From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42456C433E0 for ; Fri, 5 Jun 2020 06:41:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11B6E207D5 for ; Fri, 5 Jun 2020 06:41:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="IrxIHTOt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726117AbgFEGlz (ORCPT ); Fri, 5 Jun 2020 02:41:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725280AbgFEGly (ORCPT ); Fri, 5 Jun 2020 02:41:54 -0400 Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D249C08C5C2; Thu, 4 Jun 2020 23:41:54 -0700 (PDT) Received: by ozlabs.org (Postfix, from userid 1007) id 49dY336tn3z9sT8; Fri, 5 Jun 2020 16:41:51 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1591339311; bh=4xfwcfWg3fYDkvoSshyHr3xzme+hp4xxgCEBnrJPiQA=; h=From:To:Cc:Subject:Date:From; b=IrxIHTOtq36n7hL5oemlz8t7GEAZpF+h8mTGZWroOBqSOJhlOm51dSAX5GS8JjdQw WHPJOGd2sMRNJx6TszW1g1u49Df8BhbVSg50aDEDD0Kr11VDFLFtDyVVb6LQh/IizZ 9MyDft/8Rp9JAU6KU9KeE06jCzBBToAxZF9pO1V4= From: David Gibson To: Michael Ellerman , Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , Stefan Berger , Nayna Jain Cc: Paul Mackerras , linuxppc-dev@lists.ozlabs.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, David Gibson Subject: [PATCH] tpm: ibmvtpm: Wait for ready buffer before probing for TPM2 attributes Date: Fri, 5 Jun 2020 16:37:19 +1000 Message-Id: <20200605063719.456277-1-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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