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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 220ABC433EF for ; Wed, 27 Oct 2021 09:54:37 +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 D164260F21 for ; Wed, 27 Oct 2021 09:54:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D164260F21 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=oderland.se Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.216846.376606 (Exim 4.92) (envelope-from ) id 1mffdc-0004cn-5T; Wed, 27 Oct 2021 09:54:28 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 216846.376606; Wed, 27 Oct 2021 09:54:28 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mffdc-0004cg-1F; Wed, 27 Oct 2021 09:54:28 +0000 Received: by outflank-mailman (input) for mailman id 216846; Wed, 27 Oct 2021 09:54:26 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1mffda-0004cW-9m for xen-devel@lists.xenproject.org; Wed, 27 Oct 2021 09:54:26 +0000 Received: from office.oderland.com (unknown [91.201.60.5]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 55d0c856-024d-4e26-90fa-4b03ec1e4164; Wed, 27 Oct 2021 09:54:24 +0000 (UTC) Received: from [193.180.18.161] (port=57000 helo=[10.137.0.14]) by office.oderland.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1mffdX-00APdA-AN; Wed, 27 Oct 2021 11:54:23 +0200 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: 55d0c856-024d-4e26-90fa-4b03ec1e4164 Message-ID: Date: Wed, 27 Oct 2021 11:54:19 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:93.0) Gecko/20100101 Thunderbird/93.0 Subject: Re: [PATCH] PCI/MSI: Move non-mask check back into low level accessors Content-Language: en-US To: Thomas Gleixner Cc: boris.ostrovsky@oracle.com, helgaas@kernel.org, jgross@suse.com, linux-pci@vger.kernel.org, maz@kernel.org, xen-devel@lists.xenproject.org, David Woodhouse , Jason Andryuk References: <90277228-cf14-0cfa-c95e-d42e7d533353@oderland.se> <20211025012503.33172-1-jandryuk@gmail.com> <87fssmg8k4.ffs@tglx> <87cznqg5k8.ffs@tglx> From: Josef Johansson In-Reply-To: <87cznqg5k8.ffs@tglx> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - office.oderland.com X-AntiAbuse: Original Domain - lists.xenproject.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - oderland.se X-Get-Message-Sender-Via: office.oderland.com: authenticated_id: josjoh@oderland.se X-Authenticated-Sender: office.oderland.com: josjoh@oderland.se On 10/27/21 11:50, Thomas Gleixner wrote: > The recent rework of PCI/MSI[X] masking moved the non-mask checks from the > low level accessors into the higher level mask/unmask functions. > > This missed the fact that these accessors can be invoked from other places > as well. The missing checks break XEN-PV which sets pci_msi_ignore_mask and > also violates the virtual MSIX and the msi_attrib.maskbit protections. > > Instead of sprinkling checks all over the place, lift them back into the > low level accessor functions. To avoid checking three different conditions > combine them into one property of msi_desc::msi_attrib. > > Reported-by: Josef Johansson > Fixes: fcacdfbef5a1 ("PCI/MSI: Provide a new set of mask and unmask functions") > Signed-off-by: Thomas Gleixner > Cc: Jason Andryuk > Cc: Marc Zyngier > Cc: Bjorn Helgaas > Cc: linux-pci@vger.kernel.org > Cc: xen-devel > Cc: Juergen Gross > Cc: Boris Ostrovsky > Cc: David Woodhouse > --- > drivers/pci/msi.c | 26 ++++++++++++++------------ > include/linux/msi.h | 2 +- > 2 files changed, 15 insertions(+), 13 deletions(-) > > --- a/drivers/pci/msi.c > +++ b/drivers/pci/msi.c > @@ -148,6 +148,9 @@ static noinline void pci_msi_update_mask > raw_spinlock_t *lock = &desc->dev->msi_lock; > unsigned long flags; > > + if (!desc->msi_attrib.can_mask) > + return; > + > raw_spin_lock_irqsave(lock, flags); > desc->msi_mask &= ~clear; > desc->msi_mask |= set; > @@ -181,7 +184,8 @@ static void pci_msix_write_vector_ctrl(s > { > void __iomem *desc_addr = pci_msix_desc_addr(desc); > > - writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL); > + if (desc->msi_attrib.can_mask) > + writel(ctrl, desc_addr + PCI_MSIX_ENTRY_VECTOR_CTRL); > } > > static inline void pci_msix_mask(struct msi_desc *desc) > @@ -200,23 +204,17 @@ static inline void pci_msix_unmask(struc > > static void __pci_msi_mask_desc(struct msi_desc *desc, u32 mask) > { > - if (pci_msi_ignore_mask || desc->msi_attrib.is_virtual) > - return; > - > if (desc->msi_attrib.is_msix) > pci_msix_mask(desc); > - else if (desc->msi_attrib.maskbit) > + else > pci_msi_mask(desc, mask); > } > > static void __pci_msi_unmask_desc(struct msi_desc *desc, u32 mask) > { > - if (pci_msi_ignore_mask || desc->msi_attrib.is_virtual) > - return; > - > if (desc->msi_attrib.is_msix) > pci_msix_unmask(desc); > - else if (desc->msi_attrib.maskbit) > + else > pci_msi_unmask(desc, mask); > } > > @@ -484,7 +482,8 @@ msi_setup_entry(struct pci_dev *dev, int > entry->msi_attrib.is_64 = !!(control & PCI_MSI_FLAGS_64BIT); > entry->msi_attrib.is_virtual = 0; > entry->msi_attrib.entry_nr = 0; > - entry->msi_attrib.maskbit = !!(control & PCI_MSI_FLAGS_MASKBIT); > + entry->msi_attrib.can_mask = !pci_msi_ignore_mask && > + !!(control & PCI_MSI_FLAGS_MASKBIT); > entry->msi_attrib.default_irq = dev->irq; /* Save IOAPIC IRQ */ > entry->msi_attrib.multi_cap = (control & PCI_MSI_FLAGS_QMASK) >> 1; > entry->msi_attrib.multiple = ilog2(__roundup_pow_of_two(nvec)); > @@ -495,7 +494,7 @@ msi_setup_entry(struct pci_dev *dev, int > entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_32; > > /* Save the initial mask status */ > - if (entry->msi_attrib.maskbit) > + if (entry->msi_attrib.can_mask) > pci_read_config_dword(dev, entry->mask_pos, &entry->msi_mask); > > out: > @@ -638,10 +637,13 @@ static int msix_setup_entries(struct pci > entry->msi_attrib.is_virtual = > entry->msi_attrib.entry_nr >= vec_count; > > + entry->msi_attrib.can_mask = !pci_msi_ignore_mask && > + !entry->msi_attrib.is_virtual; > + > entry->msi_attrib.default_irq = dev->irq; > entry->mask_base = base; > > - if (!entry->msi_attrib.is_virtual) { > + if (!entry->msi_attrib.can_mask) { > addr = pci_msix_desc_addr(entry); > entry->msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL); > } > --- a/include/linux/msi.h > +++ b/include/linux/msi.h > @@ -148,7 +148,7 @@ struct msi_desc { > u8 is_msix : 1; > u8 multiple : 3; > u8 multi_cap : 3; > - u8 maskbit : 1; > + u8 can_mask : 1; > u8 is_64 : 1; > u8 is_virtual : 1; > u16 entry_nr; Thanks, I'll test this out ASAP.