Commit 146922ec79 ("iommu/vt-d: Make get_domain_for_dev() take struct
device") introduced new variables bridge_bus and bridge_devfn to
identify the upstream PCIe to PCI bridge responsible for the given
target device. Leaving the original bus/devfn variables to identify
the target device itself, now that it is no longer assumed to be PCI
and we can no longer trivially find that information.
However, the patch failed to correctly use the new variables in all
cases; instead using the as-yet-uninitialised 'bus' and 'devfn'
variables.
Reported-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Commit ea8ea46 "iommu/vt-d: Clean up and fix page table clear/free
behaviour" introduces possible leakage of DMA page tables due to:
for (pte = page_address(pg); !first_pte_in_page(pte); pte++) {
if (dma_pte_present(pte) && !dma_pte_superpage(pte))
freelist = dma_pte_list_pagetables(domain, level - 1,
pte, freelist);
}
For the first pte in a page, first_pte_in_page(pte) will always be true,
thus dma_pte_list_pagetables() will never be called and leak DMA page
tables if level is bigger than 1.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
If we hit this error condition then we want to return a NULL pointer and
not a freed variable.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Mostly made redundant by using dev_name() instead of pci_name(), and one
instance of using *dev->dma_mask instead of pdev->dma_mask.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Should hopefully never happen (RMRRs are an abomination) but while we're
busy eliminating all the PCI assumptions, we might as well do it.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Pass the struct device to it, and also make it return the bus/devfn to use,
since that is also stored in the DMAR table.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This was problematic because it works by domain/bus/devfn and we want
to make device_to_iommu() use only a struct device * (for handling non-PCI
devices). Now that the iommu pointer is reliably stored in the
device_domain_info, we don't need to look it up.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
By moving this into get_domain_for_dev() we can make dmar_insert_dev_info()
suitable for use with "special" domains such as the si_domain, which
currently use domain_add_dev_info().
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
It's not only for PCI devices any more, and the scope information for an
ACPI device provides the bus and devfn so that has to be stored here too.
It is the device pointer itself which needs to be protected with RCU,
so the __rcu annotation follows it into the definition of struct
dmar_dev_scope, since we're no longer just passing arrays of device
pointers around.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
In commit 2e12bc29 ("intel-iommu: Default to non-coherent for domains
unattached to iommus") we decided to err on the side of caution and
always assume that it's possible that a device will be attached which is
behind a non-coherent IOMMU.
In some cases, however, that just *cannot* happen. If there *are* no
IOMMUs in the system which are non-coherent, then we don't need to do
it. And flushing the dcache is a *significant* performance hit.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
There is a race condition between the existing clear/free code and the
hardware. The IOMMU is actually permitted to cache the intermediate
levels of the page tables, and doesn't need to walk the table from the
very top of the PGD each time. So the existing back-to-back calls to
dma_pte_clear_range() and dma_pte_free_pagetable() can lead to a
use-after-free where the IOMMU reads from a freed page table.
When freeing page tables we actually need to do the IOTLB flush, with
the 'invalidation hint' bit clear to indicate that it's not just a
leaf-node flush, after unlinking each page table page from the next level
up but before actually freeing it.
So in the rewritten domain_unmap() we just return a list of pages (using
pg->freelist to make a list of them), and then the caller is expected to
do the appropriate IOTLB flush (or tear down the domain completely,
whatever), before finally calling dma_free_pagelist() to free the pages.
As an added bonus, we no longer need to flush the CPU's data cache for
pages which are about to be *removed* from the page table hierarchy anyway,
in the non-cache-coherent case. This drastically improves the performance
of large unmaps.
As a side-effect of all these changes, this also fixes the fact that
intel_iommu_unmap() was neglecting to free the page tables for the range
in question after clearing them.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
We have this horrid API where iommu_unmap() can unmap more than it's asked
to, if the IOVA in question happens to be mapped with a large page.
Instead of propagating this nonsense to the point where we end up returning
the page order from dma_pte_clear_range(), let's just do it once and adjust
the 'size' parameter accordingly.
Augment pfn_to_dma_pte() to return the level at which the PTE was found,
which will also be useful later if we end up changing the API for
iommu_iova_to_phys() to behave the same way as is being discussed upstream.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Now we have a PCI bus notification based mechanism to update DMAR
device scope array, we could extend the mechanism to support boot
time initialization too, which will help to unify and simplify
the implementation.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Current Intel DMAR/IOMMU driver assumes that all PCI devices associated
with DMAR/RMRR/ATSR device scope arrays are created at boot time and
won't change at runtime, so it caches pointers of associated PCI device
object. That assumption may be wrong now due to:
1) introduction of PCI host bridge hotplug
2) PCI device hotplug through sysfs interfaces.
Wang Yijing has tried to solve this issue by caching <bus, dev, func>
tupple instead of the PCI device object pointer, but that's still
unreliable because PCI bus number may change in case of hotplug.
Please refer to http://lkml.org/lkml/2013/11/5/64
Message from Yingjing's mail:
after remove and rescan a pci device
[ 611.857095] dmar: DRHD: handling fault status reg 2
[ 611.857109] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff7000
[ 611.857109] DMAR:[fault reason 02] Present bit in context entry is clear
[ 611.857524] dmar: DRHD: handling fault status reg 102
[ 611.857534] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff6000
[ 611.857534] DMAR:[fault reason 02] Present bit in context entry is clear
[ 611.857936] dmar: DRHD: handling fault status reg 202
[ 611.857947] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff5000
[ 611.857947] DMAR:[fault reason 02] Present bit in context entry is clear
[ 611.858351] dmar: DRHD: handling fault status reg 302
[ 611.858362] dmar: DMAR:[DMA Read] Request device [86:00.3] fault addr ffff4000
[ 611.858362] DMAR:[fault reason 02] Present bit in context entry is clear
[ 611.860819] IPv6: ADDRCONF(NETDEV_UP): eth3: link is not ready
[ 611.860983] dmar: DRHD: handling fault status reg 402
[ 611.860995] dmar: INTR-REMAP: Request device [[86:00.3] fault index a4
[ 611.860995] INTR-REMAP:[fault reason 34] Present field in the IRTE entry is clear
This patch introduces a new mechanism to update the DRHD/RMRR/ATSR device scope
caches by hooking PCI bus notification.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Global DMA and interrupt remapping resources may be accessed in
interrupt context, so use RCU instead of rwsem to protect them
in such cases.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Introduce a global rwsem dmar_global_lock, which will be used to
protect DMAR related global data structures from DMAR/PCI/memory
device hotplug operations in process context.
DMA and interrupt remapping related data structures are read most,
and only change when memory/PCI/DMAR hotplug event happens.
So a global rwsem solution is adopted for balance between simplicity
and performance.
For interrupt remapping driver, function intel_irq_remapping_supported(),
dmar_table_init(), intel_enable_irq_remapping(), disable_irq_remapping(),
reenable_irq_remapping() and enable_drhd_fault_handling() etc
are called during booting, suspending and resuming with interrupt
disabled, so no need to take the global lock.
For interrupt remapping entry allocation, the locking model is:
down_read(&dmar_global_lock);
/* Find corresponding iommu */
iommu = map_hpet_to_ir(id);
if (iommu)
/*
* Allocate remapping entry and mark entry busy,
* the IOMMU won't be hot-removed until the
* allocated entry has been released.
*/
index = alloc_irte(iommu, irq, 1);
up_read(&dmar_global_lock);
For DMA remmaping driver, we only uses the dmar_global_lock rwsem to
protect functions which are only called in process context. For any
function which may be called in interrupt context, we will use RCU
to protect them in following patches.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Introduce for_each_dev_scope()/for_each_active_dev_scope() to walk
{active} device scope entries. This will help following RCU lock
related patches.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Reduce duplicated code to handle virtual machine domains, there's no
functionality changes. It also improves code readability.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Enhance function get_domain_for_dev() to release allocated resources
if failed to create domain for PCIe endpoint, otherwise the allocated
resources will get lost.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Function get_domain_for_dev() is a little complex, simplify it
by factoring out dmar_search_domain_by_dev_info() and
dmar_insert_dev_info().
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Move private structures and variables into intel-iommu.c, which will
help to simplify locking policy for hotplug. Also delete redundant
declarations.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Function device_notifier() in intel-iommu.c only remove domain_device_info
data structure associated with a PCI device when handling PCI device
driver unbinding events. If a PCI device has never been bound to a PCI
device driver, there won't be BUS_NOTIFY_UNBOUND_DRIVER event when
hot-removing the PCI device. So associated domain_device_info data
structure may get lost.
On the other hand, if iommu_pass_through is enabled, function
iommu_prepare_static_indentify_mapping() will create domain_device_info
data structure for each PCIe to PCIe bridge and PCIe endpoint,
no matter whether there are drivers associated with those PCIe devices
or not. So those domain_device_info data structures will get lost when
hot-removing the assocated PCIe devices if they have never bound to
any PCI device driver.
To be even worse, it's not only an memory leak issue, but also an
caching of stale information bug because the memory are kept in
device_domain_list and domain->devices lists.
Fix the bug by trying to remove domain_device_info data structure when
handling BUS_NOTIFY_DEL_DEVICE event.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
Function device_notifier() in intel-iommu.c fails to remove
device_domain_info data structures for PCI devices if they are
associated with si_domain because iommu_no_mapping() returns true
for those PCI devices. This will cause memory leak and caching of
stale information in domain->devices list.
So fix the issue by not calling iommu_no_mapping() and skipping check
of iommu_pass_through.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>
