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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2CF31E7C70D for ; Sun, 1 Feb 2026 06:38:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 597CA6B0005; Sun, 1 Feb 2026 01:38:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 51B266B008C; Sun, 1 Feb 2026 01:38:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3FB556B0092; Sun, 1 Feb 2026 01:38:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 296D56B0005 for ; Sun, 1 Feb 2026 01:38:39 -0500 (EST) Received: from smtpin30.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id DD7875B95D for ; Sun, 1 Feb 2026 06:38:38 +0000 (UTC) X-FDA: 84394934316.30.31FF622 Received: from out-183.mta1.migadu.com (out-183.mta1.migadu.com [95.215.58.183]) by imf12.hostedemail.com (Postfix) with ESMTP id AA08A40003 for ; Sun, 1 Feb 2026 06:38:36 +0000 (UTC) Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=smbFLQG3; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf12.hostedemail.com: domain of yanjun.zhu@linux.dev designates 95.215.58.183 as permitted sender) smtp.mailfrom=yanjun.zhu@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1769927917; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ZwyK35BqHJ9vMxdC101Hpkz7OEl6VsmM8t+q1gtlYtQ=; b=BosWOcRfap6aSXTSsOneynF+w2p14GsRfxgQGdHWg5akpzhzSLj7UfNR91Wui9vQFlgiW+ f4cATEZ29za8nkyle3HWHZshlmSoTUQeX9Lo0xnk9Eb1JBESHQzBPL7jLQufFDHXtAGyXu GwniK8BKyJrjlG+5k7gltx/py2kC7/M= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1769927917; a=rsa-sha256; cv=none; b=lGIAK7iueOORBVZ55lMRdClqoqHIfFpEkveBNB5QE8hr+qEkiWPzx9LxqHW2hPIZHH1/ha raQz+zD3jXuZ8edo2jaohJP4FE0vm1iSRcJEzKtRwgHqpmB34Ml0p9rxGscUXUaS1Z7oPn cgNC1Xhe3ueWQwd9l83QUecvcchmmYE= ARC-Authentication-Results: i=1; imf12.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=smbFLQG3; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf12.hostedemail.com: domain of yanjun.zhu@linux.dev designates 95.215.58.183 as permitted sender) smtp.mailfrom=yanjun.zhu@linux.dev Message-ID: <44484594-5b5d-4237-993c-ac1e173ad62e@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1769927913; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZwyK35BqHJ9vMxdC101Hpkz7OEl6VsmM8t+q1gtlYtQ=; b=smbFLQG3fxi0EmdEQh5EfbtGQ62LpS961djirjg538qndfMoJIldCdV/L2GKzWYzuysN/1 /GumBEceCbaFABLQT0FDfy4W6hBDyhGvjE/RBwgY8Fercg7NI2raGGc+bgtYZDTz4/ErLu bI04FQJ+kIrizpByKTlcv8fJSr/4ST4= Date: Sat, 31 Jan 2026 22:38:18 -0800 MIME-Version: 1.0 Subject: Re: [PATCH v2 02/22] PCI: Add API to track PCI devices preserved across Live Update To: David Matlack , Alex Williamson Cc: Adithya Jayachandran , Alexander Graf , Alex Mastro , Alistair Popple , Andrew Morton , Ankit Agrawal , Bjorn Helgaas , Chris Li , David Rientjes , Jacob Pan , Jason Gunthorpe , Jason Gunthorpe , Jonathan Corbet , Josh Hilke , Kevin Tian , kexec@lists.infradead.org, kvm@vger.kernel.org, Leon Romanovsky , Leon Romanovsky , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, Lukas Wunner , =?UTF-8?Q?Micha=C5=82_Winiarski?= , Mike Rapoport , Parav Pandit , Pasha Tatashin , Pranjal Shrivastava , Pratyush Yadav , Raghavendra Rao Ananta , Rodrigo Vivi , Saeed Mahameed , Samiullah Khawaja , Shuah Khan , =?UTF-8?Q?Thomas_Hellstr=C3=B6m?= , Tomita Moeko , Vipin Sharma , Vivek Kasireddy , William Tu , Yi Liu References: <20260129212510.967611-1-dmatlack@google.com> <20260129212510.967611-3-dmatlack@google.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Zhu Yanjun In-Reply-To: <20260129212510.967611-3-dmatlack@google.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: AA08A40003 X-Stat-Signature: xj99earfiwneoaqnudmn75w11yu8au45 X-Rspam-User: X-Rspamd-Server: rspam02 X-HE-Tag: 1769927916-519739 X-HE-Meta: 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 Str2wJqf t9bon1tvAFfDL8NtqkIxGfVoByyt8MfOj2Uc36AwRoZUjtRX6zJmK96kfCZ4xUxF1NlIHb2GharEpBqXBlOXr8dN1IxOOlN9WCjIdNLZIdYUPZ5iHs/PxKaPLfGhHH78PW4TmXU7CYG+xX077mNyXZOQTdPQPTxjj/TGdysCU/WFLYx4tHpCdy2j1Ijxm81rar6KOigEKhvuBMtpYrVr9GMRewBhLOW6HzkoFcD9nv3THZTfRvG5yoSsmpHTc5cWKyu7x X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 在 2026/1/29 13:24, David Matlack 写道: > Add an API to enable the PCI subsystem to track all devices that are > preserved across a Live Update, including both incoming devices (passed > from the previous kernel) and outgoing devices (passed to the next > kernel). > > Use PCI segment number and BDF to keep track of devices across Live > Update. This means the kernel must keep both identifiers constant across > a Live Update for any preserved device. VFs are not supported for now, > since that requires preserving SR-IOV state on the device to ensure the > same number of VFs appear after kexec and with the same BDFs. > > Drivers that preserve devices across Live Update can now register their > struct liveupdate_file_handler with the PCI subsystem so that the PCI > subsystem can allocate and manage File-Lifecycle-Bound (FLB) global data > to track the list of incoming and outgoing preserved devices. > > pci_liveupdate_register_fh(driver_fh) > pci_liveupdate_unregister_fh(driver_fh) Can the above 2 functions support the virtual devices? For example, bonding, veth, iSWAP and RXE. These virtual devices do not have BDF. As such, I am not sure if your patches take these virtual devices in to account. Thanks a lot. Zhu Yanjun > > Drivers can notify the PCI subsystem whenever a device is preserved and > unpreserved with the following APIs: > > pci_liveupdate_outgoing_preserve(pci_dev) > pci_liveupdate_outgoing_unpreserve(pci_dev) > > After a Live Update, the PCI subsystem fetches its FLB global data > from the previous kernel from the Live Update Orchestrator (LUO) during > device initialization to determine which devices were preserved. > > Drivers can check if a device was preserved before userspace retrieves > the file for it via pci_dev->liveupdate_incoming. > > Once a driver has finished restoring an incoming preserved device, it > can notify the PCI subsystem with the following call, which clears > pci_dev->liveupdate_incoming. > > pci_liveupdate_incoming_finish(pci_dev) > > This API will be used in subsequent commits by the vfio-pci driver to > preserve VFIO devices across Live Update and by the PCI subsystem. > > Signed-off-by: David Matlack > --- > drivers/pci/Makefile | 1 + > drivers/pci/liveupdate.c | 212 ++++++++++++++++++++++++++++++++++++ > drivers/pci/probe.c | 2 + > include/linux/kho/abi/pci.h | 55 ++++++++++ > include/linux/pci.h | 47 ++++++++ > 5 files changed, 317 insertions(+) > create mode 100644 drivers/pci/liveupdate.c > create mode 100644 include/linux/kho/abi/pci.h > > diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile > index 8c259a9a8796..a32f7658b9e5 100644 > --- a/drivers/pci/Makefile > +++ b/drivers/pci/Makefile > @@ -16,6 +16,7 @@ obj-$(CONFIG_PROC_FS) += proc.o > obj-$(CONFIG_SYSFS) += pci-sysfs.o slot.o > obj-$(CONFIG_ACPI) += pci-acpi.o > obj-$(CONFIG_GENERIC_PCI_IOMAP) += iomap.o > +obj-$(CONFIG_LIVEUPDATE) += liveupdate.o > endif > > obj-$(CONFIG_OF) += of.o > diff --git a/drivers/pci/liveupdate.c b/drivers/pci/liveupdate.c > new file mode 100644 > index 000000000000..182cfc793b80 > --- /dev/null > +++ b/drivers/pci/liveupdate.c > @@ -0,0 +1,212 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +/* > + * Copyright (c) 2025, Google LLC. > + * David Matlack > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +static DEFINE_MUTEX(pci_flb_outgoing_lock); > + > +static int pci_flb_preserve(struct liveupdate_flb_op_args *args) > +{ > + struct pci_dev *dev = NULL; > + int max_nr_devices = 0; > + struct pci_ser *ser; > + unsigned long size; > + > + for_each_pci_dev(dev) > + max_nr_devices++; > + > + size = struct_size_t(struct pci_ser, devices, max_nr_devices); > + > + ser = kho_alloc_preserve(size); > + if (IS_ERR(ser)) > + return PTR_ERR(ser); > + > + ser->max_nr_devices = max_nr_devices; > + > + args->obj = ser; > + args->data = virt_to_phys(ser); > + return 0; > +} > + > +static void pci_flb_unpreserve(struct liveupdate_flb_op_args *args) > +{ > + struct pci_ser *ser = args->obj; > + > + WARN_ON_ONCE(ser->nr_devices); > + kho_unpreserve_free(ser); > +} > + > +static int pci_flb_retrieve(struct liveupdate_flb_op_args *args) > +{ > + args->obj = phys_to_virt(args->data); > + return 0; > +} > + > +static void pci_flb_finish(struct liveupdate_flb_op_args *args) > +{ > + kho_restore_free(args->obj); > +} > + > +static struct liveupdate_flb_ops pci_liveupdate_flb_ops = { > + .preserve = pci_flb_preserve, > + .unpreserve = pci_flb_unpreserve, > + .retrieve = pci_flb_retrieve, > + .finish = pci_flb_finish, > + .owner = THIS_MODULE, > +}; > + > +static struct liveupdate_flb pci_liveupdate_flb = { > + .ops = &pci_liveupdate_flb_ops, > + .compatible = PCI_LUO_FLB_COMPATIBLE, > +}; > + > +#define INIT_PCI_DEV_SER(_dev) { \ > + .domain = pci_domain_nr((_dev)->bus), \ > + .bdf = pci_dev_id(_dev), \ > +} > + > +static int pci_dev_ser_cmp(const void *__a, const void *__b) > +{ > + const struct pci_dev_ser *a = __a, *b = __b; > + > + return cmp_int(a->domain << 16 | a->bdf, b->domain << 16 | b->bdf); > +} > + > +static struct pci_dev_ser *pci_ser_find(struct pci_ser *ser, > + struct pci_dev *dev) > +{ > + const struct pci_dev_ser key = INIT_PCI_DEV_SER(dev); > + > + return bsearch(&key, ser->devices, ser->nr_devices, > + sizeof(key), pci_dev_ser_cmp); > +} > + > +static int pci_ser_delete(struct pci_ser *ser, struct pci_dev *dev) > +{ > + struct pci_dev_ser *dev_ser; > + int i; > + > + dev_ser = pci_ser_find(ser, dev); > + if (!dev_ser) > + return -ENOENT; > + > + for (i = dev_ser - ser->devices; i < ser->nr_devices - 1; i++) > + ser->devices[i] = ser->devices[i + 1]; > + > + ser->nr_devices--; > + return 0; > +} > + > +int pci_liveupdate_outgoing_preserve(struct pci_dev *dev) > +{ > + struct pci_dev_ser new = INIT_PCI_DEV_SER(dev); > + struct pci_ser *ser; > + int i, ret; > + > + /* Preserving VFs is not supported yet. */ > + if (dev->is_virtfn) > + return -EINVAL; > + > + guard(mutex)(&pci_flb_outgoing_lock); > + > + if (dev->liveupdate_outgoing) > + return -EBUSY; > + > + ret = liveupdate_flb_get_outgoing(&pci_liveupdate_flb, (void **)&ser); > + if (ret) > + return ret; > + > + if (ser->nr_devices == ser->max_nr_devices) > + return -E2BIG; > + > + for (i = ser->nr_devices; i > 0; i--) { > + struct pci_dev_ser *prev = &ser->devices[i - 1]; > + int cmp = pci_dev_ser_cmp(&new, prev); > + > + if (WARN_ON_ONCE(!cmp)) > + return -EBUSY; > + > + if (cmp > 0) > + break; > + > + ser->devices[i] = *prev; > + } > + > + ser->devices[i] = new; > + ser->nr_devices++; > + dev->liveupdate_outgoing = true; > + return 0; > +} > +EXPORT_SYMBOL_GPL(pci_liveupdate_outgoing_preserve); > + > +void pci_liveupdate_outgoing_unpreserve(struct pci_dev *dev) > +{ > + struct pci_ser *ser; > + int ret; > + > + guard(mutex)(&pci_flb_outgoing_lock); > + > + ret = liveupdate_flb_get_outgoing(&pci_liveupdate_flb, (void **)&ser); > + if (WARN_ON_ONCE(ret)) > + return; > + > + WARN_ON_ONCE(pci_ser_delete(ser, dev)); > + dev->liveupdate_outgoing = false; > +} > +EXPORT_SYMBOL_GPL(pci_liveupdate_outgoing_unpreserve); > + > +u32 pci_liveupdate_incoming_nr_devices(void) > +{ > + struct pci_ser *ser; > + int ret; > + > + ret = liveupdate_flb_get_incoming(&pci_liveupdate_flb, (void **)&ser); > + if (ret) > + return 0; > + > + return ser->nr_devices; > +} > +EXPORT_SYMBOL_GPL(pci_liveupdate_incoming_nr_devices); > + > +void pci_liveupdate_setup_device(struct pci_dev *dev) > +{ > + struct pci_ser *ser; > + int ret; > + > + ret = liveupdate_flb_get_incoming(&pci_liveupdate_flb, (void **)&ser); > + if (ret) > + return; > + > + dev->liveupdate_incoming = !!pci_ser_find(ser, dev); > +} > +EXPORT_SYMBOL_GPL(pci_liveupdate_setup_device); > + > +void pci_liveupdate_incoming_finish(struct pci_dev *dev) > +{ > + dev->liveupdate_incoming = false; > +} > +EXPORT_SYMBOL_GPL(pci_liveupdate_incoming_finish); > + > +int pci_liveupdate_register_fh(struct liveupdate_file_handler *fh) > +{ > + return liveupdate_register_flb(fh, &pci_liveupdate_flb); > +} > +EXPORT_SYMBOL_GPL(pci_liveupdate_register_fh); > + > +int pci_liveupdate_unregister_fh(struct liveupdate_file_handler *fh) > +{ > + return liveupdate_unregister_flb(fh, &pci_liveupdate_flb); > +} > +EXPORT_SYMBOL_GPL(pci_liveupdate_unregister_fh); > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 37329095e5fe..af6356c5a156 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -2060,6 +2060,8 @@ int pci_setup_device(struct pci_dev *dev) > if (pci_early_dump) > early_dump_pci_device(dev); > > + pci_liveupdate_setup_device(dev); > + > /* Need to have dev->class ready */ > dev->cfg_size = pci_cfg_space_size(dev); > > diff --git a/include/linux/kho/abi/pci.h b/include/linux/kho/abi/pci.h > new file mode 100644 > index 000000000000..6577767f8da6 > --- /dev/null > +++ b/include/linux/kho/abi/pci.h > @@ -0,0 +1,55 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +/* > + * Copyright (c) 2025, Google LLC. > + * David Matlack > + */ > + > +#ifndef _LINUX_KHO_ABI_PCI_H > +#define _LINUX_KHO_ABI_PCI_H > + > +#include > +#include > + > +/** > + * DOC: PCI File-Lifecycle Bound (FLB) Live Update ABI > + * > + * This header defines the ABI for preserving core PCI state across kexec using > + * Live Update File-Lifecycle Bound (FLB) data. > + * > + * This interface is a contract. Any modification to any of the serialization > + * structs defined here constitutes a breaking change. Such changes require > + * incrementing the version number in the PCI_LUO_FLB_COMPATIBLE string. > + */ > + > +#define PCI_LUO_FLB_COMPATIBLE "pci-v1" > + > +/** > + * struct pci_dev_ser - Serialized state about a single PCI device. > + * > + * @domain: The device's PCI domain number (segment). > + * @bdf: The device's PCI bus, device, and function number. > + */ > +struct pci_dev_ser { > + u16 domain; > + u16 bdf; > +} __packed; > + > +/** > + * struct pci_ser - PCI Subsystem Live Update State > + * > + * This struct tracks state about all devices that are being preserved across > + * a Live Update for the next kernel. > + * > + * @max_nr_devices: The length of the devices[] flexible array. > + * @nr_devices: The number of devices that were preserved. > + * @devices: Flexible array of pci_dev_ser structs for each device. Guaranteed > + * to be sorted ascending by domain and bdf. > + */ > +struct pci_ser { > + u64 max_nr_devices; > + u64 nr_devices; > + struct pci_dev_ser devices[]; > +} __packed; > + > +#endif /* _LINUX_KHO_ABI_PCI_H */ > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 7e36936bb37a..9ead6d84aef6 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -40,6 +40,7 @@ > #include > #include > #include > +#include > > #include > > @@ -582,6 +583,10 @@ struct pci_dev { > u8 tph_mode; /* TPH mode */ > u8 tph_req_type; /* TPH requester type */ > #endif > +#ifdef CONFIG_LIVEUPDATE > + unsigned int liveupdate_incoming:1; /* Preserved by previous kernel */ > + unsigned int liveupdate_outgoing:1; /* Preserved for next kernel */ > +#endif > }; > > static inline struct pci_dev *pci_physfn(struct pci_dev *dev) > @@ -2854,4 +2859,46 @@ void pci_uevent_ers(struct pci_dev *pdev, enum pci_ers_result err_type); > WARN_ONCE(condition, "%s %s: " fmt, \ > dev_driver_string(&(pdev)->dev), pci_name(pdev), ##arg) > > +#ifdef CONFIG_LIVEUPDATE > +int pci_liveupdate_outgoing_preserve(struct pci_dev *dev); > +void pci_liveupdate_outgoing_unpreserve(struct pci_dev *dev); > +void pci_liveupdate_setup_device(struct pci_dev *dev); > +u32 pci_liveupdate_incoming_nr_devices(void); > +void pci_liveupdate_incoming_finish(struct pci_dev *dev); > +int pci_liveupdate_register_fh(struct liveupdate_file_handler *fh); > +int pci_liveupdate_unregister_fh(struct liveupdate_file_handler *fh); > +#else /* !CONFIG_LIVEUPDATE */ > +static inline int pci_liveupdate_outgoing_preserve(struct pci_dev *dev) > +{ > + return -EOPNOTSUPP; > +} > + > +static inline void pci_liveupdate_outgoing_unpreserve(struct pci_dev *dev) > +{ > +} > + > +static inline void pci_liveupdate_setup_device(struct pci_dev *dev) > +{ > +} > + > +static inline u32 pci_liveupdate_incoming_nr_devices(void) > +{ > + return 0; > +} > + > +static inline void pci_liveupdate_incoming_finish(struct pci_dev *dev) > +{ > +} > + > +static inline int pci_liveupdate_register_fh(struct liveupdate_file_handler *fh) > +{ > + return -EOPNOTSUPP; > +} > + > +static inline int pci_liveupdate_unregister_fh(struct liveupdate_file_handler *fh) > +{ > + return -EOPNOTSUPP; > +} > +#endif /* !CONFIG_LIVEUPDATE */ > + > #endif /* LINUX_PCI_H */ > -- Best Regards, Yanjun.Zhu