Messages in this thread Patch in this message | | | Date | Thu, 22 Dec 2016 14:41:52 -0600 | From | "Dr. Greg Wettstein" <> | Subject | [PATCH] tpm: Restore functionality to xen vtpm driver. |
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Functionality of the xen-tpmfront driver was lost secondary to the introduction of xenbus multi-page support in the following commit:
ccc9d90a9a8b5c4ad7e9708ec41f75ff9e98d61d
xenbus_client: Extend interface to support multi-page ring
In this commit a pointer to the shared page address was being passed to the xenbus_grant_ring() function rather then the address of the shared page itself. This resulted in a situation where the driver would attach to the vtpm-stubdom but any attempt to send a command to the stub domain would timeout.
A diagnostic finding for this regression is the following error message being generated when the xen-tpmfront driver probes for a device:
<3>vtpm vtpm-0: tpm_transmit: tpm_send: error -62
<3>vtpm vtpm-0: A TPM error (-62) occurred attempting to determine the timeouts
This fix is relevant to all kernels from 4.1 forward which is the release in which multi-page xenbus support was introduced.
Daniel De Graaf formulated the fix by code inspection after the regression point was located.
Signed-off-by: Dr. Greg Wettstein <greg@enjellic.com> --- drivers/char/tpm/xen-tpmfront.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c index 5aaa268..dd83a07 100644 --- a/drivers/char/tpm/xen-tpmfront.c +++ b/drivers/char/tpm/xen-tpmfront.c @@ -203,7 +203,7 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv) return -ENOMEM; } - rv = xenbus_grant_ring(dev, &priv->shr, 1, &gref); + rv = xenbus_grant_ring(dev, priv->shr, 1, &gref); if (rv < 0) return rv; -- 2.2.2
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