From patchwork Sat Mar 15 07:42:36 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Michael Tokarev X-Patchwork-Id: 14017826 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 081EFC28B2F for ; Sat, 15 Mar 2025 07:50:02 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ttMDV-0001FO-7G; Sat, 15 Mar 2025 03:45:57 -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 1ttMDD-00006A-W4; Sat, 15 Mar 2025 03:45:41 -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 1ttMDC-0005K6-4e; Sat, 15 Mar 2025 03:45:39 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 138B9FFB16; Sat, 15 Mar 2025 10:41:56 +0300 (MSK) Received: from gandalf.tls.msk.ru (mjt.wg.tls.msk.ru [192.168.177.130]) by tsrv.corpit.ru (Postfix) with ESMTP id 01CAE1CACE0; Sat, 15 Mar 2025 10:42:50 +0300 (MSK) Received: by gandalf.tls.msk.ru (Postfix, from userid 1000) id A999B55A18; Sat, 15 Mar 2025 10:42:49 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, =?utf-8?q?Eugenio_P=C3=A9rez?= , Lei Yang , Jonah Palmer , Jason Wang , Michael Tokarev Subject: [Stable-8.2.10 34/42] net: move backend cleanup to NIC cleanup Date: Sat, 15 Mar 2025 10:42:36 +0300 Message-Id: <20250315074249.634718-34-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 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, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org From: Eugenio Pérez Commit a0d7215e33 ("vhost-vdpa: do not cleanup the vdpa/vhost-net structures if peer nic is present") effectively delayed the backend cleanup, allowing the frontend or the guest to access it resources as long as the frontend is still visible to the guest. However it does not clean up the resources until the qemu process is over. This causes an effective leak if the device is deleted with device_del, as there is no way to close the vdpa device. This makes impossible to re-add that device to this or other QEMU instances until the first instance of QEMU is finished. Move the cleanup from qemu_cleanup to the NIC deletion and to net_cleanup. Fixes: a0d7215e33 ("vhost-vdpa: do not cleanup the vdpa/vhost-net structures if peer nic is present") Reported-by: Lei Yang Signed-off-by: Eugenio Pérez Signed-off-by: Jonah Palmer Signed-off-by: Jason Wang (cherry picked from commit e7891c575fb294618b172119a91c892b8f4384a2) Signed-off-by: Michael Tokarev diff --git a/net/net.c b/net/net.c index 11e19d3bed..40d6a5ca2d 100644 --- a/net/net.c +++ b/net/net.c @@ -422,7 +422,13 @@ void qemu_del_net_client(NetClientState *nc) object_unparent(OBJECT(nf)); } - /* If there is a peer NIC, delete and cleanup client, but do not free. */ + /* + * If there is a peer NIC, transfer ownership to it. Delete the client + * from net_client list but do not cleanup nor free. This way NIC can + * still access to members of the backend. + * + * The cleanup and free will be done when the NIC is free. + */ if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) { NICState *nic = qemu_get_nic(nc->peer); if (nic->peer_deleted) { @@ -432,16 +438,13 @@ void qemu_del_net_client(NetClientState *nc) for (i = 0; i < queues; i++) { ncs[i]->peer->link_down = true; + QTAILQ_REMOVE(&net_clients, ncs[i], next); } if (nc->peer->info->link_status_changed) { nc->peer->info->link_status_changed(nc->peer); } - for (i = 0; i < queues; i++) { - qemu_cleanup_net_client(ncs[i], true); - } - return; } @@ -459,8 +462,12 @@ void qemu_del_nic(NICState *nic) for (i = 0; i < queues; i++) { NetClientState *nc = qemu_get_subqueue(nic, i); - /* If this is a peer NIC and peer has already been deleted, free it now. */ + /* + * If this is a peer NIC and peer has already been deleted, clean it up + * and free it now. + */ if (nic->peer_deleted) { + qemu_cleanup_net_client(nc->peer, false); qemu_free_net_client(nc->peer); } else if (nc->peer) { /* if there are RX packets pending, complete them */ @@ -1536,6 +1543,9 @@ void net_cleanup(void) * of the latest NET_CLIENT_DRIVER_NIC, and operate on *p as we walk * the list. * + * However, the NIC may have peers that trust to be clean beyond this + * point. For example, if they have been removed with device_del. + * * The 'nc' variable isn't part of the list traversal; it's purely * for convenience as too much '(*p)->' has a tendency to make the * readers' eyes bleed. @@ -1543,6 +1553,17 @@ void net_cleanup(void) while (*p) { nc = *p; if (nc->info->type == NET_CLIENT_DRIVER_NIC) { + NICState *nic = qemu_get_nic(nc); + + if (nic->peer_deleted) { + int queues = MAX(nic->conf->peers.queues, 1); + + for (int i = 0; i < queues; i++) { + nc = qemu_get_subqueue(nic, i); + qemu_cleanup_net_client(nc->peer, false); + } + } + /* Skip NET_CLIENT_DRIVER_NIC entries */ p = &QTAILQ_NEXT(nc, next); } else { diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c index d0614d7954..94b68063e4 100644 --- a/net/vhost-vdpa.c +++ b/net/vhost-vdpa.c @@ -221,14 +221,6 @@ static void vhost_vdpa_cleanup(NetClientState *nc) { VhostVDPAState *s = DO_UPCAST(VhostVDPAState, nc, nc); - /* - * If a peer NIC is attached, do not cleanup anything. - * Cleanup will happen as a part of qemu_cleanup() -> net_cleanup() - * when the guest is shutting down. - */ - if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_NIC) { - return; - } munmap(s->cvq_cmd_out_buffer, vhost_vdpa_net_cvq_cmd_page_len()); munmap(s->status, vhost_vdpa_net_cvq_cmd_page_len()); if (s->vhost_net) {