From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 17BC61CDA31; Fri, 11 Oct 2024 08:09:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728634172; cv=none; b=qCzjDBY+8tGZAimqeUQSlQ13B8cTB6whBB1XuLhmuHx6rVtOpKMVM1O9vMOutNEjXBfyMMHCEAUj1plw7olix1yC3Btwnx0WaKrYSUCNOXf26ruRtuOt8Wjef1lSg9w1yQWsZhdNX4bzhGmreEwN+ykVDjTIS0tazy+3Kh3GSQs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728634172; c=relaxed/simple; bh=AdashH52wwCwy8N71iUO2XZjU04DU4pbYNNd/eIOTVk=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: Content-Type:MIME-Version; b=lwvjZvBB4H2jRkGZv7gy0l/HMKEd6HszDjazVE1tP9pB3yOejgyhlZWCG5OLG1iAwoo6MMXmWWVMmcwYKqtz8P2bSfHNcGBCfJ2tDXLremjIz7kH5Y53VQWVhavzN7VMSWauH0FZ9YhL4IWJ+grXJmQW+kLGdfQgxxuP4VSx0n0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.31]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4XPzmH5N6Zz6JB8F; Fri, 11 Oct 2024 16:09:03 +0800 (CST) Received: from frapeml500007.china.huawei.com (unknown [7.182.85.172]) by mail.maildlp.com (Postfix) with ESMTPS id A0DDC140581; Fri, 11 Oct 2024 16:09:26 +0800 (CST) Received: from frapeml500008.china.huawei.com (7.182.85.71) by frapeml500007.china.huawei.com (7.182.85.172) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Fri, 11 Oct 2024 10:09:26 +0200 Received: from frapeml500008.china.huawei.com ([7.182.85.71]) by frapeml500008.china.huawei.com ([7.182.85.71]) with mapi id 15.01.2507.039; Fri, 11 Oct 2024 10:09:26 +0200 From: Shameerali Kolothum Thodi To: liulongfang , "alex.williamson@redhat.com" , "jgg@nvidia.com" , "Jonathan Cameron" CC: "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linuxarm@openeuler.org" Subject: RE: [PATCH v9 3/4] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver Thread-Topic: [PATCH v9 3/4] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver Thread-Index: AQHbBcQkh6V22o+1AUK1m5LoEXCq+rKBW/sQ Date: Fri, 11 Oct 2024 08:09:26 +0000 Message-ID: <25ff48eaa1194484b5b4ef016d01191c@huawei.com> References: <20240913095502.22940-1-liulongfang@huawei.com> <20240913095502.22940-4-liulongfang@huawei.com> In-Reply-To: <20240913095502.22940-4-liulongfang@huawei.com> Accept-Language: en-GB, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 > -----Original Message----- > From: liulongfang > Sent: Friday, September 13, 2024 10:55 AM > To: alex.williamson@redhat.com; jgg@nvidia.com; Shameerali Kolothum > Thodi ; Jonathan Cameron > > Cc: kvm@vger.kernel.org; linux-kernel@vger.kernel.org; > linuxarm@openeuler.org; liulongfang > Subject: [PATCH v9 3/4] hisi_acc_vfio_pci: register debugfs for hisilicon > migration driver >=20 > On the debugfs framework of VFIO, if the CONFIG_VFIO_DEBUGFS macro is > enabled, the debug function is registered for the live migration driver > of the HiSilicon accelerator device. >=20 > After registering the HiSilicon accelerator device on the debugfs > framework of live migration of vfio, a directory file "hisi_acc" > of debugfs is created, and then three debug function files are > created in this directory: >=20 > vfio > | > +--- > | +---migration > | +--state > | +--hisi_acc > | +--dev_data > | +--migf_data > | +--cmd_state > | > +--- > +---migration > +--state > +--hisi_acc > +--dev_data > +--migf_data > +--cmd_state >=20 > dev_data file: read device data that needs to be migrated from the > current device in real time > migf_data file: read the migration data of the last live migration > from the current driver. > cmd_state: used to get the cmd channel state for the device. >=20 > +----------------+ +--------------+ +---------------+ > | migration dev | | src dev | | dst dev | > +-------+--------+ +------+-------+ +-------+-------+ > | | | > | +------v-------+ +-------v-------+ > | | saving_migf | | resuming_migf | > read | | file | | file | > | +------+-------+ +-------+-------+ > | | copy | > | +------------+----------+ > | | > +-------v--------+ +-------v--------+ > | data buffer | | debug_migf | > +-------+--------+ +-------+--------+ > | | > cat | cat | > +-------v--------+ +-------v--------+ > | dev_data | | migf_data | > +----------------+ +----------------+ >=20 > When accessing debugfs, user can obtain the most recent status data > of the device through the "dev_data" file. It can read recent > complete status data of the device. If the current device is being > migrated, it will wait for it to complete. > The data for the last completed migration function will be stored > in debug_migf. Users can read it via "migf_data". >=20 > Signed-off-by: Longfang Liu > --- > .../vfio/pci/hisilicon/hisi_acc_vfio_pci.c | 204 ++++++++++++++++++ > .../vfio/pci/hisilicon/hisi_acc_vfio_pci.h | 7 + > 2 files changed, 211 insertions(+) >=20 > diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c > b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c > index a8c53952d82e..da9f5b9e6c5b 100644 > --- a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c > +++ b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c > @@ -627,15 +627,30 @@ static void hisi_acc_vf_disable_fd(struct > hisi_acc_vf_migration_file *migf) > mutex_unlock(&migf->lock); > } >=20 > +static void hisi_acc_debug_migf_copy(struct hisi_acc_vf_core_device > *hisi_acc_vdev, > + struct hisi_acc_vf_migration_file *src_migf) > +{ > + struct hisi_acc_vf_migration_file *dst_migf =3D hisi_acc_vdev- > >debug_migf; > + > + if (!dst_migf) > + return; > + > + dst_migf->total_length =3D src_migf->total_length; > + memcpy(&dst_migf->vf_data, &src_migf->vf_data, > + sizeof(struct acc_vf_data)); > +} > + > static void hisi_acc_vf_disable_fds(struct hisi_acc_vf_core_device > *hisi_acc_vdev) > { > if (hisi_acc_vdev->resuming_migf) { > + hisi_acc_debug_migf_copy(hisi_acc_vdev, hisi_acc_vdev- > >resuming_migf); > hisi_acc_vf_disable_fd(hisi_acc_vdev->resuming_migf); > fput(hisi_acc_vdev->resuming_migf->filp); > hisi_acc_vdev->resuming_migf =3D NULL; > } >=20 > if (hisi_acc_vdev->saving_migf) { > + hisi_acc_debug_migf_copy(hisi_acc_vdev, hisi_acc_vdev- > >saving_migf); > hisi_acc_vf_disable_fd(hisi_acc_vdev->saving_migf); > fput(hisi_acc_vdev->saving_migf->filp); > hisi_acc_vdev->saving_migf =3D NULL; > @@ -1294,6 +1309,181 @@ static long hisi_acc_vfio_pci_ioctl(struct > vfio_device *core_vdev, unsigned int > return vfio_pci_core_ioctl(core_vdev, cmd, arg); > } >=20 > +static int hisi_acc_vf_debug_check(struct seq_file *seq, struct vfio_dev= ice > *vdev) > +{ > + struct hisi_acc_vf_core_device *hisi_acc_vdev =3D > hisi_acc_get_vf_dev(vdev); > + struct hisi_qm *vf_qm =3D &hisi_acc_vdev->vf_qm; > + int ret; > + > + lockdep_assert_held(&hisi_acc_vdev->open_mutex); > + /* > + * When the device is not opened, the io_base is not mapped. > + * The driver cannot perform device read and write operations. > + */ > + if (!hisi_acc_vdev->dev_opened) { > + seq_printf(seq, "device not opened!\n"); > + return -EINVAL; > + } > + > + ret =3D qm_wait_dev_not_ready(vf_qm); > + if (ret) { > + seq_printf(seq, "VF device not ready!\n"); > + return -EBUSY; > + } Still not very sure this vf_qm ready() check actually helps or not? What gu= arantee is there that the qm will stay Ready after this call? Any read/write after= wards will eventually fail if it is not ready later for some reason, right?=20 Perhaps helps in early detection and bails out. > + return 0; > +} > + > +static int hisi_acc_vf_debug_cmd(struct seq_file *seq, void *data) > +{ > + struct device *vf_dev =3D seq->private; > + struct vfio_pci_core_device *core_device =3D > dev_get_drvdata(vf_dev); > + struct vfio_device *vdev =3D &core_device->vdev; > + struct hisi_acc_vf_core_device *hisi_acc_vdev =3D > hisi_acc_get_vf_dev(vdev); > + struct hisi_qm *vf_qm =3D &hisi_acc_vdev->vf_qm; > + u64 value; > + int ret; > + > + mutex_lock(&hisi_acc_vdev->open_mutex); > + ret =3D hisi_acc_vf_debug_check(seq, vdev); > + if (ret) { > + mutex_unlock(&hisi_acc_vdev->open_mutex); > + return ret; > + } > + > + value =3D readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE); > + if (value =3D=3D QM_MB_CMD_NOT_READY) { > + mutex_unlock(&hisi_acc_vdev->open_mutex); > + seq_printf(seq, "mailbox cmd channel not ready!\n"); > + return -EINVAL; > + } > + mutex_unlock(&hisi_acc_vdev->open_mutex); > + seq_printf(seq, "mailbox cmd channel ready!\n"); > + > + return 0; > +} > + > +static int hisi_acc_vf_dev_read(struct seq_file *seq, void *data) > +{ > + struct device *vf_dev =3D seq->private; > + struct vfio_pci_core_device *core_device =3D > dev_get_drvdata(vf_dev); > + struct vfio_device *vdev =3D &core_device->vdev; > + struct hisi_acc_vf_core_device *hisi_acc_vdev =3D > hisi_acc_get_vf_dev(vdev); > + size_t vf_data_sz =3D offsetofend(struct acc_vf_data, padding); > + struct acc_vf_data *vf_data =3D NULL; > + int ret; > + > + vf_data =3D kzalloc(sizeof(struct acc_vf_data), GFP_KERNEL); > + if (!vf_data) > + return -ENOMEM;\ You could move the allocation after the below checks and to just before vf_qm_read_data(). > + > + mutex_lock(&hisi_acc_vdev->open_mutex); > + ret =3D hisi_acc_vf_debug_check(seq, vdev); > + if (ret) { > + mutex_unlock(&hisi_acc_vdev->open_mutex); > + goto migf_err; > + } > + > + mutex_lock(&hisi_acc_vdev->state_mutex); > + vf_data->vf_qm_state =3D hisi_acc_vdev->vf_qm_state; > + ret =3D vf_qm_read_data(&hisi_acc_vdev->vf_qm, vf_data); > + if (ret) { > + mutex_unlock(&hisi_acc_vdev->open_mutex); > + mutex_unlock(&hisi_acc_vdev->state_mutex); I think it is better to unlock in the reverse order. Also probably you can = move the unlocks to a goto area. > + goto migf_err; > + } > + > + mutex_unlock(&hisi_acc_vdev->open_mutex); > + mutex_unlock(&hisi_acc_vdev->state_mutex); Same as above. > + seq_hex_dump(seq, "Dev Data:", DUMP_PREFIX_OFFSET, 16, 1, > + (unsigned char *)vf_data, > + vf_data_sz, false); > + > + seq_printf(seq, > + "acc device:\n" > + "guest driver load: %u\n" > + "data size: %lu\n", > + hisi_acc_vdev->vf_qm_state, > + sizeof(struct acc_vf_data)); > + > +migf_err: > + kfree(vf_data); > + > + return ret; > +} > + > +static int hisi_acc_vf_migf_read(struct seq_file *seq, void *data) > +{ > + struct device *vf_dev =3D seq->private; > + struct vfio_pci_core_device *core_device =3D > dev_get_drvdata(vf_dev); > + struct vfio_device *vdev =3D &core_device->vdev; > + struct hisi_acc_vf_core_device *hisi_acc_vdev =3D > hisi_acc_get_vf_dev(vdev); > + size_t vf_data_sz =3D offsetofend(struct acc_vf_data, padding); > + struct hisi_acc_vf_migration_file *debug_migf =3D hisi_acc_vdev- > >debug_migf; > + > + /* Check whether the live migration operation has been performed > */ > + if (debug_migf->total_length < QM_MATCH_SIZE) { > + seq_printf(seq, "device not migrated!\n"); > + return -EAGAIN; > + } > + > + seq_hex_dump(seq, "Mig Data:", DUMP_PREFIX_OFFSET, 16, 1, > + (unsigned char *)&debug_migf->vf_data, > + vf_data_sz, false); > + > + seq_printf(seq, > + "acc device:\n" > + "guest driver load: %u\n" > + "device opened: %d\n" > + "migrate data length: %lu\n", > + hisi_acc_vdev->vf_qm_state, > + hisi_acc_vdev->dev_opened, > + debug_migf->total_length); > + > + return 0; > +} > + > +static void hisi_acc_vfio_debug_init(struct hisi_acc_vf_core_device > *hisi_acc_vdev) > +{ > + struct vfio_device *vdev =3D &hisi_acc_vdev->core_device.vdev; > + struct dentry *vfio_dev_migration =3D NULL; > + struct dentry *vfio_hisi_acc =3D NULL; > + struct device *dev =3D vdev->dev; > + void *migf =3D NULL; > + > + if (!debugfs_initialized() || > + !IS_ENABLED(CONFIG_VFIO_DEBUGFS)) > + return; > + > + vfio_dev_migration =3D debugfs_lookup("migration", vdev- > >debug_root); > + if (!vfio_dev_migration) { > + dev_err(dev, "failed to lookup migration debugfs file!\n"); > + return; > + } > + > + migf =3D kzalloc(sizeof(struct hisi_acc_vf_migration_file), > GFP_KERNEL); > + if (!migf) > + return; > + hisi_acc_vdev->debug_migf =3D migf; > + > + vfio_hisi_acc =3D debugfs_create_dir("hisi_acc", vfio_dev_migration); > + debugfs_create_devm_seqfile(dev, "dev_data", vfio_hisi_acc, > + hisi_acc_vf_dev_read); > + debugfs_create_devm_seqfile(dev, "migf_data", vfio_hisi_acc, > + hisi_acc_vf_migf_read); > + debugfs_create_devm_seqfile(dev, "cmd_state", vfio_hisi_acc, > + hisi_acc_vf_debug_cmd); > +} > + > +static void hisi_acc_vf_debugfs_exit(struct hisi_acc_vf_core_device > *hisi_acc_vdev) > +{ > + if (hisi_acc_vdev->debug_migf) { > + kfree(hisi_acc_vdev->debug_migf); > + hisi_acc_vdev->debug_migf =3D NULL; > + } > +} > + > static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev) > { > struct hisi_acc_vf_core_device *hisi_acc_vdev =3D > hisi_acc_get_vf_dev(core_vdev); > @@ -1305,12 +1495,16 @@ static int hisi_acc_vfio_pci_open_device(struct > vfio_device *core_vdev) > return ret; >=20 > if (core_vdev->mig_ops) { > + mutex_lock(&hisi_acc_vdev->open_mutex); > ret =3D hisi_acc_vf_qm_init(hisi_acc_vdev); > if (ret) { > + mutex_unlock(&hisi_acc_vdev->open_mutex); > vfio_pci_core_disable(vdev); > return ret; > } > hisi_acc_vdev->mig_state =3D VFIO_DEVICE_STATE_RUNNING; > + hisi_acc_vdev->dev_opened =3D true; > + mutex_unlock(&hisi_acc_vdev->open_mutex); > } >=20 > vfio_pci_core_finish_enable(vdev); > @@ -1322,7 +1516,10 @@ static void hisi_acc_vfio_pci_close_device(struct > vfio_device *core_vdev) > struct hisi_acc_vf_core_device *hisi_acc_vdev =3D > hisi_acc_get_vf_dev(core_vdev); > struct hisi_qm *vf_qm =3D &hisi_acc_vdev->vf_qm; >=20 > + mutex_lock(&hisi_acc_vdev->open_mutex); > + hisi_acc_vdev->dev_opened =3D false; > iounmap(vf_qm->io_base); > + mutex_unlock(&hisi_acc_vdev->open_mutex); > vfio_pci_core_close_device(core_vdev); > } >=20 > @@ -1342,6 +1539,7 @@ static int hisi_acc_vfio_pci_migrn_init_dev(struct > vfio_device *core_vdev) > hisi_acc_vdev->pf_qm =3D pf_qm; > hisi_acc_vdev->vf_dev =3D pdev; > mutex_init(&hisi_acc_vdev->state_mutex); > + mutex_init(&hisi_acc_vdev->open_mutex); >=20 > core_vdev->migration_flags =3D VFIO_MIGRATION_STOP_COPY | > VFIO_MIGRATION_PRE_COPY; > core_vdev->mig_ops =3D &hisi_acc_vfio_pci_migrn_state_ops; > @@ -1413,6 +1611,9 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev > *pdev, const struct pci_device > ret =3D vfio_pci_core_register_device(&hisi_acc_vdev->core_device); > if (ret) > goto out_put_vdev; > + > + if (ops =3D=3D &hisi_acc_vfio_pci_migrn_ops) > + hisi_acc_vfio_debug_init(hisi_acc_vdev); I think there was a comment earlier on this. Still not sure why it is not p= ossible to move ops =3D=3D &hisi_acc_vfio_pci_migrn_ops check inside hisi_acc_vfio_deb= ug_init(). > return 0; >=20 > out_put_vdev: > @@ -1423,8 +1624,11 @@ static int hisi_acc_vfio_pci_probe(struct pci_dev > *pdev, const struct pci_device > static void hisi_acc_vfio_pci_remove(struct pci_dev *pdev) > { > struct hisi_acc_vf_core_device *hisi_acc_vdev =3D > hisi_acc_drvdata(pdev); > + struct vfio_device *vdev =3D &hisi_acc_vdev->core_device.vdev; >=20 > vfio_pci_core_unregister_device(&hisi_acc_vdev->core_device); > + if (vdev->ops =3D=3D &hisi_acc_vfio_pci_migrn_ops) > + hisi_acc_vf_debugfs_exit(hisi_acc_vdev); Do we need to do vdev->ops =3D=3D &hisi_acc_vfio_pci_migrn_ops check here? Since we are checking hisi_acc_vdev->debug_migf inside the exit function, which I think is onl= y set when the ops =3D=3D migrn_ops. Right? Thanks, Shameer