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iommu/vt-d: Check identity map for hot-added devices 

The Intel IOMMU driver will put devices into a static identity
mapped domain during boot if the kernel parameter "iommu=pt" is
used. That means the IOMMU hardware will translate a DMA address
into the same memory address.

Unfortunately, hot-added devices are not subject to this. That
results in some devices not working properly after hot added. A
quick way to reproduce this issue is to boot a system with

    iommu=pt

and, remove then readd the pci device with

    echo 1 > /sys/bus/pci/devices/[pci_source_id]/remove
    echo 1 > /sys/bus/pci/rescan

You will find the identity mapped domain was replaced with a
normal domain.

Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: stable@vger.kernel.org
Reported-by: Jis Ben <jisben@google.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: James Dong <xmdong@google.com>
Fixes: 99dcadede4 ('intel-iommu: Support PCIe hot-plug')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
hifive-unleashed-5.1
Lu Baolu 2019-02-25 10:46:36 +08:00 committed by Joerg Roedel
parent 61363c1474
commit 117266fd59
1 changed files with 12 additions and 9 deletions
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21
drivers/iommu/intel-iommu.c
View File

@ -4567,16 +4567,19 @@ static int device_notifier(struct notifier_block *nb,
if (iommu_dummy(dev))
return 0;
if (action != BUS_NOTIFY_REMOVED_DEVICE)
return 0;
if (action == BUS_NOTIFY_REMOVED_DEVICE) {
domain = find_domain(dev);
if (!domain)
return 0;
domain = find_domain(dev);
if (!domain)
return 0;
dmar_remove_one_dev_info(dev);
if (!domain_type_is_vm_or_si(domain) && list_empty(&domain->devices))
domain_exit(domain);
dmar_remove_one_dev_info(dev);
if (!domain_type_is_vm_or_si(domain) &&
list_empty(&domain->devices))
domain_exit(domain);
} else if (action == BUS_NOTIFY_ADD_DEVICE) {
if (iommu_should_identity_map(dev, 1))
domain_add_dev_info(si_domain, dev);
}
return 0;
}