From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65169C433F5 for ; Fri, 27 May 2022 06:01:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243882AbiE0GBz (ORCPT ); Fri, 27 May 2022 02:01:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243768AbiE0GBt (ORCPT ); Fri, 27 May 2022 02:01:49 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 30631FC6 for ; Thu, 26 May 2022 23:01:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631303; 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=lynSeVT1NfwEzANWSPivWToMg2lFwBVUR0GD7hlFiwg=; b=QUPta452Lv7Wg5guaezfZZL10WyT3/b85Jtpu0EpiZqKUlxtaou8R6aizVmIX+5p2kEHdk JXC9aIMvm+XX00lx+twB989AB2+AMzN3qMtdlntYmunj9i7U37yFc54Im9YHplafS52NwT i05fBWv20+hcFt3VeQV+gPNH2Cl7PPw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-587-mZNTa0xxM2Os7yz2KbfjHg-1; Fri, 27 May 2022 02:01:40 -0400 X-MC-Unique: mZNTa0xxM2Os7yz2KbfjHg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B1B3E811E7A; Fri, 27 May 2022 06:01:39 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id 608292166B26; Fri, 27 May 2022 06:01:31 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 1/9] virtio: use virtio_device_ready() in virtio_device_restore() Date: Fri, 27 May 2022 14:01:12 +0800 Message-Id: <20220527060120.20964-2-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Stefano Garzarella It will allow us to do extension on virtio_device_ready() without duplicating code. Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Reviewed-by: Cornelia Huck Signed-off-by: Stefano Garzarella Signed-off-by: Jason Wang Reviewed-by: Xuan Zhuo --- drivers/virtio/virtio.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index ce424c16997d..938e975029d4 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -526,8 +526,9 @@ int virtio_device_restore(struct virtio_device *dev) goto err; } =20 - /* Finally, tell the device we're all set */ - virtio_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK); + /* If restore didn't do it, mark device DRIVER_OK ourselves. */ + if (!(dev->config->get_status(dev) & VIRTIO_CONFIG_S_DRIVER_OK)) + virtio_device_ready(dev); =20 virtio_config_enable(dev); =20 --=20 2.25.1 From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32D59C433F5 for ; Fri, 27 May 2022 06:02:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244129AbiE0GCa (ORCPT ); Fri, 27 May 2022 02:02:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244009AbiE0GCK (ORCPT ); Fri, 27 May 2022 02:02:10 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9B0821179 for ; Thu, 26 May 2022 23:01:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631315; 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=8mYK00a7UR4B8Uf7OoMylov9T5hCzf7730+L4Uy7mis=; b=i6quxanQl3RsByK1SnMNFgXlmVetu3wmnU6gyeukZiqRAZ/wzuuf80gU00zEGWneM1vXhQ wR2cb/mVa92vLXWcJPksvijRGbfkOA19r4vLxn7spF3GhMTCrBb5NNpDzQjAgcWOQVkUdb XGHkRVMVFWOVJBN66HmKfmfa1K14MPc= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-403-5C-lqayINPC7G6eSBY2K-A-1; Fri, 27 May 2022 02:01:49 -0400 X-MC-Unique: 5C-lqayINPC7G6eSBY2K-A-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 0AC562949BA6; Fri, 27 May 2022 06:01:49 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id F09702166B26; Fri, 27 May 2022 06:01:40 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 2/9] virtio: use virtio_reset_device() when possible Date: Fri, 27 May 2022 14:01:13 +0800 Message-Id: <20220527060120.20964-3-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This allows us to do common extension without duplicating code. Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Reviewed-by: Cornelia Huck Signed-off-by: Jason Wang Reviewed-by: Eugenio P=C3=A9rez Reviewed-by: Stefano Garzarella Reviewed-by: Xuan Zhuo --- drivers/virtio/virtio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index 938e975029d4..aa1eb5132767 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -430,7 +430,7 @@ int register_virtio_device(struct virtio_device *dev) =20 /* We always start by resetting the device, in case a previous * driver messed it up. This also tests that code path a little. */ - dev->config->reset(dev); + virtio_reset_device(dev); =20 /* Acknowledge that we've seen the device. */ virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); @@ -496,7 +496,7 @@ int virtio_device_restore(struct virtio_device *dev) =20 /* We always start by resetting the device, in case a previous * driver messed it up. */ - dev->config->reset(dev); + virtio_reset_device(dev); =20 /* Acknowledge that we've seen the device. */ virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); --=20 2.25.1 From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6866DC433F5 for ; Fri, 27 May 2022 06:02:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244303AbiE0GCX (ORCPT ); Fri, 27 May 2022 02:02:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244014AbiE0GCL (ORCPT ); Fri, 27 May 2022 02:02:11 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C199A25C6 for ; Thu, 26 May 2022 23:01:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631318; 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=OVF7ZOKQjlZaNtrOn5007e/TWK4CcFV8q+LPrrFaKRw=; b=SxbdWtSj0EdOOQSKHxUhotr7qMArGJDJJN77SIycB6V19zuHutbl4cPILkIRDQKOXFI7SM syARxJ/T8LCurzOyVSd0uQHtb6Q90QGy2+G6lHqNbkLw+4DGbuNtboZGglyzhIhICHee0O 9Ywhx0+yYfut9RsaxlPWRns6VRtvo/4= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-179-gElugDpbOLqiMMZF789AsA-1; Fri, 27 May 2022 02:01:57 -0400 X-MC-Unique: gElugDpbOLqiMMZF789AsA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 80D05382ECD2; Fri, 27 May 2022 06:01:56 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id A7CD52166B26; Fri, 27 May 2022 06:01:49 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 3/9] virtio: introduce config op to synchronize vring callbacks Date: Fri, 27 May 2022 14:01:14 +0800 Message-Id: <20220527060120.20964-4-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This patch introduces new virtio config op to vring callbacks. Transport specific method is required to make sure the write before this function is visible to the vring_interrupt() that is called after the return of this function. For the transport that doesn't provide synchronize_vqs(), use synchornize_rcu() which synchronize with IRQ implicitly as a fallback. Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Reviewed-by: Cornelia Huck Signed-off-by: Jason Wang Reviewed-by: Stefano Garzarella Reviewed-by: Xuan Zhuo --- include/linux/virtio_config.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index b341dd62aa4d..25be018810a7 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -57,6 +57,11 @@ struct virtio_shm_region { * include a NULL entry for vqs unused by driver * Returns 0 on success or error status * @del_vqs: free virtqueues found by find_vqs(). + * @synchronize_cbs: synchronize with the virtqueue callbacks (optional) + * The function guarantees that all memory operations on the + * queue before it are visible to the vring_interrupt() that is + * called after it. + * vdev: the virtio_device * @get_features: get the array of feature bits for this device. * vdev: the virtio_device * Returns the first 64 feature bits (all we currently need). @@ -89,6 +94,7 @@ struct virtio_config_ops { const char * const names[], const bool *ctx, struct irq_affinity *desc); void (*del_vqs)(struct virtio_device *); + void (*synchronize_cbs)(struct virtio_device *); u64 (*get_features)(struct virtio_device *vdev); int (*finalize_features)(struct virtio_device *vdev); const char *(*bus_name)(struct virtio_device *vdev); @@ -217,6 +223,25 @@ int virtio_find_vqs_ctx(struct virtio_device *vdev, un= signed nvqs, desc); } =20 +/** + * virtio_synchronize_cbs - synchronize with virtqueue callbacks + * @vdev: the device + */ +static inline +void virtio_synchronize_cbs(struct virtio_device *dev) +{ + if (dev->config->synchronize_cbs) { + dev->config->synchronize_cbs(dev); + } else { + /* + * A best effort fallback to synchronize with + * interrupts, preemption and softirq disabled + * regions. See comment above synchronize_rcu(). + */ + synchronize_rcu(); + } +} + /** * virtio_device_ready - enable vq use in probe function * @vdev: the device --=20 2.25.1 From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 03B99C433EF for ; Fri, 27 May 2022 06:02:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244437AbiE0GCf (ORCPT ); Fri, 27 May 2022 02:02:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244171AbiE0GCP (ORCPT ); Fri, 27 May 2022 02:02:15 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 96A991103 for ; Thu, 26 May 2022 23:02:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631331; 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=azptH0eLhY99MFcwGd7saymGVV8++WdmhoOQ1a4MqFs=; b=PoPjc+LPmB8WJ3EemlsJ7tnWCoBPt9wGYb06AKiVEwT0YOIEd3Jy3BhWbRHLjmazAu/TMh yMa/TW0F7OEcdVmbnb0sQUx8+6HWeG4llNNt5HLjQdfMIcXBavrCgFH+BxQmukQ4vArzMv hExGdXz2pc2bw5mc4GFws6tEZ/hfsnk= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-517-GmR5d0FAOwGhaI5pRcA9UQ-1; Fri, 27 May 2022 02:02:08 -0400 X-MC-Unique: GmR5d0FAOwGhaI5pRcA9UQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AE6293C10225; Fri, 27 May 2022 06:02:07 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3529B2166B26; Fri, 27 May 2022 06:01:56 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 4/9] virtio-pci: implement synchronize_cbs() Date: Fri, 27 May 2022 14:01:15 +0800 Message-Id: <20220527060120.20964-5-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We can simply reuse vp_synchronize_vectors() for .synchronize_cbs(). Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Reviewed-by: Cornelia Huck Signed-off-by: Jason Wang Reviewed-by: Xuan Zhuo --- drivers/virtio/virtio_pci_legacy.c | 1 + drivers/virtio/virtio_pci_modern.c | 2 ++ 2 files changed, 3 insertions(+) diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci= _legacy.c index 7fe4caa4b519..a5e5721145c7 100644 --- a/drivers/virtio/virtio_pci_legacy.c +++ b/drivers/virtio/virtio_pci_legacy.c @@ -192,6 +192,7 @@ static const struct virtio_config_ops virtio_pci_config= _ops =3D { .reset =3D vp_reset, .find_vqs =3D vp_find_vqs, .del_vqs =3D vp_del_vqs, + .synchronize_cbs =3D vp_synchronize_vectors, .get_features =3D vp_get_features, .finalize_features =3D vp_finalize_features, .bus_name =3D vp_bus_name, diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci= _modern.c index 4acb34409f0b..623906b4996c 100644 --- a/drivers/virtio/virtio_pci_modern.c +++ b/drivers/virtio/virtio_pci_modern.c @@ -394,6 +394,7 @@ static const struct virtio_config_ops virtio_pci_config= _nodev_ops =3D { .reset =3D vp_reset, .find_vqs =3D vp_modern_find_vqs, .del_vqs =3D vp_del_vqs, + .synchronize_cbs =3D vp_synchronize_vectors, .get_features =3D vp_get_features, .finalize_features =3D vp_finalize_features, .bus_name =3D vp_bus_name, @@ -411,6 +412,7 @@ static const struct virtio_config_ops virtio_pci_config= _ops =3D { .reset =3D vp_reset, .find_vqs =3D vp_modern_find_vqs, .del_vqs =3D vp_del_vqs, + .synchronize_cbs =3D vp_synchronize_vectors, .get_features =3D vp_get_features, .finalize_features =3D vp_finalize_features, .bus_name =3D vp_bus_name, --=20 2.25.1 From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BEE6CC433EF for ; Fri, 27 May 2022 06:02:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244050AbiE0GCx (ORCPT ); Fri, 27 May 2022 02:02:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39402 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244055AbiE0GC0 (ORCPT ); Fri, 27 May 2022 02:02:26 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id AF8D125D7 for ; Thu, 26 May 2022 23:02:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631343; 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=a2AG63orrKCpw2C/hrorxbwfbuZWC+KiL5/NIOQfX70=; b=B/5kz/DwV+141ymkhnjcmVIQGXrn3KS31njRagRfP4jW5eDY9xESYqJDdrvtVLCSWdtgoW XoS9013wk5LIWIXlWf/xF9PvEtF6qBAgJV4ECgGfEm9XeRJMWZ8YY4g/y9R4AXCF6JFDQp L3NHH0FxiFhLhJsl1nv58m7NqbCrHrI= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-49-CL_5IMauPUGU_Y-WldBfVg-1; Fri, 27 May 2022 02:02:20 -0400 X-MC-Unique: CL_5IMauPUGU_Y-WldBfVg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 64D8C1C0690C; Fri, 27 May 2022 06:02:19 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id B7C742166B26; Fri, 27 May 2022 06:02:08 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 5/9] virtio-mmio: implement synchronize_cbs() Date: Fri, 27 May 2022 14:01:16 +0800 Message-Id: <20220527060120.20964-6-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Simply synchronize the platform irq that is used by us. Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Reviewed-by: Cornelia Huck Signed-off-by: Jason Wang Reviewed-by: Xuan Zhuo --- drivers/virtio/virtio_mmio.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 839684d672af..c9699a59f93c 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -345,6 +345,13 @@ static void vm_del_vqs(struct virtio_device *vdev) free_irq(platform_get_irq(vm_dev->pdev, 0), vm_dev); } =20 +static void vm_synchronize_cbs(struct virtio_device *vdev) +{ + struct virtio_mmio_device *vm_dev =3D to_virtio_mmio_device(vdev); + + synchronize_irq(platform_get_irq(vm_dev->pdev, 0)); +} + static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned = int index, void (*callback)(struct virtqueue *vq), const char *name, bool ctx) @@ -541,6 +548,7 @@ static const struct virtio_config_ops virtio_mmio_confi= g_ops =3D { .finalize_features =3D vm_finalize_features, .bus_name =3D vm_bus_name, .get_shm_region =3D vm_get_shm_region, + .synchronize_cbs =3D vm_synchronize_cbs, }; =20 =20 --=20 2.25.1 From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACF99C433F5 for ; Fri, 27 May 2022 06:02:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243896AbiE0GCt (ORCPT ); Fri, 27 May 2022 02:02:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244386AbiE0GCe (ORCPT ); Fri, 27 May 2022 02:02:34 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id D33CF2BE6 for ; Thu, 26 May 2022 23:02:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631349; 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=txm7DjcKuANfsEZ3GBtdkhzXAQmx0UitZyi9sP1Io7U=; b=V3dRNeiDSs4JIDa4nggnIWH3cwANct2Bd2zf8zLdQ7fzl8AHkqkVewN8RXwJMWgm0hye3Q GBad+LRmZUKDEtvx1tPwFSiakenQWasXL53CtbnWg/+GQUZZ79R6a3LIWkN+DE93AVv8mw WqgKexiVJc5v9aqvkJ/kn79vnb7Dv+Y= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-546-7bDIP2W9Nq-RFigjdhVmww-1; Fri, 27 May 2022 02:02:26 -0400 X-MC-Unique: 7bDIP2W9Nq-RFigjdhVmww-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CA90E858F0C; Fri, 27 May 2022 06:02:25 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id 138CF2166B2F; Fri, 27 May 2022 06:02:18 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 6/9] virtio-ccw: implement synchronize_cbs() Date: Fri, 27 May 2022 14:01:17 +0800 Message-Id: <20220527060120.20964-7-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This patch tries to implement the synchronize_cbs() for ccw. For the vring_interrupt() that is called via virtio_airq_handler(), the synchronization is simply done via the airq_info's lock. For the vring_interrupt() that is called via virtio_ccw_int_handler(), a per device rwlock is introduced and used in the synchronization method. Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Reviewed-by: Halil Pasic Signed-off-by: Jason Wang Reviewed-by: Cornelia Huck --- drivers/s390/virtio/virtio_ccw.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_= ccw.c index d35e7a3f7067..c188e4f20ca3 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -62,6 +62,7 @@ struct virtio_ccw_device { unsigned int revision; /* Transport revision */ wait_queue_head_t wait_q; spinlock_t lock; + rwlock_t irq_lock; struct mutex io_lock; /* Serializes I/O requests */ struct list_head virtqueues; bool is_thinint; @@ -984,6 +985,30 @@ static const char *virtio_ccw_bus_name(struct virtio_d= evice *vdev) return dev_name(&vcdev->cdev->dev); } =20 +static void virtio_ccw_synchronize_cbs(struct virtio_device *vdev) +{ + struct virtio_ccw_device *vcdev =3D to_vc_device(vdev); + struct airq_info *info =3D vcdev->airq_info; + + if (info) { + /* + * This device uses adapter interrupts: synchronize with + * vring_interrupt() called by virtio_airq_handler() + * via the indicator area lock. + */ + write_lock_irq(&info->lock); + write_unlock_irq(&info->lock); + } else { + /* This device uses classic interrupts: synchronize + * with vring_interrupt() called by + * virtio_ccw_int_handler() via the per-device + * irq_lock + */ + write_lock_irq(&vcdev->irq_lock); + write_unlock_irq(&vcdev->irq_lock); + } +} + static const struct virtio_config_ops virtio_ccw_config_ops =3D { .get_features =3D virtio_ccw_get_features, .finalize_features =3D virtio_ccw_finalize_features, @@ -995,6 +1020,7 @@ static const struct virtio_config_ops virtio_ccw_confi= g_ops =3D { .find_vqs =3D virtio_ccw_find_vqs, .del_vqs =3D virtio_ccw_del_vqs, .bus_name =3D virtio_ccw_bus_name, + .synchronize_cbs =3D virtio_ccw_synchronize_cbs, }; =20 =20 @@ -1106,6 +1132,8 @@ static void virtio_ccw_int_handler(struct ccw_device = *cdev, vcdev->err =3D -EIO; } virtio_ccw_check_activity(vcdev, activity); + /* Interrupts are disabled here */ + read_lock(&vcdev->irq_lock); for_each_set_bit(i, indicators(vcdev), sizeof(*indicators(vcdev)) * BITS_PER_BYTE) { /* The bit clear must happen before the vring kick. */ @@ -1114,6 +1142,7 @@ static void virtio_ccw_int_handler(struct ccw_device = *cdev, vq =3D virtio_ccw_vq_by_ind(vcdev, i); vring_interrupt(0, vq); } + read_unlock(&vcdev->irq_lock); if (test_bit(0, indicators2(vcdev))) { virtio_config_changed(&vcdev->vdev); clear_bit(0, indicators2(vcdev)); @@ -1284,6 +1313,7 @@ static int virtio_ccw_online(struct ccw_device *cdev) init_waitqueue_head(&vcdev->wait_q); INIT_LIST_HEAD(&vcdev->virtqueues); spin_lock_init(&vcdev->lock); + rwlock_init(&vcdev->irq_lock); mutex_init(&vcdev->io_lock); =20 spin_lock_irqsave(get_ccwdev_lock(cdev), flags); --=20 2.25.1 From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C0A4C433F5 for ; Fri, 27 May 2022 06:03:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239866AbiE0GDH (ORCPT ); Fri, 27 May 2022 02:03:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244135AbiE0GCv (ORCPT ); Fri, 27 May 2022 02:02:51 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C70902BDC for ; Thu, 26 May 2022 23:02:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631360; 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=0C6hcQ5Jjv81qlifMWaFIwQcLt5pTYV5jL+U8XNNh0g=; b=ZiY3AXOzC/sGr0SbYIh1MEQBxiJTgGs0s9Fzy9qiFoysrKYbLyhXC6I0hNcXVOu3trdCHc viPR2DEofv2gsClyjzhTBC6riLJYmZsnZz37bQqrhOdVZuzIwGmEo3sB5qHKP5yuEuq8XF 2SJTPkjrFXucLOVq6mSxAw5DtBJIr2A= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-640-9J-8aTfMME68fJLEUeCfHQ-1; Fri, 27 May 2022 02:02:36 -0400 X-MC-Unique: 9J-8aTfMME68fJLEUeCfHQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 974C3803B22; Fri, 27 May 2022 06:02:35 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id 70C8D2166B26; Fri, 27 May 2022 06:02:26 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 7/9] virtio: allow to unbreak virtqueue Date: Fri, 27 May 2022 14:01:18 +0800 Message-Id: <20220527060120.20964-8-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This patch allows the new introduced __virtio_break_device() to unbreak the virtqueue. Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Signed-off-by: Jason Wang Reviewed-by: Cornelia Huck Reviewed-by: Xuan Zhuo --- drivers/virtio/virtio_ring.c | 22 ++++++++++++++++++++++ include/linux/virtio.h | 1 + 2 files changed, 23 insertions(+) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 9d0bae4293be..9c231e1fded7 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -2395,6 +2395,28 @@ void virtio_break_device(struct virtio_device *dev) } EXPORT_SYMBOL_GPL(virtio_break_device); =20 +/* + * This should allow the device to be used by the driver. You may + * need to grab appropriate locks to flush the write to + * vq->broken. This should only be used in some specific case e.g + * (probing and restoring). This function should only be called by the + * core, not directly by the driver. + */ +void __virtio_unbreak_device(struct virtio_device *dev) +{ + struct virtqueue *_vq; + + spin_lock(&dev->vqs_list_lock); + list_for_each_entry(_vq, &dev->vqs, list) { + struct vring_virtqueue *vq =3D to_vvq(_vq); + + /* Pairs with READ_ONCE() in virtqueue_is_broken(). */ + WRITE_ONCE(vq->broken, false); + } + spin_unlock(&dev->vqs_list_lock); +} +EXPORT_SYMBOL_GPL(__virtio_unbreak_device); + dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq) { struct vring_virtqueue *vq =3D to_vvq(_vq); diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 5464f398912a..d8fdf170637c 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -131,6 +131,7 @@ void unregister_virtio_device(struct virtio_device *dev= ); bool is_virtio_device(struct device *dev); =20 void virtio_break_device(struct virtio_device *dev); +void __virtio_unbreak_device(struct virtio_device *dev); =20 void virtio_config_changed(struct virtio_device *dev); #ifdef CONFIG_PM_SLEEP --=20 2.25.1 From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 947DAC433F5 for ; Fri, 27 May 2022 06:03:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244568AbiE0GDY (ORCPT ); Fri, 27 May 2022 02:03:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244439AbiE0GCy (ORCPT ); Fri, 27 May 2022 02:02:54 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0E14B624A for ; Thu, 26 May 2022 23:02:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631367; 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=18WQBid1QGXVg+QHLgcRuT6xbcOBi4aseNYhzOEIOx8=; b=L4YXWzKbrjDjqJiVC1a4RXTzxoOpuoIujGlBBmUf/9dYWMVMJEKttyhJyYUFxLbVBOrfgd q9EeDZC+/Kp2taRD9ovK6oMZclW5ct2NHRNBHZZjr+IJmAxYer42wFcoQXQQ26kjY6u+oJ gJLlq1vUj9mMUpTdVQFCSXetAi3VN8U= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-513-1yzvGschPfSNIFvz1rHPmQ-1; Fri, 27 May 2022 02:02:43 -0400 X-MC-Unique: 1yzvGschPfSNIFvz1rHPmQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2E10038349B3; Fri, 27 May 2022 06:02:43 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id 430C12166B26; Fri, 27 May 2022 06:02:35 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 8/9] virtio: harden vring IRQ Date: Fri, 27 May 2022 14:01:19 +0800 Message-Id: <20220527060120.20964-9-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This is a rework on the previous IRQ hardening that is done for virtio-pci where several drawbacks were found and were reverted: 1) try to use IRQF_NO_AUTOEN which is not friendly to affinity managed IRQ that is used by some device such as virtio-blk 2) done only for PCI transport The vq->broken is re-used in this patch for implementing the IRQ hardening. The vq->broken is set to true during both initialization and reset. And the vq->broken is set to false in virtio_device_ready(). Then vring_interrupt() can check and return when vq->broken is true. And in this case, switch to return IRQ_NONE to let the interrupt core aware of such invalid interrupt to prevent IRQ storm. The reason of using a per queue variable instead of a per device one is that we may need it for per queue reset hardening in the future. Note that the hardening is only done for vring interrupt since the config interrupt hardening is already done in commit 22b7050a024d7 ("virtio: defer config changed notifications"). But the method that is used by config interrupt can't be reused by the vring interrupt handler because it uses spinlock to do the synchronization which is expensive. Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Signed-off-by: Jason Wang Reviewed-by: Cornelia Huck Reviewed-by: Xuan Zhuo --- drivers/s390/virtio/virtio_ccw.c | 4 ++++ drivers/virtio/virtio.c | 15 ++++++++++++--- drivers/virtio/virtio_mmio.c | 5 +++++ drivers/virtio/virtio_pci_modern_dev.c | 5 +++++ drivers/virtio/virtio_ring.c | 11 +++++++---- include/linux/virtio_config.h | 20 ++++++++++++++++++++ 6 files changed, 53 insertions(+), 7 deletions(-) diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_= ccw.c index c188e4f20ca3..97e51c34e6cf 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -971,6 +971,10 @@ static void virtio_ccw_set_status(struct virtio_device= *vdev, u8 status) ccw->flags =3D 0; ccw->count =3D sizeof(status); ccw->cda =3D (__u32)(unsigned long)&vcdev->dma_area->status; + /* We use ssch for setting the status which is a serializing + * instruction that guarantees the memory writes have + * completed before ssch. + */ ret =3D ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_STATUS); /* Write failed? We assume status is unchanged. */ if (ret) diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c index aa1eb5132767..95fac4c97c8b 100644 --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -220,6 +220,15 @@ static int virtio_features_ok(struct virtio_device *de= v) * */ void virtio_reset_device(struct virtio_device *dev) { + /* + * The below virtio_synchronize_cbs() guarantees that any + * interrupt for this line arriving after + * virtio_synchronize_vqs() has completed is guaranteed to see + * vq->broken as true. + */ + virtio_break_device(dev); + virtio_synchronize_cbs(dev); + dev->config->reset(dev); } EXPORT_SYMBOL_GPL(virtio_reset_device); @@ -428,6 +437,9 @@ int register_virtio_device(struct virtio_device *dev) dev->config_enabled =3D false; dev->config_change_pending =3D false; =20 + INIT_LIST_HEAD(&dev->vqs); + spin_lock_init(&dev->vqs_list_lock); + /* We always start by resetting the device, in case a previous * driver messed it up. This also tests that code path a little. */ virtio_reset_device(dev); @@ -435,9 +447,6 @@ int register_virtio_device(struct virtio_device *dev) /* Acknowledge that we've seen the device. */ virtio_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE); =20 - INIT_LIST_HEAD(&dev->vqs); - spin_lock_init(&dev->vqs_list_lock); - /* * device_add() causes the bus infrastructure to look for a matching * driver. diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index c9699a59f93c..f9a36bc7ac27 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -253,6 +253,11 @@ static void vm_set_status(struct virtio_device *vdev, = u8 status) /* We should never be setting status to 0. */ BUG_ON(status =3D=3D 0); =20 + /* + * Per memory-barriers.txt, wmb() is not needed to guarantee + * that the the cache coherent memory writes have completed + * before writing to the MMIO region. + */ writel(status, vm_dev->base + VIRTIO_MMIO_STATUS); } =20 diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio= _pci_modern_dev.c index 4093f9cca7a6..a0fa14f28a7f 100644 --- a/drivers/virtio/virtio_pci_modern_dev.c +++ b/drivers/virtio/virtio_pci_modern_dev.c @@ -467,6 +467,11 @@ void vp_modern_set_status(struct virtio_pci_modern_dev= ice *mdev, { struct virtio_pci_common_cfg __iomem *cfg =3D mdev->common; =20 + /* + * Per memory-barriers.txt, wmb() is not needed to guarantee + * that the the cache coherent memory writes have completed + * before writing to the MMIO region. + */ vp_iowrite8(status, &cfg->device_status); } EXPORT_SYMBOL_GPL(vp_modern_set_status); diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 9c231e1fded7..13a7348cedff 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -1688,7 +1688,7 @@ static struct virtqueue *vring_create_virtqueue_packe= d( vq->we_own_ring =3D true; vq->notify =3D notify; vq->weak_barriers =3D weak_barriers; - vq->broken =3D false; + vq->broken =3D true; vq->last_used_idx =3D 0; vq->event_triggered =3D false; vq->num_added =3D 0; @@ -2134,8 +2134,11 @@ irqreturn_t vring_interrupt(int irq, void *_vq) return IRQ_NONE; } =20 - if (unlikely(vq->broken)) - return IRQ_HANDLED; + if (unlikely(vq->broken)) { + dev_warn_once(&vq->vq.vdev->dev, + "virtio vring IRQ raised before DRIVER_OK"); + return IRQ_NONE; + } =20 /* Just a hint for performance: so it's ok that this can be racy! */ if (vq->event) @@ -2177,7 +2180,7 @@ struct virtqueue *__vring_new_virtqueue(unsigned int = index, vq->we_own_ring =3D false; vq->notify =3D notify; vq->weak_barriers =3D weak_barriers; - vq->broken =3D false; + vq->broken =3D true; vq->last_used_idx =3D 0; vq->event_triggered =3D false; vq->num_added =3D 0; diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 25be018810a7..d4edfd7d91bb 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -256,6 +256,26 @@ void virtio_device_ready(struct virtio_device *dev) unsigned status =3D dev->config->get_status(dev); =20 BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); + + /* + * The virtio_synchronize_cbs() makes sure vring_interrupt() + * will see the driver specific setup if it sees vq->broken + * as false (even if the notifications come before DRIVER_OK). + */ + virtio_synchronize_cbs(dev); + __virtio_unbreak_device(dev); + /* + * The transport should ensure the visibility of vq->broken + * before setting DRIVER_OK. See the comments for the transport + * specific set_status() method. + * + * A well behaved device will only notify a virtqueue after + * DRIVER_OK, this means the device should "see" the coherenct + * memory write that set vq->broken as false which is done by + * the driver when it sees DRIVER_OK, then the following + * driver's vring_interrupt() will see vq->broken as false so + * we won't lose any notification. + */ dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK); } =20 --=20 2.25.1 From nobody Tue Apr 28 23:19:01 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CFFF5C433F5 for ; Fri, 27 May 2022 06:03:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244135AbiE0GDp (ORCPT ); Fri, 27 May 2022 02:03:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41646 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244095AbiE0GDT (ORCPT ); Fri, 27 May 2022 02:03:19 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 49D02BE0E for ; Thu, 26 May 2022 23:03:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1653631381; 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=kh5bzm9uSUhv1Ghb3VPdW30fst72Lni+h8xDpA05+tI=; b=hlAwl3rI9s0ho7kzLVB9EYNRqkSE3zICjUdlE1BW3gE9MW/sqE7FKSroVPn8z1/m0uQE0d 2+XZJAHuNSJmfojdh6sxOkAs5nb3MJTgQEHg1KxAuNn3+AHfXMoip4gZmMCckCvtUVdsFT 4noanCDmXrXvcNHH6IXIHDzMmmh9p8M= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-448-JGgvjHr2OASmEVE7-HdU3g-1; Fri, 27 May 2022 02:02:55 -0400 X-MC-Unique: JGgvjHr2OASmEVE7-HdU3g-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id BB77618013BC; Fri, 27 May 2022 06:02:54 +0000 (UTC) Received: from localhost.localdomain (ovpn-13-240.pek2.redhat.com [10.72.13.240]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0696F2166B26; Fri, 27 May 2022 06:02:45 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, peterz@infradead.org, paulmck@kernel.org, maz@kernel.org, pasic@linux.ibm.com, cohuck@redhat.com, eperezma@redhat.com, lulu@redhat.com, sgarzare@redhat.com, xuanzhuo@linux.alibaba.com, Vineeth Vijayan , Peter Oberparleiter , linux-s390@vger.kernel.org Subject: [PATCH V6 9/9] virtio: use WARN_ON() to warning illegal status value Date: Fri, 27 May 2022 14:01:20 +0800 Message-Id: <20220527060120.20964-10-jasowang@redhat.com> In-Reply-To: <20220527060120.20964-1-jasowang@redhat.com> References: <20220527060120.20964-1-jasowang@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" We used to use BUG_ON() in virtio_device_ready() to detect illegal status value, this seems sub-optimal since the value is under the control of the device. Switch to use WARN_ON() instead. Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: "Paul E. McKenney" Cc: Marc Zyngier Cc: Halil Pasic Cc: Cornelia Huck Cc: Vineeth Vijayan Cc: Peter Oberparleiter Cc: linux-s390@vger.kernel.org Signed-off-by: Jason Wang Reviewed-by: Stefano Garzarella Reviewed-by: Xuan Zhuo --- include/linux/virtio_config.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index d4edfd7d91bb..9a36051ceb76 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -255,7 +255,7 @@ void virtio_device_ready(struct virtio_device *dev) { unsigned status =3D dev->config->get_status(dev); =20 - BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); + WARN_ON(status & VIRTIO_CONFIG_S_DRIVER_OK); =20 /* * The virtio_synchronize_cbs() makes sure vring_interrupt() --=20 2.25.1