From nobody Fri May 3 07:40:29 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1569433667; cv=none; d=zoho.com; s=zohoarc; b=OiA47bmYrO0wwUKoUf9sshoWI6JAhzoe3p/gSbVtJtd3Tdd79Ii2p0J408iIVxggXv3mNnWTaKHgerrv39ofZz3F0gn8oRYkzeQ54eqli2swN4LcSXh2EWihbKUAoVUMS387jx8VvwK1gWqF5YnL4nxUkfL17fiVgYPwGmW4Q1Q= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1569433667; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=ZMPWBA0E2JhyIoYHr5mR+P0cFwXdPs0nW4IT94Fl1Fs=; b=gNnXTL/vmb0cUSu3x8B2eQj6En6/e9/kui+m1BmYheoxWG+bktP3nZJiDYoCbDqKxji8XwT8xkyqNmbzaRmH0tUHLf+8PLN82X1OeyrZco0jqRP6CW9Vro88xeW1Sj74bOX0ot5GspTEpFUvSza9xlkvjfNKYXktbvs3lNbKj9I= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1569433667711175.36475990377528; Wed, 25 Sep 2019 10:47:47 -0700 (PDT) Received: from localhost ([::1]:55504 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iDBOD-0004yC-P0 for importer@patchew.org; Wed, 25 Sep 2019 13:47:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53365) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iDBKt-0002jC-4F for qemu-devel@nongnu.org; Wed, 25 Sep 2019 13:44:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iDBKs-000330-7Q for qemu-devel@nongnu.org; Wed, 25 Sep 2019 13:44:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50246) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iDBKq-000319-73; Wed, 25 Sep 2019 13:44:16 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 41F08210A; Wed, 25 Sep 2019 17:44:15 +0000 (UTC) Received: from localhost (ovpn-116-64.ams2.redhat.com [10.36.116.64]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7443B61F24; Wed, 25 Sep 2019 17:44:08 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PULL 1/2] util/ioc.c: try to reassure Coverity about qemu_iovec_init_extended Date: Wed, 25 Sep 2019 18:43:59 +0100 Message-Id: <20190925174400.8578-2-stefanha@redhat.com> In-Reply-To: <20190925174400.8578-1-stefanha@redhat.com> References: <20190925174400.8578-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.6.2 (mx1.redhat.com [10.5.110.71]); Wed, 25 Sep 2019 17:44:15 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Peter Maydell , Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org, "Michael S. Tsirkin" , Max Reitz , Stefan Hajnoczi Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" From: Vladimir Sementsov-Ogievskiy Make it more obvious, that filling qiov corresponds to qiov allocation, which in turn corresponds to total_niov calculation, based on mid_niov (not mid_len). Still add an assertion to show that there should be no difference. Reported-by: Coverity (CID 1405302) Signed-off-by: Vladimir Sementsov-Ogievskiy Message-id: 20190910090310.14032-1-vsementsov@virtuozzo.com Suggested-by: Peter Maydell Signed-off-by: Vladimir Sementsov-Ogievskiy Message-Id: <20190910090310.14032-1-vsementsov@virtuozzo.com> Signed-off-by: Stefan Hajnoczi --- util/iov.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/util/iov.c b/util/iov.c index 5059e10431..a4689ff3c9 100644 --- a/util/iov.c +++ b/util/iov.c @@ -446,7 +446,8 @@ void qemu_iovec_init_extended( p++; } =20 - if (mid_len) { + assert(!mid_niov =3D=3D !mid_len); + if (mid_niov) { memcpy(p, mid_iov, mid_niov * sizeof(*p)); p[0].iov_base =3D (uint8_t *)p[0].iov_base + mid_head; p[0].iov_len -=3D mid_head; --=20 2.21.0 From nobody Fri May 3 07:40:29 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1569433645; cv=none; d=zoho.com; s=zohoarc; b=kBoJr0rXXxxvHuu4Z5pSGxtdn8Y0bob4HWxY2dw8fkcRS5TQL7oVyw4hE+MmLOCNGQxdxJQmVDNitab1z+yuNeFSzw/vaDIvDAFxPGN2uz7lKS2OQNQqV6JWNsVCdUpS8e2CvttCBOhBVplde+MDbTZGqoBk6XcVwoHnhtE0pDg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1569433645; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=NgrubDeC1x5zMxlExcKYP9AlkSpHY8UdgNEeSW2gzok=; b=BelWcujbbXBHE6niJXy+88MdJtHOQ2XVYG+DlztEhpOGJ3TpQUj3mSGeYnUQoRf68Vglz0FM+NFrXzwLCRTK0tuZYk5HVTTCkDbMD09+sfrEPGKQW1Z/tL31dTRr7Qi9EFrg4ULOfEl7dTcARJDCeqjgb8YLfEFMFEgivc7ITU0= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1569433645380102.55553936425565; Wed, 25 Sep 2019 10:47:25 -0700 (PDT) Received: from localhost ([::1]:55502 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iDBNo-0004gB-8p for importer@patchew.org; Wed, 25 Sep 2019 13:47:24 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53404) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iDBL4-0002zF-Ox for qemu-devel@nongnu.org; Wed, 25 Sep 2019 13:44:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iDBL3-00038n-GF for qemu-devel@nongnu.org; Wed, 25 Sep 2019 13:44:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51046) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iDBL1-00036x-6j; Wed, 25 Sep 2019 13:44:27 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7BE0285539; Wed, 25 Sep 2019 17:44:25 +0000 (UTC) Received: from localhost (ovpn-116-64.ams2.redhat.com [10.36.116.64]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8AC5961F40; Wed, 25 Sep 2019 17:44:16 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PULL 2/2] virtio-blk: schedule virtio_notify_config to run on main context Date: Wed, 25 Sep 2019 18:44:00 +0100 Message-Id: <20190925174400.8578-3-stefanha@redhat.com> In-Reply-To: <20190925174400.8578-1-stefanha@redhat.com> References: <20190925174400.8578-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 25 Sep 2019 17:44:25 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Peter Maydell , Sergio Lopez , qemu-block@nongnu.org, "Michael S. Tsirkin" , Max Reitz , Stefan Hajnoczi Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" From: Sergio Lopez virtio_notify_config() needs to acquire the global mutex, which isn't allowed from an iothread, and may lead to a deadlock like this: - main thead * Has acquired: qemu_global_mutex. * Is trying the acquire: iothread AioContext lock via AIO_WAIT_WHILE (after aio_poll). - iothread * Has acquired: AioContext lock. * Is trying to acquire: qemu_global_mutex (via virtio_notify_config->prepare_mmio_access). If virtio_blk_resize() is called from an iothread, schedule virtio_notify_config() to be run in the main context BH. [Removed unnecessary newline as suggested by Kevin Wolf . --Stefan] Signed-off-by: Sergio Lopez Reviewed-by: Kevin Wolf Message-id: 20190916112411.21636-1-slp@redhat.com Message-Id: <20190916112411.21636-1-slp@redhat.com> Signed-off-by: Stefan Hajnoczi --- hw/block/virtio-blk.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 18851601cb..ed2ddebd2b 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -16,6 +16,7 @@ #include "qemu/iov.h" #include "qemu/module.h" #include "qemu/error-report.h" +#include "qemu/main-loop.h" #include "trace.h" #include "hw/block/block.h" #include "hw/qdev-properties.h" @@ -1086,11 +1087,24 @@ static int virtio_blk_load_device(VirtIODevice *vde= v, QEMUFile *f, return 0; } =20 +static void virtio_resize_cb(void *opaque) +{ + VirtIODevice *vdev =3D opaque; + + assert(qemu_get_current_aio_context() =3D=3D qemu_get_aio_context()); + virtio_notify_config(vdev); +} + static void virtio_blk_resize(void *opaque) { VirtIODevice *vdev =3D VIRTIO_DEVICE(opaque); =20 - virtio_notify_config(vdev); + /* + * virtio_notify_config() needs to acquire the global mutex, + * so it can't be called from an iothread. Instead, schedule + * it to be run in the main context BH. + */ + aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev= ); } =20 static const BlockDevOps virtio_block_ops =3D { --=20 2.21.0