From patchwork Sun Nov 19 20:49:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arseniy Krasnov X-Patchwork-Id: 13460691 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=salutedevices.com header.i=@salutedevices.com header.b="HVcrHT2g" Received: from mx1.sberdevices.ru (mx1.sberdevices.ru [37.18.73.165]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 049E7115; Sun, 19 Nov 2023 12:57:20 -0800 (PST) Received: from p-infra-ksmg-sc-msk01 (localhost [127.0.0.1]) by mx1.sberdevices.ru (Postfix) with ESMTP id EF9D5100008; Sun, 19 Nov 2023 23:57:17 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.sberdevices.ru EF9D5100008 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=salutedevices.com; s=mail; t=1700427437; bh=mRb/bYfuuaUieEXvIZ5BkaqWVB+4bPPbZGGcwyRzJOc=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type:From; b=HVcrHT2gVzVJiiVTc6DH3IbTrt1Y7+FlUWupXjLDiuqyz+FiUejLQ0COx0mm62CmK OuUccqjSQ5hsraEiuxfWus3TQH14C7yD+0ORimzFfaulcqeaUlA4kDB2vLiltBphBG uVSTYCKXmQB64X0SjmEMUIEFss0tgD47N+HlmbWsg3oikHbUxIkNy8jlZXO2HK2wMg ym1u76Lt4ewjtrEwKVXmsSI0P463s+fzSPpg7z27BRmpPMcwsMKYQPP6tvX9rwpvnn TfgYMXvJID/PleHLpVmoJCItEi/oKXS9fywAVMiHLixuT63XDFcONT4PoZPW2N2izc XaqBh4r9aVhfg== Received: from p-i-exch-sc-m01.sberdevices.ru (p-i-exch-sc-m01.sberdevices.ru [172.16.192.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.sberdevices.ru (Postfix) with ESMTPS; Sun, 19 Nov 2023 23:57:17 +0300 (MSK) Received: from localhost.localdomain (100.64.160.123) by p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Sun, 19 Nov 2023 23:57:17 +0300 From: Arseniy Krasnov To: Stefan Hajnoczi , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Jason Wang , Bobby Eshleman CC: , , , , , , Subject: [RFC PATCH v2 0/3] send credit update during setting SO_RCVLOWAT Date: Sun, 19 Nov 2023 23:49:19 +0300 Message-ID: <20231119204922.2251912-1-avkrasnov@salutedevices.com> X-Mailer: git-send-email 2.35.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Originating-IP: [100.64.160.123] X-ClientProxiedBy: p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) To p-i-exch-sc-m01.sberdevices.ru (172.16.192.107) X-KSMG-Rule-ID: 10 X-KSMG-Message-Action: clean X-KSMG-AntiSpam-Lua-Profiles: 181465 [Nov 19 2023] X-KSMG-AntiSpam-Version: 6.0.0.2 X-KSMG-AntiSpam-Envelope-From: avkrasnov@salutedevices.com X-KSMG-AntiSpam-Rate: 0 X-KSMG-AntiSpam-Status: not_detected X-KSMG-AntiSpam-Method: none X-KSMG-AntiSpam-Auth: dkim=none X-KSMG-AntiSpam-Info: LuaCore: 543 543 1e3516af5cdd92079dfeb0e292c8747a62cb1ee4, {Tracking_uf_ne_domains}, {Tracking_from_domain_doesnt_match_to}, git.kernel.org:7.1.1;salutedevices.com:7.1.1;p-i-exch-sc-m01.sberdevices.ru:7.1.1,5.0.1;127.0.0.199:7.1.2;lore.kernel.org:7.1.1;d41d8cd98f00b204e9800998ecf8427e.com:7.1.1;100.64.160.123:7.1.2, FromAlignment: s, ApMailHostAddress: 100.64.160.123 X-MS-Exchange-Organization-SCL: -1 X-KSMG-AntiSpam-Interceptor-Info: scan successful X-KSMG-AntiPhishing: Clean, bases: 2023/11/19 19:47:00 X-KSMG-LinksScanning: Clean, bases: 2023/11/19 19:47:00 X-KSMG-AntiVirus: Kaspersky Secure Mail Gateway, version 2.0.1.6960, bases: 2023/11/19 19:33:00 #22482963 X-KSMG-AntiVirus-Status: Clean, skipped X-Patchwork-State: RFC Hello, DESCRIPTION This patchset fixes old problem with hungup of both rx/tx sides and adds test for it. This happens due to non-default SO_RCVLOWAT value and deferred credit update in virtio/vsock. Link to previous old patchset: https://lore.kernel.org/netdev/39b2e9fd-601b-189d-39a9-914e5574524c@sberdevices.ru/ Here is what happens step by step: TEST INITIAL CONDITIONS 1) Vsock buffer size is 128KB. 2) Maximum packet size is also 64KB as defined in header (yes it is hardcoded, just to remind about that value). 3) SO_RCVLOWAT is default, e.g. 1 byte. STEPS SENDER RECEIVER 1) sends 128KB + 1 byte in a single buffer. 128KB will be sent, but for 1 byte sender will wait for free space at peer. Sender goes to sleep. 2) reads 64KB, credit update not sent 3) sets SO_RCVLOWAT to 64KB + 1 4) poll() -> wait forever, there is only 64KB available to read. So in step 4) receiver also goes to sleep, waiting for enough data or connection shutdown message from the sender. Idea to fix it is that rx kicks tx side to continue transmission (and may be close connection) when rx changes number of bytes to be woken up (e.g. SO_RCVLOWAT) and this value is bigger than number of available bytes to read. I've added small test for this, but not sure as it uses hardcoded value for maximum packet length, this value is defined in kernel header and used to control deferred credit update. And as this is not available to userspace, I can't control test parameters correctly (if one day this define will be changed - test may become useless). Head for this patchset is: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/?id=18de1e517ed37ebaf33e771e46faf052e966e163 Link to v1: https://lore.kernel.org/netdev/20231108072004.1045669-1-avkrasnov@salutedevices.com/ Changelog: * Patchset rebased and tested on new HEAD of net-next (see hash above). * New patch is added as 0001 - it removes return from SO_RCVLOWAT set callback in 'af_vsock.c' when transport callback is set - with that we can set 'sk_rcvlowat' only once in 'af_vsock.c' and in future do not copy-paste it to every transport. It was discussed in v1. * See per-patch changelog after ---. Arseniy Krasnov (3): vsock: update SO_RCVLOWAT setting callback virtio/vsock: send credit update during setting SO_RCVLOWAT vsock/test: SO_RCVLOWAT + deferred credit update test drivers/vhost/vsock.c | 2 + include/linux/virtio_vsock.h | 1 + net/vmw_vsock/af_vsock.c | 9 +- net/vmw_vsock/virtio_transport.c | 2 + net/vmw_vsock/virtio_transport_common.c | 28 +++++ net/vmw_vsock/vsock_loopback.c | 2 + tools/testing/vsock/vsock_test.c | 136 ++++++++++++++++++++++++ 7 files changed, 178 insertions(+), 2 deletions(-)