From nobody Fri Dec 19 22:05:03 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1747403646138775.8681022962464; Fri, 16 May 2025 06:54:06 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uFvV5-0005Vf-Ts; Fri, 16 May 2025 09:53:24 -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 1uFvV3-0005TJ-Rx for qemu-devel@nongnu.org; Fri, 16 May 2025 09:53:21 -0400 Received: from vps-ovh.mhejs.net ([145.239.82.108]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uFvV1-000182-Vy for qemu-devel@nongnu.org; Fri, 16 May 2025 09:53:21 -0400 Received: from MUA by vps-ovh.mhejs.net with esmtpsa (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.98.1) (envelope-from ) id 1uFvUr-00000003pkd-0PbA; Fri, 16 May 2025 15:53:09 +0200 From: "Maciej S. Szmigiero" To: Peter Xu , Fabiano Rosas Cc: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= , Joao Martins , Elena Ufimtseva , qemu-devel@nongnu.org Subject: [PATCH] migration/multifd: Don't send device state packets with zerocopy flag Date: Fri, 16 May 2025 15:53:03 +0200 Message-ID: <3bd5f48578e29f3a78f41b1e4fbea3d4b2d9b136.1747403393.git.maciej.szmigiero@oracle.com> X-Mailer: git-send-email 2.49.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.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; Received-SPF: pass client-ip=145.239.82.108; envelope-from=mhej@vps-ovh.mhejs.net; helo=vps-ovh.mhejs.net X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1747403648840116600 Content-Type: text/plain; charset="utf-8" From: "Maciej S. Szmigiero" If zerocopy is enabled for multifd then QIO_CHANNEL_WRITE_FLAG_ZERO_COPY flag is forced into all multifd channel write calls via p->write_flags that was setup in multifd_nocomp_send_setup(). However, device state packets aren't compatible with zerocopy - the data buffer isn't getting kept pinned until multifd channel flush. Make sure to mask that QIO_CHANNEL_WRITE_FLAG_ZERO_COPY flag in a multifd send thread if the data being sent is device state. Fixes: 0525b91a0b99 ("migration/multifd: Device state transfer support - se= nd side") Signed-off-by: Maciej S. Szmigiero Reviewed-by: Fabiano Rosas --- migration/multifd.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/migration/multifd.c b/migration/multifd.c index ec108af6245a..843c7740a4ec 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -690,6 +690,7 @@ static void *multifd_send_thread(void *opaque) if (qatomic_load_acquire(&p->pending_job)) { bool is_device_state =3D multifd_payload_device_state(p->data); size_t total_size; + int write_flags_masked =3D 0; =20 p->flags =3D 0; p->iovs_num =3D 0; @@ -697,6 +698,9 @@ static void *multifd_send_thread(void *opaque) =20 if (is_device_state) { multifd_device_state_send_prepare(p); + + /* Device state packets cannot be sent via zerocopy */ + write_flags_masked |=3D QIO_CHANNEL_WRITE_FLAG_ZERO_COPY; } else { ret =3D multifd_send_state->ops->send_prepare(p, &local_er= r); if (ret !=3D 0) { @@ -718,7 +722,8 @@ static void *multifd_send_thread(void *opaque) &p->data->u.ram, &local_err); } else { ret =3D qio_channel_writev_full_all(p->c, p->iov, p->iovs_= num, - NULL, 0, p->write_flags, + NULL, 0, + p->write_flags & ~write_= flags_masked, &local_err); }