From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 43D801E8825 for ; Tue, 5 Nov 2024 18:21:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730830877; cv=none; b=FihMWQETTIf9bNC2JpN+GRtcUPdPVJoeuMl+kyIShUwgvUhJykokQVb85TtiCsCOcvhXxz3ink6mMk/4Xi7mVoLQ+3s0ujWTpitnJmhe9pnrPwPR5+GdoyHL+NFI6+Tw7YcIVczPtQ2rVXvUfTPVUiWC0h5N2E0ZZCUpBlDiLx8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730830877; c=relaxed/simple; bh=ZZi3BcgW8dU/FmeUVRlwP7F9yP6S9iLsceuLt7FnGRk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Hw/t5ezBoA8llZHdDXlKR1F7GpBzKSAzMg0EK228m2tvatjvY+pV4cLqdhHz76EQf4XjzxCiU+BVElXznnVygpftjcg8nPDKrgbyIKTnifucPOZ9Taru+pWkpCZvrBiDloxQfSMTJO+UBIor6r7kHEoJkth6C/BcUDiKeVHlzN0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=cqTtEW+z; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cqTtEW+z" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1730830874; 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=tEbuJjrTaFih7whargvvzvNhhaeDsTSzRPC2gHGEaos=; b=cqTtEW+zTJHglQ/Jktk6mDQ0z9K3NJE3SwGADwnkNJUkq9762r6pVAegHjICClYiB0KlLQ K7pjWKn7OwkUA/okNtlODkja4vnfnyDKSZX/QPn1C1OkLq3NTeAQwAEeW4AVoMYslsYx2R O2sJ6J0fpidJv3jKeOUCscitWepvqYc= Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-183-9tSTJChdOyy6xfjhYTzXOA-1; Tue, 05 Nov 2024 13:21:12 -0500 X-MC-Unique: 9tSTJChdOyy6xfjhYTzXOA-1 Received: by mail-il1-f198.google.com with SMTP id e9e14a558f8ab-3a6c1e8c9c3so5034145ab.1 for ; Tue, 05 Nov 2024 10:21:11 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730830871; x=1731435671; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=tEbuJjrTaFih7whargvvzvNhhaeDsTSzRPC2gHGEaos=; b=KNka6daeSpNBbGs3bW5p4zu3yQiiP+NSyJ4sPYS9q/WxzT+1jUVsoSKDd+2CXfVO6v IjGpG9L0k8xczbr297FAmxP+jlEnwTXVNwygvmjWJrVeVftGk0lJ5E/+kgH2/lCkcUNG 4IwIber/7AcEw6BJUDT1JdhzVvLTZDe4imjq6nMH10aU9NJQgfG4THYWj0WOJzxmzjuZ zN00mfkbUcjFBzOzWv1Fyn59ZtjpzboMoh5iw5CdwDWwFN/Gd+xlwC/GTgw+6J8M2Wch CE8r/nD1SVA3at+x4r8GAcCafdZHF4g9J30ypc6oQg/kclir0ZHAFIYn4Ph9oxhbQc3E kSRw== X-Forwarded-Encrypted: i=1; AJvYcCUyYIqeURzirlODUXjzsehB0zn9wqu74Rg9MX5JWOr4IOQ8262fQeA5vug8Hw4Lf40VO6H68djXYtHYShw=@vger.kernel.org X-Gm-Message-State: AOJu0Yw5REAulWzLduBLgTqit+y0PHu3pJHzKVoMs/wUG8cUmzX5SW36 SsvdLBu/ePqUkJQID0jdDKIyVRluxQm6qzNoKIdlKE5z9FiO8DYXtPG51e692jg+98mHJnZCOHG Ao+Zn8FB4gNuPWGpSrU0oPippgdO9gCv4O4uVGNRCBJpxAtGzq2JMXzYICYiekg== X-Received: by 2002:a05:6602:258c:b0:83a:96ce:342e with SMTP id ca18e2360f4ac-83b1c5d15cfmr819571839f.3.1730830871071; Tue, 05 Nov 2024 10:21:11 -0800 (PST) X-Google-Smtp-Source: AGHT+IFBPbW7d/AXkUPWEwQLaNHgfje0IBrygT+rEkkO4QMX7PEgzzDLAxuZwgIdrUXOYP5FjL8+6A== X-Received: by 2002:a05:6602:258c:b0:83a:96ce:342e with SMTP id ca18e2360f4ac-83b1c5d15cfmr819571539f.3.1730830870691; Tue, 05 Nov 2024 10:21:10 -0800 (PST) Received: from redhat.com ([38.15.36.11]) by smtp.gmail.com with ESMTPSA id ca18e2360f4ac-83b67b2542fsm278088839f.12.2024.11.05.10.21.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 05 Nov 2024 10:21:10 -0800 (PST) Date: Tue, 5 Nov 2024 11:21:08 -0700 From: Alex Williamson To: Shameerali Kolothum Thodi Cc: liulongfang , "jgg@nvidia.com" , "Jonathan Cameron" , "kvm@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linuxarm@openeuler.org" Subject: Re: [PATCH v12 3/4] hisi_acc_vfio_pci: register debugfs for hisilicon migration driver Message-ID: <20241105112108.14255a9e.alex.williamson@redhat.com> In-Reply-To: References: <20241105035254.24636-1-liulongfang@huawei.com> <20241105035254.24636-4-liulongfang@huawei.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.43; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 5 Nov 2024 08:55:51 +0000 Shameerali Kolothum Thodi wrote: > > -----Original Message----- > > From: liulongfang > > Sent: Tuesday, November 5, 2024 3:53 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 v12 3/4] hisi_acc_vfio_pci: register debugfs for hisilicon > > migration driver > > Hi, > > Few minor comments below. Please don't re-spin just for these yet. > Please wait for others to review as well. > > Thanks, > Shameer > > > diff --git a/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c > > b/drivers/vfio/pci/hisilicon/hisi_acc_vfio_pci.c > > index a8c53952d82e..7728c9745b9d 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); > > } > > > > +static void hisi_acc_debug_migf_copy(struct hisi_acc_vf_core_device > > *hisi_acc_vdev, > > + struct hisi_acc_vf_migration_file *src_migf) > > Alignment should match open parenthesis here. I might also shorten the first line to 80 chars by putting "static" or "static void" on a line by itself, but we're getting into personal preference at that point and this driver already has lines exceeding 80 columns. > > +{ > > + struct hisi_acc_vf_migration_file *dst_migf = hisi_acc_vdev- > > >debug_migf; > > + > > + if (!dst_migf) > > + return; > > + > > + dst_migf->total_length = src_migf->total_length; > > + memcpy(&dst_migf->vf_data, &src_migf->vf_data, > > + sizeof(struct acc_vf_data)); > > Here too, alignment not correct. It is better to run, > ./scripts/checkpatch --strict on these patches if you haven't done already. Yup. Only those two were missed as far as I see, but checkpatch does warn several places where we should use seq_puts() rather than seq_printf() for cases of printing a constant format without additional arguments. For example "device not opened!\n" is the first one below but there are others. > > +} > > + > > 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 = NULL; > > } > > > > 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 = NULL; > > @@ -1294,6 +1309,129 @@ static long hisi_acc_vfio_pci_ioctl(struct > > vfio_device *core_vdev, unsigned int > > return vfio_pci_core_ioctl(core_vdev, cmd, arg); > > } > > > > +static int hisi_acc_vf_debug_check(struct seq_file *seq, struct vfio_device > > *vdev) > > +{ > > + struct hisi_acc_vf_core_device *hisi_acc_vdev = > > hisi_acc_get_vf_dev(vdev); > > + struct hisi_qm *vf_qm = &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 = qm_wait_dev_not_ready(vf_qm); > > + if (ret) { > > + seq_printf(seq, "VF device not ready!\n"); > > + return -EBUSY; > > + } > > + > > + return 0; > > +} > > + > > +static int hisi_acc_vf_debug_cmd(struct seq_file *seq, void *data) > > +{ > > + struct device *vf_dev = seq->private; > > + struct vfio_pci_core_device *core_device = > > dev_get_drvdata(vf_dev); > > + struct vfio_device *vdev = &core_device->vdev; > > + struct hisi_acc_vf_core_device *hisi_acc_vdev = > > hisi_acc_get_vf_dev(vdev); > > + struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm; > > + u64 value; > > + int ret; > > + > > + mutex_lock(&hisi_acc_vdev->open_mutex); > > + ret = hisi_acc_vf_debug_check(seq, vdev); > > + if (ret) { > > + mutex_unlock(&hisi_acc_vdev->open_mutex); > > + return ret; > > + } > > + > > + value = readl(vf_qm->io_base + QM_MB_CMD_SEND_BASE); > > + if (value == 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 = seq->private; > > + struct vfio_pci_core_device *core_device = > > dev_get_drvdata(vf_dev); > > + struct vfio_device *vdev = &core_device->vdev; > > + struct hisi_acc_vf_core_device *hisi_acc_vdev = > > hisi_acc_get_vf_dev(vdev); > > + size_t vf_data_sz = offsetofend(struct acc_vf_data, padding); > > + struct acc_vf_data *vf_data; > > + int ret; > > + > > + mutex_lock(&hisi_acc_vdev->open_mutex); > > + ret = hisi_acc_vf_debug_check(seq, vdev); > > + if (ret) { > > + mutex_unlock(&hisi_acc_vdev->open_mutex); > > + return ret; > > + } > > + > > + mutex_lock(&hisi_acc_vdev->state_mutex); > > + vf_data = kzalloc(sizeof(struct acc_vf_data), GFP_KERNEL); > > + if (!vf_data) { > > + ret = -ENOMEM; > > + goto mutex_release; > > + } > > + > > + vf_data->vf_qm_state = hisi_acc_vdev->vf_qm_state; > > + ret = vf_qm_read_data(&hisi_acc_vdev->vf_qm, vf_data); > > + if (ret) > > + goto migf_err; > > + > > + seq_hex_dump(seq, "Dev Data:", DUMP_PREFIX_OFFSET, 16, 1, > > + (const void *)vf_data, vf_data_sz, false); > > + > > + seq_printf(seq, > > + "guest driver load: %u\n" > > + "data size: %lu\n", > > + hisi_acc_vdev->vf_qm_state, > > + sizeof(struct acc_vf_data)); > > There was a suggestion to add a comment here to describe vf_qm_state better. > May be something like, > > vf_qm_state here indicates whether the Guest has loaded the driver for the ACC VF > device or not. I think the comment ended up at the declaration of vf_qm_state in the header file: > @@ -107,9 +114,17 @@ struct hisi_acc_vf_core_device { > struct pci_dev *vf_dev; > struct hisi_qm *pf_qm; > struct hisi_qm vf_qm; > + /* > + * Record whether a driver is added to the acc device in Guest OS. > + * The value of QM_VF_STATE is set by the acc device driver. > + * The migration driver queries through the QM_VF_STATE register. > + */ > u32 vf_qm_state; > int vf_id; > struct hisi_acc_vf_migration_file *resuming_migf; > struct hisi_acc_vf_migration_file *saving_migf; > + > + /* An extra buffer for reporting migration data via debugfs */ > + struct hisi_acc_vf_migration_file *debug_migf; > }; > #endif /* HISI_ACC_VFIO_PCI_H */ Is that satisfactory? > > + > > +migf_err: > > + kfree(vf_data); > > +mutex_release: > > + mutex_unlock(&hisi_acc_vdev->state_mutex); > > + mutex_unlock(&hisi_acc_vdev->open_mutex); > > + > > + return ret; > > +} > > + > > +static int hisi_acc_vf_migf_read(struct seq_file *seq, void *data) > > +{ > > + struct device *vf_dev = seq->private; > > + struct vfio_pci_core_device *core_device = > > dev_get_drvdata(vf_dev); > > + struct vfio_device *vdev = &core_device->vdev; > > + struct hisi_acc_vf_core_device *hisi_acc_vdev = > > hisi_acc_get_vf_dev(vdev); > > + size_t vf_data_sz = offsetofend(struct acc_vf_data, padding); > > + struct hisi_acc_vf_migration_file *debug_migf = 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, > > + (const void *)&debug_migf->vf_data, vf_data_sz, false); > > + seq_printf(seq, "migrate data length: %lu\n", debug_migf- > > >total_length); > > + > > + return 0; > > +} > > + > > static int hisi_acc_vfio_pci_open_device(struct vfio_device *core_vdev) > > { > > struct hisi_acc_vf_core_device *hisi_acc_vdev = > > hisi_acc_get_vf_dev(core_vdev); > > @@ -1305,12 +1443,16 @@ static int hisi_acc_vfio_pci_open_device(struct > > vfio_device *core_vdev) > > return ret; > > > > if (core_vdev->mig_ops) { > > + mutex_lock(&hisi_acc_vdev->open_mutex); > > ret = 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 = VFIO_DEVICE_STATE_RUNNING; > > + hisi_acc_vdev->dev_opened = true; > > + mutex_unlock(&hisi_acc_vdev->open_mutex); > > } > > > > vfio_pci_core_finish_enable(vdev); > > @@ -1322,7 +1464,10 @@ static void hisi_acc_vfio_pci_close_device(struct > > vfio_device *core_vdev) > > struct hisi_acc_vf_core_device *hisi_acc_vdev = > > hisi_acc_get_vf_dev(core_vdev); > > struct hisi_qm *vf_qm = &hisi_acc_vdev->vf_qm; > > > > + mutex_lock(&hisi_acc_vdev->open_mutex); > > + hisi_acc_vdev->dev_opened = false; > > iounmap(vf_qm->io_base); > > + mutex_unlock(&hisi_acc_vdev->open_mutex); > > vfio_pci_core_close_device(core_vdev); > > } > > > > @@ -1342,6 +1487,7 @@ static int hisi_acc_vfio_pci_migrn_init_dev(struct > > vfio_device *core_vdev) > > hisi_acc_vdev->pf_qm = pf_qm; > > hisi_acc_vdev->vf_dev = pdev; > > mutex_init(&hisi_acc_vdev->state_mutex); > > + mutex_init(&hisi_acc_vdev->open_mutex); > > > > core_vdev->migration_flags = VFIO_MIGRATION_STOP_COPY | > > VFIO_MIGRATION_PRE_COPY; > > core_vdev->mig_ops = &hisi_acc_vfio_pci_migrn_state_ops; > > @@ -1387,6 +1533,48 @@ static const struct vfio_device_ops > > hisi_acc_vfio_pci_ops = { > > .detach_ioas = vfio_iommufd_physical_detach_ioas, > > }; > > > > +static void hisi_acc_vfio_debug_init(struct hisi_acc_vf_core_device > > *hisi_acc_vdev) > > +{ > > + struct vfio_device *vdev = &hisi_acc_vdev->core_device.vdev; > > + struct dentry *vfio_dev_migration = NULL; > > + struct dentry *vfio_hisi_acc = NULL; > > + struct device *dev = vdev->dev; > > + void *migf = NULL; > > + > > + if (!debugfs_initialized() || > > + !IS_ENABLED(CONFIG_VFIO_DEBUGFS)) > > + return; > > + > > + if (vdev->ops != &hisi_acc_vfio_pci_migrn_ops) > > + return; > > + > > + vfio_dev_migration = debugfs_lookup("migration", vdev- > > >debug_root); > > + if (!vfio_dev_migration) { > > + dev_err(dev, "failed to lookup migration debugfs file!\n"); > > + return; > > + } > > + > > + migf = kzalloc(sizeof(struct hisi_acc_vf_migration_file), > > GFP_KERNEL); checkpatch --strict also advises this could be written as: migf = kzalloc(sizeof(*migf), GFP_KERNEL); There's another one above with acc_vf_data. I'd consider these optional, but I think it is good practice and is more consistent with existing allocations in this file. > > + if (!migf) > > + return; > > + hisi_acc_vdev->debug_migf = migf; > > + > > + vfio_hisi_acc = 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 migrn_ops is not used, kfree(NULL) is valid */ > > The above comment is not required. Please remove. I don't have a problem with it, but I'll let the two of you decide as co-owners of the file. Thanks, Alex > > + kfree(hisi_acc_vdev->debug_migf); > > + hisi_acc_vdev->debug_migf = NULL; > > +} > > + >