Commit Graph

201 Commits

Author SHA1 Message Date
Alex Williamson 5c6c2b21ec vfio: Provide module option to disable vfio_iommu_type1 hugepage support
Add a module option to vfio_iommu_type1 to disable IOMMU hugepage
support.  This causes iommu_map to only be called with single page
mappings, disabling the IOMMU driver's ability to use hugepages.
This option can be enabled by loading vfio_iommu_type1 with
disable_hugepages=1 or dynamically through sysfs.  If enabled
dynamically, only new mappings are restricted.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-06-21 09:38:11 -06:00
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
Alex Williamson cd9b22685e vfio: Convert type1 iommu to use rbtree
We need to keep track of all the DMA mappings of an iommu container so
that it can be automatically unmapped when the user releases the file
descriptor.  We currently do this using a simple list, where we merge
entries with contiguous iovas and virtual addresses.  Using a tree for
this is a bit more efficient and allows us to use common code instead
of inventing our own.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-06-21 09:37:50 -06:00
Alexey Kardashevskiy 5b25199eff powerpc/vfio: Enable on pSeries platform
The enables VFIO on the pSeries platform, enabling user space
programs to access PCI devices directly.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: David Gibson <david@gibson.dropbear.id.au>
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 16:55:15 +10:00
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
Alexey Kardashevskiy 9a6aa279d3 vfio: fix crash on rmmod
devtmpfs_delete_node() calls devnode() callback with mode==NULL but
vfio still tries to write there.

The patch fixes this.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-06-05 08:54:16 -06:00
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.
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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
Alex Williamson 664e9386bd vfio: Set container device mode
Minor 0 is the VFIO container device (/dev/vfio/vfio).  On it's own
the container does not provide a user with any privileged access.  It
only supports API version check and extension check ioctls.  Only by
attaching a VFIO group to the container does it gain any access.  Set
the mode of the container to allow access.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-04-30 15:42:28 -06:00
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)
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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
Alex Williamson 0b43c08233 vfio: Use down_reads to protect iommu disconnects
If a group or device is released or a container is unset from a group
it can race against file ops on the container.  Protect these with
down_reads to allow concurrent users.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reported-by: Michael S. Tsirkin <mst@redhat.com>
2013-04-29 08:41:36 -06:00
Alex Williamson 9587f44aa6 vfio: Convert container->group_lock to rwsem
All current users are writers, maintaining current mutual exclusion.
This lets us add read users next.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-04-25 16:12:38 -06:00
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
Yijing Wang aa2cba51a0 PCI/VFIO: use pcie_flags_reg instead of access PCI-E Capabilities Register
Currently, we use pcie_flags_reg to cache PCI-E Capabilities Register,
because PCI-E Capabilities Register bits are almost read-only. This patch
use pcie_caps_reg() instead of another access PCI-E Capabilities Register.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-04-15 08:45:10 -06:00
Alex Williamson a7d1ea1c11 vfio-pci: Enable raw access to unassigned config space
Devices like be2net hide registers between the gaps in capabilities
and architected regions of PCI config space.  Our choices to support
such devices is to either build an ever growing and unmanageable white
list or rely on hardware isolation to protect us.  These registers are
really no different than MMIO or I/O port space registers, which we
don't attempt to regulate, so treat PCI config space in the same way.

Reported-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Gavin Shan <shangw@linux.vnet.ibm.com>
2013-04-01 09:04:12 -06:00
Alex Williamson 180b138107 vfio-pci: Use byte granularity in config map
The config map previously used a byte per dword to map regions of
config space to capabilities.  Modulo a bug where we round the length
of capabilities down instead of up, this theoretically works well and
saves space so long as devices don't try to hide registers in the gaps
between capabilities.  Unfortunately they do exactly that so we need
byte granularity on our config space map.  Increase the allocation of
the config map and split accesses at capability region boundaries.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Gavin Shan <shangw@linux.vnet.ibm.com>
2013-04-01 09:03:44 -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
Wei Yongjun 0bced2f728 vfio: make local function vfio_pci_intx_unmask_handler() static
vfio_pci_intx_unmask_handler() was not declared. It should be static.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-03-25 11:15:44 -06:00
Arnd Bergmann 25e9789ddd vfio: include <linux/slab.h> for kmalloc
The vfio drivers call kmalloc or kzalloc, but do not
include <linux/slab.h>, which causes build errors on
ARM.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org
2013-03-15 12:58:20 -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
Vijay Mohan Pandarathil 44f507163d VFIO: Wrapper for getting reference to vfio_device
- Added vfio_device_get_from_dev() as wrapper to get
  reference to vfio_device from struct device.

- Added vfio_device_data() as a wrapper to get device_data from
  vfio_device.

Signed-off-by: Vijay Mohan Pandarathil <vijaymohan.pandarathil@hp.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-03-11 09:28:44 -06:00
Tejun Heo a1c36b166b vfio: convert to idr_alloc()
Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:19 -08:00
Kees Cook d65530fbc7 drivers/vfio: remove depends on CONFIG_EXPERIMENTAL
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-02-24 09:59:44 -07:00
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 2dd1194833 vfio-pci: Manage user power state transitions
We give the user access to change the power state of the device but
certain transitions result in an uninitialized state which the user
cannot resolve.  To fix this we need to mark the PowerState field of
the PMCSR register read-only and effect the requested change on behalf
of the user.  This has the added benefit that pdev->current_state
remains accurate while controlled by the user.

The primary example of this bug is a QEMU guest doing a reboot where
the device it put into D3 on shutdown and becomes unusable on the next
boot because the device did a soft reset on D3->D0 (NoSoftRst-).

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-02-18 10:10:33 -07:00
Alex Williamson 2b489a45f6 vfio: whitelist pcieport
pcieport does nice things like manage AER and we know it doesn't do
DMA or expose any user accessible devices on the host.  It also keeps
the Memory, I/O, and Busmaster bits enabled, which is pretty handy
when trying to use anyting below it.  Devices owned by pcieport cannot
be given to users via vfio, but we can tolerate them not being owned
by vfio-pci.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-02-14 14:02:13 -07:00
Alex Williamson e014e9444a vfio: Protect vfio_dev_present against device_del
vfio_dev_present is meant to give us a wait_event callback so that we
can block removing a device from vfio until it becomes unused.  The
root of this check depends on being able to get the iommu group from
the device.  Unfortunately if the BUS_NOTIFY_DEL_DEVICE notifier has
fired then the device-group reference is no longer searchable and we
fail the lookup.

We don't need to go to such extents for this though.  We have a
reference to the device, from which we can acquire a reference to the
group.  We can then use the group reference to search for the device
and properly block removal.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-02-14 14:02:13 -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 5641ade41f vfio-pci: Enable PCIe extended capabilities on v1
Even PCIe 1.x had extended config space.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2013-02-14 10:45:31 -07:00
Alex Williamson ec1287e511 vfio-pci: Fix buffer overfill
A read from a range hidden from the user (ex. MSI-X vector table)
attempts to fill the user buffer up to the end of the excluded range
instead of up to the requested count.  Fix it.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org
2013-01-15 10:45:26 -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
Jiang Liu 05bf3aac93 VFIO: fix out of order labels for error recovery in vfio_pci_init()
The two labels for error recovery in function vfio_pci_init() is out of
order, so fix it.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-12-07 13:43:51 -07:00
Jiang Liu de2b3eeafb VFIO: use ACCESS_ONCE() to guard access to dev->driver
Comments from dev_driver_string(),
/* dev->driver can change to NULL underneath us because of unbinding,
 * so be careful about accessing it.
 */

So use ACCESS_ONCE() to guard access to dev->driver field.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-12-07 13:43:50 -07:00
Jiang Liu 9df7b25ab7 VFIO: unregister IOMMU notifier on error recovery path
On error recovery path in function vfio_create_group(), it should
unregister the IOMMU notifier for the new VFIO group. Otherwise it may
cause invalid memory access later when handling bus notifications.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-12-07 13:43:50 -07:00
Alex Williamson 2007722a60 vfio-pci: Re-order device reset
Move the device reset to the end of our disable path, the device
should already be stopped from pci_disable_device().  This also allows
us to manipulate the save/restore to avoid the save/reset/restore +
save/restore that we had before.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-12-07 13:43:50 -07:00
Fengguang Wu 3a1f7041dd vfio: simplify kmalloc+copy_from_user to memdup_user
Generated by: coccinelle/api/memdup_user.cocci

Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-12-07 13:43:49 -07:00
Alex Williamson 899649b7d4 vfio: Fix PCI INTx disable consistency
The virq_disabled flag tracks the userspace view of INTx masking
across interrupt mode changes, but we're not consistently applying
this to the interrupt and masking handler notion of the device.
Currently if the user sets DisINTx while in MSI or MSIX mode, then
returns to INTx mode (ex. rebooting a qemu guest), the hardware has
DisINTx+, but the management of INTx thinks it's enabled, making it
impossible to actually clear DisINTx.  Fix this by updating the
handler state when INTx is re-enabled.

Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-10-10 09:10:32 -06:00
Alex Williamson 9dbdfd23b7 vfio: Move PCI INTx eventfd setting earlier
We need to be ready to recieve an interrupt as soon as we call
request_irq, so our eventfd context setting needs to be moved
earlier.  Without this, an interrupt from our device or one
sharing the interrupt line can pass a NULL into eventfd_signal
and oops.

Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-10-10 09:10:32 -06:00
Alex Williamson 34002f54d2 vfio: Fix PCI mmap after b3b9c293
Our mmap path mistakely relied on vma->vm_pgoff to get set in
remap_pfn_range.  After b3b9c293, that path only applies to
copy-on-write mappings.  Set it in our own code.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-10-10 09:10:31 -06:00
Linus Torvalds 547b1e81af Fix staging driver use of VM_RESERVED
The VM_RESERVED flag was killed off in commit 314e51b985 ("mm: kill
vma flag VM_RESERVED and mm->reserved_vm counter"), and replaced by the
proper semantic flags (eg "don't core-dump" etc).  But there was a new
use of VM_RESERVED that got missed by the merge.

Fix the remaining use of VM_RESERVED in the vfio_pci driver, replacing
the VM_RESERVED flag with VM_DONTEXPAND | VM_DONTDUMP.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation,org>
2012-10-09 21:06:41 +09:00
Al Viro 2903ff019b switch simple cases of fget_light to fdget
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 22:20:08 -04:00
Al Viro 1d3653a79c switch vfio_group_set_container() to fget_light()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-26 21:10:09 -04:00
Alex Williamson b68e7fa879 vfio: Fix virqfd release race
vfoi-pci supports a mechanism like KVM's irqfd for unmasking an
interrupt through an eventfd.  There are two ways to shutdown this
interface: 1) close the eventfd, 2) ioctl (such as disabling the
interrupt).  Both of these do the release through a workqueue,
which can result in a segfault if two jobs get queued for the same
virqfd.

Fix this by protecting the pointer to these virqfds by a spinlock.
The vfio pci device will therefore no longer have a reference to it
once the release job is queued under lock.  On the ioctl side, we
still flush the workqueue to ensure that any outstanding releases
are completed.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-09-21 10:48:28 -06:00
Al Viro 31605debdf vfio: grab vfio_device reference *before* exposing the sucker via fd_install()
It's not critical (anymore) since another thread closing the file will block
on ->device_lock before it gets to dropping the final reference, but it's
definitely cleaner that way...

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-22 10:26:42 -04:00
Al Viro 90b1253e41 vfio: get rid of vfio_device_put()/vfio_group_get_device* races
we really need to make sure that dropping the last reference happens
under the group->device_lock; otherwise a loop (under device_lock)
might find vfio_device instance that is being freed right now, has
already dropped the last reference and waits on device_lock to exclude
the sucker from the list.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-22 10:26:13 -04:00
Al Viro 6d2cd3ce81 vfio: get rid of open-coding kref_put_mutex
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-22 10:25:19 -04:00
Al Viro 934ad4c235 vfio: don't dereference after kfree...
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-08-22 10:23:04 -04:00
Alex Williamson 89e1f7d4c6 vfio: Add PCI device driver
Add PCI device support for VFIO.  PCI devices expose regions
for accessing config space, I/O port space, and MMIO areas
of the device.  PCI config access is virtualized in the kernel,
allowing us to ensure the integrity of the system, by preventing
various accesses while reducing duplicate support across various
userspace drivers.  I/O port supports read/write access while
MMIO also supports mmap of sufficiently sized regions.  Support
for INTx, MSI, and MSI-X interrupts are provided using eventfds to
userspace.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-07-31 08:16:24 -06:00
Alex Williamson 73fa0d10d0 vfio: Type1 IOMMU implementation
This VFIO IOMMU backend is designed primarily for AMD-Vi and Intel
VT-d hardware, but is potentially usable by anything supporting
similar mapping functionality.  We arbitrarily call this a Type1
backend for lack of a better name.  This backend has no IOVA
or host memory mapping restrictions for the user and is optimized
for relatively static mappings.  Mapped areas are pinned into system
memory.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-07-31 08:16:23 -06:00
Alex Williamson cba3345cc4 vfio: VFIO core
VFIO is a secure user level driver for use with both virtual machines
and user level drivers.  VFIO makes use of IOMMU groups to ensure the
isolation of devices in use, allowing unprivileged user access.  It's
intended that VFIO will replace KVM device assignment and UIO drivers
(in cases where the target platform includes a sufficiently capable
IOMMU).

New in this version of VFIO is support for IOMMU groups managed
through the IOMMU core as well as a rework of the API, removing the
group merge interface.  We now go back to a model more similar to
original VFIO with UIOMMU support where the file descriptor obtained
from /dev/vfio/vfio allows access to the IOMMU, but only after a
group is added, avoiding the previous privilege issues with this type
of model.  IOMMU support is also now fully modular as IOMMUs have
vastly different interface requirements on different platforms.  VFIO
users are able to query and initialize the IOMMU model of their
choice.

Please see the follow-on Documentation commit for further description
and usage example.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2012-07-31 08:16:22 -06:00