From: Dan Carpenter <dan.carpenter@linaro.org>
To: Ethan Zhao <haifeng.zhao@linux.intel.com>
Cc: baolu.lu@linux.intel.com, bhelgaas@google.com,
robin.murphy@arm.com, jgg@ziepe.ca, kevin.tian@intel.com,
dwmw2@infradead.org, will@kernel.org, lukas@wunner.de,
yi.l.liu@intel.com, iommu@lists.linux.dev,
linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org
Subject: Re: [PATCH v13 3/3] iommu/vt-d: improve ITE fault handling if target device isn't valid
Date: Tue, 27 Feb 2024 07:54:06 +0300 [thread overview]
Message-ID: <8a220db4-a784-4dbf-9c6d-dcb4b47c0083@moroto.mountain> (raw)
In-Reply-To: <623ce65f-da43-4493-8a21-4fd6dfe86dbb@linux.intel.com>
On Tue, Feb 27, 2024 at 04:00:33AM +0800, Ethan Zhao wrote:
> > + if (!dev || !dev_is_pci(dev))
> > + return -ETIMEDOUT;
> > + pdev = to_pci_dev(dev);
> > + if (!pci_device_is_present(pdev) &&
> > + ite_sid == pci_dev_id(pci_physfn(pdev)))
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > Unless the device_rbtree_find() is returning garbage then these things
> > must be true.
> >
> > + return -ETIMEDOUT;
> >
> > I tried to double check how we were storing devices into the rbtree,
> > but then I discovered that the device_rbtree_find() doesn't exist in
> > linux-next and this patch breaks the build.
> >
> > This is very frustrating thing. But let's say a buggy BIOS could mess
> > up the rbtree. In that situation, we would still want to change the &&
> > to an ||. If the divice is not present and^W or the rbtree is corrupted
>
> Maybe you meant
> + if (!pci_device_is_present(pdev) ||
> + ite_sid != pci_dev_id(pci_physfn(pdev)))
Yep, that's what I was asking.
>
> Unfortunately, the ite_sid we got from the "Invalidation Queue Error Record Register" is the *PCI Requester-id* of faulty device, that could be different
> BDF as the sid in the ATS invalidation request for devices:
>
> 1. behind the PCIe to PCI bridges.
> 2. behindConventional PCI Bridges 3.PCI Express* Devices Using Phantom
> Functions 4.Intel® Scalable I/O Virtualization Capable Devices (e.g. ADI)
> 5. devices with ARI function.
> 6. behind root port without ACS enabled.
> ... ...
Fair enough... Thanks.
regards,
dan carpenter
next prev parent reply other threads:[~2024-02-27 7:20 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-22 9:02 [PATCH v13 0/3] fix vt-d hard lockup when hotplug ATS capable device Ethan Zhao
2024-02-22 9:02 ` [PATCH v13 1/3] PCI: make pci_dev_is_disconnected() helper public for other drivers Ethan Zhao
2024-02-22 12:54 ` Baolu Lu
2024-02-23 6:47 ` Dan Carpenter
2024-02-23 7:35 ` Ethan Zhao
2024-02-26 23:05 ` Bjorn Helgaas
2024-02-29 1:58 ` Ethan Zhao
2024-02-29 22:33 ` Bjorn Helgaas
2024-03-01 2:03 ` Ethan Zhao
2024-02-29 22:26 ` Bjorn Helgaas
2024-02-22 9:02 ` [PATCH v13 2/3] iommu/vt-d: don't issue ATS Invalidation request when device is disconnected Ethan Zhao
2024-02-22 9:02 ` [PATCH v13 3/3] iommu/vt-d: improve ITE fault handling if target device isn't valid Ethan Zhao
2024-02-22 11:24 ` Dan Carpenter
2024-02-23 2:29 ` Ethan Zhao
2024-02-23 6:08 ` Dan Carpenter
2024-02-23 7:32 ` Ethan Zhao
2024-02-23 8:19 ` Dan Carpenter
2024-02-26 2:48 ` Ethan Zhao
2024-02-26 20:00 ` Ethan Zhao
2024-02-27 4:54 ` Dan Carpenter [this message]
2024-02-26 22:52 ` Bjorn Helgaas
2024-02-27 2:30 ` Ethan Zhao
2024-02-27 16:29 ` Bjorn Helgaas
2024-02-28 9:00 ` Ethan Zhao
2024-02-26 11:48 ` kernel test robot
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