Commit Graph

56 Commits

Author SHA1 Message Date
Alex Williamson
450744051d vfio/pci: Hide broken INTx support from user
INTx masking has two components, the first is that we need the ability
to prevent the device from continuing to assert INTx.  This is
provided via the DisINTx bit in the command register and is the only
thing we can really probe for when testing if INTx masking is
supported.  The second component is that the device needs to indicate
if INTx is asserted via the interrupt status bit in the device status
register.  With these two features we can generically determine if one
of the devices we own is asserting INTx, signal the user, and mask the
interrupt while the user services the device.

Generally if one or both of these components is broken we resort to
APIC level interrupt masking, which requires an exclusive interrupt
since we have no way to determine the source of the interrupt in a
shared configuration.  This often makes it difficult or impossible to
configure the system for userspace use of the device, for an interrupt
mode that the user may not need.

One possible configuration of broken INTx masking is that the DisINTx
support is fully functional, but the interrupt status bit never
signals interrupt assertion.  In this case we do have the ability to
prevent the device from asserting INTx, but lack the ability to
identify the interrupt source.  For this case we can simply pretend
that the device lacks INTx support entirely, keeping DisINTx set on
the physical device, virtualizing this bit for the user, and
virtualizing the interrupt pin register to indicate no INTx support.
We already support virtualization of the DisINTx bit and already
virtualize the interrupt pin for platforms without INTx support.  By
tying these components together, setting DisINTx on open and reset,
and identifying devices broken in this particular way, we can provide
support for them w/o the handicap of APIC level INTx masking.

Intel i40e (XL710/X710) 10/20/40GbE NICs have been identified as being
broken in this specific way.  We leave the vfio-pci.nointxmask option
as a mechanism to bypass this support, enabling INTx on the device
with all the requirements of APIC level masking.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: John Ronciak <john.ronciak@intel.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
2016-04-28 11:12:27 -06:00
Linus Torvalds
45cb5230f8 VFIO updates for v4.6-rc1
Various enablers for assignment of Intel graphics devices and future
 support of vGPU devices (Alex Williamson).  This includes
 
  - Handling the vfio type1 interface as an API rather than a specific
    implementation, allowing multiple type1 providers.
 
  - Capability chains, similar to PCI device capabilities, that allow
    extending ioctls.  Extensions here include device specific regions
    and sparse mmap descriptions.  The former is used to expose non-PCI
    regions for IGD, including the OpRegion (particularly the Video
    BIOS Table), and read only PCI config access to the host and LPC
    bridge as drivers often depend on identifying those devices.
    Sparse mmaps here are used to describe the MSIx vector table,
    which vfio has always protected from mmap, but never had an API to
    explicitly define that protection.  In future vGPU support this is
    expected to allow the description of PCI BARs that may mix direct
    access and emulated access within a single region.
 
  - The ability to expose the shadow ROM as an option ROM as IGD use
    cases may rely on the ROM even though the physical device does not
    make use of a PCI option ROM BAR.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.14 (GNU/Linux)
 
 iQIcBAABAgAGBQJW6aT1AAoJECObm247sIsiiP4P/1xf7Z08/2QWVFQzex9CLcZk
 +/iJlyb/fTpPVQE+NTKPz3Qh5h6ZhSd/57s85IUqq0T6tgVPkoGx8kkyCjBaw2y1
 yMezXZlQqJdZqGzQNI4OiHWvO+/vGxYKjQMfUnMlDM6dJgz4lGncGFoSouFPa3Vp
 mB12hGxrlk1cfIdb+C1KbfZcEdS0WhtigQtz8flBKgOfO+hYWmUO+CClJBhVw8Z4
 RNcWNAxFfLuwUPVsPb6uOLG2g65SC2vmQ9k0Tnknf1znV3PFFVjITf0aM6uChLNP
 S3SgqtPX+6yOFyCuSEs8UKhhmCbeQmAyKgt5BpxV3Rw3OMP4PsVAehr82vQmSj6g
 2o96pR2s8MDPBr8eG7gdRe4DQe3PonpLkpDfaghcpYqhkGEqNVeW5/GjiOzGQqD3
 xMshzxJ1Iz7DOHkQRUVqOfupDB0TusJmTVKwvXe6yIYL9pjkUS/sbN9U563HYSES
 JTV68TMj0VKfKwD3XKYXvGH3km1sL4i5NMlAUrsDtsMkGlXEswoGbj82Mjc8+jUo
 BvWQTJb+kouJQ88VhsO2abg1UrO9E6u82iHFHy9fEObxE8KH7pvROlS93ihMT1Wv
 WQNuUcltdpHMRVX0BDknaPs3YtC3/TGgm3RcU5SZPbv/ys1471ZmJxMlAAKcfITr
 SuvkMTYElF5b1pigv46c
 =/lJn
 -----END PGP SIGNATURE-----

Merge tag 'vfio-v4.6-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:
 "Various enablers for assignment of Intel graphics devices and future
  support of vGPU devices (Alex Williamson).  This includes

   - Handling the vfio type1 interface as an API rather than a specific
     implementation, allowing multiple type1 providers.

   - Capability chains, similar to PCI device capabilities, that allow
     extending ioctls.  Extensions here include device specific regions
     and sparse mmap descriptions.  The former is used to expose non-PCI
     regions for IGD, including the OpRegion (particularly the Video
     BIOS Table), and read only PCI config access to the host and LPC
     bridge as drivers often depend on identifying those devices.

     Sparse mmaps here are used to describe the MSIx vector table, which
     vfio has always protected from mmap, but never had an API to
     explicitly define that protection.  In future vGPU support this is
     expected to allow the description of PCI BARs that may mix direct
     access and emulated access within a single region.

   - The ability to expose the shadow ROM as an option ROM as IGD use
     cases may rely on the ROM even though the physical device does not
     make use of a PCI option ROM BAR"

* tag 'vfio-v4.6-rc1' of git://github.com/awilliam/linux-vfio:
  vfio/pci: return -EFAULT if copy_to_user fails
  vfio/pci: Expose shadow ROM as PCI option ROM
  vfio/pci: Intel IGD host and LCP bridge config space access
  vfio/pci: Intel IGD OpRegion support
  vfio/pci: Enable virtual register in PCI config space
  vfio/pci: Add infrastructure for additional device specific regions
  vfio: Define device specific region type capability
  vfio/pci: Include sparse mmap capability for MSI-X table regions
  vfio: Define sparse mmap capability for regions
  vfio: Add capability chain helpers
  vfio: Define capability chains
  vfio: If an IOMMU backend fails, keep looking
  vfio/pci: Fix unsigned comparison overflow
2016-03-17 13:05:09 -07:00
Michael S. Tsirkin
8160c4e455 vfio: fix ioctl error handling
Calling return copy_to_user(...) in an ioctl will not
do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied
in this case.

Fix up vfio to do
	return copy_to_user(...)) ?
		-EFAULT : 0;

everywhere.

Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-28 07:38:52 -07:00
Dan Carpenter
c4aec31013 vfio/pci: return -EFAULT if copy_to_user fails
The copy_to_user() function returns the number of bytes that were not
copied but we want to return -EFAULT on error here.

Fixes: 188ad9d6cb ('vfio/pci: Include sparse mmap capability for MSI-X table regions')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-25 21:48:42 -07:00
Alex Williamson
a13b645917 vfio/pci: Expose shadow ROM as PCI option ROM
Integrated graphics may have their ROM shadowed at 0xc0000 rather than
implement a PCI option ROM.  Make this ROM appear to the user using
the ROM BAR.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:09 -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
28541d41c9 vfio/pci: Add infrastructure for additional device specific regions
Add support for additional regions with indexes started after the
already defined fixed regions.  Device specific code can register
these regions with the new vfio_pci_register_dev_region() function.
The ops structure per region currently only includes read/write
access and a release function, allowing automatic cleanup when the
device is closed.  mmap support is only missing here because it's
not needed by the first user queued for this support.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:09 -07:00
Alex Williamson
188ad9d6cb vfio/pci: Include sparse mmap capability for MSI-X table regions
vfio-pci has never allowed the user to directly mmap the MSI-X vector
table, but we've always relied on implicit knowledge of the user that
they cannot do this.  Now that we have capability chains that we can
expose in the region info ioctl and a sparse mmap capability that
represents the sub-areas within the region that can be mmap'd, we can
make the mmap constraints more explicit.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:09 -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
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
Julia Lawall
7d10f4e079 vfio-pci: constify pci_error_handlers structures
This pci_error_handlers structure is never modified, like all the other
pci_error_handlers structures, so declare it as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-19 16:53:07 -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
Alex Williamson
20f300175a vfio/pci: Fix racy vfio_device_get_from_dev() call
Testing the driver for a PCI device is racy, it can be all but
complete in the release path and still report the driver as ours.
Therefore we can't trust drvdata to be valid.  This race can sometimes
be seen when one port of a multifunction device is being unbound from
the vfio-pci driver while another function is being released by the
user and attempting a bus reset.  The device in the remove path is
found as a dependent device for the bus reset of the release path
device, the driver is still set to vfio-pci, but the drvdata has
already been cleared, resulting in a null pointer dereference.

To resolve this, fix vfio_device_get_from_dev() to not take the
dev_get_drvdata() shortcut and instead traverse through the
iommu_group, vfio_group, vfio_device path to get a reference we
can trust.  Once we have that reference, we know the device isn't
in transition and we can test to make sure the driver is still what
we expect, so that we don't interfere with devices we don't own.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-06-09 10:08:57 -06:00
Alex Williamson
5f55d2ae69 vfio-pci: Log device requests more verbosely
Log some clues indicating whether the user is receiving device
request interfaces or not listening.  This can help indicate why a
driver unbind is blocked or explain why QEMU automatically unplugged
a device from the VM.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-05-01 14:00:53 -06:00
Alex Williamson
5a0ff17741 vfio-pci: Fix use after free
Reported by 0-day test infrastructure.

Fixes: ecaa1f6a01 ("vfio-pci: Add VGA arbiter client")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-08 08:11:51 -06:00
Alex Williamson
6eb7018705 vfio-pci: Move idle devices to D3hot power state
We can save some power by putting devices that are bound to vfio-pci
but not in use by the user in the D3hot power state.  Devices get
woken into D0 when opened by the user.  Resets return the device to
D0, so we need to re-apply the low power state after a bus reset.
It's tempting to try to use D3cold, but we have no reason to inhibit
hotplug of idle devices and we might get into a loop of having the
device disappear before we have a chance to try to use it.

A new module parameter allows this feature to be disabled if there are
devices that misbehave as a result of this change.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07 11:14:46 -06:00
Alex Williamson
561d72ddbb vfio-pci: Remove warning if try-reset fails
As indicated in the comment, this is not entirely uncommon and
causes user concern for no reason.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07 11:14:44 -06:00
Alex Williamson
80c7e8cc2a vfio-pci: Allow PCI IDs to be specified as module options
This copies the same support from pci-stub for exactly the same
purpose, enabling a set of PCI IDs to be automatically added to the
driver's dynamic ID table at module load time.  The code here is
pretty simple and both vfio-pci and pci-stub are fairly unique in
being meta drivers, capable of attaching to any device, so there's no
attempt made to generalize the code into pci-core.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07 11:14:43 -06:00
Alex Williamson
ecaa1f6a01 vfio-pci: Add VGA arbiter client
If VFIO VGA access is disabled for the user, either by CONFIG option
or module parameter, we can often opt-out of VGA arbitration.  We can
do this when PCI bridge control of VGA routing is possible.  This
means that we must have a parent bridge and there must only be a
single VGA device below that bridge.  Fortunately this is the typical
case for discrete GPUs.

Doing this allows us to minimize the impact of additional GPUs, in
terms of VGA arbitration, when they are only used via vfio-pci for
non-VGA applications.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07 11:14:41 -06:00
Alex Williamson
88c0dead9f vfio-pci: Add module option to disable VGA region access
Add a module option so that we don't require a CONFIG change and
kernel rebuild to disable VGA support.  Not only can VGA support be
troublesome in itself, but by disabling it we can reduce the impact
to host devices by doing a VGA arbitration opt-out.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-04-07 11:14:40 -06:00
Antonios Motakis
42ac9bd18d vfio: initialize the virqfd workqueue in VFIO generic code
Now we have finally completely decoupled virqfd from VFIO_PCI. We can
initialize it from the VFIO generic code, in order to safely use it from
multiple independent VFIO bus drivers.

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 14:08:54 -06:00
Antonios Motakis
bb78e9eaab vfio: virqfd: rename vfio_pci_virqfd_init and vfio_pci_virqfd_exit
The functions vfio_pci_virqfd_init and vfio_pci_virqfd_exit are not really
PCI specific, since we plan to reuse the virqfd code with more VFIO drivers
in addition to VFIO_PCI.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
[Baptiste Reynal: Move rename vfio_pci_virqfd_init and vfio_pci_virqfd_exit
from "vfio: add a vfio_ prefix to virqfd_enable and virqfd_disable and export"]
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 14:08:52 -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
Wei Yang
7c2e211f3c vfio-pci: Fix the check on pci device type in vfio_pci_probe()
Current vfio-pci just supports normal pci device, so vfio_pci_probe() will
return if the pci device is not a normal device. While current code makes a
mistake. PCI_HEADER_TYPE is the offset in configuration space of the device
type, but we use this value to mask the type value.

This patch fixs this by do the check directly on the pci_dev->hdr_type.

Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org # v3.6+
2015-01-07 10:29:11 -07:00
Frank Blaschka
1d53a3a7d3 vfio: make vfio run on s390
add Kconfig switch to hide INTx
add Kconfig switch to let vfio announce PCI BARs are not mapable

Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-11-07 09:52:22 -07:00
Alex Williamson
93899a679f vfio-pci: Fix remove path locking
Locking both the remove() and release() path results in a deadlock
that should have been obvious.  To fix this we can get and hold the
vfio_device reference as we evaluate whether to do a bus/slot reset.
This will automatically block any remove() calls, allowing us to
remove the explict lock.  Fixes 61d792562b.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org	[3.17]
2014-09-29 17:18:39 -06:00
Alexey Kardashevskiy
9b936c960f drivers/vfio: Enable VFIO if EEH is not supported
The existing vfio_pci_open() fails upon error returned from
vfio_spapr_pci_eeh_open(), which breaks POWER7's P5IOC2 PHB
support which this patch brings back.

The patch fixes the issue by dropping the return value of
vfio_spapr_pci_eeh_open().

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-08-08 10:39:16 -06:00
Alex Williamson
bc4fba7712 vfio-pci: Attempt bus/slot reset on release
Each time a device is released, mark whether a local reset was
successful or whether a bus/slot reset is needed.  If a reset is
needed and all of the affected devices are bound to vfio-pci and
unused, allow the reset.  This is most useful when the userspace
driver is killed and releases all the devices in an unclean state,
such as when a QEMU VM quits.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-08-07 11:12:07 -06:00
Alex Williamson
61d792562b vfio-pci: Use mutex around open, release, and remove
Serializing open/release allows us to fix a refcnt error if we fail
to enable the device and lets us prevent devices from being unbound
or opened, giving us an opportunity to do bus resets on release.  No
restriction added to serialize binding devices to vfio-pci while the
mutex is held though.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-08-07 11:12:04 -06:00
Alex Williamson
9c22e660ce vfio-pci: Release devices with BusMaster disabled
Our current open/release path looks like this:

vfio_pci_open
  vfio_pci_enable
    pci_enable_device
    pci_save_state
    pci_store_saved_state

vfio_pci_release
  vfio_pci_disable
    pci_disable_device
    pci_restore_state

pci_enable_device() doesn't modify PCI_COMMAND_MASTER, so if a device
comes to us with it enabled, it persists through the open and gets
stored as part of the device saved state.  We then restore that saved
state when released, which can allow the device to attempt to continue
to do DMA.  When the group is disconnected from the domain, this will
get caught by the IOMMU, but if there are other devices in the group,
the device may continue running and interfere with the user.  Even in
the former case, IOMMUs don't necessarily behave well and a stream of
blocked DMA can result in unpleasant behavior on the host.

Explicitly disable Bus Master as we're enabling the device and
slightly re-work release to make sure that pci_disable_device() is
the last thing that touches the device.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-08-07 11:12:02 -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
Gavin Shan
fd49c81f08 drivers/vfio/pci: Fix wrong MSI interrupt count
According PCI local bus specification, the register of Message
Control for MSI (offset: 2, length: 2) has bit#0 to enable or
disable MSI logic and it shouldn't be part contributing to the
calculation of MSI interrupt count. The patch fixes the issue.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-05-30 11:35:54 -06:00
Alex Williamson
eb5685f0de vfio/pci: Fix unchecked return value
There's nothing we can do different if pci_load_and_free_saved_state()
fails, other than maybe print some log message, but the actual re-load
of the state is an unnecessary step here since we've only just saved
it.  We can cleanup a coverity warning and eliminate the unnecessary
step by freeing the state ourselves.

Detected by Coverity: CID 753101

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-05-30 11:35:53 -06:00
Linus Torvalds
2d08cd0ef8 - Convert to misc driver to support module auto loading
- Remove unnecessary and dangerous use of device_lock
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJS4T1aAAoJECObm247sIsiLMkQAKn11qSLk880dJO+cfW2VpqL
 vm3WreShOxNsKTEQfcbrnJtS+kYGkiyo8+Vve377QDIg+xeXpNZa0PbAEfh4HyuJ
 NH+vn0FYDf3rzF4Z9snm2HOHWCAsqLCE0guyMwwhUYH+fks4+YTJWCm4YWZOXbIS
 aI++G+5LBxGzMRbotoovqUhQy474fpQN/GFIlIZHP2bGtdeXiRuH0qH3BxVKafOF
 50RtAgJsLm1Nb+S20Umsz+llL3sop1wcPLKOlgCXqd+545CJAoq/qqEPjUtOrr+S
 qXvXhb0XM7zo73H2WzkVmS09HZWX4sMoHBYp8D6ToOIFF01LOVsXBKduPCPpTD7E
 zohhjgag9/RQ99l2B153IIIv0Bsg7b4YXBQ6qkWFoJolPL94LTq1PXk0f9mNhyPo
 mSqatcAeI5qtjqu9ncSd4YYTdBgp7SJcgwji8fI44tvzzpz8iheVUrpwcU1UumAK
 TpXLBoTLXllK1op3u9xgFrF4ISBMl7lZeZp3c1/1YRga7Ch6SdlB0tcLPfuSBRF0
 1Qb5jQrWz4qt/oZSkapcFALXQDgwoK8am9I0a5YXdhy9gSYm+o/TLwG5pTEnF4In
 xxuibmmJAmNcTJ9q6rUKjLLU/TqRKin+vyqW6is41IredgvNX8XDS3YokA5Fgv01
 mu1s7odFi08xjPRuYvmq
 =t9+R
 -----END PGP SIGNATURE-----

Merge tag 'vfio-v3.14-rc1' of git://github.com/awilliam/linux-vfio

Pull vfio update from Alex Williamson:
 - convert to misc driver to support module auto loading
 - remove unnecessary and dangerous use of device_lock

* tag 'vfio-v3.14-rc1' of git://github.com/awilliam/linux-vfio:
  vfio-pci: Don't use device_lock around AER interrupt setup
  vfio: Convert control interface to misc driver
  misc: Reserve minor for VFIO
2014-01-24 17:42:31 -08:00
Alex Williamson
890ed578df vfio-pci: Use pci "try" reset interface
PCI resets will attempt to take the device_lock for any device to be
reset.  This is a problem if that lock is already held, for instance
in the device remove path.  It's not sufficient to simply kill the
user process or skip the reset if called after .remove as a race could
result in the same deadlock.  Instead, we handle all resets as "best
effort" using the PCI "try" reset interfaces.  This prevents the user
from being able to induce a deadlock by triggering a reset.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-01-15 10:43:17 -07:00
Alex Williamson
3be3a074cf vfio-pci: Don't use device_lock around AER interrupt setup
device_lock is much too prone to lockups.  For instance if we have a
pending .remove then device_lock is already held.  If userspace
attempts to modify AER signaling after that point, a deadlock occurs.
eventfd setup/teardown is already protected in vfio with the igate
mutex.  AER is not a high performance interrupt, so we can also use
the same mutex to protect signaling versus setup races.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2014-01-14 16:12:55 -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
Alex Williamson
d24cdbfd28 vfio-pci: Avoid deadlock on remove
If an attempt is made to unbind a device from vfio-pci while that
device is in use, the request is blocked until the device becomes
unused.  Unfortunately, that unbind path still grabs the device_lock,
which certain things like __pci_reset_function() also want to take.
This means we need to try to acquire the locks ourselves and use the
pre-locked version, __pci_reset_function_locked().

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-07-24 16:36:41 -06:00
Al Viro
a47df1518e vfio: remap_pfn_range() sets all those flags...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:46:41 +04:00
Linus Torvalds
0b2e3b6bb4 vfio updates for v3.10
Changes include extension to support PCI AER notification to userspace, byte granularity of PCI config space and access to unarchitected PCI config space, better protection around IOMMU driver accesses, default file mode fix, and a few misc cleanups.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.13 (GNU/Linux)
 
 iQIcBAABAgAGBQJRgox9AAoJECObm247sIsizJwP/23KprR6BuRt168Obo+xC/lp
 kj1E4Hd4XHx6T/5XRexa4GqhmyLqgoqbS19uj/K6ebY9rouVKo0V6OYNFDQiFR/F
 yEGjYIBKV9/eBZMQI4RbZpZKGDXTeFrXyjsac1m51JrR3st8zsvZlNPE/TjzhSfz
 jMnsCC99ZwIFjmptw/yWwgInswy1n9H9iICS14Xn1x7v71iyOE32reTG6M9HsPHe
 Xm5F0K5iLQX8qoISHAomrTnFmCLxp5Y2qhh7nZWmC2gCbPBEnGdqx4prwzJayAaC
 DAN8osaYldoKQuwI4wFYMICHxxCEFk8xU58FeKCmeQJZgomefVAoRKf86gAEsSLR
 XHptBQOktWVKNFhzZWyOuAX3iua/hmWcOa05I6inycV1x2ZAGlNhvJnj1iKIphLk
 +neBFAD9wDcAJZdXkfudq0jJ9jJTSAWBv8d+hozNfkjTVhF+wRnhZ7V6dZfb9+W6
 kPGbgwqKApLoOabQbxbZ5Ftr6S7344prB/HAMywGa+xZfoxoYPxBHCi0rSTvUTWy
 oWLtzrKRbjBDc0qF4eEK9RZlmVt2ZmCUnUB3kbWED4mrJAHu4LlFghnAloePrIZ3
 kXlMARWbyw/E+1WIMO4Ito5+1s3zVsJJgzVsAQDJkTQw2aYDhns73/Y25Dj7x7QS
 BKebrXnh2xVCN6OIu+eX
 =F0Cc
 -----END PGP SIGNATURE-----

Merge tag 'vfio-for-v3.10' of git://github.com/awilliam/linux-vfio

Pull vfio updates from Alex Williamson:
 "Changes include extension to support PCI AER notification to
  userspace, byte granularity of PCI config space and access to
  unarchitected PCI config space, better protection around IOMMU driver
  accesses, default file mode fix, and a few misc cleanups."

* tag 'vfio-for-v3.10' of git://github.com/awilliam/linux-vfio:
  vfio: Set container device mode
  vfio: Use down_reads to protect iommu disconnects
  vfio: Convert container->group_lock to rwsem
  PCI/VFIO: use pcie_flags_reg instead of access PCI-E Capabilities Register
  vfio-pci: Enable raw access to unassigned config space
  vfio-pci: Use byte granularity in config map
  vfio: make local function vfio_pci_intx_unmask_handler() static
  VFIO-AER: Vfio-pci driver changes for supporting AER
  VFIO: Wrapper for getting reference to vfio_device
2013-05-02 14:02:32 -07:00
Linus Torvalds
96a3e8af5a PCI changes for the v3.10 merge window:
PCI device hotplug
     - Remove ACPI PCI subdrivers (Jiang Liu, Myron Stowe)
     - Make acpiphp builtin only, not modular (Jiang Liu)
     - Add acpiphp mutual exclusion (Jiang Liu)
 
   Power management
     - Skip "PME enabled/disabled" messages when not supported (Rafael Wysocki)
     - Fix fallback to PCI_D0 (Rafael Wysocki)
 
   Miscellaneous
     - Factor quirk_io_region (Yinghai Lu)
     - Cache MSI capability offsets & cleanup (Gavin Shan, Bjorn Helgaas)
     - Clean up EISA resource initialization and logging (Bjorn Helgaas)
     - Fix prototype warnings (Andy Shevchenko, Bjorn Helgaas)
     - MIPS: Initialize of_node before scanning bus (Gabor Juhos)
     - Fix pcibios_get_phb_of_node() declaration "weak" annotation (Gabor Juhos)
     - Add MSI INTX_DISABLE quirks for AR8161/AR8162/etc (Xiong Huang)
     - Fix aer_inject return values (Prarit Bhargava)
     - Remove PME/ACPI dependency (Andrew Murray)
     - Use shared PCI_BUS_NUM() and PCI_DEVID() (Shuah Khan)
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQIcBAABAgAGBQJRfhSWAAoJEFmIoMA60/r8GrYQAIHDsyZIuJSf6g+8Td1h+PIC
 YD3wQhbyrDqQDuKU4+9cz+JsbHmnozUGA4UmlwmOGBxEa/Uauspb6yX1P1+x9Ok1
 WD7Ar3BlA5OuYI/1L1mgCiA428MTujwoR4fPnC0+KFy8xk1tBpmhzzeOFohbKyFF
 hMBO/Xt9tCzPATJ1LhjIH4xAykfDkbnPNHNcUKRoAkRo0CO0lS8gcTk0shXXSNng
 p9kQ6c4cYZvlRIJTwlawWV09nr7mDsBYa3JClqXYZufUWfEwvIuhisJxCJ57sWi9
 t+Ev8dm7VM6Cr5dV+ORArlboBFrq4f/W5U9j9GPFrRplwf+WbNT6tNGSpSDq8XhU
 Q7JjNgPWVdWXe1vIsMwaO49zi45/bNehuCSFLZiyPZwedMk764tys+iYw+tMRtv1
 tBR7lwESSXfagmvWyQAuQOTy6Rj26BPd2T8e2lMsvsuQO9mCyTK6Ey3YyKuqKQK/
 l5Gns4vv4eaCjGXqqDGiydUjSes+r/v1bu43XiRnwPQJUKb5kr5SjN5/zSMBuUgm
 TLT/bnv8qvdFxCpVQJFv4k/uzULARMdbvLtTy8osB14vNHX9jPn+xORjLaZNiO6O
 7fFispMU8Om56hNkD6C451r3icRjjGlD7OA8KOlbZ8f876sLzGV9i6P9gwCoRdEB
 wclDPsN7kAzw/V2sEE60
 =bj8i
 -----END PGP SIGNATURE-----

Merge tag 'pci-v3.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "PCI changes for the v3.10 merge window:

  PCI device hotplug
   - Remove ACPI PCI subdrivers (Jiang Liu, Myron Stowe)
   - Make acpiphp builtin only, not modular (Jiang Liu)
   - Add acpiphp mutual exclusion (Jiang Liu)

  Power management
   - Skip "PME enabled/disabled" messages when not supported (Rafael
     Wysocki)
   - Fix fallback to PCI_D0 (Rafael Wysocki)

  Miscellaneous
   - Factor quirk_io_region (Yinghai Lu)
   - Cache MSI capability offsets & cleanup (Gavin Shan, Bjorn Helgaas)
   - Clean up EISA resource initialization and logging (Bjorn Helgaas)
   - Fix prototype warnings (Andy Shevchenko, Bjorn Helgaas)
   - MIPS: Initialize of_node before scanning bus (Gabor Juhos)
   - Fix pcibios_get_phb_of_node() declaration "weak" annotation (Gabor
     Juhos)
   - Add MSI INTX_DISABLE quirks for AR8161/AR8162/etc (Xiong Huang)
   - Fix aer_inject return values (Prarit Bhargava)
   - Remove PME/ACPI dependency (Andrew Murray)
   - Use shared PCI_BUS_NUM() and PCI_DEVID() (Shuah Khan)"

* tag 'pci-v3.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (63 commits)
  vfio-pci: Use cached MSI/MSI-X capabilities
  vfio-pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK
  PCI: Remove "extern" from function declarations
  PCI: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK
  PCI: Drop msi_mask_reg() and remove drivers/pci/msi.h
  PCI: Use msix_table_size() directly, drop multi_msix_capable()
  PCI: Drop msix_table_offset_reg() and msix_pba_offset_reg() macros
  PCI: Drop is_64bit_address() and is_mask_bit_support() macros
  PCI: Drop msi_data_reg() macro
  PCI: Drop msi_lower_address_reg() and msi_upper_address_reg() macros
  PCI: Drop msi_control_reg() macro and use PCI_MSI_FLAGS directly
  PCI: Use cached MSI/MSI-X offsets from dev, not from msi_desc
  PCI: Clean up MSI/MSI-X capability #defines
  PCI: Use cached MSI-X cap while enabling MSI-X
  PCI: Use cached MSI cap while enabling MSI interrupts
  PCI: Remove MSI/MSI-X cap check in pci_msi_check_device()
  PCI: Cache MSI/MSI-X capability offsets in struct pci_dev
  PCI: Use u8, not int, for PM capability offset
  [SCSI] megaraid_sas: Use correct #define for MSI-X capability
  PCI: Remove "extern" from function declarations
  ...
2013-04-29 09:30:25 -07:00
Bjorn Helgaas
a9047f24df vfio-pci: Use cached MSI/MSI-X capabilities
We now cache the MSI/MSI-X capability offsets in the struct pci_dev,
so no need to find the capabilities again.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
2013-04-24 11:35:56 -06:00
Bjorn Helgaas
508d1aa602 vfio-pci: Use PCI_MSIX_TABLE_BIR, not PCI_MSIX_FLAGS_BIRMASK
PCI_MSIX_FLAGS_BIRMASK is mis-named because the BIR mask is in the
Table Offset register, not the flags ("Message Control" per spec)
register.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
2013-04-24 11:35:56 -06:00
Alex Williamson
904c680c7b vfio-pci: Fix possible integer overflow
The VFIO_DEVICE_SET_IRQS ioctl takes a start and count parameter, both
of which are unsigned.  We attempt to bounds check these, but fail to
account for the case where start is a very large number, allowing
start + count to wrap back into the valid range.  Bounds check both
start and start + count.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-03-26 11:33:16 -06:00
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
Alex Williamson
906ee99dd2 vfio-pci: Cleanup BAR access
We can actually handle MMIO and I/O port from the same access function
since PCI already does abstraction of this.  The ROM BAR only requires
a minor difference, so it gets included too.  vfio_pci_config_readwrite
gets renamed for consistency.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-02-14 14:02:12 -07:00
Alex Williamson
5b279a11d3 vfio-pci: Cleanup read/write functions
The read and write functions are nearly identical, combine them
and convert to a switch statement.  This also makes it easy to
narrow the scope of when we use the io/mem accessors in case new
regions are added.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-02-14 14:02:12 -07:00
Alex Williamson
9a92c5091a vfio-pci: Enable device before attempting reset
Devices making use of PM reset are getting incorrectly identified as
not supporting reset because pci_pm_reset() fails unless the device is
in D0 power state.  When first attached to vfio_pci devices are
typically in an unknown power state.  We can fix this by explicitly
setting the power state or simply calling pci_enable_device() before
attempting a pci_reset_function().  We need to enable the device
anyway, so move this up in our vfio_pci_enable() function, which also
simplifies the error path a bit.

Note that pci_disable_device() does not explicitly set the power
state, so there's no need to re-order vfio_pci_disable().

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-12-07 13:43:51 -07:00