From patchwork Fri Jun 19 03:30:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 1312540 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 49p49W36Sqz9sNR for ; Fri, 19 Jun 2020 13:31:59 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=201602 header.b=RWj1rESw; dkim-atps=neutral Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49p49W11fGzDrNW for ; Fri, 19 Jun 2020 13:31:59 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49p4851j2vzDrM2 for ; Fri, 19 Jun 2020 13:30:45 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=201602 header.b=RWj1rESw; dkim-atps=neutral Received: by ozlabs.org (Postfix, from userid 1007) id 49p4841Nvrz9sRk; Fri, 19 Jun 2020 13:30:44 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1592537444; bh=Z1znwFCrCzh+F1jGYnmAR0Tyf0EyfbusOiN3r/JH274=; h=From:To:Cc:Subject:Date:From; b=RWj1rESwwED1Om1JkEYHeCzam7cyKUIKly+0faRqHG717UTanjkbwH5ElVDAqko9S OSHLW0NYSO1vvGNnD+SG0fWsNczuNKaGJLTBQQwPrxM7Tt4gGT0w+wTMc6aLpD6lIX cRw1em/kjjIBENV9rY+9U7ezQNwhgEPwfi8vFwQE= From: David Gibson To: jarkko.sakkinen@linux.intel.com, stefanb@linux.ibm.com Subject: [PATCHv2] tpm: ibmvtpm: Wait for ready buffer before probing for TPM2 attributes Date: Fri, 19 Jun 2020 13:30:40 +1000 Message-Id: <20200619033040.121412-1-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nayna@linux.ibm.com, linux-kernel@vger.kernel.org, jgg@ziepe.ca, paulus@samba.org, peterhuewe@gmx.de, linuxppc-dev@lists.ozlabs.org, linux-integrity@vger.kernel.org, David Gibson Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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 Reviewed-by: Jerry Snitselaar Reviewed-by: Jarkko Sakkinen --- Changes from v1: * Fixed a formatting error in the commit message * Added some more detail to the commit message 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 09fe45246b8cc..994385bf37c0c 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 {