8955bc2e76817) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 26 lines checked |
| snowpatch_ozlabs/needsstable | warning | Please consider tagging this patch for stable! |
On 6/5/20 2:37 AM, David Gibson wrote: > The tpm2_get_cc_attrs_tbl() call will result in TPM commands being issued, > which will need the use of the internal command/response buffer. But, > we're issuing this *before* we've waited to make sure that buffer is > allocated. > > This can result in intermittent failures to probe if the hypervisor / TPM > implementation doesn't respond quickly enough. I find it fails almost > every time with an 8 vcpu guest under KVM with software emulated TPM. Uuuh. Thanks! > Fixes: 18b3670d79ae9 "tpm: ibmvtpm: Add support for TPM2" > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Reviewed-by: Stefan Berger <stefanb@linux.ibm.com> > --- > drivers/char/tpm/tpm_ibmvtpm.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c > index 09fe45246b8c..994385bf37c0 100644 > --- a/drivers/char/tpm/tpm_ibmvtpm.c > +++ b/drivers/char/tpm/tpm_ibmvtpm.c > @@ -683,13 +683,6 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, > if (rc) > goto init_irq_cleanup; > > - if (!strcmp(id->compat, "IBM,vtpm20")) { > - chip->flags |= TPM_CHIP_FLAG_TPM2; > - rc = tpm2_get_cc_attrs_tbl(chip); > - if (rc) > - goto init_irq_cleanup; > - } > - > if (!wait_event_timeout(ibmvtpm->crq_queue.wq, > ibmvtpm->rtce_buf != NULL, > HZ)) { > @@ -697,6 +690,13 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, > goto init_irq_cleanup; > } > > + if (!strcmp(id->compat, "IBM,vtpm20")) { > + chip->flags |= TPM_CHIP_FLAG_TPM2; > + rc = tpm2_get_cc_attrs_tbl(chip); > + if (rc) > + goto init_irq_cleanup; > + } > + > return tpm_chip_register(chip); > init_irq_cleanup: > do {
On Fri, Jun 05, 2020 at 04:37:19PM +1000, David Gibson wrote: > The tpm2_get_cc_attrs_tbl() call will result in TPM commands being issued, > which will need the use of the internal command/response buffer. But, > we're issuing this *before* we've waited to make sure that buffer is > allocated. > > This can result in intermittent failures to probe if the hypervisor / TPM > implementation doesn't respond quickly enough. I find it fails almost > every time with an 8 vcpu guest under KVM with software emulated TPM. > > Fixes: 18b3670d79ae9 "tpm: ibmvtpm: Add support for TPM2" Should be Fixes: 18b3670d79ae ("tpm: ibmvtpm: Add support for TPM2") Also briefly state what the commit does, not just the problem description. The code change looks legit. Please send v2 with these changes. > Signed-off-by: David Gibson <david@gibson.dropbear.id.au> > --- > drivers/char/tpm/tpm_ibmvtpm.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c > index 09fe45246b8c..994385bf37c0 100644 > --- a/drivers/char/tpm/tpm_ibmvtpm.c > +++ b/drivers/char/tpm/tpm_ibmvtpm.c > @@ -683,13 +683,6 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, > if (rc) > goto init_irq_cleanup; > > - if (!strcmp(id->compat, "IBM,vtpm20")) { > - chip->flags |= TPM_CHIP_FLAG_TPM2; > - rc = tpm2_get_cc_attrs_tbl(chip); > - if (rc) > - goto init_irq_cleanup; > - } > - > if (!wait_event_timeout(ibmvtpm->crq_queue.wq, > ibmvtpm->rtce_buf != NULL, > HZ)) { > @@ -697,6 +690,13 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, > goto init_irq_cleanup; > } > > + if (!strcmp(id->compat, "IBM,vtpm20")) { > + chip->flags |= TPM_CHIP_FLAG_TPM2; > + rc = tpm2_get_cc_attrs_tbl(chip); > + if (rc) > + goto init_irq_cleanup; > + } > + > return tpm_chip_register(chip); > init_irq_cleanup: > do { > -- > 2.26.2 > /Jarkko
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 09fe45246b8c..994385bf37c0 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -683,13 +683,6 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, if (rc) goto init_irq_cleanup; - if (!strcmp(id->compat, "IBM,vtpm20")) { - chip->flags |= TPM_CHIP_FLAG_TPM2; - rc = tpm2_get_cc_attrs_tbl(chip); - if (rc) - goto init_irq_cleanup; - } - if (!wait_event_timeout(ibmvtpm->crq_queue.wq, ibmvtpm->rtce_buf != NULL, HZ)) { @@ -697,6 +690,13 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, goto init_irq_cleanup; } + if (!strcmp(id->compat, "IBM,vtpm20")) { + chip->flags |= TPM_CHIP_FLAG_TPM2; + rc = tpm2_get_cc_attrs_tbl(chip); + if (rc) + goto init_irq_cleanup; + } + return tpm_chip_register(chip); init_irq_cleanup: do {
The tpm2_get_cc_attrs_tbl() call will result in TPM commands being issued, which will need the use of the internal command/response buffer. But, we're issuing this *before* we've waited to make sure that buffer is allocated. This can result in intermittent failures to probe if the hypervisor / TPM implementation doesn't respond quickly enough. I find it fails almost every time with an 8 vcpu guest under KVM with software emulated TPM. Fixes: 18b3670d79ae9 "tpm: ibmvtpm: Add support for TPM2" Signed-off-by: David Gibson <david@gibson.dropbear.id.au> --- drivers/char/tpm/tpm_ibmvtpm.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)