When a 'struct device_domain_info' is created as an alias
for another device, this struct will not be re-used when the
real device is encountered. Fix that to avoid duplicate
device_domain_info structures being added.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

For devices without an PCI alias there will be two
device_domain_info structures added. Prevent that by
checking if the alias is different from the device.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This struct contains all necessary information for the
function already. Also handle the info->dev == NULL case
while at it.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The code in the locked section does not touch anything
protected by the dmar_global_lock. Remove it from there.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

When this lock is held the device_domain_lock is also
required to make sure the device_domain_info does not vanish
while in use. So this lock can be removed as it gives no
additional protection.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

There is no need to make a difference here between VM and
non-VM domains, so simplify this code here.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Move the code to attach/detach domains to iommus and vice
verce into a single function to make sure there are no
dangling references.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This makes domain attachment more synchronous with domain
deattachment. The domain<->iommu link is released in
dmar_remove_one_dev_info.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This allows to do domain->iommu attachment after domain_init
has run.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Rename this function and the ones further down its
call-chain to domain_context_clear_*. In particular this
means:

	iommu_detach_dependent_devices -> domain_context_clear
		   iommu_detach_dev_cb -> domain_context_clear_one_cb
		      iommu_detach_dev -> domain_context_clear_one

These names match a lot better with its
domain_context_mapping counterparts.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Rename the function to dmar_remove_one_dev_info to match is
name better with its dmar_insert_one_dev_info counterpart.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Rename this function to dmar_insert_one_dev_info() to match
the name better with its counter part function
domain_remove_one_dev_info().
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Do the context-mapping of devices from a single place in the
call-path and clean up the other call-sites.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Just call domain_remove_one_dev_info() for all devices in
the domain instead of reimplementing the functionality.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Simplify this function as much as possible with the new
iommu_refcnt field.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

We don't need to do an expensive search for domain-ids
anymore, as we keep track of per-iommu domain-ids.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This replaces the dmar_domain->iommu_bmp with a similar
reference count array. This allows us to keep track of how
many devices behind each iommu are attached to the domain.

This is necessary for further simplifications and
optimizations to the iommu<->domain attachment code.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This field is now obsolete because all places use the
per-iommu domain-ids. Kill the remaining uses of this field
and remove it.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

There is no reason for this special handling of the
si_domain. The per-iommu domain-id can be allocated
on-demand like for any other domain. So remove the
pre-allocation code.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This function can figure out the domain-id to use itself
from the iommu_did array. This is more reliable over
different domain types and brings us one step further to
remove the domain->id field.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Get rid of the special cases for VM domains vs. non-VM
domains and simplify the code further to just handle the
hardware passthrough vs. page-table case.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

There is no reason to pass the translation type through
multiple layers. It can also be determined in the
domain_context_mapping_one function directly.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

The special case for VM domains is not needed, as other
domains could be attached to the iommu in the same way. So
get rid of this special case.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This array is indexed by the domain-id and contains the
pointers to the domains attached to this iommu. Modern
systems support 65536 domain ids, so that this array has a
size of 512kb, per iommu.

This is a huge waste of space, as the array is usually
sparsely populated. This patch makes the array
two-dimensional and allocates the memory for the domain
pointers on-demand.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This makes it easier to change the layout of the data
structure later.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Instead of searching in the domain array for already
allocated domain ids, keep track of them explicitly.
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Debugging domain ID leakage typically requires long running tests in
order to exhaust the domain ID space or kernel instrumentation to
track the setting and clearing of bits.  A couple trivial intel-iommu
specific sysfs extensions make it much easier to expose the IOMMU
capabilities and current usage.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This makes sure it won't be possible to accidentally leak format
strings into iommu device names. Current name allocations are safe,
but this makes the "%s" explicit.
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This continues the attempt to fix commit fb170fb4 ("iommu/vt-d:
Introduce helper functions to make code symmetric for readability").
The previous attempt in commit 71684406 ("iommu/vt-d: Detach
domain *only* from attached iommus") overlooked the fact that
dmar_domain.iommu_bmp gets cleared for VM domains when devices are
detached:

intel_iommu_detach_device
  domain_remove_one_dev_info
    domain_detach_iommu

The domain is detached from the iommu, but the iommu is still attached
to the domain, for whatever reason.  Thus when we get to domain_exit(),
we can't rely on iommu_bmp for VM domains to find the active iommus,
we must check them all.  Without that, the corresponding bit in
intel_iommu.domain_ids doesn't get cleared and repeated VM domain
creation and destruction will run out of domain IDs.  Meanwhile we
still can't call iommu_detach_domain() on arbitrary non-VM domains or
we risk clearing in-use domain IDs, as 71684406 attempted to
address.

It's tempting to modify iommu_detach_domain() to test the domain
iommu_bmp, but the call ordering from domain_remove_one_dev_info()
prevents it being able to work as fb170fb4 seems to have intended.
Caching of unused VM domains on the iommu object seems to be the root
of the problem, but this code is far too fragile for that kind of
rework to be proposed for stable, so we simply revert this chunk to
its state prior to fb170fb4.

Fixes: fb170fb4 ("iommu/vt-d: Introduce helper functions to make
                      code symmetric for readability")
Fixes: 71684406 ("iommu/vt-d: Detach domain *only* from attached
                      iommus")
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: stable@vger.kernel.org # v3.17+
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Do not touch the TE bit unless we know translation is
disabled.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

For all the copy-translation code to run, we have to keep
translation enabled in intel_iommu_init(). So remove the
code disabling it.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

We can't change the RTT bit when translation is enabled, so
don't copy translation tables when we would change the bit
with our new root entry.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

When we copied over context tables from an old kernel, we
need to defer assignment of devices to domains until the
device driver takes over. So skip this part of
initialization when we copied over translation tables from
the old kernel.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

This seperates the allocation of the si_domain from its
assignment to devices. It makes sure that the iommu=pt case
still works in the kdump kernel, when we have to defer the
assignment of devices to domains to device driver
initialization time.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Mark the context entries we copied over from the old kernel,
so that we don't detect them as present in other code paths.
This makes sure we safely overwrite old context entries when
a new domain is assigned.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Mark all domain-ids we find as reserved, so that there could
be no collision between domains from the previous kernel and
our domains in the IOMMU TLB.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

If we are in a kdump kernel and find translation enabled in
the iommu, try to copy the translation tables from the old
kernel to preserve the mappings until the device driver
takes over.
This supports old and the extended root-entry and
context-table formats.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Add code to detect whether translation is already enabled in
the IOMMU. Save this state in a flags field added to
struct intel_iommu.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

In case there was an old root entry, make our new one
visible immediately after it was allocated.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

QI needs to be available when we write the root entry into
hardware because flushes might be necessary after this.
Tested-by: NZhenHua Li <zhen-hual@hp.com>
Tested-by: NBaoquan He <bhe@redhat.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>