From patchwork Wed Sep 20 12:15:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 1837223 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RrHc64d5rz1yhR for ; Wed, 20 Sep 2023 22:17:58 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qiw7i-000234-Ox; Wed, 20 Sep 2023 08:16:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiw7e-0001wN-7J; Wed, 20 Sep 2023 08:16:04 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qiw7b-0005Ej-4m; Wed, 20 Sep 2023 08:16:01 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 88CC6239FA; Wed, 20 Sep 2023 15:16:13 +0300 (MSK) Received: from tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with SMTP id DD0BA296F1; Wed, 20 Sep 2023 15:15:53 +0300 (MSK) Received: (nullmailer pid 105874 invoked by uid 1000); Wed, 20 Sep 2023 12:15:53 -0000 From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Kevin Wolf , Stefan Hajnoczi , Michael Tokarev Subject: [Stable-7.2.6 52/63] virtio: Drop out of coroutine context in virtio_load() Date: Wed, 20 Sep 2023 15:15:37 +0300 Message-Id: <20230920121553.105832-1-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.2 In-Reply-To: References: MIME-Version: 1.0 Received-SPF: pass client-ip=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Kevin Wolf virtio_load() as a whole should run in coroutine context because it reads from the migration stream and we don't want this to block. However, it calls virtio_set_features_nocheck() and devices don't expect their .set_features callback to run in a coroutine and therefore call functions that may not be called in coroutine context. To fix this, drop out of coroutine context for calling virtio_set_features_nocheck(). Without this fix, the following crash was reported: #0 __pthread_kill_implementation (threadid=, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44 #1 0x00007efc738c05d3 in __pthread_kill_internal (signo=6, threadid=) at pthread_kill.c:78 #2 0x00007efc73873d26 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26 #3 0x00007efc738477f3 in __GI_abort () at abort.c:79 #4 0x00007efc7384771b in __assert_fail_base (fmt=0x7efc739dbcb8 "", assertion=assertion@entry=0x560aebfbf5cf "!qemu_in_coroutine()", file=file@entry=0x560aebfcd2d4 "../block/graph-lock.c", line=line@entry=275, function=function@entry=0x560aebfcd34d "void bdrv_graph_rdlock_main_loop(void)") at assert.c:92 #5 0x00007efc7386ccc6 in __assert_fail (assertion=0x560aebfbf5cf "!qemu_in_coroutine()", file=0x560aebfcd2d4 "../block/graph-lock.c", line=275, function=0x560aebfcd34d "void bdrv_graph_rdlock_main_loop(void)") at assert.c:101 #6 0x0000560aebcd8dd6 in bdrv_register_buf () #7 0x0000560aeb97ed97 in ram_block_added.llvm () #8 0x0000560aebb8303f in ram_block_add.llvm () #9 0x0000560aebb834fa in qemu_ram_alloc_internal.llvm () #10 0x0000560aebb2ac98 in vfio_region_mmap () #11 0x0000560aebb3ea0f in vfio_bars_register () #12 0x0000560aebb3c628 in vfio_realize () #13 0x0000560aeb90f0c2 in pci_qdev_realize () #14 0x0000560aebc40305 in device_set_realized () #15 0x0000560aebc48e07 in property_set_bool.llvm () #16 0x0000560aebc46582 in object_property_set () #17 0x0000560aebc4cd58 in object_property_set_qobject () #18 0x0000560aebc46ba7 in object_property_set_bool () #19 0x0000560aeb98b3ca in qdev_device_add_from_qdict () #20 0x0000560aebb1fbaf in virtio_net_set_features () #21 0x0000560aebb46b51 in virtio_set_features_nocheck () #22 0x0000560aebb47107 in virtio_load () #23 0x0000560aeb9ae7ce in vmstate_load_state () #24 0x0000560aeb9d2ee9 in qemu_loadvm_state_main () #25 0x0000560aeb9d45e1 in qemu_loadvm_state () #26 0x0000560aeb9bc32c in process_incoming_migration_co.llvm () #27 0x0000560aebeace56 in coroutine_trampoline.llvm () Cc: qemu-stable@nongnu.org Buglink: https://issues.redhat.com/browse/RHEL-832 Signed-off-by: Kevin Wolf Message-ID: <20230905145002.46391-3-kwolf@redhat.com> Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf (cherry picked from commit 92e2e6a867334a990f8d29f07ca34e3162fdd6ec) Signed-off-by: Michael Tokarev (Mjt: remove coroutine_mixed_fn markings introduced in v7.2.0-909-g0f3de970fe) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 384c8f0f08..b7da7f074d 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -3451,6 +3451,39 @@ static int virtio_set_features_nocheck(VirtIODevice *vdev, uint64_t val) return bad ? -1 : 0; } +typedef struct VirtioSetFeaturesNocheckData { + Coroutine *co; + VirtIODevice *vdev; + uint64_t val; + int ret; +} VirtioSetFeaturesNocheckData; + +static void virtio_set_features_nocheck_bh(void *opaque) +{ + VirtioSetFeaturesNocheckData *data = opaque; + + data->ret = virtio_set_features_nocheck(data->vdev, data->val); + aio_co_wake(data->co); +} + +static int +virtio_set_features_nocheck_maybe_co(VirtIODevice *vdev, uint64_t val) +{ + if (qemu_in_coroutine()) { + VirtioSetFeaturesNocheckData data = { + .co = qemu_coroutine_self(), + .vdev = vdev, + .val = val, + }; + aio_bh_schedule_oneshot(qemu_get_current_aio_context(), + virtio_set_features_nocheck_bh, &data); + qemu_coroutine_yield(); + return data.ret; + } else { + return virtio_set_features_nocheck(vdev, val); + } +} + int virtio_set_features(VirtIODevice *vdev, uint64_t val) { int ret; @@ -3621,14 +3654,14 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) * host_features. */ uint64_t features64 = vdev->guest_features; - if (virtio_set_features_nocheck(vdev, features64) < 0) { + if (virtio_set_features_nocheck_maybe_co(vdev, features64) < 0) { error_report("Features 0x%" PRIx64 " unsupported. " "Allowed features: 0x%" PRIx64, features64, vdev->host_features); return -1; } } else { - if (virtio_set_features_nocheck(vdev, features) < 0) { + if (virtio_set_features_nocheck_maybe_co(vdev, features) < 0) { error_report("Features 0x%x unsupported. " "Allowed features: 0x%" PRIx64, features, vdev->host_features);