From nobody Sun Dec 14 06:16:01 2025 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 1E053C00140 for ; Mon, 15 Aug 2022 19:37:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343529AbiHOTht (ORCPT ); Mon, 15 Aug 2022 15:37:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344827AbiHOTbs (ORCPT ); Mon, 15 Aug 2022 15:31:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AEE561134; Mon, 15 Aug 2022 11:44:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0F4E9611DD; Mon, 15 Aug 2022 18:44:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03E25C433C1; Mon, 15 Aug 2022 18:44:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660589095; bh=+qo1pC4Ttl+/9j8G+c7N7G61muT841xoBx/FamNTO98=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p62m7FXkV8e/HiThWm4nOEh5/gcP/aYRr6+rdBCC1zG/L/Q0rs4iDMDw8H2Mmu6pI iDHPKNi5ctJoXg8nzrANcLE1l2lzDCTIiJS0Hh8GowPTMAiGi079qB1RsIpYU0Fkp4 P5r1hpwl/srCEg3Nzok/tZpH9EQR3mUZ+v7Dhc4k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Farman , Matthew Rosato , Alex Williamson , Sasha Levin Subject: [PATCH 5.15 594/779] vfio/ccw: Do not change FSM state in subchannel event Date: Mon, 15 Aug 2022 20:03:58 +0200 Message-Id: <20220815180402.727715424@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180337.130757997@linuxfoundation.org> References: <20220815180337.130757997@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Eric Farman [ Upstream commit cffcc109fd682075dee79bade3d60a07152a8fd1 ] The routine vfio_ccw_sch_event() is tasked with handling subchannel events, specifically machine checks, on behalf of vfio-ccw. It correctly calls cio_update_schib(), and if that fails (meaning the subchannel is gone) it makes an FSM event call to mark the subchannel Not Operational. If that worked, however, then it decides that if the FSM state was already Not Operational (implying the subchannel just came back), then it should simply change the FSM to partially- or fully-open. Remove this trickery, since a subchannel returning will require more probing than simply "oh all is well again" to ensure it works correctly. Fixes: bbe37e4cb8970 ("vfio: ccw: introduce a finite state machine") Signed-off-by: Eric Farman Reviewed-by: Matthew Rosato Link: https://lore.kernel.org/r/20220707135737.720765-4-farman@linux.ibm.com Signed-off-by: Alex Williamson Signed-off-by: Sasha Levin --- drivers/s390/cio/vfio_ccw_drv.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_dr= v.c index 76099bcb765b..b9091e22ca57 100644 --- a/drivers/s390/cio/vfio_ccw_drv.c +++ b/drivers/s390/cio/vfio_ccw_drv.c @@ -287,19 +287,11 @@ static int vfio_ccw_sch_event(struct subchannel *sch,= int process) if (work_pending(&sch->todo_work)) goto out_unlock; =20 - if (cio_update_schib(sch)) { - vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); - rc =3D 0; - goto out_unlock; - } - - private =3D dev_get_drvdata(&sch->dev); - if (private->state =3D=3D VFIO_CCW_STATE_NOT_OPER) { - private->state =3D private->mdev ? VFIO_CCW_STATE_IDLE : - VFIO_CCW_STATE_STANDBY; - } rc =3D 0; =20 + if (cio_update_schib(sch)) + vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER); + out_unlock: spin_unlock_irqrestore(sch->lock, flags); =20 --=20 2.35.1