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 X-Spam-Level: X-Spam-Status: No, score=-12.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D97DC433E0 for ; Sat, 6 Mar 2021 16:18:47 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E3F2764FCF for ; Sat, 6 Mar 2021 16:18:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E3F2764FCF Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.94311.177803 (Exim 4.92) (envelope-from ) id 1lIZdN-00028H-Uv; Sat, 06 Mar 2021 16:18:29 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 94311.177803; Sat, 06 Mar 2021 16:18:29 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lIZdN-00028A-RK; Sat, 06 Mar 2021 16:18:29 +0000 Received: by outflank-mailman (input) for mailman id 94311; Sat, 06 Mar 2021 16:18:28 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lIZdM-000285-6e for xen-devel@lists.xenproject.org; Sat, 06 Mar 2021 16:18:28 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 43495617-6245-49a2-9c48-a163c2a7a1b3; Sat, 06 Mar 2021 16:18:26 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 0F0B2ACBF; Sat, 6 Mar 2021 16:18:26 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 43495617-6245-49a2-9c48-a163c2a7a1b3 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1615047506; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=nukSOwxYWB0nbFvij2/Dm4omz/vg/Y2S787KBEpkjPQ=; b=ikq+lyIUCyWydGZBrbc/5vetOXvA7c9Q6hQJW0KBEmRC9tFWwX0wFFanEWxAZbeoDsxu74 J7hdq2bBlhniAgRF14O9XCLXvRIk9ujSdaYEc1+JSKoGpc1pQ4YIfgug7gB2edU3FkEwzy nsuGkx/XECs/lscQfYjAWefZvBz6Qe0= Subject: Re: [PATCH v3 2/8] xen/events: don't unmask an event channel when an eoi is pending To: Ross Lagerwall , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Boris Ostrovsky , Stefano Stabellini , stable@vger.kernel.org, Julien Grall References: <20210219154030.10892-1-jgross@suse.com> <20210219154030.10892-3-jgross@suse.com> From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= Message-ID: <134540c1-40ac-3607-6ca0-3dcd5f83a013@suse.com> Date: Sat, 6 Mar 2021 17:18:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="kTuR8myBCAf9zSbzIMWx6GIuaVMSZMcto" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --kTuR8myBCAf9zSbzIMWx6GIuaVMSZMcto Content-Type: multipart/mixed; boundary="tI9qAvQfSWeoIIbUUygUcu92S5FGuW44I"; protected-headers="v1" From: =?UTF-8?B?SsO8cmdlbiBHcm/Dnw==?= To: Ross Lagerwall , xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org Cc: Boris Ostrovsky , Stefano Stabellini , stable@vger.kernel.org, Julien Grall Message-ID: <134540c1-40ac-3607-6ca0-3dcd5f83a013@suse.com> Subject: Re: [PATCH v3 2/8] xen/events: don't unmask an event channel when an eoi is pending References: <20210219154030.10892-1-jgross@suse.com> <20210219154030.10892-3-jgross@suse.com> In-Reply-To: --tI9qAvQfSWeoIIbUUygUcu92S5FGuW44I Content-Type: multipart/mixed; boundary="------------93BA1965D22E272FDC5B4750" Content-Language: en-US This is a multi-part message in MIME format. --------------93BA1965D22E272FDC5B4750 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable On 23.02.21 10:26, Ross Lagerwall wrote: > On 2021-02-19 15:40, Juergen Gross wrote: >> An event channel should be kept masked when an eoi is pending for it. >> When being migrated to another cpu it might be unmasked, though. >> >> In order to avoid this keep three different flags for each event chann= el >> to be able to distinguish "normal" masking/unmasking from eoi related >> masking/unmasking and temporary masking. The event channel should only= >> be able to generate an interrupt if all flags are cleared. >> >> Cc: stable@vger.kernel.org >> Fixes: 54c9de89895e0a36047 ("xen/events: add a new late EOI evtchn fra= mework") >> Reported-by: Julien Grall >> Signed-off-by: Juergen Gross >=20 > I tested this patch series backported to a 4.19 kernel and found that > when doing a reboot loop of Windows with PV drivers, occasionally it wi= ll > end up in a state with some event channels pending and masked in dom0 > which breaks networking in the guest. >=20 > The issue seems to have been introduced with this patch, though at firs= t > glance it appears correct. I haven't yet looked into why it is happenin= g. > Have you seen anything like this with this patch? I have found the issue. lateeoi_mask_ack_dynirq() must not set the "eoi" mask reason flag, as this callback will be called when the handler will not be called later, so there will never be a call of xen_irq_lateeoi() to unmask the event channel again. Juergen --------------93BA1965D22E272FDC5B4750 Content-Type: application/pgp-keys; name="OpenPGP_0xB0DE9DD628BF132F.asc" Content-Transfer-Encoding: quoted-printable Content-Disposition: attachment; filename="OpenPGP_0xB0DE9DD628BF132F.asc" -----BEGIN PGP PUBLIC KEY BLOCK----- xsBNBFOMcBYBCACgGjqjoGvbEouQZw/ToiBg9W98AlM2QHV+iNHsEs7kxWhKMjrioyspZKOBy= cWx w3ie3j9uvg9EOB3aN4xiTv4qbnGiTr3oJhkB1gsb6ToJQZ8uxGq2kaV2KL9650I1SJvedYm8O= f8Z d621lSmoKOwlNClALZNew72NjJLEzTalU1OdT7/i1TXkH09XSSI8mEQ/ouNcMvIJNwQpd369y= 9bf IhWUiVXEK7MlRgUG6MvIj6Y3Am/BBLUVbDa4+gmzDC9ezlZkTZG2t14zWPvxXP3FAp2pkW0xq= G7/ 377qptDmrk42GlSKN4z76ELnLxussxc7I2hx18NUcbP8+uty4bMxABEBAAHNHEp1ZXJnZW4gR= 3Jv c3MgPGpnQHBmdXBmLm5ldD7CwHkEEwECACMFAlOMcBYCGwMHCwkIBwMCAQYVCAIJCgsEFgIDA= QIe AQIXgAAKCRCw3p3WKL8TL0KdB/93FcIZ3GCNwFU0u3EjNbNjmXBKDY4FUGNQH2lvWAUy+dnyT= hpw dtF/jQ6j9RwE8VP0+NXcYpGJDWlNb9/JmYqLiX2Q3TyevpB0CA3dbBQp0OW0fgCetToGIQrg0= MbD 1C/sEOv8Mr4NAfbauXjZlvTj30H2jO0u+6WGM6nHwbh2l5O8ZiHkH32iaSTfN7Eu5RnNVUJbv= oPH Z8SlM4KWm8rG+lIkGurqqu5gu8q8ZMKdsdGC4bBxdQKDKHEFExLJK/nRPFmAuGlId1E3fe10v= 5QL +qHI3EIPtyfE7i9Hz6rVwi7lWKgh7pe0ZvatAudZ+JNIlBKptb64FaiIOAWDCx1SzR9KdWVyZ= 2Vu IEdyb3NzIDxqZ3Jvc3NAc3VzZS5jb20+wsB5BBMBAgAjBQJTjHCvAhsDBwsJCAcDAgEGFQgCC= QoL BBYCAwECHgECF4AACgkQsN6d1ii/Ey/HmQf/RtI7kv5A2PS4RF7HoZhPVPogNVbC4YA6lW7Dr= Wf0 teC0RR3MzXfy6pJ+7KLgkqMlrAbN/8Dvjoz78X+5vhH/rDLa9BuZQlhFmvcGtCF8eR0T1v0nC= /nu AFVGy+67q2DH8As3KPu0344TBDpAvr2uYM4tSqxK4DURx5INz4ZZ0WNFHcqsfvlGJALDeE0Lh= ITT d9jLzdDad1pQSToCnLl6SBJZjDOX9QQcyUigZFtCXFst4dlsvddrxyqT1f17+2cFSdu7+ynLm= XBK 7abQ3rwJY8SbRO2iRulogc5vr/RLMMlscDAiDkaFQWLoqHHOdfO9rURssHNN8WkMnQfvUewRz= 80h SnVlcmdlbiBHcm9zcyA8amdyb3NzQG5vdmVsbC5jb20+wsB5BBMBAgAjBQJTjHDXAhsDBwsJC= AcD AgEGFQgCCQoLBBYCAwECHgECF4AACgkQsN6d1ii/Ey8PUQf/ehmgCI9jB9hlgexLvgOtf7PJn= FOX gMLdBQgBlVPO3/D9R8LtF9DBAFPNhlrsfIG/SqICoRCqUcJ96Pn3P7UUinFG/I0ECGF4EvTE1= jnD kfJZr6jrbjgyoZHiw/4BNwSTL9rWASyLgqlA8u1mf+c2yUwcGhgkRAd1gOwungxcwzwqgljf0= N51 N5JfVRHRtyfwq/ge+YEkDGcTU6Y0sPOuj4Dyfm8fJzdfHNQsWq3PnczLVELStJNdapwPOoE+l= otu fe3AM2vAEYJ9rTz3Cki4JFUsgLkHFqGZarrPGi1eyQcXeluldO3m91NK/1xMI3/+8jbO0tsn1= tqS EUGIJi7ox80eSnVlcmdlbiBHcm9zcyA8amdyb3NzQHN1c2UuZGU+wsB5BBMBAgAjBQJTjHDrA= hsD BwsJCAcDAgEGFQgCCQoLBBYCAwECHgECF4AACgkQsN6d1ii/Ey+LhQf9GL45eU5vOowA2u5N3= g3O ZUEBmDHVVbqMtzwlmNC4k9Kx39r5s2vcFl4tXqW7g9/ViXYuiDXb0RfUpZiIUW89siKrkzmQ5= dM7 wRqzgJpJwK8Bn2MIxAKArekWpiCKvBOB/Cc+3EXE78XdlxLyOi/NrmSGRIov0karw2RzMNOu5= D+j LRZQd1Sv27AR+IP3I8U4aqnhLpwhK7MEy9oCILlgZ1QZe49kpcumcZKORmzBTNh30FVKK1Evm= V2x AKDoaEOgQB4iFQLhJCdP1I5aSgM5IVFdn7v5YgEYuJYx37IoN1EblHI//x/e2AaIHpzK5h88N= Eaw QsaNRpNSrcfbFmAg987ATQRTjHAWAQgAyzH6AOODMBjgfWE9VeCgsrwH3exNAU32gLq2xvjpW= nHI s98ndPUDpnoxWQugJ6MpMncr0xSwFmHEgnSEjK/PAjppgmyc57BwKII3sV4on+gDVFJR6Y8ZR= wgn BC5mVM6JjQ5xDk8WRXljExRfUX9pNhdE5eBOZJrDRoLUmmjDtKzWaDhIg/+1Hzz93X4fCQkNV= bVF LELU9bMaLPBG/x5q4iYZ2k2ex6d47YE1ZFdMm6YBYMOljGkZKwYde5ldM9mo45mmwe0icXKLk= pEd IXKTZeKDO+Hdv1aqFuAcccTg9RXDQjmwhC3yEmrmcfl0+rPghO0Iv3OOImwTEe4co3c1mwARA= QAB wsBfBBgBAgAJBQJTjHAWAhsMAAoJELDendYovxMvQ/gH/1ha96vm4P/L+bQpJwrZ/dneZcmEw= Tbe 8YFsw2V/Buv6Z4Mysln3nQK5ZadD534CF7TDVft7fC4tU4PONxF5D+/tvgkPfDAfF77zy2AH1= vJz Q1fOU8lYFpZXTXIHb+559UqvIB8AdgR3SAJGHHt4RKA0F7f5ipYBBrC6cyXJyyoprT10EMvU8= VGi wXvTyJz3fjoYsdFzpWPlJEBRMedCot60g5dmbdrZ5DWClAr0yau47zpWj3enf1tLWaqcsuylW= svi uGjKGw7KHQd3bxALOknAp4dN3QwBYCKuZ7AddY9yjynVaD5X7nF9nO5BjR/i1DG86lem3iBDX= zXs ZDn8R38=3D =3D2wuH -----END PGP PUBLIC KEY BLOCK----- --------------93BA1965D22E272FDC5B4750-- --tI9qAvQfSWeoIIbUUygUcu92S5FGuW44I-- --kTuR8myBCAf9zSbzIMWx6GIuaVMSZMcto Content-Type: application/pgp-signature; name="OpenPGP_signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="OpenPGP_signature" -----BEGIN PGP SIGNATURE----- wsB5BAABCAAjFiEEhRJncuj2BJSl0Jf3sN6d1ii/Ey8FAmBDq1EFAwAAAAAACgkQsN6d1ii/Ey8J 7Qf+NHVK97kON4roGF5RJItEisdxbr0ccBbz9u1cZr1HZERP3O8P79ah2OdFk0Xw2sgEp3Hgfvce /rmWAZIt0bfRZua04Z4q2jzoahX1bROTAqZ68/m9Dj3esK/st6gp+SKt7SwWlCDvv3JT7Zm8UR9U FGGf+ar0Sr6E01dC+KaOf7pUuZiGCbor60s4Ko9hZDvW3cGp2ofwaKX4IfVTCUmnHRX5ZGGSr6R7 ZoCa1Mo1kS78RhVQ5zlGrS3HVR2p1+9xZwCcXdpO5py9iFI/5pwkBdZty7hFEolV5vnPyF8kLt8Q RbU2euBuFCYwCyQgv6zKRBtzoqZYZiCMcVcJH1a4cA== =2K6b -----END PGP SIGNATURE----- --kTuR8myBCAf9zSbzIMWx6GIuaVMSZMcto--