From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=MsjYfNqb; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTPS id E2B6A5A0623 for ; Fri, 03 Apr 2026 10:02:09 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1775203328; 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; bh=NqmJ/VNs0Q1Yl05HoExDmimzdhum75L4/FH1f8pUrlc=; b=MsjYfNqbRr82f1qTl2P7WDlwTq+VuhWDi6a9bUht1SrXPs/6OJFNwZSZfhqYyohlsrrcJC /Dml3bcAw/iZr1U3HTlAD1APCzfjy48fuFW2Rs1LnMDIaUFNeAuieqEex3XaqOX2AxwRyU WwpD6PuIy1UtKXSznPDiwhEgleIoVP0= Received: from mx-prod-mc-01.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-690-loQGfGXAMpyN_3_WNqMDCg-1; Fri, 03 Apr 2026 04:02:07 -0400 X-MC-Unique: loQGfGXAMpyN_3_WNqMDCg-1 X-Mimecast-MFC-AGG-ID: loQGfGXAMpyN_3_WNqMDCg_1775203326 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (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-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7F321195608C for ; Fri, 3 Apr 2026 08:02:06 +0000 (UTC) Received: from lenovo-t14s.redhat.corp (headnet01.pony-001.prod.iad2.dc.redhat.com [10.2.32.101]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id B7D8B19560A6; Fri, 3 Apr 2026 08:02:05 +0000 (UTC) From: Laurent Vivier To: passt-dev@passt.top Subject: [PATCH 0/2] vhost-user, dhcp: Fix iPXE network boot over vhost-user Date: Fri, 3 Apr 2026 10:02:02 +0200 Message-ID: <20260403080204.2364581-1-lvivier@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 9Y8ropCYdH4raLOzChpIIw7Mqcpyz8PDvbS6OI8h2LM_1775203326 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-ID-Hash: QAA2AQR4ALJ5LFIZQTTASARMFFJSCI5R X-Message-ID-Hash: QAA2AQR4ALJ5LFIZQTTASARMFFJSCI5R X-MailFrom: lvivier@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Laurent Vivier X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: iPXE network boot over vhost-user was broken because passt unconditionally skipped TCP/UDP checksum computation, relying on VIRTIO_NET_HDR_F_DATA_VALID to tell the guest the checksums were valid. Linux guests happened to work because their virtio-net driver honours DATA_VALID regardless of feature negotiation, but iPXE verifies checksums strictly and never negotiates VIRTIO_NET_F_GUEST_CSUM. This series handles correctly VIRTIO_NET_F_GUEST_CSUM feature to fix that and adds a minimal --dhcp-boot option that populates the BOOTP/DHCP 'file' field, providing just enough for testing iPXE UDP and TCP support. This can be tested as following: - Create an ipxe file configuration cat > boot-alpine.ipxe <:8080/boot-alpine.ipxe --vhost-user - Start QEMU without boot disk but with passt as networking backend Based-on: 20260401215508.2149752-1-lvivier@redhat.com Laurent Vivier (2): vhost_user: Offer VIRTIO_NET_F_GUEST_CSUM dhcp: Add --dhcp-boot option to set boot filename in DHCP replies conf.c | 10 ++++++++++ dhcp.c | 5 ++++- passt.1 | 6 ++++++ passt.h | 1 + tcp_vu.c | 8 ++++++-- udp_vu.c | 7 ++++--- vhost_user.c | 1 + 7 files changed, 32 insertions(+), 6 deletions(-) -- 2.53.0