From: Thomas Gleixner <tglx@linutronix.de> To: "Eric W. Biederman" <ebiederm@xmission.com>, Bjorn Helgaas <helgaas@kernel.org> Cc: "Guilherme G. Piccoli" <gpiccoli@canonical.com>, lukas@wunner.de, linux-pci@vger.kernel.org, kernelfans@gmail.com, andi@firstfloor.org, hpa@zytor.com, bhe@redhat.com, x86@kernel.org, okaya@kernel.org, mingo@redhat.com, jay.vosburgh@canonical.com, dyoung@redhat.com, gavin.guo@canonical.com, bp@alien8.de, bhelgaas@google.com, Guowen Shan <gshan@redhat.com>, "Rafael J. Wysocki" <rjw@rjwysocki.net>, kernel@gpiccoli.net, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, ddstreet@canonical.com, vgoyal@redhat.com Subject: Re: [PATCH 1/3] x86/quirks: Scan all busses for early PCI quirks Date: Tue, 17 Nov 2020 10:53:49 +0100 [thread overview] Message-ID: <873618xqaa.fsf@nanos.tec.linutronix.de> (raw) In-Reply-To: <87h7poeqqn.fsf@x220.int.ebiederm.org> On Mon, Nov 16 2020 at 19:06, Eric W. Biederman wrote: > Bjorn Helgaas <helgaas@kernel.org> writes: > My two top candidates are poking the IOMMUs early to shut things off, > and figuring out if we can delay enabling interrupts until we have > initialized pci. Keeping interrupts disabled post PCI initialization would be nice, but that requires feeding the whole init machinery through a shredder and collecting the bits and pieces. > Poking at IOMMUs early should work for most systems with ``enterprise'' > hardware. Systems where people care about kdump the most. The IOMMU IRQ remapping part _is_ initialized early and _before_ interrupts are enabled. But that does not solve the problem either simply because then the IOMMU will catch the rogue MSIs and you get an interrupt storm on the IOMMU error interrupt. This one is not going to be turned off because the IOMMU error interrupt handler will handle each of them and tell the core code that everything is under control. As I explained several times now, the only way to shut this up reliably is at the source. Curing the symptom is almost never a good solution. Thanks, tglx
WARNING: multiple messages have this Message-ID (diff)
From: Thomas Gleixner <tglx@linutronix.de> To: "Eric W. Biederman" <ebiederm@xmission.com>, Bjorn Helgaas <helgaas@kernel.org> Cc: Guowen Shan <gshan@redhat.com>, linux-pci@vger.kernel.org, kernelfans@gmail.com, andi@firstfloor.org, hpa@zytor.com, bhe@redhat.com, x86@kernel.org, okaya@kernel.org, mingo@redhat.com, jay.vosburgh@canonical.com, dyoung@redhat.com, vgoyal@redhat.com, "Guilherme G. Piccoli" <gpiccoli@canonical.com>, bp@alien8.de, bhelgaas@google.com, kexec@lists.infradead.org, kernel@gpiccoli.net, "Rafael J. Wysocki" <rjw@rjwysocki.net>, linux-kernel@vger.kernel.org, ddstreet@canonical.com, lukas@wunner.de, gavin.guo@canonical.com Subject: Re: [PATCH 1/3] x86/quirks: Scan all busses for early PCI quirks Date: Tue, 17 Nov 2020 10:53:49 +0100 [thread overview] Message-ID: <873618xqaa.fsf@nanos.tec.linutronix.de> (raw) In-Reply-To: <87h7poeqqn.fsf@x220.int.ebiederm.org> On Mon, Nov 16 2020 at 19:06, Eric W. Biederman wrote: > Bjorn Helgaas <helgaas@kernel.org> writes: > My two top candidates are poking the IOMMUs early to shut things off, > and figuring out if we can delay enabling interrupts until we have > initialized pci. Keeping interrupts disabled post PCI initialization would be nice, but that requires feeding the whole init machinery through a shredder and collecting the bits and pieces. > Poking at IOMMUs early should work for most systems with ``enterprise'' > hardware. Systems where people care about kdump the most. The IOMMU IRQ remapping part _is_ initialized early and _before_ interrupts are enabled. But that does not solve the problem either simply because then the IOMMU will catch the rogue MSIs and you get an interrupt storm on the IOMMU error interrupt. This one is not going to be turned off because the IOMMU error interrupt handler will handle each of them and tell the core code that everything is under control. As I explained several times now, the only way to shut this up reliably is at the source. Curing the symptom is almost never a good solution. Thanks, tglx _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2020-11-17 9:54 UTC|newest] Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-10-18 18:37 [PATCH 1/3] x86/quirks: Scan all busses for early PCI quirks Guilherme G. Piccoli 2018-10-18 18:37 ` Guilherme G. Piccoli 2018-10-18 18:37 ` [PATCH 2/3] x86/PCI: Export find_cap() to be used in early PCI code Guilherme G. Piccoli 2018-10-18 18:37 ` Guilherme G. Piccoli 2018-10-18 18:37 ` [PATCH 3/3] x86/quirks: Add parameter to clear MSIs early on boot Guilherme G. Piccoli 2018-10-18 18:37 ` Guilherme G. Piccoli 2018-10-18 20:08 ` Sinan Kaya 2018-10-18 20:08 ` Sinan Kaya 2018-10-18 20:13 ` Guilherme G. Piccoli 2018-10-18 20:13 ` Guilherme G. Piccoli 2018-10-18 20:30 ` Sinan Kaya 2018-10-18 20:30 ` Sinan Kaya 2018-10-22 19:44 ` Guilherme G. Piccoli 2018-10-22 19:44 ` Guilherme G. Piccoli 2018-10-18 22:15 ` [PATCH 1/3] x86/quirks: Scan all busses for early PCI quirks Bjorn Helgaas 2018-10-18 22:15 ` Bjorn Helgaas 2018-10-22 20:35 ` Guilherme G. Piccoli 2018-10-22 20:35 ` Guilherme G. Piccoli 2018-10-23 17:03 ` Bjorn Helgaas 2018-10-23 17:03 ` Bjorn Helgaas 2020-11-06 13:14 ` Guilherme G. Piccoli 2020-11-06 13:14 ` Guilherme G. Piccoli 2020-11-13 16:46 ` Bjorn Helgaas 2020-11-13 16:46 ` Bjorn Helgaas 2020-11-13 23:31 ` Thomas Gleixner 2020-11-13 23:31 ` Thomas Gleixner 2020-11-13 23:40 ` Thomas Gleixner 2020-11-13 23:40 ` Thomas Gleixner 2020-11-14 20:39 ` Bjorn Helgaas 2020-11-14 20:39 ` Bjorn Helgaas 2020-11-14 20:58 ` Thomas Gleixner 2020-11-14 20:58 ` Thomas Gleixner 2020-11-14 21:22 ` Bjorn Helgaas 2020-11-14 21:22 ` Bjorn Helgaas 2020-11-15 14:05 ` Eric W. Biederman 2020-11-15 14:05 ` Eric W. Biederman 2020-11-15 14:29 ` Eric W. Biederman 2020-11-15 14:29 ` Eric W. Biederman 2020-11-15 15:11 ` Thomas Gleixner 2020-11-15 15:11 ` Thomas Gleixner 2020-11-15 17:01 ` Lukas Wunner 2020-11-15 19:18 ` Thomas Gleixner 2020-11-15 19:18 ` Thomas Gleixner 2020-11-15 20:46 ` Eric W. Biederman 2020-11-15 20:46 ` Eric W. Biederman 2020-11-16 20:31 ` Guilherme G. Piccoli 2020-11-16 20:31 ` Guilherme G. Piccoli 2020-11-16 21:45 ` Eric W. Biederman 2020-11-16 21:45 ` Eric W. Biederman 2020-11-16 21:49 ` Guilherme Piccoli 2020-11-16 21:49 ` Guilherme Piccoli 2020-11-17 0:19 ` Bjorn Helgaas 2020-11-17 0:19 ` Bjorn Helgaas 2020-11-17 1:06 ` Eric W. Biederman 2020-11-17 1:06 ` Eric W. Biederman 2020-11-17 9:53 ` Thomas Gleixner [this message] 2020-11-17 9:53 ` Thomas Gleixner 2020-11-17 12:19 ` David Woodhouse 2020-11-17 12:19 ` David Woodhouse 2020-11-17 19:34 ` Thomas Gleixner 2020-11-17 19:34 ` Thomas Gleixner 2020-11-17 22:25 ` Eric W. Biederman 2020-11-17 22:25 ` Eric W. Biederman 2020-11-17 12:04 ` Guilherme Piccoli 2020-11-17 12:04 ` Guilherme Piccoli 2020-11-18 21:05 ` Bjorn Helgaas 2020-11-18 21:05 ` Bjorn Helgaas 2020-11-18 22:36 ` Guilherme Piccoli 2020-11-18 22:36 ` Guilherme Piccoli 2020-11-30 20:20 ` Bjorn Helgaas 2020-11-30 20:20 ` Bjorn Helgaas 2020-12-14 18:32 ` Guilherme Piccoli 2020-12-14 18:32 ` Guilherme Piccoli
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