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=-24.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 2C9BAC43216 for ; Tue, 24 Aug 2021 17:39:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 17578611C8 for ; Tue, 24 Aug 2021 17:39:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240513AbhHXRkW (ORCPT ); Tue, 24 Aug 2021 13:40:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:43444 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242308AbhHXRhP (ORCPT ); Tue, 24 Aug 2021 13:37:15 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9D37561BF6; Tue, 24 Aug 2021 17:07:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824875; bh=s2dEDNG237iZxL7T6a4x4jPZHm0X1EOJ5Xl8njIP3gU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EOVLn8EvE8Wa9skImIAEU3VfyJl0nUR2sijVBG15XFGoiJRmoaF+BXRrarla7RQr9 MvoSDiJPt11UAPsR640Efif+dywlr5bsgbxWv/HHBOmnLIl8+9VGNucLDgE/c8rHzx elI46vJAftiCsQ7oLbEKWwugYx0mnff7kOM0Qzy7EJTZEd6fEtC7uMUZTlSc0wHEWL ggYLJAT5HLw0k1nPGbmcIY7CwnQ2aoBoiLyJvQNIu2/fdlL20v6pyudUetJgy4U1QP d21YbBBNZmEdw9n5jf5O8E4cbwOnD2KKFOfcFUSCPle4V5kA1DXn7NVMlIRADQYc9b /pz6agDWo2Fhg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Thomas Gleixner , Marc Zyngier , Bjorn Helgaas , Greg Kroah-Hartman Subject: [PATCH 4.4 11/31] PCI/MSI: Mask all unused MSI-X entries Date: Tue, 24 Aug 2021 13:07:23 -0400 Message-Id: <20210824170743.710957-12-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824170743.710957-1-sashal@kernel.org> References: <20210824170743.710957-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.4.282-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.4.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.4.282-rc1 X-KernelTest-Deadline: 2021-08-26T17:07+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Gleixner commit 7d5ec3d3612396dc6d4b76366d20ab9fc06f399f upstream. When MSI-X is enabled the ordering of calls is: msix_map_region(); msix_setup_entries(); pci_msi_setup_msi_irqs(); msix_program_entries(); This has a few interesting issues: 1) msix_setup_entries() allocates the MSI descriptors and initializes them except for the msi_desc:masked member which is left zero initialized. 2) pci_msi_setup_msi_irqs() allocates the interrupt descriptors and sets up the MSI interrupts which ends up in pci_write_msi_msg() unless the interrupt chip provides its own irq_write_msi_msg() function. 3) msix_program_entries() does not do what the name suggests. It solely updates the entries array (if not NULL) and initializes the masked member for each MSI descriptor by reading the hardware state and then masks the entry. Obviously this has some issues: 1) The uninitialized masked member of msi_desc prevents the enforcement of masking the entry in pci_write_msi_msg() depending on the cached masked bit. Aside of that half initialized data is a NONO in general 2) msix_program_entries() only ensures that the actually allocated entries are masked. This is wrong as experimentation with crash testing and crash kernel kexec has shown. This limited testing unearthed that when the production kernel had more entries in use and unmasked when it crashed and the crash kernel allocated a smaller amount of entries, then a full scan of all entries found unmasked entries which were in use in the production kernel. This is obviously a device or emulation issue as the device reset should mask all MSI-X table entries, but obviously that's just part of the paper specification. Cure this by: 1) Masking all table entries in hardware 2) Initializing msi_desc::masked in msix_setup_entries() 3) Removing the mask dance in msix_program_entries() 4) Renaming msix_program_entries() to msix_update_entries() to reflect the purpose of that function. As the masking of unused entries has never been done the Fixes tag refers to a commit in: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Fixes: f036d4ea5fa7 ("[PATCH] ia32 Message Signalled Interrupt support") Signed-off-by: Thomas Gleixner Tested-by: Marc Zyngier Reviewed-by: Marc Zyngier Acked-by: Bjorn Helgaas Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.403833459@linutronix.de Signed-off-by: Greg Kroah-Hartman --- drivers/pci/msi.c | 45 +++++++++++++++++++++++++++++++-------------- 1 file changed, 31 insertions(+), 14 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index dffa5c5bcc76..9cc4a598c652 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -208,6 +208,12 @@ static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag) __pci_msi_desc_mask_irq(desc, mask, flag); } +static void __iomem *pci_msix_desc_addr(struct msi_desc *desc) +{ + return desc->mask_base + + desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE; +} + /* * This internal function does not flush PCI writes to the device. * All users must ensure that they read from the device before either @@ -678,6 +684,7 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, struct msix_entry *entries, int nvec) { struct msi_desc *entry; + void __iomem *addr; int i; for (i = 0; i < nvec; i++) { @@ -698,29 +705,35 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base, entry->mask_base = base; entry->nvec_used = 1; + addr = pci_msix_desc_addr(entry); + entry->masked = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); list_add_tail(&entry->list, dev_to_msi_list(&dev->dev)); } return 0; } -static void msix_program_entries(struct pci_dev *dev, - struct msix_entry *entries) +static void msix_update_entries(struct pci_dev *dev, struct msix_entry *entries) { struct msi_desc *entry; - int i = 0; for_each_pci_msi_entry(entry, dev) { - int offset = entries[i].entry * PCI_MSIX_ENTRY_SIZE + - PCI_MSIX_ENTRY_VECTOR_CTRL; - - entries[i].vector = entry->irq; - entry->masked = readl(entry->mask_base + offset); - msix_mask_irq(entry, 1); - i++; + if (entries) { + entries->vector = entry->irq; + entries++; + } } } +static void msix_mask_all(void __iomem *base, int tsize) +{ + u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT; + int i; + + for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE) + writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL); +} + /** * msix_capability_init - configure device's MSI-X capability * @dev: pointer to the pci_dev data structure of MSI-X device function @@ -734,9 +747,9 @@ static void msix_program_entries(struct pci_dev *dev, static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, int nvec) { - int ret; - u16 control; void __iomem *base; + int ret, tsize; + u16 control; /* * Some devices require MSI-X to be enabled before the MSI-X @@ -748,12 +761,16 @@ static int msix_capability_init(struct pci_dev *dev, pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control); /* Request & Map MSI-X table region */ - base = msix_map_region(dev, msix_table_size(control)); + tsize = msix_table_size(control); + base = msix_map_region(dev, tsize); if (!base) { ret = -ENOMEM; goto out_disable; } + /* Ensure that all table entries are masked. */ + msix_mask_all(base, tsize); + ret = msix_setup_entries(dev, base, entries, nvec); if (ret) goto out_disable; @@ -767,7 +784,7 @@ static int msix_capability_init(struct pci_dev *dev, if (ret) goto out_free; - msix_program_entries(dev, entries); + msix_update_entries(dev, entries); ret = populate_msi_sysfs(dev); if (ret) -- 2.30.2