Commit Graph

30 Commits

Author SHA1 Message Date
Dong Jia Shi 120e214e50 vfio: ccw: realize VFIO_DEVICE_G(S)ET_IRQ_INFO ioctls
Realize VFIO_DEVICE_GET_IRQ_INFO ioctl to retrieve
VFIO_CCW_IO_IRQ information.

Realize VFIO_DEVICE_SET_IRQS ioctl to set an eventfd fd for
VFIO_CCW_IO_IRQ. Once a write operation to the ccw_io_region
was performed, trigger a signal on this fd.

Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Message-Id: <20170317031743.40128-12-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-03-31 12:55:09 +02:00
Dong Jia Shi e01bcdd613 vfio: ccw: realize VFIO_DEVICE_GET_REGION_INFO ioctl
Introduce device information about vfio-ccw: VFIO_DEVICE_FLAGS_CCW.
Realize VFIO_DEVICE_GET_REGION_INFO ioctl for vfio-ccw.

Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Message-Id: <20170317031743.40128-10-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-03-31 12:55:08 +02:00
Dong Jia Shi aec390b937 vfio: ccw: define device_api strings
Define vfio-ccw device API strings. CCW vendor driver using mediated
device framework should use this string for device_api attribute.

Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Message-Id: <20170317031743.40128-4-bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2017-03-31 12:55:04 +02:00
Kirti Wankhede 2818c6e919 vfio: Define device_api strings
Defined device API strings. Vendor driver using mediated device
framework should use corresponding string for device_api attribute.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17 08:33:20 -07:00
Alex Williamson f572a960a1 vfio/pci: Intel IGD host and LCP bridge config space access
Provide read-only access to PCI config space of the PCI host bridge
and LPC bridge through device specific regions.  This may be used to
configure a VM with matching register contents to satisfy driver
requirements.  Providing this through the vfio file descriptor removes
an additional userspace requirement for access through pci-sysfs and
removes the CAP_SYS_ADMIN requirement that doesn't appear to apply to
the specific devices we're accessing.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:09 -07:00
Alex Williamson 5846ff54e8 vfio/pci: Intel IGD OpRegion support
This is the first consumer of vfio device specific resource support,
providing read-only access to the OpRegion for Intel graphics devices.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:09 -07:00
Alex Williamson c7bb4cb40f vfio: Define device specific region type capability
To this point vfio has only provided an interface to the user that
allows them to determine the number of regions and specifics about
each region.  What the region represents is left to the vfio bus
driver.  vfio-pci chooses to use fixed indexes for fixed resources,
index 0 is BAR0, 1 is BAR1,... 7 is config space, etc.  This works
pretty well since all PCI devices have these regions, even if they
don't necessarily populate all of them.  Then we start to add things
like VGA, which only certain device even support.  We added this the
same way, but now we've wasted a region index, and due to our offset
implementation the corresponding address space, for all devices.

Rather than continuing that process, let's try to make regions self
describing by including a capability that defines their type.  For
vfio-pci we'll make the current VFIO_PCI_NUM_REGIONS fixed, defining
the end of the static indexes and the beginning of self describing
regions.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:09 -07:00
Alex Williamson ff63eb638d vfio: Define sparse mmap capability for regions
We can't always support mmap across an entire device region, for
example we deny mmaps covering the MSI-X table of PCI devices, but
we don't really have a way to report it.  We expect the user to
implicitly know this restriction.  We also can't split the region
because vfio-pci defines an API with fixed region index to BAR
number mapping.  We therefore define a new capability which lists
areas within the region that may be mmap'd.  In addition to the
MSI-X case, this potentially enables in-kernel emulation and
extensions to devices.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:08 -07:00
Alex Williamson c84982adb2 vfio: Define capability chains
We have a few cases where we need to extend the data returned from the
INFO ioctls in VFIO.  For instance we already have devices exposed
through vfio-pci where VFIO_DEVICE_GET_REGION_INFO reports the region
as mmap-capable, but really only supports sparse mmaps, avoiding the
MSI-X table.  If we wanted to provide in-kernel emulation or extended
functionality for devices, we'd also want the ability to tell the
user not to mmap various regions, rather than forcing them to figure
it out on their own.

Another example is VFIO_IOMMU_GET_INFO.  We'd really like to expose
the actual IOVA capabilities of the IOMMU rather than letting the
user assume the address space they have available to them.  We could
add IOVA base and size fields to struct vfio_iommu_type1_info, but
what if we have multiple IOVA ranges.  For instance x86 uses a range
of addresses at 0xfee00000 for MSI vectors.  These typically are not
available for standard DMA IOVA mappings and splits our available IOVA
space into two ranges.  POWER systems have both an IOVA window below
4G as well as dynamic data window which they can use to remap all of
guest memory.

Representing variable sized arrays within a fixed structure makes it
very difficult to parse, we'd therefore like to put this data beyond
fixed fields within the data structures.  One way to do this is to
emulate capabilities in PCI configuration space.  A new flag indciates
whether capabilties are supported and a new fixed field reports the
offset of the first entry.  Users can then walk the chain to find
capabilities, adding capabilities does not require additional fields
in the fixed structure, and parsing variable sized data becomes
trivial.

This patch outlines the theory and base header structure, which
should be shared by all future users.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:08 -07:00
Alex Williamson 03a76b60f8 vfio: Include No-IOMMU mode
There is really no way to safely give a user full access to a DMA
capable device without an IOMMU to protect the host system.  There is
also no way to provide DMA translation, for use cases such as device
assignment to virtual machines.  However, there are still those users
that want userspace drivers even under those conditions.  The UIO
driver exists for this use case, but does not provide the degree of
device access and programming that VFIO has.  In an effort to avoid
code duplication, this introduces a No-IOMMU mode for VFIO.

This mode requires building VFIO with CONFIG_VFIO_NOIOMMU and enabling
the "enable_unsafe_noiommu_mode" option on the vfio driver.  This
should make it very clear that this mode is not safe.  Additionally,
CAP_SYS_RAWIO privileges are necessary to work with groups and
containers using this mode.  Groups making use of this support are
named /dev/vfio/noiommu-$GROUP and can only make use of the special
VFIO_NOIOMMU_IOMMU for the container.  Use of this mode, specifically
binding a device without a native IOMMU group to a VFIO bus driver
will taint the kernel and should therefore not be considered
supported.  This patch includes no-iommu support for the vfio-pci bus
driver only.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
2015-12-21 15:28:11 -07:00
Alexey Kardashevskiy 77d6bd47cc vfio: Add explicit alignments in vfio_iommu_spapr_tce_create
The vfio_iommu_spapr_tce_create struct has 4x32bit and 2x64bit fields
which should have resulted in sizeof(fio_iommu_spapr_tce_create) equal
to 32 bytes. However due to the gcc's default alignment, the actual
size of this struct is 40 bytes.

This fills gaps with __resv1/2 fields.

This should not cause any change in behavior.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-12-21 15:28:11 -07:00
Alex Williamson ae5515d663 Revert: "vfio: Include No-IOMMU mode"
Revert commit 033291eccb ("vfio: Include No-IOMMU mode") due to lack
of a user.  This was originally intended to fill a need for the DPDK
driver, but uptake has been slow so rather than support an unproven
kernel interface revert it and revisit when userspace catches up.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-12-04 08:38:42 -07:00
Alex Williamson 033291eccb vfio: Include No-IOMMU mode
There is really no way to safely give a user full access to a DMA
capable device without an IOMMU to protect the host system.  There is
also no way to provide DMA translation, for use cases such as device
assignment to virtual machines.  However, there are still those users
that want userspace drivers even under those conditions.  The UIO
driver exists for this use case, but does not provide the degree of
device access and programming that VFIO has.  In an effort to avoid
code duplication, this introduces a No-IOMMU mode for VFIO.

This mode requires building VFIO with CONFIG_VFIO_NOIOMMU and enabling
the "enable_unsafe_noiommu_mode" option on the vfio driver.  This
should make it very clear that this mode is not safe.  Additionally,
CAP_SYS_RAWIO privileges are necessary to work with groups and
containers using this mode.  Groups making use of this support are
named /dev/vfio/noiommu-$GROUP and can only make use of the special
VFIO_NOIOMMU_IOMMU for the container.  Use of this mode, specifically
binding a device without a native IOMMU group to a VFIO bus driver
will taint the kernel and should therefore not be considered
supported.  This patch includes no-iommu support for the vfio-pci bus
driver only.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
2015-11-04 09:56:16 -07:00
Alexey Kardashevskiy e633bc86a9 vfio: powerpc/spapr: Support Dynamic DMA windows
This adds create/remove window ioctls to create and remove DMA windows.
sPAPR defines a Dynamic DMA windows capability which allows
para-virtualized guests to create additional DMA windows on a PCI bus.
The existing linux kernels use this new window to map the entire guest
memory and switch to the direct DMA operations saving time on map/unmap
requests which would normally happen in a big amounts.

This adds 2 ioctl handlers - VFIO_IOMMU_SPAPR_TCE_CREATE and
VFIO_IOMMU_SPAPR_TCE_REMOVE - to create and remove windows.
Up to 2 windows are supported now by the hardware and by this driver.

This changes VFIO_IOMMU_SPAPR_TCE_GET_INFO handler to return additional
information such as a number of supported windows and maximum number
levels of TCE tables.

DDW is added as a capability, not as a SPAPR TCE IOMMU v2 unique feature
as we still want to support v2 on platforms which cannot do DDW for
the sake of TCE acceleration in KVM (coming soon).

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:16:55 +10:00
Alexey Kardashevskiy 2157e7b82f vfio: powerpc/spapr: Register memory and define IOMMU v2
The existing implementation accounts the whole DMA window in
the locked_vm counter. This is going to be worse with multiple
containers and huge DMA windows. Also, real-time accounting would requite
additional tracking of accounted pages due to the page size difference -
IOMMU uses 4K pages and system uses 4K or 64K pages.

Another issue is that actual pages pinning/unpinning happens on every
DMA map/unmap request. This does not affect the performance much now as
we spend way too much time now on switching context between
guest/userspace/host but this will start to matter when we add in-kernel
DMA map/unmap acceleration.

This introduces a new IOMMU type for SPAPR - VFIO_SPAPR_TCE_v2_IOMMU.
New IOMMU deprecates VFIO_IOMMU_ENABLE/VFIO_IOMMU_DISABLE and introduces
2 new ioctls to register/unregister DMA memory -
VFIO_IOMMU_SPAPR_REGISTER_MEMORY and VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY -
which receive user space address and size of a memory region which
needs to be pinned/unpinned and counted in locked_vm.
New IOMMU splits physical pages pinning and TCE table update
into 2 different operations. It requires:
1) guest pages to be registered first
2) consequent map/unmap requests to work only with pre-registered memory.
For the default single window case this means that the entire guest
(instead of 2GB) needs to be pinned before using VFIO.
When a huge DMA window is added, no additional pinning will be
required, otherwise it would be guest RAM + 2GB.

The new memory registration ioctls are not supported by
VFIO_SPAPR_TCE_IOMMU. Dynamic DMA window and in-kernel acceleration
will require memory to be preregistered in order to work.

The accounting is done per the user process.

This advertises v2 SPAPR TCE IOMMU and restricts what the userspace
can do with v1 or v2 IOMMUs.

In order to support memory pre-registration, we need a way to track
the use of every registered memory region and only allow unregistration
if a region is not in use anymore. So we need a way to tell from what
region the just cleared TCE was from.

This adds a userspace view of the TCE table into iommu_table struct.
It contains userspace address, one per TCE entry. The table is only
allocated when the ownership over an IOMMU group is taken which means
it is only used from outside of the powernv code (such as VFIO).

As v2 IOMMU supports IODA2 and pre-IODA2 IOMMUs (which do not support
DDW API), this creates a default DMA window for IODA2 for consistency.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:16:55 +10:00
Gavin Shan 68cbbc3a9d drivers/vfio: Support EEH error injection
The patch adds one more EEH sub-command (VFIO_EEH_PE_INJECT_ERR)
to inject the specified EEH error, which is represented by
(struct vfio_eeh_pe_err), to the indicated PE for testing purpose.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-12 20:33:35 +10:00
Antonios Motakis 36fe431f28 vfio: amba: VFIO support for AMBA devices
Add support for discovering AMBA devices with VFIO and handle them
similarly to Linux platform devices.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-16 14:08:44 -06:00
Antonios Motakis 9df85aaa43 vfio: platform: probe to devices on the platform bus
Driver to bind to Linux platform devices, and callbacks to discover their
resources to be used by the main VFIO PLATFORM code.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
Signed-off-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-16 14:08:43 -06:00
Alex Williamson 6140a8f562 vfio-pci: Add device request interface
Userspace can opt to receive a device request notification,
indicating that the device should be released.  This is setup
the same way as the error IRQ and also supports eventfd signaling.
Future support may forcefully remove the device from the user if
the request is ignored.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-02-10 12:38:14 -07:00
Will Deacon f5c9ecebaf vfio/iommu_type1: add new VFIO_TYPE1_NESTING_IOMMU IOMMU type
VFIO allows devices to be safely handed off to userspace by putting
them behind an IOMMU configured to ensure DMA and interrupt isolation.
This enables userspace KVM clients, such as kvmtool and qemu, to further
map the device into a virtual machine.

With IOMMUs such as the ARM SMMU, it is then possible to provide SMMU
translation services to the guest operating system, which are nested
with the existing translation installed by VFIO. However, enabling this
feature means that the IOMMU driver must be informed that the VFIO domain
is being created for the purposes of nested translation.

This patch adds a new IOMMU type (VFIO_TYPE1_NESTING_IOMMU) to the VFIO
type-1 driver. The new IOMMU type acts identically to the
VFIO_TYPE1v2_IOMMU type, but additionally sets the DOMAIN_ATTR_NESTING
attribute on its IOMMU domains.

Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-09-29 10:06:19 -06:00
Gavin Shan 1b69be5e8a drivers/vfio: EEH support for VFIO PCI device
The patch adds new IOCTL commands for sPAPR VFIO container device
to support EEH functionality for PCI devices, which have been passed
through from host to somebody else via VFIO.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexander Graf <agraf@suse.de>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-08-05 15:28:48 +10:00
Alex Williamson aa42931827 vfio/type1: Add extension to test DMA cache coherence of IOMMU
Now that the type1 IOMMU backend can support IOMMU_CACHE, we need to
be able to test whether coherency is currently enforced.  Add an
extension for this.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-02-26 11:38:37 -07:00
Alex Williamson 1ef3e2bc04 vfio/iommu_type1: Multi-IOMMU domain support
We currently have a problem that we cannot support advanced features
of an IOMMU domain (ex. IOMMU_CACHE), because we have no guarantee
that those features will be supported by all of the hardware units
involved with the domain over its lifetime.  For instance, the Intel
VT-d architecture does not require that all DRHDs support snoop
control.  If we create a domain based on a device behind a DRHD that
does support snoop control and enable SNP support via the IOMMU_CACHE
mapping option, we cannot then add a device behind a DRHD which does
not support snoop control or we'll get reserved bit faults from the
SNP bit in the pagetables.  To add to the complexity, we can't know
the properties of a domain until a device is attached.

We could pass this problem off to userspace and require that a
separate vfio container be used, but we don't know how to handle page
accounting in that case.  How do we know that a page pinned in one
container is the same page as a different container and avoid double
billing the user for the page.

The solution is therefore to support multiple IOMMU domains per
container.  In the majority of cases, only one domain will be required
since hardware is typically consistent within a system.  However, this
provides us the ability to validate compatibility of domains and
support mixed environments where page table flags can be different
between domains.

To do this, our DMA tracking needs to change.  We currently try to
coalesce user mappings into as few tracking entries as possible.  The
problem then becomes that we lose granularity of user mappings.  We've
never guaranteed that a user is able to unmap at a finer granularity
than the original mapping, but we must honor the granularity of the
original mapping.  This coalescing code is therefore removed, allowing
only unmaps covering complete maps.  The change in accounting is
fairly small here, a typical QEMU VM will start out with roughly a
dozen entries, so it's arguable if this coalescing was ever needed.

We also move IOMMU domain creation to the point where a group is
attached to the container.  An interesting side-effect of this is that
we now have access to the device at the time of domain creation and
can probe the devices within the group to determine the bus_type.
This finally makes vfio_iommu_type1 completely device/bus agnostic.
In fact, each IOMMU domain can host devices on different buses managed
by different physical IOMMUs, and present a single DMA mapping
interface to the user.  When a new domain is created, mappings are
replayed to bring the IOMMU pagetables up to the state of the current
container.  And of course, DMA mapping and unmapping automatically
traverse all of the configured IOMMU domains.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Varun Sethi <Varun.Sethi@freescale.com>
2014-02-26 11:38:36 -07:00
Alex Williamson 8b27ee60bf vfio-pci: PCI hot reset interface
The current VFIO_DEVICE_RESET interface only maps to PCI use cases
where we can isolate the reset to the individual PCI function.  This
means the device must support FLR (PCIe or AF), PM reset on D3hot->D0
transition, device specific reset, or be a singleton device on a bus
for a secondary bus reset.  FLR does not have widespread support,
PM reset is not very reliable, and bus topology is dictated by the
system and device design.  We need to provide a means for a user to
induce a bus reset in cases where the existing mechanisms are not
available or not reliable.

This device specific extension to VFIO provides the user with this
ability.  Two new ioctls are introduced:
 - VFIO_DEVICE_PCI_GET_HOT_RESET_INFO
 - VFIO_DEVICE_PCI_HOT_RESET

The first provides the user with information about the extent of
devices affected by a hot reset.  This is essentially a list of
devices and the IOMMU groups they belong to.  The user may then
initiate a hot reset by calling the second ioctl.  We must be
careful that the user has ownership of all the affected devices
found via the first ioctl, so the second ioctl takes a list of file
descriptors for the VFIO groups affected by the reset.  Each group
must have IOMMU protection established for the ioctl to succeed.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-09-04 11:28:04 -06:00
Linus Torvalds 15a49b9a90 vfio Updates for v3.11
Largely hugepage support for vfio/type1 iommu and surrounding cleanups and fixes.
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Merge tag 'vfio-v3.11' of git://github.com/awilliam/linux-vfio

Pull vfio updates from Alex Williamson:
 "Largely hugepage support for vfio/type1 iommu and surrounding cleanups
  and fixes"

* tag 'vfio-v3.11' of git://github.com/awilliam/linux-vfio:
  vfio/type1: Fix leak on error path
  vfio: Limit group opens
  vfio/type1: Fix missed frees and zero sized removes
  vfio: fix documentation
  vfio: Provide module option to disable vfio_iommu_type1 hugepage support
  vfio: hugepage support for vfio_iommu_type1
  vfio: Convert type1 iommu to use rbtree
2013-07-10 14:50:08 -07:00
Alex Williamson 166fd7d94a vfio: hugepage support for vfio_iommu_type1
We currently send all mappings to the iommu in PAGE_SIZE chunks,
which prevents the iommu from enabling support for larger page sizes.
We still need to pin pages, which means we step through them in
PAGE_SIZE chunks, but we can batch up contiguous physical memory
chunks to allow the iommu the opportunity to use larger pages.  The
approach here is a bit different that the one currently used for
legacy KVM device assignment.  Rather than looking at the vma page
size and using that as the maximum size to pass to the iommu, we
instead simply look at whether the next page is physically
contiguous.  This means we might ask the iommu to map a 4MB region,
while legacy KVM might limit itself to a maximum of 2MB.

Splitting our mapping path also allows us to be smarter about locked
memory because we can more easily unwind if the user attempts to
exceed the limit.  Therefore, rather than assuming that a mapping
will result in locked memory, we test each page as it is pinned to
determine whether it locks RAM vs an mmap'd MMIO region.  This should
result in better locking granularity and less locked page fudge
factors in userspace.

The unmap path uses the same algorithm as legacy KVM.  We don't want
to track the pfn for each mapping ourselves, but we need the pfn in
order to unpin pages.  We therefore ask the iommu for the iova to
physical address translation, ask it to unpin a page, and see how many
pages were actually unpinned.  iommus supporting large pages will
often return something bigger than a page here, which we know will be
physically contiguous and we can unpin a batch of pfns.  iommus not
supporting large mappings won't see an improvement in batching here as
they only unmap a page at a time.

With this change, we also make a clarification to the API for mapping
and unmapping DMA.  We can only guarantee unmaps at the same
granularity as used for the original mapping.  In other words,
unmapping a subregion of a previous mapping is not guaranteed and may
result in a larger or smaller unmapping than requested.  The size
field in the unmapping structure is updated to reflect this.
Previously this was unmodified on mapping, always returning the the
requested unmap size.  This is now updated to return the actual unmap
size on success, allowing userspace to appropriately track mappings.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-06-21 09:38:02 -06:00
Alexey Kardashevskiy 5ffd229c02 powerpc/vfio: Implement IOMMU driver for VFIO
VFIO implements platform independent stuff such as
a PCI driver, BAR access (via read/write on a file descriptor
or direct mapping when possible) and IRQ signaling.

The platform dependent part includes IOMMU initialization
and handling.  This implements an IOMMU driver for VFIO
which does mapping/unmapping pages for the guest IO and
provides information about DMA window (required by a POWER
guest).

Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-20 16:55:14 +10:00
Vijay Mohan Pandarathil dad9f8972e VFIO-AER: Vfio-pci driver changes for supporting AER
- New VFIO_SET_IRQ ioctl option to pass the eventfd that is signaled when
  an error occurs in the vfio_pci_device

- Register pci_error_handler for the vfio_pci driver

- When the device encounters an error, the error handler registered by
  the vfio_pci driver gets invoked by the AER infrastructure

- In the error handler, signal the eventfd registered for the device.

- This results in the qemu eventfd handler getting invoked and
  appropriate action taken for the guest.

Signed-off-by: Vijay Mohan Pandarathil <vijaymohan.pandarathil@hp.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-03-11 09:31:22 -06:00
Alex Williamson 84237a826b vfio-pci: Add support for VGA region access
PCI defines display class VGA regions at I/O port address 0x3b0, 0x3c0
and MMIO address 0xa0000.  As these are non-overlapping, we can ignore
the I/O port vs MMIO difference and expose them both in a single
region.  We make use of the VGA arbiter around each access to
configure chipset access as necessary.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-02-18 10:11:13 -07:00
David Howells 607ca46e97 UAPI: (Scripted) Disintegrate include/linux
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-13 10:46:48 +01:00