Re: [PATCHv2] tpm: ibmvtpm: Wait for ready buffer before probing for TPM2 attributes
From: Jarkko Sakkinen <hidden>
Date: 2020-06-23 00:48:22
Also in:
linux-integrity, lkml
On Fri, Jun 19, 2020 at 01:30:40PM +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.
To fix it, just move the tpm2_get_cc_attrs_tlb() call after the
existing code to wait for initialization, which will ensure the buffer
is allocated.
Fixes: 18b3670d79ae9 ("tpm: ibmvtpm: Add support for TPM2")
Signed-off-by: David Gibson <redacted>Reviewed-by: Jarkko Sakkinen <redacted> /Jarkko