From mboxrd@z Thu Jan 1 00:00:00 1970 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 lists1p.gnu.org (lists1p.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 7D367C624D4 for ; Wed, 2 Sep 2026 19:21:55 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists1p.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1x1qWc-0004Lh-E6; Wed, 02 Sep 2026 15:21:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x1qWX-0004Kr-Bs for qemu-devel@nongnu.org; Wed, 02 Sep 2026 15:21:29 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1x1qWV-0002Az-R4 for qemu-devel@nongnu.org; Wed, 02 Sep 2026 15:21:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1788376887; 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=6ZSKL6HWR0rPEMkkB/ou9RK4eePiGyNILtJrIWNEFfo=; b=SjJa7ug0KIJ1mojy8XWAaS8oT6NfTkGXUNYOTQ4DvPWfcmfey/uZP/m73w4Shtlwprf9Hc G1eXeK0ENpELx6K5Pi2TdmRfBvgpuEMWe1hpvcVzVsFpt798c0IDfcrLungkYFwSTNwNFQ qT4Ls1Uu5m0SxFhafi3CLivJdbskTF0= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-642-okXES1p9PJWrsEI6hrI1yA-1; Wed, 02 Sep 2026 15:21:22 -0400 X-MC-Unique: okXES1p9PJWrsEI6hrI1yA-1 X-Mimecast-MFC-AGG-ID: okXES1p9PJWrsEI6hrI1yA_1788376881 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7CA0B19560A2; Wed, 2 Sep 2026 19:21:21 +0000 (UTC) Received: from corto.redhat.com (unknown [10.44.32.5]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 633E93000DA3; Wed, 2 Sep 2026 19:21:19 +0000 (UTC) From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= To: qemu-devel@nongnu.org Cc: Akihiko Odaki , Sriram Yagnaraman , Jason Wang , Alex Williamson , Peter Xu , =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Subject: [RFC PATCH v2 7/9] igb: Fix post-migration RX ring deadlock Date: Wed, 2 Sep 2026 21:20:52 +0200 Message-ID: <20260902192054.3329753-8-clg@redhat.com> In-Reply-To: <20260902192054.3329753-1-clg@redhat.com> References: <20260902192054.3329753-1-clg@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Received-SPF: pass client-ip=170.10.133.124; envelope-from=clg@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: 12 X-Spam_score: 1.2 X-Spam_bar: + X-Spam_report: (1.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_SBL_CSS=3.335, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development 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 After restoring VFRE/VFTE on the destination, the VF's RX rings may be stalled because the guest driver is waiting for an interrupt that was pending at the time of migration. Re-raise any pending EICR causes for the VF (both RX and TX) via igb_set_eics() to break the deadlock. AI-used-for: analysis, code (prototype) Signed-off-by: Cédric Le Goater --- hw/net/igb_core.h | 1 + hw/net/igb_core.c | 16 ++++++++++++++++ hw/net/igb_migration.c | 4 ++-- 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/hw/net/igb_core.h b/hw/net/igb_core.h index 7fdc41690b36..7d6f44b7ffe9 100644 --- a/hw/net/igb_core.h +++ b/hw/net/igb_core.h @@ -150,6 +150,7 @@ igb_start_recv(IGBCore *core); IGBCore *igb_pf_get_core(void *pf); void igb_core_vf_propagate_irqs(IGBCore *core, uint16_t vfn); +void igb_core_vf_rearm_irqs(IGBCore *core, uint16_t vfn); void igb_core_vf_propagate_ivar(IGBCore *core, uint16_t vfn); #endif diff --git a/hw/net/igb_core.c b/hw/net/igb_core.c index 12329a1aff58..1de8d95102e4 100644 --- a/hw/net/igb_core.c +++ b/hw/net/igb_core.c @@ -4632,3 +4632,19 @@ void igb_core_vf_propagate_ivar(IGBCore *core, uint16_t vfn) core->mac[IVAR0 + n / 4] &= ~mask; } } + +/* + * Re-apply VF interrupt enables to PF aggregates and raise the + * pending causes so the guest driver resumes polling after migration. + */ +void igb_core_vf_rearm_irqs(IGBCore *core, uint16_t vfn) +{ + uint32_t shift = 22 - vfn * IGBVF_MSIX_VEC_NUM; + uint32_t pvt_idx = PVTEICR0 + vfn * 0x40; + uint32_t causes = (core->mac[pvt_idx] & 0x7) << shift; + + igb_core_vf_propagate_irqs(core, vfn); + if (causes) { + igb_set_eics(core, EICS, causes); + } +} diff --git a/hw/net/igb_migration.c b/hw/net/igb_migration.c index 435bd0d1623b..46299ff77ab9 100644 --- a/hw/net/igb_migration.c +++ b/hw/net/igb_migration.c @@ -813,8 +813,8 @@ static void igb_core_vf_unquiesce(IgbVfState *s) trace_igbvf_mig_unquiesce(s->vfn, core->mac[VFRE], core->mac[VFTE]); - if (re) { - igb_start_recv(core); + if (re || te) { + igb_core_vf_rearm_irqs(core, s->vfn); } } -- 2.55.0