From nobody Fri Apr 3 06:16:11 2026 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66183374177; Tue, 17 Feb 2026 18:23:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771352598; cv=none; b=IC5/aTCsJCl6lXH88GfcowgYxV23fdZZaBXq5EU/RZntfk/51mLWKafLYeE5qpaKs7kIfcenoJz8svrGKy4sXotSqxXFm3SfKpIkpQDZxyYtlWh4IpBcqqYMZzQVA/MAdjvAP5G3Q+Ws0YitO2m1Pb52qcIjrNAKlb6Cvq+W6rY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771352598; c=relaxed/simple; bh=Tx2b5lfRhhMk7paCJmquplbWt2xL8rFkNh9AWCi0s7g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Gnc0GBgClyMcnMaDkUH2xHYGI7QsHmmz3+5rc/duAVFIXjozOQaw6v76MfM5+dayYTlgs3Z7pnzB1gEYjRrKQ/u9a+/vv0FyESV75vc5Yerkj0nG5NxfmFFPZGkcmIbvCJfN7GzLS4lO7e+r4MJbWtIr88m5nBrJqHKqWBQRdCM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=fPTq348a; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="fPTq348a" Received: from pps.filterd (m0353729.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 61HEUVkm2392296; Tue, 17 Feb 2026 18:23:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=VW/rkVDi1lqpakrO5 y4VKV3NO8EEFq33TSGYTFobHoU=; b=fPTq348aKVPu77ptlzENZ2+28v5ecYV8o mUT8YJjLYsZ2yQ29r7oEG/42bV0PakfUPjfB4dvH868AiLa23yRo6O+ocOrCD9mD 72Szz8X0IkySVQeIruy4HGaUP3iKVrw8ocmFzbFnpITJwT1zI6zl4rlrZaunO7Fy moYHBgak5xHgMQvpVrF64/UzDzfCX4TBKShSwQNDXiF/fbkrn/9aZ/Pq5n7saJub uhrOI1l/IOYY8J0r+qdHa6eTpj8e7YB/LOMT3pXL2L3NF3D62wy+MEWAm5oZqod2 wlHCmYMJ5UphklCwYYAdN1WNe5RnZbs5c9WpAbbuE/9adwwrgamzA== Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4caj6rwjfg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 Feb 2026 18:23:07 +0000 (GMT) Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 61HFnccr015670; Tue, 17 Feb 2026 18:23:06 GMT Received: from smtprelay06.dal12v.mail.ibm.com ([172.16.1.8]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4ccb4543k8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 Feb 2026 18:23:05 +0000 Received: from smtpav05.dal12v.mail.ibm.com (smtpav05.dal12v.mail.ibm.com [10.241.53.104]) by smtprelay06.dal12v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 61HIN4HE31523334 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 Feb 2026 18:23:04 GMT Received: from smtpav05.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id A574B58056; Tue, 17 Feb 2026 18:23:04 +0000 (GMT) Received: from smtpav05.dal12v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D9B1F58052; Tue, 17 Feb 2026 18:23:03 +0000 (GMT) Received: from IBM-D32RQW3.ibm.com (unknown [9.61.242.249]) by smtpav05.dal12v.mail.ibm.com (Postfix) with ESMTP; Tue, 17 Feb 2026 18:23:03 +0000 (GMT) From: Farhan Ali To: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Cc: helgaas@kernel.org, lukas@wunner.de, alex@shazbot.org, clg@redhat.com, stable@vger.kernel.org, alifm@linux.ibm.com, schnelle@linux.ibm.com, mjrosato@linux.ibm.com Subject: [PATCH v9 6/9] s390/pci: Store PCI error information for passthrough devices Date: Tue, 17 Feb 2026 10:22:54 -0800 Message-ID: <20260217182257.1582-7-alifm@linux.ibm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260217182257.1582-1-alifm@linux.ibm.com> References: <20260217182257.1582-1-alifm@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=dvvWylg4 c=1 sm=1 tr=0 ts=6994b20b cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=HzLeVaNsDn8A:10 a=VkNPw1HP01LnGYTKEx00:22 a=Mpw57Om8IfrbqaoTuvik:22 a=GgsMoib0sEa3-_RKJdDe:22 a=VnNF1IyMAAAA:8 a=JwDFWkoFWNOLAMzFnh4A:9 X-Proofpoint-GUID: 0gIzvLNjDi448JO4n5SyYpe7K0Sbq3oR X-Proofpoint-ORIG-GUID: 0gIzvLNjDi448JO4n5SyYpe7K0Sbq3oR X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMjE3MDE0OCBTYWx0ZWRfXxRBTz/WYRD8V Bgy9gcNnqYdIZyjwyANFpAgBRVSYl7yYzKAOJHpkwcyexZIbj47w6I0H572TBeA0SN8jKd+be92 /ZV6hSq5ttI8bRCfTuCv68wte3HeUlX02z+br/t5iZVCnp5kkqSFAtymSTGX5xocwCghQQNU/Dz 4r1Y/fo3wowxSgasC+Shqy6lXs4tO0xNBk81qGueo/kF02Ch6C7PygBR0j4wOg4XOQaoSivJwOO SwD7JxTDDxa1H7dhyr3mWzY+acYTazy68hFYlFonlZRySpidYsBvJMc8yRigaLndKNYWd+10Aiw IdJWEcREZFosgWANjd2McCtVx5cWu89k18Q6JBthbBDlmnWAD76/L8y7INz8xnvNXOwatGV7wZi Vq0FWSRWSslu+qB3xBgEC9ml6wP/uZo8blnmuFBht9X3L5xHobo0J8PQO46KdLUCFPJYfY95kSS lRSSxu8H0+GcaxjVGhA== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-02-17_03,2026-02-16_04,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 lowpriorityscore=0 impostorscore=0 adultscore=0 priorityscore=1501 clxscore=1015 malwarescore=0 phishscore=0 suspectscore=0 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2601150000 definitions=main-2602170148 Content-Type: text/plain; charset="utf-8" For a passthrough device we need co-operation from user space to recover the device. This would require to bubble up any error information to user space. Let's store this error information for passthrough devices, so it can be retrieved later. Reviewed-by: Niklas Schnelle Signed-off-by: Farhan Ali --- arch/s390/include/asm/pci.h | 28 ++++++++++ arch/s390/pci/pci.c | 1 + arch/s390/pci/pci_event.c | 95 +++++++++++++++++++------------- drivers/vfio/pci/vfio_pci_zdev.c | 2 + 4 files changed, 88 insertions(+), 38 deletions(-) diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h index ec8a772bf526..383f6483b656 100644 --- a/arch/s390/include/asm/pci.h +++ b/arch/s390/include/asm/pci.h @@ -118,6 +118,31 @@ struct zpci_bus { enum pci_bus_speed max_bus_speed; }; =20 +/* Content Code Description for PCI Function Error */ +struct zpci_ccdf_err { + u32 reserved1; + u32 fh; /* function handle */ + u32 fid; /* function id */ + u32 ett : 4; /* expected table type */ + u32 mvn : 12; /* MSI vector number */ + u32 dmaas : 8; /* DMA address space */ + u32 reserved2 : 6; + u32 q : 1; /* event qualifier */ + u32 rw : 1; /* read/write */ + u64 faddr; /* failing address */ + u32 reserved3; + u16 reserved4; + u16 pec; /* PCI event code */ +} __packed; + +#define ZPCI_ERR_PENDING_MAX 4 +struct zpci_ccdf_pending { + u8 count; + u8 head; + u8 tail; + struct zpci_ccdf_err err[ZPCI_ERR_PENDING_MAX]; +}; + /* Private data per function */ struct zpci_dev { struct zpci_bus *zbus; @@ -193,6 +218,8 @@ struct zpci_dev { struct iommu_domain *s390_domain; /* attached IOMMU domain */ struct kvm_zdev *kzdev; struct mutex kzdev_lock; + struct zpci_ccdf_pending pending_errs; + struct mutex pending_errs_lock; spinlock_t dom_lock; /* protect s390_domain change */ }; =20 @@ -331,6 +358,7 @@ void zpci_debug_exit_device(struct zpci_dev *); int zpci_report_error(struct pci_dev *, struct zpci_report_error_header *); int zpci_clear_error_state(struct zpci_dev *zdev); int zpci_reset_load_store_blocked(struct zpci_dev *zdev); +void zpci_cleanup_pending_errors(struct zpci_dev *zdev); =20 #ifdef CONFIG_NUMA =20 diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c index b2e6b53ea8e6..9f02c2bd29d4 100644 --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -915,6 +915,7 @@ struct zpci_dev *zpci_create_device(u32 fid, u32 fh, en= um zpci_state state) mutex_init(&zdev->state_lock); mutex_init(&zdev->fmb_lock); mutex_init(&zdev->kzdev_lock); + mutex_init(&zdev->pending_errs_lock); =20 return zdev; =20 diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c index de504925f709..9f4ccd79771a 100644 --- a/arch/s390/pci/pci_event.c +++ b/arch/s390/pci/pci_event.c @@ -17,23 +17,6 @@ #include "pci_bus.h" #include "pci_report.h" =20 -/* Content Code Description for PCI Function Error */ -struct zpci_ccdf_err { - u32 reserved1; - u32 fh; /* function handle */ - u32 fid; /* function id */ - u32 ett : 4; /* expected table type */ - u32 mvn : 12; /* MSI vector number */ - u32 dmaas : 8; /* DMA address space */ - u32 : 6; - u32 q : 1; /* event qualifier */ - u32 rw : 1; /* read/write */ - u64 faddr; /* failing address */ - u32 reserved3; - u16 reserved4; - u16 pec; /* PCI event code */ -} __packed; - /* Content Code Description for PCI Function Availability */ struct zpci_ccdf_avail { u32 reserved1; @@ -75,6 +58,42 @@ static bool is_driver_supported(struct pci_driver *drive= r) return true; } =20 +static void zpci_store_pci_error(struct pci_dev *pdev, + struct zpci_ccdf_err *ccdf) +{ + struct zpci_dev *zdev =3D to_zpci(pdev); + int i; + + mutex_lock(&zdev->pending_errs_lock); + if (zdev->pending_errs.count >=3D ZPCI_ERR_PENDING_MAX) { + pr_err("%s: Maximum number (%d) of pending error events queued", + pci_name(pdev), ZPCI_ERR_PENDING_MAX); + mutex_unlock(&zdev->pending_errs_lock); + return; + } + + i =3D zdev->pending_errs.tail % ZPCI_ERR_PENDING_MAX; + memcpy(&zdev->pending_errs.err[i], ccdf, sizeof(struct zpci_ccdf_err)); + zdev->pending_errs.tail++; + zdev->pending_errs.count++; + mutex_unlock(&zdev->pending_errs_lock); +} + +void zpci_cleanup_pending_errors(struct zpci_dev *zdev) +{ + struct pci_dev *pdev =3D NULL; + + mutex_lock(&zdev->pending_errs_lock); + pdev =3D pci_get_slot(zdev->zbus->bus, zdev->devfn); + if (zdev->pending_errs.count) + pr_info("%s: Unhandled PCI error events count=3D%d", + pci_name(pdev), zdev->pending_errs.count); + memset(&zdev->pending_errs, 0, sizeof(struct zpci_ccdf_pending)); + pci_dev_put(pdev); + mutex_unlock(&zdev->pending_errs_lock); +} +EXPORT_SYMBOL_GPL(zpci_cleanup_pending_errors); + static pci_ers_result_t zpci_event_notify_error_detected(struct pci_dev *p= dev, struct pci_driver *driver) { @@ -169,7 +188,8 @@ static pci_ers_result_t zpci_event_do_reset(struct pci_= dev *pdev, * and the platform determines which functions are affected for * multi-function devices. */ -static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *= pdev) +static pci_ers_result_t zpci_event_attempt_error_recovery(struct pci_dev *= pdev, + struct zpci_ccdf_err *ccdf) { pci_ers_result_t ers_res =3D PCI_ERS_RESULT_DISCONNECT; struct zpci_dev *zdev =3D to_zpci(pdev); @@ -188,13 +208,6 @@ static pci_ers_result_t zpci_event_attempt_error_recov= ery(struct pci_dev *pdev) } pdev->error_state =3D pci_channel_io_frozen; =20 - if (needs_mediated_recovery(pdev)) { - pr_info("%s: Cannot be recovered in the host because it is a pass-throug= h device\n", - pci_name(pdev)); - status_str =3D "failed (pass-through)"; - goto out_unlock; - } - driver =3D to_pci_driver(pdev->dev.driver); if (!is_driver_supported(driver)) { if (!driver) { @@ -210,12 +223,23 @@ static pci_ers_result_t zpci_event_attempt_error_reco= very(struct pci_dev *pdev) goto out_unlock; } =20 + if (needs_mediated_recovery(pdev)) + zpci_store_pci_error(pdev, ccdf); + ers_res =3D zpci_event_notify_error_detected(pdev, driver); if (ers_result_indicates_abort(ers_res)) { status_str =3D "failed (abort on detection)"; goto out_unlock; } =20 + if (needs_mediated_recovery(pdev)) { + pr_info("%s: Leaving recovery of pass-through device to user-space\n", + pci_name(pdev)); + ers_res =3D PCI_ERS_RESULT_RECOVERED; + status_str =3D "in progress"; + goto out_unlock; + } + if (ers_res !=3D PCI_ERS_RESULT_NEED_RESET) { ers_res =3D zpci_event_do_error_state_clear(pdev, driver); if (ers_result_indicates_abort(ers_res)) { @@ -260,25 +284,20 @@ static pci_ers_result_t zpci_event_attempt_error_reco= very(struct pci_dev *pdev) * @pdev: PCI function for which to report * @es: PCI channel failure state to report */ -static void zpci_event_io_failure(struct pci_dev *pdev, pci_channel_state_= t es) +static void zpci_event_io_failure(struct pci_dev *pdev, pci_channel_state_= t es, + struct zpci_ccdf_err *ccdf) { struct pci_driver *driver; =20 pci_dev_lock(pdev); pdev->error_state =3D es; - /** - * While vfio-pci's error_detected callback notifies user-space QEMU - * reacts to this by freezing the guest. In an s390 environment PCI - * errors are rarely fatal so this is overkill. Instead in the future - * we will inject the error event and let the guest recover the device - * itself. - */ + if (needs_mediated_recovery(pdev)) - goto out; + zpci_store_pci_error(pdev, ccdf); driver =3D to_pci_driver(pdev->dev.driver); if (driver && driver->err_handler && driver->err_handler->error_detected) driver->err_handler->error_detected(pdev, pdev->error_state); -out: + pci_dev_unlock(pdev); } =20 @@ -324,12 +343,12 @@ static void __zpci_event_error(struct zpci_ccdf_err *= ccdf) break; case 0x0040: /* Service Action or Error Recovery Failed */ case 0x003b: - zpci_event_io_failure(pdev, pci_channel_io_perm_failure); + zpci_event_io_failure(pdev, pci_channel_io_perm_failure, ccdf); break; default: /* PCI function left in the error state attempt to recover */ - ers_res =3D zpci_event_attempt_error_recovery(pdev); + ers_res =3D zpci_event_attempt_error_recovery(pdev, ccdf); if (ers_res !=3D PCI_ERS_RESULT_RECOVERED) - zpci_event_io_failure(pdev, pci_channel_io_perm_failure); + zpci_event_io_failure(pdev, pci_channel_io_perm_failure, ccdf); break; } pci_dev_put(pdev); diff --git a/drivers/vfio/pci/vfio_pci_zdev.c b/drivers/vfio/pci/vfio_pci_z= dev.c index a7bc23ce8483..2be37eab9279 100644 --- a/drivers/vfio/pci/vfio_pci_zdev.c +++ b/drivers/vfio/pci/vfio_pci_zdev.c @@ -168,6 +168,8 @@ void vfio_pci_zdev_close_device(struct vfio_pci_core_de= vice *vdev) =20 zdev->mediated_recovery =3D false; =20 + zpci_cleanup_pending_errors(zdev); + if (!vdev->vdev.kvm) return; =20 --=20 2.43.0