From patchwork Tue May 28 04:03:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shawn Anastasio X-Patchwork-Id: 10963685 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4D0BE6C5 for ; Tue, 28 May 2019 04:03:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 34EB528741 for ; Tue, 28 May 2019 04:03:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2627A2874F; Tue, 28 May 2019 04:03:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BCBE828741 for ; Tue, 28 May 2019 04:03:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725817AbfE1EDV (ORCPT ); Tue, 28 May 2019 00:03:21 -0400 Received: from alpha.anastas.io ([104.248.188.109]:36881 "EHLO alpha.anastas.io" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726930AbfE1EDU (ORCPT ); Tue, 28 May 2019 00:03:20 -0400 Received: from authenticated-user (alpha.anastas.io [104.248.188.109]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alpha.anastas.io (Postfix) with ESMTPSA id 38C037F8EF; Mon, 27 May 2019 23:03:19 -0500 (CDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=anastas.io; s=mail; t=1559016200; bh=EbMGqvTbpmYpoY6l4LV+r9ViCc9hu4tEns2XXtxyPZ4=; h=From:To:Cc:Subject:Date:From; b=LByL6UKRIDR1c8RW+kQOJ3nBQiDIju1ahGKqda1v4yFnScHg9l4+zupmgModnYw0V 1g8Ah3gQfhnnOtQAxEYWhoWv3f9HzUvO9R2vFW0S1jLFh5Um6gtOAAqt3ED4eOKL+H hClUWlRnDQWpdnM+Ju1c1ba07njhTxE+CC/zeD1iPtrImjfjrSfSWliV2vJLiucvf7 KR4tlJazilVXT4tlkm8A9Jh036IFAzRcy9EF7GTVcYSmN8TG3popcNvomvyeXfQ25Q TV8cdv5mTR6ZgtULAAHipjCl2fJMtbOeB04xNjWnr6yWDzfKx78ZCmnIhPt9x2Wme6 o0dyEtNvcennA== From: Shawn Anastasio To: linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: bhelgaas@google.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, sbobroff@linux.ibm.com, xyjxie@linux.vnet.ibm.com, rppt@linux.ibm.com, linux-kernel@vger.kernel.org Subject: [PATCH v3 0/3] Allow custom PCI resource alignment on pseries Date: Mon, 27 May 2019 23:03:10 -0500 Message-Id: <20190528040313.35582-1-shawn@anastas.io> MIME-Version: 1.0 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Changes from v2 to v3: - Fix wrong return type of ppc pcibios_ignore_alignment_request (Not sure how my local compile didn't catch that!) Hello all, This patch set implements support for user-specified PCI resource alignment on the pseries platform for hotplugged PCI devices. Currently on pseries, PCI resource alignments specified with the pci=resource_alignment commandline argument are ignored, since the firmware is in charge of managing the PCI resources. In the case of hotplugged devices, though, the kernel is in charge of configuring the resources and should obey alignment requirements. The current behavior of ignoring the alignment for hotplugged devices results in sub-page BARs landing between page boundaries and becoming un-mappable from userspace via the VFIO framework. This issue was observed on a pseries KVM guest with hotplugged ivshmem devices. With these changes, users can specify an appropriate pci=resource_alignment argument on boot for devices they wish to use with VFIO. In the future, this could be extended to provide page-aligned resources by default for hotplugged devices, similar to what is done on powernv by commit 382746376993 ("powerpc/powernv: Override pcibios_default_alignment() to force PCI devices to be page aligned"). Feedback is appreciated. Thanks, Shawn Shawn Anastasio (3): PCI: Introduce pcibios_ignore_alignment_request powerpc/64: Enable pcibios_after_init hook on ppc64 powerpc/pseries: Allow user-specified PCI resource alignment after init arch/powerpc/include/asm/machdep.h | 6 ++++-- arch/powerpc/kernel/pci-common.c | 9 +++++++++ arch/powerpc/kernel/pci_64.c | 4 ++++ arch/powerpc/platforms/pseries/setup.c | 22 ++++++++++++++++++++++ drivers/pci/pci.c | 9 +++++++-- include/linux/pci.h | 1 + 6 files changed, 47 insertions(+), 4 deletions(-)