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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1642FC433F5 for ; Mon, 30 May 2022 02:16:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232220AbiE3CQg (ORCPT ); Sun, 29 May 2022 22:16:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55226 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229960AbiE3CQd (ORCPT ); Sun, 29 May 2022 22:16:33 -0400 Received: from ssh248.corpemail.net (ssh248.corpemail.net [210.51.61.248]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C37BB5DE5A for ; Sun, 29 May 2022 19:16:29 -0700 (PDT) Received: from ([60.208.111.195]) by ssh248.corpemail.net ((D)) with ASMTP (SSL) id YXU00120; Mon, 30 May 2022 10:16:20 +0800 Received: from jtjnmail201625.home.langchao.com (10.100.2.35) by jtjnmail201623.home.langchao.com (10.100.2.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.27; Mon, 30 May 2022 10:16:21 +0800 Received: from jtjnmail201622.home.langchao.com (10.100.2.22) by jtjnmail201625.home.langchao.com (10.100.2.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.27; Mon, 30 May 2022 10:16:20 +0800 Received: from jtjnmail201622.home.langchao.com ([fe80::15c3:8d74:3aa6:25f6]) by jtjnmail201622.home.langchao.com ([fe80::15c3:8d74:3aa6:25f6%7]) with mapi id 15.01.2308.027; Mon, 30 May 2022 10:16:20 +0800 From: =?utf-8?B?Qm8gTGl1ICjliJjms6IpLea1qua9ruS/oeaBrw==?= To: "mst@redhat.com" CC: "david@redhat.com" , "jasowang@redhat.com" , "virtualization@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] virtio_balloon: check virtqueue_add_outbuf() return value Thread-Topic: [PATCH] virtio_balloon: check virtqueue_add_outbuf() return value Thread-Index: Adhzyz2fsD+wPQmJQcewGCBYifyKJQ== Date: Mon, 30 May 2022 02:16:20 +0000 Message-ID: <7a413652a9a9469f948fbfa2eae5c401@inspur.com> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: yes X-MS-TNEF-Correlator: x-originating-ip: [10.200.104.97] Content-Type: multipart/signed; protocol="application/x-pkcs7-signature"; micalg=SHA1; boundary="----=_NextPart_000_0007_01D8740E.4E0193C0" MIME-Version: 1.0 tUid: 202253010162063bd8be69aac7875a5a91817b3525f29 X-Abuse-Reports-To: service@corp-email.com Abuse-Reports-To: service@corp-email.com X-Complaints-To: service@corp-email.com X-Report-Abuse-To: service@corp-email.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ------=_NextPart_000_0007_01D8740E.4E0193C0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Adding this patch can avoid unnecessary VM exits and reduce the number = of VM exits -----=E9=82=AE=E4=BB=B6=E5=8E=9F=E4=BB=B6----- =E5=8F=91=E4=BB=B6=E4=BA=BA: Michael S. Tsirkin =20 =E5=8F=91=E9=80=81=E6=97=B6=E9=97=B4: 2022=E5=B9=B45=E6=9C=8827=E6=97=A5 = 18:58 =E6=94=B6=E4=BB=B6=E4=BA=BA: Bo Liu = (=E5=88=98=E6=B3=A2)-=E6=B5=AA=E6=BD=AE=E4=BF=A1=E6=81=AF = =E6=8A=84=E9=80=81: david@redhat.com; jasowang@redhat.com; = virtualization@lists.linux-foundation.org; linux-kernel@vger.kernel.org =E4=B8=BB=E9=A2=98: Re: [PATCH] virtio_balloon: check = virtqueue_add_outbuf() return value On Fri, May 27, 2022 at 10:43:30AM +0000, Bo Liu = (=E5=88=98=E6=B3=A2)-=E6=B5=AA=E6=BD=AE=E4=BF=A1=E6=81=AF wrote: > The purpose of this patch is, virtqueue_add_outbuf() adding data to=20 > virtqueue may succeed or fail. If successful, it will call=20 > virtqueue_kick() to notifie the host backend driver, but if the=20 > virtqueue_add_outbuf() fails, the data is not successfully added to=20 > the virtqueue, and the host back-end driver does not need to be = notified for processing. >=20 > Thanks. Why is it a problem if we do? -- MST ------=_NextPart_000_0007_01D8740E.4E0193C0 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIK8DCCA6Iw ggKKoAMCAQICEGPKUixTOHaaTcIS5DrQVuowDQYJKoZIhvcNAQELBQAwWTETMBEGCgmSJomT8ixk ARkWA2NvbTEYMBYGCgmSJomT8ixkARkWCGxhbmdjaGFvMRQwEgYKCZImiZPyLGQBGRYEaG9tZTES MBAGA1UEAxMJSU5TUFVSLUNBMB4XDTE3MDEwOTA5MjgzMFoXDTI3MDEwOTA5MzgyOVowWTETMBEG CgmSJomT8ixkARkWA2NvbTEYMBYGCgmSJomT8ixkARkWCGxhbmdjaGFvMRQwEgYKCZImiZPyLGQB GRYEaG9tZTESMBAGA1UEAxMJSU5TUFVSLUNBMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKC AQEAq+Q17xtjJLyp5hgXDie1r4DeNj76VUvbZNSywWU5zhx+e0Lu0kwcZ0T3KncZdgdWyqYvRJMQ /VVqX3gS4VxtLw3zBrg9kGuD0LfpH0cA2b0ZHpxRh5WapP14flcSh/lnawig29z44wfUEg43yTZO lOfPKos/Dm6wyrJtaPmD6AF7w4+vFZH0zMYfjQkSN/xGgS3OPBNAB8PTHM2sV+fFmnnlTFpyRg0O IIA2foALZvjIjNdUfp8kMGSh/ZVMfHqTH4eo+FcZPZ+t9nTaJQz9cSylw36+Ig6FGZHA/Zq+0fYy 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