From patchwork Thu Jun 25 14:56:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Stefan Berger X-Patchwork-Id: 11625515 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6B85D92A for ; Thu, 25 Jun 2020 14:56:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5556620781 for ; Thu, 25 Jun 2020 14:56:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405660AbgFYO4s (ORCPT ); Thu, 25 Jun 2020 10:56:48 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:2314 "EHLO mx0b-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405638AbgFYO4s (ORCPT ); Thu, 25 Jun 2020 10:56:48 -0400 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 05PEWas2084447; Thu, 25 Jun 2020 10:56:45 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 31uwyj4e81-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 25 Jun 2020 10:56:45 -0400 Received: from m0098417.ppops.net (m0098417.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 05PEX0rx086617; Thu, 25 Jun 2020 10:56:45 -0400 Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0a-001b2d01.pphosted.com with ESMTP id 31uwyj4e7p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 25 Jun 2020 10:56:45 -0400 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 05PEjcGY031517; Thu, 25 Jun 2020 14:56:44 GMT Received: from b01cxnp23032.gho.pok.ibm.com (b01cxnp23032.gho.pok.ibm.com [9.57.198.27]) by ppma04dal.us.ibm.com with ESMTP id 31uurq81gh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 25 Jun 2020 14:56:44 +0000 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 05PEuhH848824676 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 25 Jun 2020 14:56:43 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ABE8F112064; Thu, 25 Jun 2020 14:56:43 +0000 (GMT) Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9CE32112061; Thu, 25 Jun 2020 14:56:43 +0000 (GMT) Received: from sbct-3.pok.ibm.com (unknown [9.47.158.153]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 25 Jun 2020 14:56:43 +0000 (GMT) To: Jerry Snitselaar , linux-integrity , Jarkko Sakkinen From: Stefan Berger Subject: Enabling interrupts in QEMU TPM TIS Cc: LSM List , LKML Message-ID: <1ca3a53d-2b83-7522-5ce1-83d9cc2f207d@linux.ibm.com> Date: Thu, 25 Jun 2020 10:56:43 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 Content-Language: en-US X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.687 definitions=2020-06-25_10:2020-06-25,2020-06-25 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 cotscore=-2147483648 spamscore=0 phishscore=0 suspectscore=0 bulkscore=0 impostorscore=0 mlxscore=0 mlxlogscore=872 lowpriorityscore=0 malwarescore=0 adultscore=0 clxscore=1015 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006250091 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Hello!  I want to enable IRQs now in QEMU's TPM TIS device model and I need to work with the following patch to Linux TIS. I am wondering whether the changes there look reasonable to you? Windows works with the QEMU modifications as-is, so maybe it's a bug in the TIS code (which I had not run into before). The point of the loop I need to introduce in the interrupt handler is that while the interrupt handler is running another interrupt may occur/be posted that then does NOT cause the interrupt handler to be invoked again but causes a stall, unless the loop is there. The 'o' in the dmesg log indicates the original IRQ for which the handler was invoked. The interrupt values have the following meaning. 0x2: STS valid 0x4: locality changed 0x80: command ready So the first 'looping entry' [in log below] indicates that a locality change interrupt occurred while the interrupt handler was running due to STS_valid + command ready. This sounds reasonable considering that we are frequently acquiring and releasing the locality. The loop then deals with the locality change interrupt and the interrupts then settle. [  210.365129] tpm_tis MSFT0101:00: 2.0 TPM (device-id 0x1, rev-id 1) [  210.367124] looping: 0x4  (o: 0x82) [  212.375045] looping: 0x80  (o: 0x2) [  212.389218] looping: 0x4  (o: 0x82) [  212.404161] looping: 0x80  (o: 0x2) [  212.526427] looping: 0x4  (o: 0x82) [  212.595488] looping: 0x4  (o: 0x82) [  212.614357] looping: 0x80  (o: 0x2)      rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt); @@ -715,6 +715,7 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id)          return IRQ_NONE;      priv->irq_tested = true; +again:      if (interrupt & TPM_INTF_DATA_AVAIL_INT)          wake_up_interruptible(&priv->read_queue);      if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT) @@ -731,7 +732,12 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id)      if (rc < 0)          return IRQ_NONE; +    o = interrupt;      tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt); +    if (interrupt != 0) { +        printk("looping: 0x%x  (o: 0x%x)\n", interrupt, o); +        goto again; +    }      return IRQ_HANDLED;  } @@ -1062,6 +1068,8 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,              goto out_err;          } +        tpm_chip_start(chip); +        chip->flags |= TPM_CHIP_FLAG_IRQ;          if (irq) {              tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,                           irq); @@ -1074,6 +1082,7 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,          } else {              tpm_tis_probe_irq(chip, intmask);          } +        tpm_chip_stop(chip);      }      rc = tpm_chip_register(chip); diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index 65ab1b027949..f77544563fb1 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -704,7 +704,7 @@ static irqreturn_t tis_int_handler(int dummy, void *dev_id)  {      struct tpm_chip *chip = dev_id;      struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev); -    u32 interrupt; +    u32 interrupt, o;      int i, rc;