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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id DE2F3EB64DC for ; Tue, 27 Jun 2023 11:33:27 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.556087.868337 (Exim 4.92) (envelope-from ) id 1qE6wT-0002LV-OG; Tue, 27 Jun 2023 11:33:05 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 556087.868337; Tue, 27 Jun 2023 11:33:05 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qE6wT-0002LO-LX; Tue, 27 Jun 2023 11:33:05 +0000 Received: by outflank-mailman (input) for mailman id 556087; Tue, 27 Jun 2023 11:33:03 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qE6wR-0002LI-Km for xen-devel@lists.xenproject.org; Tue, 27 Jun 2023 11:33:03 +0000 Received: from mo4-p00-ob.smtp.rzone.de (mo4-p00-ob.smtp.rzone.de [81.169.146.218]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 5eb2448d-14de-11ee-8611-37d641c3527e; Tue, 27 Jun 2023 13:33:00 +0200 (CEST) Received: from sender by smtp.strato.de (RZmta 49.6.0 AUTH) with ESMTPSA id y5401az5RBWglIF (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Tue, 27 Jun 2023 13:32:42 +0200 (CEST) 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: 5eb2448d-14de-11ee-8611-37d641c3527e ARC-Seal: i=1; a=rsa-sha256; t=1687865562; cv=none; d=strato.com; s=strato-dkim-0002; b=JHvG/liOOg9x6bnQUkcNB+uwuHKGh19BHSc2yGolHCmpCFwyM8g+cf4fSLIGrYPcIQ 3zl9J56v0bksT6YYxzGc2W3LtPYwxVO+Zs0J1YhjEiY8GfKRUFBRqXtfJFGMCg05nlbe 4TXF0N/UXVkykrOYwwwXaCiKYRhsWarEC94uXqKMeGApd7ReA5NKGyrQ9c0cUAy4EOTH 9zYhp8eIHBGPmkWqKa6NO8RH51VvPMTKJqVWd2kTg2hWtFiDFcNYVYQTbmYZsA+61aAE imj/+hoV2GEICOIv/FR/WHCRH0sl11I+W+EjzKuP+QJX8H9Xqmu95QWpLu8uVw7jb0kc Rkdw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; t=1687865562; s=strato-dkim-0002; d=strato.com; h=References:In-Reply-To:Message-ID:Subject:Cc:To:From:Date:Cc:Date: From:Subject:Sender; bh=3wLDUR1nX20PA1ahDWpaygAfJBpRhBHco6snOa6yefU=; b=Pff1dk9aKUS7uTsYK9YBps7/+OabGa4UyCXeC274kjdOQFiM9jOJxti9Cl3qWrNIes 2pRI9IIUJ06WXXz1oAPlXDk8datpiYAFw8gsylcAZ565s4gBhOHMumKDe2IRRgOdvfbF glfDrVxJoc6tKG0CKoveHrtQFKDtEXy+08zloJtGTydraFc17Wx3TdW63fd7M3G3qC4K M6j/qyrDwwqWYNEOian0QwooYM7Wq3s3gst0N7ecrn1iII3hEs4tTBG3k/x/SZG+SkhT +YgjqsJ+uUXGDfchK3xPjtPiT+RxZ/lO5ES3oW5YQSON5WsZBZfRPN366A6h9XeplfJ5 ktGw== ARC-Authentication-Results: i=1; strato.com; arc=none; dkim=none X-RZG-CLASS-ID: mo00 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1687865562; s=strato-dkim-0002; d=aepfle.de; h=References:In-Reply-To:Message-ID:Subject:Cc:To:From:Date:Cc:Date: From:Subject:Sender; bh=3wLDUR1nX20PA1ahDWpaygAfJBpRhBHco6snOa6yefU=; b=HialoChl9s6Ch3YWMLvvcUSZ0m95Wzq3PsoRwJPTv2DWMjx14jpopvL7CtUEDAcCwZ jzNvCZK63rrgvs0HBNx2FDfg44Q0Q2xEvH55rCuBW3YaBEz7TPazUOyjAF0IkOaFzXT3 /hSZIPB9PaxD89PR6HIsVAhEOCNa/fnX8H/PzmCOgdVaqIsTKFaF/SLO/QmPSlYRUihv X9H2BGqeDjsZ0pwJRmORh/T7ZcxDv9DcehQ0AYLF4TEA/pCqDjMjJZ+m8frcjiJA8FCZ hJQiZt+N0R87MP1h2bGeHuOwWC5zWFoqvTEVXL+i5NpfJhjjb1k4xAo5sPz3J/AxlnkU 4f4w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; t=1687865562; s=strato-dkim-0003; d=aepfle.de; h=References:In-Reply-To:Message-ID:Subject:Cc:To:From:Date:Cc:Date: From:Subject:Sender; bh=3wLDUR1nX20PA1ahDWpaygAfJBpRhBHco6snOa6yefU=; b=jUs35QFYM0UDsF3kErXrKoeYeOdy/tHUl251QMJjmDdApYUsQCVK8SnoFwdxpDwqXM nSng0EHsy7BbFM1iT0Aw== X-RZG-AUTH: ":P2EQZWCpfu+qG7CngxMFH1J+3q8wa/QLpd5ylWvMDX3y/OuD5rXWiuRyeUQh3GC6w0BTiV2X9kN/WAr0rdTE7oY1qJzPNA==" Date: Tue, 27 Jun 2023 13:32:34 +0200 From: Olaf Hering To: Paolo Bonzini , John Snow Cc: xen-devel@lists.xenproject.org, Stefano Stabellini , qemu-devel@nongnu.org Subject: Re: [PATCH v2] piix: fix regression during unplug in Xen HVM domUs Message-ID: <20230627133234.400a2ec7.olaf@aepfle.de> In-Reply-To: <20230626231901.5b5d11c1.olaf@aepfle.de> References: <20210317070046.17860-1-olaf@aepfle.de> <4441d32f-bd52-9408-cabc-146b59f0e4dc@redhat.com> <20210325121219.7b5daf76.olaf@aepfle.de> <20230509225818.GA16290@aepfle.de> <20230626231901.5b5d11c1.olaf@aepfle.de> X-Mailer: Claws Mail 20230601T090920.68bc28c0 hat ein Softwareproblem, kann man nichts machen. MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/FGoC2=mDpSn8iKH.kGPuoRS"; protocol="application/pgp-signature"; micalg=pgp-sha256 Content-Transfer-Encoding: 7bit --Sig_/FGoC2=mDpSn8iKH.kGPuoRS Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Mon, 26 Jun 2023 23:19:01 +0200 Olaf Hering : > So far I was unable to decipher how the pci_set_word calls can > possibly affect the outcome and the owner of memory_region_ops_read. It is enough to return from piix_ide_reset right after pci_set_word(pci_conf + PCI_COMMAND, 0) to trigger the issue. One thing which was not mentioned yet: the order in which kernel drivers are loaded matters. Usually it is xen-platform-pci/uhci-hcd/ata_piix. When uhci loads, it scans the USB bus, finds the tablet, loads usbhid. While this happens, ata_piix loads. It finds the PCI device in state disabled. The PCI code enables the device. On the qemu side this ends up in pci_default_write_config for PCI device "piix3-ide" with addr=3D4, val=3D1, len=3D2. This calls pci_update_mappings, which for region #4 changes the addr from 0xc120 to 0xc100. This causes the issue. Now usbhid tries to use the USB bus, but uhci_irq fails. If ata_piix is not loaded, uhci works. If ata_piix is loaded before uhci-hcd, the USB bus can not be scanned, udev is killed after a timeout and boot proceeds. If usbhid is loaded before ata_piix, USB bus discovery usually finishes before ata_piix enables its PCI device, boot proceeds. 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