Commit Graph

358 Commits

Author SHA1 Message Date
Kirti Wankhede
c747f08aea vfio: Introduce vfio_set_irqs_validate_and_prepare()
Vendor driver using mediated device framework would use same mechnism to
validate and prepare IRQs. Introducing this function to reduce code
replication in multiple drivers.

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
Kirti Wankhede
c535d34569 vfio_pci: Update vfio_pci to use vfio_info_add_capability()
Update msix_sparse_mmap_cap() to use vfio_info_add_capability()
Update region type capability to use vfio_info_add_capability()

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
Kirti Wankhede
b3c0a866f1 vfio: Introduce common function to add capabilities
Vendor driver using mediated device framework should use
vfio_info_add_capability() to add capabilities.
Introduced this function to reduce code duplication in vendor drivers.

vfio_info_cap_shift() manipulated a data buffer to add an offset to each
element in a chain. This data buffer is documented in a uapi header.
Changing vfio_info_cap_shift symbol to be available to all drivers.

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
Kirti Wankhede
c086de818d vfio iommu: Add blocking notifier to notify DMA_UNMAP
Added blocking notifier to IOMMU TYPE1 driver to notify vendor drivers
about DMA_UNMAP.
Exported two APIs vfio_register_notifier() and vfio_unregister_notifier().
Notifier should be registered, if external user wants to use
vfio_pin_pages()/vfio_unpin_pages() APIs to pin/unpin pages.
Vendor driver should use VFIO_IOMMU_NOTIFY_DMA_UNMAP action to invalidate
mappings.

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 08:33:07 -07:00
Kirti Wankhede
a54eb55045 vfio iommu type1: Add support for mediated devices
VFIO IOMMU drivers are designed for the devices which are IOMMU capable.
Mediated device only uses IOMMU APIs, the underlying hardware can be
managed by an IOMMU domain.

Aim of this change is:
- To use most of the code of TYPE1 IOMMU driver for mediated devices
- To support direct assigned device and mediated device in single module

This change adds pin and unpin support for mediated device to TYPE1 IOMMU
backend module. More details:
- Domain for external user is tracked separately in vfio_iommu structure.
  It is allocated when group for first mdev device is attached.
- Pages pinned for external domain are tracked in each vfio_dma structure
  for that iova range.
- Page tracking rb-tree in vfio_dma keeps <iova, pfn, ref_count>. Key of
  rb-tree is iova, but it actually aims to track pfns.
- On external pin request for an iova, page is pinned once, if iova is
  already pinned and tracked, ref_count is incremented.
- External unpin request unpins pages only when ref_count is 0.
- Pinned pages list is used to find pfn from iova and then unpin it.
  WARN_ON is added if there are entires in pfn_list while detaching the
  group and releasing the domain.
- Page accounting is updated to account in its address space where the
  pages are pinned/unpinned, i.e dma->task
-  Accouting for mdev device is only done if there is no iommu capable
  domain in the container. When there is a direct device assigned to the
  container and that domain is iommu capable, all pages are already pinned
  during DMA_MAP.
- Page accouting is updated on hot plug and unplug mdev device and pass
  through device.

Tested by assigning below combinations of devices to a single VM:
- GPU pass through only
- vGPU device only
- One GPU pass through and one vGPU device
- Linux VM hot plug and unplug vGPU device while GPU pass through device
  exist
- Linux VM hot plug and unplug GPU pass through device while vGPU device
  exist

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 08:25:11 -07:00
Kirti Wankhede
8f0d5bb95f vfio iommu type1: Add task structure to vfio_dma
Add task structure to vfio_dma structure. Task structure is used for:
- During DMA_UNMAP, same task who mapped it or other task who shares same
address space is allowed to unmap, otherwise unmap fails.
QEMU maps few iova ranges initially, then fork threads and from the child
thread calls DMA_UNMAP on previously mapped iova. Since child shares same
address space, DMA_UNMAP is successful.
- Avoid accessing struct mm while process is exiting by acquiring
reference of task's mm during page accounting.
- It is also used to get task mlock capability and rlimit for mlock.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17 08:25:09 -07:00
Kirti Wankhede
7896c998f0 vfio iommu type1: Add find_iommu_group() function
Add find_iommu_group()

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17 08:25:06 -07:00
Kirti Wankhede
ea85cf353e vfio iommu type1: Update argument of vaddr_get_pfn()
Update arguments of vaddr_get_pfn() to take struct mm_struct *mm as input
argument.

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 08:25:03 -07:00
Kirti Wankhede
3624a2486c vfio iommu type1: Update arguments of vfio_lock_acct
Added task structure as input argument to vfio_lock_acct() function.

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 08:25:01 -07:00
Kirti Wankhede
2169037dc3 vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops
Added APIs for pining and unpining set of pages. These call back into
backend iommu module to actually pin and unpin pages.
Added two new callback functions to struct vfio_iommu_driver_ops. Backend
IOMMU module that supports pining and unpinning pages for mdev devices
should provide these functions.

Renamed static functions in vfio_type1_iommu.c to resolve conflicts

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17 08:24:58 -07:00
Kirti Wankhede
32f55d835b vfio: Common function to increment container_users
This change rearrange functions to have common function to increment
container_users

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17 08:24:55 -07:00
Kirti Wankhede
7ed3ea8a71 vfio: Rearrange functions to get vfio_group from dev
This patch rearranges functions to get vfio_group from device

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17 08:24:52 -07:00
Kirti Wankhede
fa3da00cb8 vfio: VFIO based driver for Mediated devices
vfio_mdev driver registers with mdev core driver.
mdev core driver creates mediated device and calls probe routine of
vfio_mdev driver for each device.
Probe routine of vfio_mdev driver adds mediated device to VFIO core module

This driver forms a shim layer that pass through VFIO devices operations
to vendor driver for mediated devices.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17 08:24:50 -07:00
Kirti Wankhede
7b96953bc6 vfio: Mediated device Core driver
Design for Mediated Device Driver:
Main purpose of this driver is to provide a common interface for mediated
device management that can be used by different drivers of different
devices.

This module provides a generic interface to create the device, add it to
mediated bus, add device to IOMMU group and then add it to vfio group.

Below is the high Level block diagram, with Nvidia, Intel and IBM devices
as example, since these are the devices which are going to actively use
this module as of now.

 +---------------+
 |               |
 | +-----------+ |  mdev_register_driver() +--------------+
 | |           | +<------------------------+ __init()     |
 | |  mdev     | |                         |              |
 | |  bus      | +------------------------>+              |<-> VFIO user
 | |  driver   | |     probe()/remove()    | vfio_mdev.ko |    APIs
 | |           | |                         |              |
 | +-----------+ |                         +--------------+
 |               |
 |  MDEV CORE    |
 |   MODULE      |
 |   mdev.ko     |
 | +-----------+ |  mdev_register_device() +--------------+
 | |           | +<------------------------+              |
 | |           | |                         |  nvidia.ko   |<-> physical
 | |           | +------------------------>+              |    device
 | |           | |        callback         +--------------+
 | | Physical  | |
 | |  device   | |  mdev_register_device() +--------------+
 | | interface | |<------------------------+              |
 | |           | |                         |  i915.ko     |<-> physical
 | |           | +------------------------>+              |    device
 | |           | |        callback         +--------------+
 | |           | |
 | |           | |  mdev_register_device() +--------------+
 | |           | +<------------------------+              |
 | |           | |                         | ccw_device.ko|<-> physical
 | |           | +------------------------>+              |    device
 | |           | |        callback         +--------------+
 | +-----------+ |
 +---------------+

Core driver provides two types of registration interfaces:
1. Registration interface for mediated bus driver:

/**
  * struct mdev_driver - Mediated device's driver
  * @name: driver name
  * @probe: called when new device created
  * @remove:called when device removed
  * @driver:device driver structure
  *
  **/
struct mdev_driver {
         const char *name;
         int  (*probe)  (struct device *dev);
         void (*remove) (struct device *dev);
         struct device_driver    driver;
};

Mediated bus driver for mdev device should use this interface to register
and unregister with core driver respectively:

int  mdev_register_driver(struct mdev_driver *drv, struct module *owner);
void mdev_unregister_driver(struct mdev_driver *drv);

Mediated bus driver is responsible to add/delete mediated devices to/from
VFIO group when devices are bound and unbound to the driver.

2. Physical device driver interface
This interface provides vendor driver the set APIs to manage physical
device related work in its driver. APIs are :

* dev_attr_groups: attributes of the parent device.
* mdev_attr_groups: attributes of the mediated device.
* supported_type_groups: attributes to define supported type. This is
			 mandatory field.
* create: to allocate basic resources in vendor driver for a mediated
         device. This is mandatory to be provided by vendor driver.
* remove: to free resources in vendor driver when mediated device is
         destroyed. This is mandatory to be provided by vendor driver.
* open: open callback of mediated device
* release: release callback of mediated device
* read : read emulation callback.
* write: write emulation callback.
* ioctl: ioctl callback.
* mmap: mmap emulation callback.

Drivers should use these interfaces to register and unregister device to
mdev core driver respectively:

extern int  mdev_register_device(struct device *dev,
                                 const struct parent_ops *ops);
extern void mdev_unregister_device(struct device *dev);

There are no locks to serialize above callbacks in mdev driver and
vfio_mdev driver. If required, vendor driver can have locks to serialize
above APIs in their driver.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Jike Song <jike.song@intel.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-11-17 08:24:48 -07:00
Vlad Tsyrklevich
05692d7005 vfio/pci: Fix integer overflows, bitmask check
The VFIO_DEVICE_SET_IRQS ioctl did not sufficiently sanitize
user-supplied integers, potentially allowing memory corruption. This
patch adds appropriate integer overflow checks, checks the range bounds
for VFIO_IRQ_SET_DATA_NONE, and also verifies that only single element
in the VFIO_IRQ_SET_DATA_TYPE_MASK bitmask is set.
VFIO_IRQ_SET_ACTION_TYPE_MASK is already correctly checked later in
vfio_pci_set_irqs_ioctl().

Furthermore, a kzalloc is changed to a kcalloc because the use of a
kzalloc with an integer multiplication allowed an integer overflow
condition to be reached without this patch. kcalloc checks for overflow
and should prevent a similar occurrence.

Signed-off-by: Vlad Tsyrklevich <vlad@tsyrklevich.net>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-10-26 13:49:29 -06:00
Christoph Hellwig
61771468e0 vfio_pci: use pci_alloc_irq_vectors
Simplify the interrupt setup by using the new PCI layer helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-09-29 13:36:38 -06:00
Alex Williamson
c93a97ee05 vfio-pci: Disable INTx after MSI/X teardown
The MSI/X shutdown path can gratuitously enable INTx, which is not
something we want to happen if we're dealing with broken INTx device.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-09-26 13:52:19 -06:00
Alex Williamson
ddf9dc0eb5 vfio-pci: Virtualize PCIe & AF FLR
We use a BAR restore trick to try to detect when a user has performed
a device reset, possibly through FLR or other backdoors, to put things
back into a working state.  This is important for backdoor resets, but
we can actually just virtualize the "front door" resets provided via
PCIe and AF FLR.  Set these bits as virtualized + writable, allowing
the default write to set them in vconfig, then we can simply check the
bit, perform an FLR of our own, and clear the bit.  We don't actually
have the granularity in PCI to specify the type of reset we want to
do, but generally devices don't implement both PCIe and AF FLR and
we'll favor these over other types of reset, so we should generally
lineup.  We do test whether the device provides the requested FLR type
to stay consistent with hardware capabilities though.

This seems to fix several instance of devices getting into bad states
with userspace drivers, like dpdk, running inside a VM.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Greg Rose <grose@lightfleet.com>
2016-09-26 13:52:16 -06:00
Baoyou Xie
2e06285655 vfio: platform: mark symbols static where possible
We get a few warnings when building kernel with W=1:
drivers/vfio/platform/vfio_platform_common.c:76:5: warning: no previous prototype for 'vfio_platform_acpi_call_reset' [-Wmissing-prototypes]
drivers/vfio/platform/vfio_platform_common.c:98:6: warning: no previous prototype for 'vfio_platform_acpi_has_reset' [-Wmissing-prototypes]
drivers/vfio/platform/vfio_platform_common.c:640:5: warning: no previous prototype for 'vfio_platform_of_probe' [-Wmissing-prototypes]
drivers/vfio/platform/reset/vfio_platform_amdxgbe.c:59:5: warning: no previous prototype for 'vfio_platform_amdxgbe_reset' [-Wmissing-prototypes]
drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c:60:5: warning: no previous prototype for 'vfio_platform_calxedaxgmac_reset' [-Wmissing-prototypes]
....

In fact, these functions are only used in the file in which they are
declared and don't need a declaration, but can be made static.
so this patch marks these functions with 'static'.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-09-13 16:11:37 -06:00
Wei Jiangang
8138dabbab vfio/pci: Fix typos in comments
Signed-off-by: Wei Jiangang <weijg.fnst@cn.fujitsu.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-08-29 12:39:09 -06:00
Alex Williamson
c8952a7075 vfio/pci: Fix NULL pointer oops in error interrupt setup handling
There are multiple cases in vfio_pci_set_ctx_trigger_single() where
we assume we can safely read from our data pointer without actually
checking whether the user has passed any data via the count field.
VFIO_IRQ_SET_DATA_NONE in particular is entirely broken since we
attempt to pull an int32_t file descriptor out before even checking
the data type.  The other data types assume the data pointer contains
one element of their type as well.

In part this is good news because we were previously restricted from
doing much sanitization of parameters because it was missed in the
past and we didn't want to break existing users.  Clearly DATA_NONE
is completely broken, so it must not have any users and we can fix
it up completely.  For DATA_BOOL and DATA_EVENTFD, we'll just
protect ourselves, returning error when count is zero since we
previously would have oopsed.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reported-by: Chris Thompson <the_cartographer@hotmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Eric Auger <eric.auger@redhat.com>
2016-08-08 16:16:23 -06:00
Sinan Kaya
0991bbdbf5 vfio: platform: check reset call return code during release
Release call is ignoring the return code from reset call and can
potentially continue even though reset call failed.

If reset_required module parameter is set, this patch is going
to validate the return code and will cause stack dump with
WARN_ON and warn the user of failure.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:54:45 -06:00
Sinan Kaya
e99442323f vfio: platform: check reset call return code during open
Open call is ignoring the return code from reset call and can
potentially continue even though reset call failed.

If reset_required module parameter is set, this patch is going
to validate the return code and will abort open if reset fails.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:54:45 -06:00
Sinan Kaya
b5add544d6 vfio, platform: make reset driver a requirement by default
The code was allowing platform devices to be used without a supporting
VFIO reset driver. The hardware can be left in some inconsistent state
after a guest machine abort.

The reset driver will put the hardware back to safe state and disable
interrupts before returning the control back to the host machine.

Adding a new reset_required kernel module option to platform VFIO drivers.
The default value is true for the DT and ACPI based drivers.
The reset requirement value for AMBA drivers is set to false and is
unchangeable to maintain the existing functionality.

New requirements are:
1. A reset function needs to be implemented by the corresponding driver
via DT/ACPI.
2. The reset function needs to be discovered via DT/ACPI.

The probe of the driver will fail if any of the above conditions are
not satisfied.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:26:46 -06:00
Sinan Kaya
d30daa33ec vfio: platform: call _RST method when using ACPI
The device tree code checks for the presence of a reset driver and calls
the of_reset function pointer by looking up the reset driver as a module.

ACPI defines _RST method to perform device level reset. After the _RST
method is executed, the OS can resume using the device. _RST method is
expected to stop DMA transfers and IRQs.

This patch introduces two functions as vfio_platform_acpi_has_reset and
vfio_platform_acpi_call_reset. The has reset method is used to declare
reset capability via the ioctl flag VFIO_DEVICE_FLAGS_RESET. The call
reset function is used to execute the _RST ACPI method.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:26:44 -06:00
Sinan Kaya
5afec27474 vfio: platform: add extra debug info argument to call reset
Getting ready to bring out extra debug information to the caller
so that more verbose information can be printed when an error is
observed.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:26:43 -06:00
Sinan Kaya
a12a9368e1 vfio: platform: add support for ACPI probe
The code is using the compatible DT string to associate a reset driver
with the actual device itself. The compatible string does not exist on
ACPI based systems. HID is the unique identifier for a device driver
instead.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:26:41 -06:00
Sinan Kaya
dc5542fb11 vfio: platform: determine reset capability
Creating a new function to determine if this driver supports reset
function or not. This is an attempt to abstract device tree calls
from the rest of the code.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:26:40 -06:00
Sinan Kaya
f084aa7495 vfio: platform: move reset call to a common function
The reset call sequence seems to replicate itself multiple times
across the file. Grouping them together for maintenance reasons.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:26:38 -06:00
Sinan Kaya
7aef80cf31 vfio: platform: rename reset function
Renaming the reset function to of_reset as it is only used
by the device tree based platforms.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-19 10:26:36 -06:00
Ilya Lesokhin
d370c917b9 vfio: fix possible use after free of vfio group
The vfio group should be released after
the vfio_group_try_dissolve_container call.
The code should not rely on someone else to hold
a reference on the group.

Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-14 14:28:16 -06:00
Yongji Xie
05f0c03fba vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive
Current vfio-pci implementation disallows to mmap
sub-page(size < PAGE_SIZE) MMIO BARs because these BARs' mmio
page may be shared with other BARs. This will cause some
performance issues when we passthrough a PCI device with
this kind of BARs. Guest will be not able to handle the mmio
accesses to the BARs which leads to mmio emulations in host.

However, not all sub-page BARs will share page with other BARs.
We should allow to mmap the sub-page MMIO BARs which we can
make sure will not share page with other BARs.

This patch adds support for this case. And we try to add a
dummy resource to reserve the remainder of the page which
hot-add device's BAR might be assigned into. But it's not
necessary to handle the case when the BAR is not page aligned.
Because we can't expect the BAR will be assigned into the same
location in a page in guest when we passthrough the BAR. And
it's hard to access this BAR in userspace because we have
no way to get the BAR's location in a page.

Signed-off-by: Yongji Xie <xyjxie@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-07-08 10:06:04 -06:00
Peng Fan
9698cbf0be vfio: platform: support No-IOMMU mode
The vfio No-IOMMU mode was supported by this
'commit 03a76b60f8 ("vfio: Include No-IOMMU mode")',
but it only support vfio-pci.

Using vfio_iommu_group_get/put, but not iommu_group_get/put,
the platform devices can be exposed to userspace with
CONFIG_VFIO_NOIOMMU and the "enable_unsafe_noiommu_mode"
option enabled.

From 'commit 03a76b60f8 ("vfio: Include No-IOMMU mode")',
"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."

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Eric Auger <eric.auger@linaro.org>
Cc: Baptiste Reynal <b.reynal@virtualopensystems.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-06-23 09:37:17 -06:00
Alex Williamson
ce7585f3c4 vfio/pci: Allow VPD short read
The size of the VPD area is not necessarily 4-byte aligned, so a
pci_vpd_read() might return less than 4 bytes.  Zero our buffer and
accept anything other than an error.  Intel X710 NICs exercise this.

Fixes: 4e1a635552 ("vfio/pci: Use kernel VPD access functions")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-05-31 21:25:52 -06:00
Alex Williamson
089f1c6b2d vfio/type1: Fix build warning
This function cannot actually be called with npage = 0, so in practice
this doesn't return an uninitialized value.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-05-30 07:58:10 -06:00
Alex Williamson
956b56a984 vfio/pci: Fix ordering of eventfd vs virqfd shutdown
Both the INTx and MSI/X disable paths do an eventfd_ctx_put() for the
trigger eventfd before calling vfio_virqfd_disable() any potential
mask and unmask eventfds.  This opens a use-after-free race where an
inopportune irqfd can reference the freed signalling eventfd.  Reorder
to avoid this possibility.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-05-30 07:50:10 -06:00
Linus Torvalds
48dd7cefa0 VFIO updates for v4.7-rc1
- Hide INTx on certain known broken devices (Alex Williamson)
  - Additional backdoor reset detection (Alex Williamson)
  - Remove unused iommudata reference (Alexey Kardashevskiy)
  - Use cfg_size to avoid probing extended config space (Alexey Kardashevskiy)
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Merge tag 'vfio-v4.7-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Hide INTx on certain known broken devices (Alex Williamson)

 - Additional backdoor reset detection (Alex Williamson)

 - Remove unused iommudata reference (Alexey Kardashevskiy)

 - Use cfg_size to avoid probing extended config space (Alexey
   Kardashevskiy)

* tag 'vfio-v4.7-rc1' of git://github.com/awilliam/linux-vfio:
  vfio_pci: Test for extended capabilities if config space > 256 bytes
  vfio_iommu_spapr_tce: Remove unneeded iommu_group_get_iommudata
  vfio/pci: Add test for BAR restore
  vfio/pci: Hide broken INTx support from user
2016-05-25 09:47:26 -07:00
Linus Torvalds
c04a588029 powerpc updates for 4.7
Highlights:
  - Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V
  - Live patching support for ppc64le (also merged via livepatching.git)
 
 Various cleanups & minor fixes from:
  - Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
    Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie, Lennart
    Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Michael
    Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras, Rashmica Gupta,
    Russell Currey, Suraj Jitindar Singh, Thiago Jung Bauermann, Valentin
    Rothberg, Vipin K Parashar.
 
 General:
  - Update LMB associativity index during DLPAR add/remove from Nathan Fontenot
  - Fix branching to OOL handlers in relocatable kernel from Hari Bathini
  - Add support for userspace Power9 copy/paste from Chris Smart
  - Always use STRICT_MM_TYPECHECKS from Michael Ellerman
  - Add mask of possible MMU features from Michael Ellerman
 
 PCI:
  - Enable pass through of NVLink to guests from Alexey Kardashevskiy
  - Cleanups in preparation for powernv PCI hotplug from Gavin Shan
  - Don't report error in eeh_pe_reset_and_recover() from Gavin Shan
  - Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan
  - Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell" from Guilherme G. Piccoli
  - Remove the dependency on EEH struct in DDW mechanism from Guilherme G. Piccoli
 
 selftests:
  - Test cp_abort during context switch from Chris Smart
  - Add several tests for transactional memory support from Rashmica Gupta
 
 perf:
  - Add support for sampling interrupt register state from Anju T
  - Add support for unwinding perf-stackdump from Chandan Kumar
 
 cxl:
  - Configure the PSL for two CAPI ports on POWER8NVL from Philippe Bergheaud
  - Allow initialization on timebase sync failures from Frederic Barrat
  - Increase timeout for detection of AFU mmio hang from Frederic Barrat
  - Handle num_of_processes larger than can fit in the SPA from Ian Munsie
  - Ensure PSL interrupt is configured for contexts with no AFU IRQs from Ian Munsie
  - Add kernel API to allow a context to operate with relocate disabled from Ian Munsie
  - Check periodically the coherent platform function's state from Christophe Lombard
 
 Freescale:
  - Updates from Scott: "Contains 86xx fixes, minor device tree fixes, an erratum
    workaround, and a kconfig dependency fix."
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Merge tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

Pull powerpc updates from Michael Ellerman:
 "Highlights:
   - Support for Power ISA 3.0 (Power9) Radix Tree MMU from Aneesh Kumar K.V
   - Live patching support for ppc64le (also merged via livepatching.git)

  Various cleanups & minor fixes from:
   - Aaro Koskinen, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V,
     Chris Smart, Daniel Axtens, Frederic Barrat, Gavin Shan, Ian Munsie,
     Lennart Sorensen, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring,
     Michael Ellerman, Oliver O'Halloran, Paul Gortmaker, Paul Mackerras,
     Rashmica Gupta, Russell Currey, Suraj Jitindar Singh, Thiago Jung
     Bauermann, Valentin Rothberg, Vipin K Parashar.

  General:
   - Update LMB associativity index during DLPAR add/remove from Nathan
     Fontenot
   - Fix branching to OOL handlers in relocatable kernel from Hari Bathini
   - Add support for userspace Power9 copy/paste from Chris Smart
   - Always use STRICT_MM_TYPECHECKS from Michael Ellerman
   - Add mask of possible MMU features from Michael Ellerman

  PCI:
   - Enable pass through of NVLink to guests from Alexey Kardashevskiy
   - Cleanups in preparation for powernv PCI hotplug from Gavin Shan
   - Don't report error in eeh_pe_reset_and_recover() from Gavin Shan
   - Restore initial state in eeh_pe_reset_and_recover() from Gavin Shan
   - Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
     from Guilherme G Piccoli
   - Remove the dependency on EEH struct in DDW mechanism from Guilherme
     G Piccoli

  selftests:
   - Test cp_abort during context switch from Chris Smart
   - Add several tests for transactional memory support from Rashmica
     Gupta

  perf:
   - Add support for sampling interrupt register state from Anju T
   - Add support for unwinding perf-stackdump from Chandan Kumar

  cxl:
   - Configure the PSL for two CAPI ports on POWER8NVL from Philippe
     Bergheaud
   - Allow initialization on timebase sync failures from Frederic Barrat
   - Increase timeout for detection of AFU mmio hang from Frederic
     Barrat
   - Handle num_of_processes larger than can fit in the SPA from Ian
     Munsie
   - Ensure PSL interrupt is configured for contexts with no AFU IRQs
     from Ian Munsie
   - Add kernel API to allow a context to operate with relocate disabled
     from Ian Munsie
   - Check periodically the coherent platform function's state from
     Christophe Lombard

  Freescale:
   - Updates from Scott: "Contains 86xx fixes, minor device tree fixes,
     an erratum workaround, and a kconfig dependency fix."

* tag 'powerpc-4.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (192 commits)
  powerpc/86xx: Fix PCI interrupt map definition
  powerpc/86xx: Move pci1 definition to the include file
  powerpc/fsl: Fix build of the dtb embedded kernel images
  powerpc/fsl: Fix rcpm compatible string
  powerpc/fsl: Remove FSL_SOC dependency from FSL_LBC
  powerpc/fsl-pci: Add a workaround for PCI 5 errata
  powerpc/fsl: Fix SPI compatible on t208xrdb and t1040rdb
  powerpc/powernv/npu: Add PE to PHB's list
  powerpc/powernv: Fix insufficient memory allocation
  powerpc/iommu: Remove the dependency on EEH struct in DDW mechanism
  Revert "powerpc/eeh: Fix crash in eeh_add_device_early() on Cell"
  powerpc/eeh: Drop unnecessary label in eeh_pe_change_owner()
  powerpc/eeh: Ignore handlers in eeh_pe_reset_and_recover()
  powerpc/eeh: Restore initial state in eeh_pe_reset_and_recover()
  powerpc/eeh: Don't report error in eeh_pe_reset_and_recover()
  Revert "powerpc/powernv: Exclude root bus in pnv_pci_reset_secondary_bus()"
  powerpc/powernv/npu: Enable NVLink pass through
  powerpc/powernv/npu: Rework TCE Kill handling
  powerpc/powernv/npu: Add set/unset window helpers
  powerpc/powernv/ioda2: Export debug helper pe_level_printk()
  ...
2016-05-20 10:12:41 -07:00
Alexey Kardashevskiy
f705528094 vfio_pci: Test for extended capabilities if config space > 256 bytes
PCI-Express spec says that reading 4 bytes at offset 100h should return
zero if there is no extended capability so VFIO reads this dword to
know if there are extended capabilities.

However it is not always possible to access the extended space so
generic PCI code in pci_cfg_space_size_ext() checks if
pci_read_config_dword() can read beyond 100h and if the check fails,
it sets the config space size to 100h.

VFIO does its own extended capabilities check by reading at offset 100h
which may produce 0xffffffff which VFIO treats as the extended config
space presense and calls vfio_ecap_init() which fails to parse
capabilities (which is expected) but right before the exit, it writes
zero at offset 100h which is beyond the buffer allocated for
vdev->vconfig (which is 256 bytes) which leads to random memory
corruption.

This makes VFIO only check for the extended capabilities if
the discovered config size is more than 256 bytes.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-05-19 15:04:40 -06:00
Alexey Kardashevskiy
54de285beb vfio/spapr: Relax the IOMMU compatibility check
We are going to have multiple different types of PHB on the same system
with POWER8 + NVLink and PHBs will have different IOMMU ops. However
we only really care about one callback - create_table - so we can
relax the compatibility check here.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
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>
2016-05-11 21:54:27 +10:00
Robin Murphy
d16e0faab9 iommu: Allow selecting page sizes per domain
Many IOMMUs support multiple page table formats, meaning that any given
domain may only support a subset of the hardware page sizes presented in
iommu_ops->pgsize_bitmap. There are also certain use-cases where the
creator of a domain may want to control which page sizes are used, for
example to force the use of hugepage mappings to reduce pagetable walk
depth.

To this end, add a per-domain pgsize_bitmap to represent the subset of
page sizes actually in use, to make it possible for domains with
different requirements to coexist.

Signed-off-by: Will Deacon <will.deacon@arm.com>
[rm: hijacked and rebased original patch with new commit message]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2016-05-09 15:33:29 +02:00
Alexey Kardashevskiy
5ed4aba126 vfio_iommu_spapr_tce: Remove unneeded iommu_group_get_iommudata
This removes iommu_group_get_iommudata() as the result is never used.
As this is a minor cleanup, no change in behavior is expected.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-04-28 11:12:41 -06:00
Alex Williamson
dc92810997 vfio/pci: Add test for BAR restore
If a device is reset without the memory or i/o bits enabled in the
command register we may not detect it, potentially leaving the device
without valid BAR programming.  Add an additional test to check the
BARs on each write to the command register.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-04-28 11:12:33 -06:00
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.
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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
345d710491 vfio/pci: Enable virtual register in PCI config space
Typically config space for a device is mapped out into capability
specific handlers and unassigned space.  The latter allows direct
read/write access to config space.  Sometimes we know about registers
living in this void space and would like an easy way to virtualize
them, similar to how BAR registers are managed.  To do this, create
one more pseudo (fake) PCI capability to be handled as purely virtual
space.  Reads and writes are serviced entirely from virtual config
space.

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
d7a8d5ed87 vfio: Add capability chain helpers
Allow sub-modules to easily reallocate a buffer for managing
capability chains for info ioctls.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:08 -07:00
Alex Williamson
7c435b46c2 vfio: If an IOMMU backend fails, keep looking
Consider an IOMMU to be an API rather than an implementation, we might
have multiple implementations supporting the same API, so try another
if one fails.  The expectation here is that we'll really only have
one implementation per device type.  For instance the existing type1
driver works with any PCI device where the IOMMU API is available.  A
vGPU vendor may have a virtual PCI device which provides DMA isolation
and mapping through other mechanisms, but can re-use userspaces that
make use of the type1 VFIO IOMMU API.  This allows that to work.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-02-22 16:10:08 -07:00
Alex Williamson
b95d9305e8 vfio/pci: Fix unsigned comparison overflow
Signed versus unsigned comparisons are implicitly cast to unsigned,
which result in a couple possible overflows.  For instance (start +
count) might overflow and wrap, getting through our validation test.
Also when unwinding setup, -1 being compared as unsigned doesn't
produce the intended stop condition.  Fix both of these and also fix
vfio_msi_set_vector_signal() to validate parameters before using the
vector index, though none of the callers should pass bad indexes
anymore.

Reported-by: Eric Auger <eric.auger@linaro.org>
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>
2016-02-22 16:03:54 -07:00
Alex Williamson
16ab8a5cbe vfio/noiommu: Don't use iommu_present() to track fake groups
Using iommu_present() to determine whether an IOMMU group is real or
fake has some problems.  First, apparently Power systems don't
register an IOMMU on the device bus, so the groups and containers get
marked as noiommu and then won't bind to their actual IOMMU driver.
Second, I expect we'll run into the same issue as we try to support
vGPUs through vfio, since they're likely to emulate this behavior of
creating an IOMMU group on a virtual device and then providing a vfio
IOMMU backend tailored to the sort of isolation they provide, which
won't necessarily be fully compatible with the IOMMU API.

The solution here is to use the existing iommudata interface to IOMMU
groups, which allows us to easily identify the fake groups we've
created for noiommu purposes.  The iommudata we set is purely
arbitrary since we're only comparing the address, so we use the
address of the noiommu switch itself.

Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Tested-by: Anatoly Burakov <anatoly.burakov@intel.com>
Tested-by: Santosh Shukla <sshukla@mvista.com>
Fixes: 03a76b60f8 ("vfio: Include No-IOMMU mode")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-01-27 11:22:25 -07:00
Pierre Morel
d4f50ee2f5 vfio/iommu_type1: make use of info.flags
The flags entry is there to tell the user that some
optional information is available.

Since we report the iova_pgsizes signal it to the user
by setting the flags to VFIO_IOMMU_INFO_PGSIZES.

Signed-off-by: Pierre Morel <pmorel@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2016-01-04 12:55:44 -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
Dan Carpenter
967628827f VFIO: platform: reset: fix a warning message condition
This loop ends with count set to -1 and not zero so the warning message
isn't printed when it should be.  I've fixed this by change the postop
to a preop.

Fixes: 0990822c98 ('VFIO: platform: reset: AMD xgbe reset module')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
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
Dan Carpenter
049af1060b vfio: fix a warning message
The first argument to the WARN() macro has to be a condition.  I'm sort
of disappointed that this code doesn't generate a compiler warning.  I
guess -Wformat-extra-args doesn't work in the kernel.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-21 06:55:58 -07:00
Kees Cook
7200be7c81 vfio: platform: remove needless stack usage
request_module already takes format strings, so no need to duplicate
the effort.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-20 09:00:10 -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
Krzysztof Kozlowski
7fe9414223 vfio: Drop owner assignment from platform_driver
platform_driver does not need to set an owner because
platform_driver_register() will set it.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-19 15:52:08 -07:00
Linus Torvalds
934f98d7e8 VFIO updates for v4.4-rc1
- Use kernel interfaces for VPD emulation (Alex Williamson)
  - Platform fix for releasing IRQs (Eric Auger)
  - Type1 IOMMU always advertises PAGE_SIZE support when smaller
    mapping sizes are available (Eric Auger)
  - Platform fixes for incorrectly using copies of structures rather
    than pointers to structures (James Morse)
  - Rework platform reset modules, fix leak, and add AMD xgbe reset
    module (Eric Auger)
  - Fix vfio_device_get_from_name() return value (Joerg Roedel)
  - No-IOMMU interface (Alex Williamson)
  - Fix potential out of bounds array access in PCI config handling
    (Dan Carpenter)
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Merge tag 'vfio-v4.4-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:
 - Use kernel interfaces for VPD emulation (Alex Williamson)
 - Platform fix for releasing IRQs (Eric Auger)
 - Type1 IOMMU always advertises PAGE_SIZE support when smaller mapping
   sizes are available (Eric Auger)
 - Platform fixes for incorrectly using copies of structures rather than
   pointers to structures (James Morse)
 - Rework platform reset modules, fix leak, and add AMD xgbe reset
   module (Eric Auger)
 - Fix vfio_device_get_from_name() return value (Joerg Roedel)
 - No-IOMMU interface (Alex Williamson)
 - Fix potential out of bounds array access in PCI config handling (Dan
   Carpenter)

* tag 'vfio-v4.4-rc1' of git://github.com/awilliam/linux-vfio:
  vfio/pci: make an array larger
  vfio: Include No-IOMMU mode
  vfio: Fix bug in vfio_device_get_from_name()
  VFIO: platform: reset: AMD xgbe reset module
  vfio: platform: reset: calxedaxgmac: fix ioaddr leak
  vfio: platform: add dev_info on device reset
  vfio: platform: use list of registered reset function
  vfio: platform: add compat in vfio_platform_device
  vfio: platform: reset: calxedaxgmac: add reset function registration
  vfio: platform: introduce module_vfio_reset_handler macro
  vfio: platform: add capability to register a reset function
  vfio: platform: introduce vfio-platform-base module
  vfio/platform: store mapped memory in region, instead of an on-stack copy
  vfio/type1: handle case where IOMMU does not support PAGE_SIZE size
  VFIO: platform: clear IRQ_NOAUTOEN when de-assigning the IRQ
  vfio/pci: Use kernel VPD access functions
  vfio: Whitelist PCI bridges
2015-11-13 17:05:32 -08:00
Dan Carpenter
222e684ca7 vfio/pci: make an array larger
Smatch complains about a possible out of bounds error:

	drivers/vfio/pci/vfio_pci_config.c:1241 vfio_cap_init()
	error: buffer overflow 'pci_cap_length' 20 <= 20

The problem is that pci_cap_length[] was defined as large enough to
hold "PCI_CAP_ID_AF + 1" elements.  The code in vfio_cap_init() assumes
it has PCI_CAP_ID_MAX + 1 elements.  Originally, PCI_CAP_ID_AF and
PCI_CAP_ID_MAX were the same but then we introduced PCI_CAP_ID_EA in
commit f80b0ba959 ("PCI: Add Enhanced Allocation register entries")
so now the array is too small.

Let's fix this by making the array size PCI_CAP_ID_MAX + 1.  And let's
make a similar change to pci_ext_cap_length[] for consistency.  Also
both these arrays can be made const.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-09 08:59:11 -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
Joerg Roedel
e324fc82ea vfio: Fix bug in vfio_device_get_from_name()
The vfio_device_get_from_name() function might return a
non-NULL pointer, when called with a device name that is not
found in the list. This causes undefined behavior, in my
case calling an invalid function pointer later on:

 kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
 BUG: unable to handle kernel paging request at ffff8800cb3ddc08

[...]

 Call Trace:
  [<ffffffffa03bd733>] ? vfio_group_fops_unl_ioctl+0x253/0x410 [vfio]
  [<ffffffff811efc4d>] do_vfs_ioctl+0x2cd/0x4c0
  [<ffffffff811f9657>] ? __fget+0x77/0xb0
  [<ffffffff811efeb9>] SyS_ioctl+0x79/0x90
  [<ffffffff81001bb0>] ? syscall_return_slowpath+0x50/0x130
  [<ffffffff8167f776>] entry_SYSCALL_64_fastpath+0x16/0x75

Fix the issue by returning NULL when there is no device with
the requested name in the list.

Cc: stable@vger.kernel.org # v4.2+
Fixes: 4bc94d5dc9 ("vfio: Fix lockdep issue")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-04 09:27:39 -07:00
Eric Auger
0990822c98 VFIO: platform: reset: AMD xgbe reset module
This patch introduces a module that registers and implements a low-level
reset function for the AMD XGBE device.

it performs the following actions:
- reset the PHY
- disable auto-negotiation
- disable & clear auto-negotiation IRQ
- soft-reset the MAC

Those tiny pieces of code are inherited from the native xgbe driver.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:55:21 -07:00
Eric Auger
daac3bbedb vfio: platform: reset: calxedaxgmac: fix ioaddr leak
In the current code the vfio_platform_region is copied on the stack.
As a consequence the ioaddr address is not iounmapped in the vfio
platform driver (vfio_platform_regions_cleanup). The patch uses the
pointer to the region instead.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:55:06 -07:00
Eric Auger
705e60bae3 vfio: platform: add dev_info on device reset
It might be helpful for the end-user to check the device reset
function was found by the vfio platform reset framework.

Lets store a pointer to the struct device in vfio_platform_device
and trace when the reset function is called or not found.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:55:05 -07:00
Eric Auger
e9e0506ee6 vfio: platform: use list of registered reset function
Remove the static lookup table and use the dynamic list of registered
reset functions instead. Also load the reset module through its alias.
The reset struct module pointer is stored in vfio_platform_device.

We also remove the useless struct device pointer parameter in
vfio_platform_get_reset.

This patch fixes the issue related to the usage of __symbol_get, which
besides from being moot, prevented compilation with CONFIG_MODULES
disabled.

Also usage of MODULE_ALIAS makes possible to add a new reset module
without needing to update the framework. This was suggested by Arnd.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:55:03 -07:00
Eric Auger
0628c4dfd3 vfio: platform: add compat in vfio_platform_device
Let's retrieve the compatibility string on probe and store it
in the vfio_platform_device struct

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:55:02 -07:00
Eric Auger
680742f644 vfio: platform: reset: calxedaxgmac: add reset function registration
This patch adds the reset function registration/unregistration.
This is handled through the module_vfio_reset_handler macro. This
latter also defines a MODULE_ALIAS which simplifies the load from
vfio-platform.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:55:00 -07:00
Eric Auger
588646529f vfio: platform: introduce module_vfio_reset_handler macro
The module_vfio_reset_handler macro
- define a module alias
- implement module init/exit function which respectively registers
  and unregisters the reset function.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:54:59 -07:00
Eric Auger
e086497d31 vfio: platform: add capability to register a reset function
In preparation for subsequent changes in reset function lookup,
lets introduce a dynamic list of reset combos (compat string,
reset module, reset function). The list can be populated/voided with
vfio_platform_register/unregister_reset. Those are not yet used in
this patch.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:54:57 -07:00
Eric Auger
32a2d71c4e vfio: platform: introduce vfio-platform-base module
To prepare for vfio platform reset rework let's build
vfio_platform_common.c and vfio_platform_irq.c in a separate
module from vfio-platform and vfio-amba. This makes possible
to have separate module inits and works around a race between
platform driver init and vfio reset module init: that way we
make sure symbols exported by base are available when vfio-platform
driver gets probed.

The open/release being implemented in the base module, the ref
count is applied to the parent module instead.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:54:56 -07:00
James Morse
1b4bb2eaa9 vfio/platform: store mapped memory in region, instead of an on-stack copy
vfio_platform_{read,write}_mmio() call ioremap_nocache() to map
a region of io memory, which they store in struct vfio_platform_region to
be eventually re-used, or unmapped by vfio_platform_regions_cleanup().

These functions receive a copy of their struct vfio_platform_region
argument on the stack - so these mapped areas are always allocated, and
always leaked.

Pass this argument as a pointer instead.

Fixes: 6e3f264560 "vfio/platform: read and write support for the device fd"
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:54:00 -07:00
Eric Auger
4644321fd3 vfio/type1: handle case where IOMMU does not support PAGE_SIZE size
Current vfio_pgsize_bitmap code hides the supported IOMMU page
sizes smaller than PAGE_SIZE. As a result, in case the IOMMU
does not support PAGE_SIZE page, the alignment check on map/unmap
is done with larger page sizes, if any. This can fail although
mapping could be done with pages smaller than PAGE_SIZE.

This patch modifies vfio_pgsize_bitmap implementation so that,
in case the IOMMU supports page sizes smaller than PAGE_SIZE
we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes.
That way the user will be able to map/unmap buffers whose size/
start address is aligned with PAGE_SIZE. Pinning code uses that
granularity while iommu driver can use the sub-PAGE_SIZE size
to map the buffer.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-11-03 12:53:53 -07:00
Eric Auger
1276ece32c VFIO: platform: clear IRQ_NOAUTOEN when de-assigning the IRQ
The vfio platform driver currently sets the IRQ_NOAUTOEN before
doing the request_irq to properly handle the user masking. However
it does not clear it when de-assigning the IRQ. This brings issues
when loading the native driver again which may not explicitly enable
the IRQ. This problem was observed with xgbe driver.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-10-27 15:02:53 -06:00
Alex Williamson
4e1a635552 vfio/pci: Use kernel VPD access functions
The PCI VPD capability operates on a set of window registers in PCI
config space.  Writing to the address register triggers either a read
or write, depending on the setting of the PCI_VPD_ADDR_F bit within
the address register.  The data register provides either the source
for writes or the target for reads.

This model is susceptible to being broken by concurrent access, for
which the kernel has adopted a set of access functions to serialize
these registers.  Additionally, commits like 932c435cab ("PCI: Add
dev_flags bit to access VPD through function 0") and 7aa6ca4d39
("PCI: Add VPD function 0 quirk for Intel Ethernet devices") indicate
that VPD registers can be shared between functions on multifunction
devices creating dependencies between otherwise independent devices.

Fortunately it's quite easy to emulate the VPD registers, simply
storing copies of the address and data registers in memory and
triggering a VPD read or write on writes to the address register.
This allows vfio users to avoid seeing spurious register changes from
accesses on other devices and enables the use of shared quirks in the
host kernel.  We can theoretically still race with access through
sysfs, but the window of opportunity is much smaller.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Mark Rustad <mark.d.rustad@intel.com>
2015-10-27 14:53:05 -06:00
Alex Williamson
5f096b14d4 vfio: Whitelist PCI bridges
When determining whether a group is viable, we already allow devices
bound to pcieport.  Generalize this to include any PCI bridge device.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-10-27 14:53:04 -06:00
Feng Wu
6d7425f109 vfio: Register/unregister irq_bypass_producer
This patch adds the registration/unregistration of an
irq_bypass_producer for MSI/MSIx on vfio pci devices.

Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Feng Wu <feng.wu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-10-01 15:06:50 +02:00
Alex Williamson
4bc94d5dc9 vfio: Fix lockdep issue
When we open a device file descriptor, we currently have the
following:

vfio_group_get_device_fd()
  mutex_lock(&group->device_lock);
    open()
    ...
    if (ret)
      release()

If we hit that error case, we call the backend driver release path,
which for vfio-pci looks like this:

vfio_pci_release()
  vfio_pci_disable()
    vfio_pci_try_bus_reset()
      vfio_pci_get_devs()
        vfio_device_get_from_dev()
          vfio_group_get_device()
            mutex_lock(&group->device_lock);

Whoops, we've stumbled back onto group.device_lock and created a
deadlock.  There's a low likelihood of ever seeing this play out, but
obviously it needs to be fixed.  To do that we can use a reference to
the vfio_device for vfio_group_get_device_fd() rather than holding the
lock.  There was a loop in this function, theoretically allowing
multiple devices with the same name, but in practice we don't expect
such a thing to happen and the code is already aborting from the loop
with break on any sort of error rather than continuing and only
parsing the first match anyway, so the loop was effectively unused
already.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Fixes: 20f300175a ("vfio/pci: Fix racy vfio_device_get_from_dev() call")
Reported-by: Joerg Roedel <joro@8bytes.org>
Tested-by: Joerg Roedel <jroedel@suse.de>
2015-07-24 15:14:04 -06:00
Linus Torvalds
b779157dd3 VFIO updates for v4.2
- Fix race with device reference versus driver release (Alex Williamson)
 - Add reset hooks and Calxeda xgmac reset for vfio-platform (Eric Auger)
 - Enable vfio-platform for ARM64 (Eric Auger)
 - Tag Baptiste Reynal as vfio-platform sub-maintainer (Alex Williamson)
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Merge tag 'vfio-v4.2-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - fix race with device reference versus driver release (Alex Williamson)

 - add reset hooks and Calxeda xgmac reset for vfio-platform (Eric Auger)

 - enable vfio-platform for ARM64 (Eric Auger)

 - tag Baptiste Reynal as vfio-platform sub-maintainer (Alex Williamson)

* tag 'vfio-v4.2-rc1' of git://github.com/awilliam/linux-vfio:
  MAINTAINERS: Add vfio-platform sub-maintainer
  VFIO: platform: enable ARM64 build
  VFIO: platform: Calxeda xgmac reset module
  VFIO: platform: populate the reset function on probe
  VFIO: platform: add reset callback
  VFIO: platform: add reset struct and lookup table
  vfio/pci: Fix racy vfio_device_get_from_dev() call
2015-06-28 12:32:13 -07:00
Linus Torvalds
08d183e3c1 powerpc updates for 4.2
- Disable the 32-bit vdso when building LE, so we can build with a 64-bit only
    toolchain.
  - EEH fixes from Gavin & Richard.
  - Enable the sys_kcmp syscall from Laurent.
  - Sysfs control for fastsleep workaround from Shreyas.
  - Expose OPAL events as an irq chip by Alistair.
  - MSI ops moved to pci_controller_ops by Daniel.
  - Fix for kernel to userspace backtraces for perf from Anton.
  - Merge pseries and pseries_le defconfigs from Cyril.
  - CXL in-kernel API from Mikey.
  - OPAL prd driver from Jeremy.
  - Fix for DSCR handling & tests from Anshuman.
  - Powernv flash mtd driver from Cyril.
  - Dynamic DMA Window support on powernv from Alexey.
  - LLVM clang fixes & workarounds from Anton.
  - Reworked version of the patch to abort syscalls when transactional.
  - Fix the swap encoding to support 4TB, from Aneesh.
  - Various fixes as usual.
  - Freescale updates from Scott: Highlights include more 8xx optimizations, an
    e6500 hugetlb optimization, QMan device tree nodes, t1024/t1023 support, and
    various fixes and cleanup.
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Merge tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux

Pull powerpc updates from Michael Ellerman:

 - disable the 32-bit vdso when building LE, so we can build with a
   64-bit only toolchain.

 - EEH fixes from Gavin & Richard.

 - enable the sys_kcmp syscall from Laurent.

 - sysfs control for fastsleep workaround from Shreyas.

 - expose OPAL events as an irq chip by Alistair.

 - MSI ops moved to pci_controller_ops by Daniel.

 - fix for kernel to userspace backtraces for perf from Anton.

 - merge pseries and pseries_le defconfigs from Cyril.

 - CXL in-kernel API from Mikey.

 - OPAL prd driver from Jeremy.

 - fix for DSCR handling & tests from Anshuman.

 - Powernv flash mtd driver from Cyril.

 - dynamic DMA Window support on powernv from Alexey.

 - LLVM clang fixes & workarounds from Anton.

 - reworked version of the patch to abort syscalls when transactional.

 - fix the swap encoding to support 4TB, from Aneesh.

 - various fixes as usual.

 - Freescale updates from Scott: Highlights include more 8xx
   optimizations, an e6500 hugetlb optimization, QMan device tree nodes,
   t1024/t1023 support, and various fixes and cleanup.

* tag 'powerpc-4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux: (180 commits)
  cxl: Fix typo in debug print
  cxl: Add CXL_KERNEL_API config option
  powerpc/powernv: Fix wrong IOMMU table in pnv_ioda_setup_bus_dma()
  powerpc/mm: Change the swap encoding in pte.
  powerpc/mm: PTE_RPN_MAX is not used, remove the same
  powerpc/tm: Abort syscalls in active transactions
  powerpc/iommu/ioda2: Enable compile with IOV=on and IOMMU_API=off
  powerpc/include: Add opal-prd to installed uapi headers
  powerpc/powernv: fix construction of opal PRD messages
  powerpc/powernv: Increase opal-irqchip initcall priority
  powerpc: Make doorbell check preemption safe
  powerpc/powernv: pnv_init_idle_states() should only run on powernv
  macintosh/nvram: Remove as unused
  powerpc: Don't use gcc specific options on clang
  powerpc: Don't use -mno-strict-align on clang
  powerpc: Only use -mtraceback=no, -mno-string and -msoft-float if toolchain supports it
  powerpc: Only use -mabi=altivec if toolchain supports it
  powerpc: Fix duplicate const clang warning in user access code
  vfio: powerpc/spapr: Support Dynamic DMA windows
  vfio: powerpc/spapr: Register memory and define IOMMU v2
  ...
2015-06-24 08:46:32 -07:00
Eric Auger
e6bcd47f8f VFIO: platform: enable ARM64 build
This patch enables building VFIO platform and derivatives on ARM64.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-06-22 09:35:47 -06:00
Eric Auger
713cc334a6 VFIO: platform: Calxeda xgmac reset module
This patch introduces a module that registers and implements a basic
reset function for the Calxeda xgmac device. This latter basically disables
interrupts and stops DMA transfers.

The reset function code is inherited from the native calxeda xgmac driver.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-06-22 09:35:38 -06:00
Eric Auger
3eeb0d510c VFIO: platform: populate the reset function on probe
The reset function lookup happens on vfio-platform probe. The reset
module load is requested  and a reference to the function symbol is
hold. The reference is released on vfio-platform remove.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-06-22 09:35:30 -06:00
Eric Auger
813ae66008 VFIO: platform: add reset callback
A new reset callback is introduced. If this callback is populated,
the reset is invoked on device first open/last close or upon userspace
ioctl.  The modality is exposed on VFIO_DEVICE_GET_INFO.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-06-22 09:35:22 -06:00
Eric Auger
9f85d8f9fa VFIO: platform: add reset struct and lookup table
This patch introduces the vfio_platform_reset_combo struct that
stores all the information useful to handle the reset modality:
compat string, name of the reset function, name of the module that
implements the reset function. A lookup table of such structures
is added, currently void.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Tested-by: Baptiste Reynal <b.reynal@virtualopensystems.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-06-17 15:39:09 -06:00
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
Alexey Kardashevskiy
46d3e1e162 vfio: powerpc/spapr: powerpc/powernv/ioda2: Use DMA windows API in ownership control
Before the IOMMU user (VFIO) would take control over the IOMMU table
belonging to a specific IOMMU group. This approach did not allow sharing
tables between IOMMU groups attached to the same container.

This introduces a new IOMMU ownership flavour when the user can not
just control the existing IOMMU table but remove/create tables on demand.
If an IOMMU implements take/release_ownership() callbacks, this lets
the user have full control over the IOMMU group. When the ownership
is taken, the platform code removes all the windows so the caller must
create them.
Before returning the ownership back to the platform code, VFIO
unprograms and removes all the tables it created.

This changes IODA2's onwership handler to remove the existing table
rather than manipulating with the existing one. From now on,
iommu_take_ownership() and iommu_release_ownership() are only called
from the vfio_iommu_spapr_tce driver.

Old-style ownership is still supported allowing VFIO to run on older
P5IOC2 and IODA IO controllers.

No change in userspace-visible behaviour is expected. Since it recreates
TCE tables on each ownership change, related kernel traces will appear
more often.

This adds a pnv_pci_ioda2_setup_default_config() which is called
when PE is being configured at boot time and when the ownership is
passed from VFIO to the platform code.

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 15:16:54 +10:00
Alexey Kardashevskiy
4793d65d1a vfio: powerpc/spapr: powerpc/powernv/ioda: Define and implement DMA windows API
This extends iommu_table_group_ops by a set of callbacks to support
dynamic DMA windows management.

create_table() creates a TCE table with specific parameters.
it receives iommu_table_group to know nodeid in order to allocate
TCE table memory closer to the PHB. The exact format of allocated
multi-level table might be also specific to the PHB model (not
the case now though).
This callback calculated the DMA window offset on a PCI bus from @num
and stores it in a just created table.

set_window() sets the window at specified TVT index + @num on PHB.

unset_window() unsets the window from specified TVT.

This adds a free() callback to iommu_table_ops to free the memory
(potentially a tree of tables) allocated for the TCE table.

create_table() and free() are supposed to be called once per
VFIO container and set_window()/unset_window() are supposed to be
called for every group in a container.

This adds IOMMU capabilities to iommu_table_group such as default
32bit window parameters and others. This makes use of new values in
vfio_iommu_spapr_tce. IODA1/P5IOC2 do not support DDW so they do not
advertise pagemasks to the userspace.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
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 15:16:52 +10:00
Alexey Kardashevskiy
05c6cfb9dc powerpc/iommu/powernv: Release replaced TCE
At the moment writing new TCE value to the IOMMU table fails with EBUSY
if there is a valid entry already. However PAPR specification allows
the guest to write new TCE value without clearing it first.

Another problem this patch is addressing is the use of pool locks for
external IOMMU users such as VFIO. The pool locks are to protect
DMA page allocator rather than entries and since the host kernel does
not control what pages are in use, there is no point in pool locks and
exchange()+put_page(oldtce) is sufficient to avoid possible races.

This adds an exchange() callback to iommu_table_ops which does the same
thing as set() plus it returns replaced TCE and DMA direction so
the caller can release the pages afterwards. The exchange() receives
a physical address unlike set() which receives linear mapping address;
and returns a physical address as the clear() does.

This implements exchange() for P5IOC2/IODA/IODA2. This adds a requirement
for a platform to have exchange() implemented in order to support VFIO.

This replaces iommu_tce_build() and iommu_clear_tce() with
a single iommu_tce_xchg().

This makes sure that TCE permission bits are not set in TCE passed to
IOMMU API as those are to be calculated by platform code from
DMA direction.

This moves SetPageDirty() to the IOMMU code to make it work for both
VFIO ioctl interface in in-kernel TCE acceleration (when it becomes
available later).

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 15:16:49 +10:00
Alexey Kardashevskiy
f87a88642e vfio: powerpc/spapr/iommu/powernv/ioda2: Rework IOMMU ownership control
This adds tce_iommu_take_ownership() and tce_iommu_release_ownership
which call in a loop iommu_take_ownership()/iommu_release_ownership()
for every table on the group. As there is just one now, no change in
behaviour is expected.

At the moment the iommu_table struct has a set_bypass() which enables/
disables DMA bypass on IODA2 PHB. This is exposed to POWERPC IOMMU code
which calls this callback when external IOMMU users such as VFIO are
about to get over a PHB.

The set_bypass() callback is not really an iommu_table function but
IOMMU/PE function. This introduces a iommu_table_group_ops struct and
adds take_ownership()/release_ownership() callbacks to it which are
called when an external user takes/releases control over the IOMMU.

This replaces set_bypass() with ownership callbacks as it is not
necessarily just bypass enabling, it can be something else/more
so let's give it more generic name.

The callbacks is implemented for IODA2 only. Other platforms (P5IOC2,
IODA1) will use the old iommu_take_ownership/iommu_release_ownership API.
The following patches will replace iommu_take_ownership/
iommu_release_ownership calls in IODA2 with full IOMMU table release/
create.

As we here and touching bypass control, this removes
pnv_pci_ioda2_setup_bypass_pe() as it does not do much
more compared to pnv_pci_ioda2_set_bypass. This moves tce_bypass_base
initialization to pnv_pci_ioda2_setup_dma_pe.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:16:47 +10:00
Alexey Kardashevskiy
0eaf4defc7 powerpc/spapr: vfio: Switch from iommu_table to new iommu_table_group
So far one TCE table could only be used by one IOMMU group. However
IODA2 hardware allows programming the same TCE table address to
multiple PE allowing sharing tables.

This replaces a single pointer to a group in a iommu_table struct
with a linked list of groups which provides the way of invalidating
TCE cache for every PE when an actual TCE table is updated. This adds
pnv_pci_link_table_and_group() and pnv_pci_unlink_table_and_group()
helpers to manage the list. However without VFIO, it is still going
to be a single IOMMU group per iommu_table.

This changes iommu_add_device() to add a device to a first group
from the group list of a table as it is only called from the platform
init code or PCI bus notifier and at these moments there is only
one group per table.

This does not change TCE invalidation code to loop through all
attached groups in order to simplify this patch and because
it is not really needed in most cases. IODA2 is fixed in a later
patch.

This should cause no behavioural change.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:16:15 +10:00
Alexey Kardashevskiy
b348aa6529 powerpc/spapr: vfio: Replace iommu_table with iommu_table_group
Modern IBM POWERPC systems support multiple (currently two) TCE tables
per IOMMU group (a.k.a. PE). This adds a iommu_table_group container
for TCE tables. Right now just one table is supported.

This defines iommu_table_group struct which stores pointers to
iommu_group and iommu_table(s). This replaces iommu_table with
iommu_table_group where iommu_table was used to identify a group:
- iommu_register_group();
- iommudata of generic iommu_group;

This removes @data from iommu_table as it_table_group provides
same access to pnv_ioda_pe.

For IODA, instead of embedding iommu_table, the new iommu_table_group
keeps pointers to those. The iommu_table structs are allocated
dynamically.

For P5IOC2, both iommu_table_group and iommu_table are embedded into
PE struct. As there is no EEH and SRIOV support for P5IOC2,
iommu_free_table() should not be called on iommu_table struct pointers
so we can keep it embedded in pnv_phb::p5ioc2.

For pSeries, this replaces multiple calls of kzalloc_node() with a new
iommu_pseries_alloc_group() helper and stores the table group struct
pointer into the pci_dn struct. For release, a iommu_table_free_group()
helper is added.

This moves iommu_table struct allocation from SR-IOV code to
the generic DMA initialization code in pnv_pci_ioda_setup_dma_pe and
pnv_pci_ioda2_setup_dma_pe as this is where DMA is actually initialized.
This change is here because those lines had to be changed anyway.

This should cause no behavioural change.

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>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:14:57 +10:00
Alexey Kardashevskiy
22af48596e vfio: powerpc/spapr: Rework groups attaching
This is to make extended ownership and multiple groups support patches
simpler for review.

This should cause no behavioural change.

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>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:14:56 +10:00
Alexey Kardashevskiy
649354b75d vfio: powerpc/spapr: Moving pinning/unpinning to helpers
This is a pretty mechanical patch to make next patches simpler.

New tce_iommu_unuse_page() helper does put_page() now but it might skip
that after the memory registering patch applied.

As we are here, this removes unnecessary checks for a value returned
by pfn_to_page() as it cannot possibly return NULL.

This moves tce_iommu_disable() later to let tce_iommu_clear() know if
the container has been enabled because if it has not been, then
put_page() must not be called on TCEs from the TCE table. This situation
is not yet possible but it will after KVM acceleration patchset is
applied.

This changes code to work with physical addresses rather than linear
mapping addresses for better code readability. Following patches will
add an xchg() callback for an IOMMU table which will accept/return
physical addresses (unlike current tce_build()) which will eliminate
redundant conversions.

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>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:14:56 +10:00
Alexey Kardashevskiy
3c56e822f8 vfio: powerpc/spapr: Disable DMA mappings on disabled container
At the moment DMA map/unmap requests are handled irrespective to
the container's state. This allows the user space to pin memory which
it might not be allowed to pin.

This adds checks to MAP/UNMAP that the container is enabled, otherwise
-EPERM is returned.

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>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:14:56 +10:00
Alexey Kardashevskiy
2d270df8f7 vfio: powerpc/spapr: Move locked_vm accounting to helpers
There moves locked pages accounting to helpers.
Later they will be reused for Dynamic DMA windows (DDW).

This reworks debug messages to show the current value and the limit.

This stores the locked pages number in the container so when unlocking
the iommu table pointer won't be needed. This does not have an effect
now but it will with the multiple tables per container as then we will
allow attaching/detaching groups on fly and we may end up having
a container with no group attached but with the counter incremented.

While we are here, update the comment explaining why RLIMIT_MEMLOCK
might be required to be bigger than the guest RAM. This also prints
pid of the current process in pr_warn/pr_debug.

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>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:14:55 +10:00
Alexey Kardashevskiy
00663d4ee0 vfio: powerpc/spapr: Use it_page_size
This makes use of the it_page_size from the iommu_table struct
as page size can differ.

This replaces missing IOMMU_PAGE_SHIFT macro in commented debug code
as recently introduced IOMMU_PAGE_XXX macros do not include
IOMMU_PAGE_SHIFT.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[aw: for the vfio related changes]
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:14:55 +10:00
Alexey Kardashevskiy
e432bc7e15 vfio: powerpc/spapr: Check that IOMMU page is fully contained by system page
This checks that the TCE table page size is not bigger that the size of
a page we just pinned and going to put its physical address to the table.

Otherwise the hardware gets unwanted access to physical memory between
the end of the actual page and the end of the aligned up TCE page.

Since compound_order() and compound_head() work correctly on non-huge
pages, there is no need for additional check whether the page is huge.

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>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:14:55 +10:00
Alexey Kardashevskiy
9b14a1ff86 vfio: powerpc/spapr: Move page pinning from arch code to VFIO IOMMU driver
This moves page pinning (get_user_pages_fast()/put_page()) code out of
the platform IOMMU code and puts it to VFIO IOMMU driver where it belongs
to as the platform code does not deal with page pinning.

This makes iommu_take_ownership()/iommu_release_ownership() deal with
the IOMMU table bitmap only.

This removes page unpinning from iommu_take_ownership() as the actual
TCE table might contain garbage and doing put_page() on it is undefined
behaviour.

Besides the last part, the rest of the patch is mechanical.

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>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-06-11 15:14:55 +10:00
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
Will Deacon
8a0a01bff8 drivers/vfio: Allow type-1 IOMMU instantiation on top of an ARM SMMUv3
The ARM SMMUv3 driver is compatible with the notion of a type-1 IOMMU in
VFIO.

This patch allows VFIO_IOMMU_TYPE1 to be selected if ARM_SMMU_V3=y.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-05-29 11:12:40 +02:00
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
Alex Williamson
db7d4d7f40 vfio: Fix runaway interruptible timeout
Commit 13060b64b8 ("vfio: Add and use device request op for vfio
bus drivers") incorrectly makes use of an interruptible timeout.
When interrupted, the signal remains pending resulting in subsequent
timeouts occurring instantly.  This makes the loop spin at a much
higher rate than intended.

Instead of making this completely non-interruptible, we can change
this into a sort of interruptible-once behavior and use the "once"
to log debug information.  The driver API doesn't allow us to abort
and return an error code.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Fixes: 13060b64b8
Cc: stable@vger.kernel.org # v4.0
2015-05-01 16:31:41 -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
Alex Williamson
71be3423a6 vfio: Split virqfd into a separate module for vfio bus drivers
An unintended consequence of commit 42ac9bd18d ("vfio: initialize
the virqfd workqueue in VFIO generic code") is that the vfio module
is renamed to vfio_core so that it can include both vfio and virqfd.
That's a user visible change that may break module loading scritps
and it imposes eventfd support as a dependency on the core vfio code,
which it's really not.  virqfd is intended to be provided as a service
to vfio bus drivers, so instead of wrapping it into vfio.ko, we can
make it a stand-alone module toggled by vfio bus drivers.  This has
the additional benefit of removing initialization and exit from the
core vfio code.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-17 08:33:38 -06:00
kbuild test robot
66fdc052d7 vfio: virqfd_lock can be static
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-17 08:20:31 -06:00
Zhen Lei
2f51bf4be9 vfio: put off the allocation of "minor" in vfio_create_group
The next code fragment "list_for_each_entry" is not depend on "minor". With this
patch, the free of "minor" in "list_for_each_entry" can be reduced, and there is
no functional change.

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-16 14:08:56 -06:00
Antonios Motakis
a7fa7c77cf vfio/platform: implement IRQ masking/unmasking via an eventfd
With this patch the VFIO user will be able to set an eventfd that can be
used in order to mask and unmask IRQs of 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>
Tested-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-16 14:08:55 -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
7e992d6927 vfio: move eventfd support code for VFIO_PCI to a separate file
The virqfd functionality that is used by VFIO_PCI to implement interrupt
masking and unmasking via an eventfd, is generic enough and can be reused
by another driver. Move it to a separate file in order to allow the code
to be shared.

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
09bbcb8810 vfio: pass an opaque pointer on virqfd initialization
VFIO_PCI passes the VFIO device structure *vdev via eventfd to the handler
that implements masking/unmasking of IRQs via an eventfd. We can replace
it in the virqfd infrastructure with an opaque type so we can make use
of the mechanism from other 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 14:08:53 -06:00
Antonios Motakis
9269c393e7 vfio: add local lock for virqfd instead of depending on VFIO PCI
The Virqfd code needs to keep accesses to any struct *virqfd safe, but
this comes into play only when creating or destroying eventfds, so sharing
the same spinlock with the VFIO bus driver is not necessary.

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 14:08:52 -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
Antonios Motakis
bdc5e1021b vfio: add a vfio_ prefix to virqfd_enable and virqfd_disable and export
We want to reuse virqfd functionality in multiple VFIO drivers; before
moving these functions to core VFIO, add the vfio_ prefix to the
virqfd_enable and virqfd_disable functions, and export them so they can
be used from other modules.

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 14:08:51 -06:00
Antonios Motakis
06211b40ce vfio/platform: support for level sensitive interrupts
Level sensitive interrupts are exposed as maskable and automasked
interrupts and are masked and disabled automatically when they fire.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
[Baptiste Reynal: Move masked interrupt initialization from "vfio/platform:
trigger an interrupt via eventfd"]
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 14:08:50 -06:00
Antonios Motakis
57f972e2b3 vfio/platform: trigger an interrupt via eventfd
This patch allows to set an eventfd for a platform device's interrupt,
and also to trigger the interrupt eventfd from userspace for testing.
Level sensitive interrupts are marked as maskable and are handled in
a later patch. Edge triggered interrupts are not advertised as maskable
and are implemented here using a simple and efficient IRQ handler.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
[Baptiste Reynal: fix masked interrupt initialization]
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 14:08:50 -06:00
Antonios Motakis
9a36321c8d vfio/platform: initial interrupts support code
This patch is a skeleton for the VFIO_DEVICE_SET_IRQS IOCTL, around which
most IRQ functionality is implemented in VFIO.

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 14:08:49 -06:00
Antonios Motakis
682704c41e vfio/platform: return IRQ info
Return information for the interrupts exposed by the device.
This patch extends VFIO_DEVICE_GET_INFO with the number of IRQs
and enables VFIO_DEVICE_GET_IRQ_INFO.

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 14:08:48 -06:00
Antonios Motakis
fad4d5b1f0 vfio/platform: support MMAP of MMIO regions
Allow to memory map the MMIO regions of the device so userspace can
directly access them. PIO regions are not being handled at this point.

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 14:08:48 -06:00
Antonios Motakis
6e3f264560 vfio/platform: read and write support for the device fd
VFIO returns a file descriptor which we can use to manipulate the memory
regions of the device. Usually, the user will mmap memory regions that are
addressable on page boundaries, however for memory regions where this is
not the case we cannot provide mmap functionality due to security concerns.
For this reason we also allow to use read and write functions to the file
descriptor pointing to the memory regions.

We implement this functionality only for MMIO regions of platform devices;
PIO regions are not being handled at this point.

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 14:08:47 -06:00
Antonios Motakis
e8909e67ca vfio/platform: return info for device memory mapped IO regions
This patch enables the IOCTLs VFIO_DEVICE_GET_REGION_INFO ioctl call,
which allows the user to learn about the available MMIO resources of
a device.

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 14:08:46 -06:00
Antonios Motakis
2e8567bbb5 vfio/platform: return info for bound device
A VFIO userspace driver will start by opening the VFIO device
that corresponds to an IOMMU group, and will use the ioctl interface
to get the basic device info, such as number of memory regions and
interrupts, and their properties. This patch enables the
VFIO_DEVICE_GET_INFO ioctl call.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
[Baptiste Reynal: added include in vfio_platform_common.c]
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 14:08:46 -06:00
Antonios Motakis
b13329adc2 vfio: amba: add the VFIO for AMBA devices module to Kconfig
Enable building the VFIO AMBA driver. VFIO_AMBA depends on VFIO_PLATFORM,
since it is sharing a portion of the code, and it is essentially implemented
as a platform device whose resources are discovered via AMBA specific APIs
in the kernel.

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 14:08:45 -06:00
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
5316153239 vfio: platform: add the VFIO PLATFORM module to Kconfig
Enable building the VFIO PLATFORM driver that allows to use Linux platform
devices with VFIO.

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 14:08:44 -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
Antonios Motakis
de49fc0d99 vfio/platform: initial skeleton of VFIO support for platform devices
This patch forms the common skeleton code for platform devices support
with VFIO. This will include the core functionality of VFIO_PLATFORM,
however binding to the device and discovering the device resources will
be done with the help of a separate file where any Linux platform bus
specific code will reside.

This will allow us to implement support for also discovering AMBA devices
and their resources, but still reuse a large part of the VFIO_PLATFORM
implementation.

Signed-off-by: Antonios Motakis <a.motakis@virtualopensystems.com>
[Baptiste Reynal: added includes in vfio_platform_private.h]
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 14:08:42 -06:00
Alexey Kardashevskiy
ec76f40070 vfio-pci: Add missing break to enable VFIO_PCI_ERR_IRQ_INDEX
This adds a missing break statement to VFIO_DEVICE_SET_IRQS handler
without which vfio_pci_set_err_trigger() would never be called.

While we are here, add another "break" to VFIO_PCI_REQ_IRQ_INDEX case
so if we add more indexes later, we won't miss it.

Fixes: 6140a8f562 ("vfio-pci: Add device request interface")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-03-12 09:51:38 -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
Alex Williamson
cac80d6e38 vfio-pci: Generalize setup of simple eventfds
We want another single vector IRQ index to support signaling of
the device request to userspace.  Generalize the error reporting
IRQ index to avoid code duplication.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-02-10 12:37:57 -07:00
Alex Williamson
13060b64b8 vfio: Add and use device request op for vfio bus drivers
When a request is made to unbind a device from a vfio bus driver,
we need to wait for the device to become unused, ie. for userspace
to release the device.  However, we have a long standing TODO in
the code to do something proactive to make that happen.  To enable
this, we add a request callback on the vfio bus driver struct,
which is intended to signal the user through the vfio device
interface to release the device.  Instead of passively waiting for
the device to become unused, we can now pester the user to give
it up.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-02-10 12:37:47 -07:00
Alex Williamson
4a68810dbb vfio: Tie IOMMU group reference to vfio group
Move the iommu_group reference from the device to the vfio_group.
This ensures that the iommu_group persists as long as the vfio_group
remains.  This can be important if all of the device from an
iommu_group are removed, but we still have an outstanding vfio_group
reference; we can still walk the empty list of devices.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-02-06 15:05:06 -07:00
Alex Williamson
60720a0fc6 vfio: Add device tracking during unbind
There's a small window between the vfio bus driver calling
vfio_del_group_dev() and the device being completely unbound where
the vfio group appears to be non-viable.  This creates a race for
users like QEMU/KVM where the kvm-vfio module tries to get an
external reference to the group in order to match and release an
existing reference, while the device is potentially being removed
from the vfio bus driver.  If the group is momentarily non-viable,
kvm-vfio may not be able to release the group reference until VM
shutdown, making the group unusable until that point.

Bridge the gap between device removal from the group and completion
of the driver unbind by tracking it in a list.  The device is added
to the list before the bus driver reference is released and removed
using the existing unbind notifier.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-02-06 15:05:06 -07:00
Alex Williamson
c5e6688752 vfio/type1: Add conditional rescheduling
IOMMU operations can be expensive and it's not very difficult for a
user to give us a lot of work to do for a map or unmap operation.
Killing a large VM will vfio assigned devices can result in soft
lockups and IOMMU tracing shows that we can easily spend 80% of our
time with need-resched set.  A sprinkling of conf_resched() calls
after map and unmap calls has a very tiny affect on performance
while resulting in traces with <1% of calls overflowing into needs-
resched.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-02-06 14:19:12 -07:00
Alex Williamson
babbf17609 vfio/type1: Chunk contiguous reserved/invalid page mappings
We currently map invalid and reserved pages, such as often occur from
mapping MMIO regions of a VM through the IOMMU, using single pages.
There's really no reason we can't instead follow the methodology we
use for normal pages and find the largest possible physically
contiguous chunk for mapping.  The only difference is that we don't
do locked memory accounting for these since they're not back by RAM.

In most applications this will be a very minor improvement, but when
graphics and GPGPU devices are in play, MMIO BARs become non-trivial.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-02-06 10:59:16 -07:00
Alex Williamson
6fe1010d6d vfio/type1: DMA unmap chunking
When unmapping DMA entries we try to rely on the IOMMU API behavior
that allows the IOMMU to unmap a larger area than requested, up to
the size of the original mapping.  This works great when the IOMMU
supports superpages *and* they're in use.  Otherwise, each PAGE_SIZE
increment is unmapped separately, resulting in poor performance.

Instead we can use the IOVA-to-physical-address translation provided
by the IOMMU API and unmap using the largest contiguous physical
memory chunk available, which is also how vfio/type1 would have
mapped the region.  For a synthetic 1TB guest VM mapping and shutdown
test on Intel VT-d (2M IOMMU pagesize support), this achieves about
a 30% overall improvement mapping standard 4K pages, regardless of
IOMMU superpage enabling, and about a 40% improvement mapping 2M
hugetlbfs pages when IOMMU superpages are not available.  Hugetlbfs
with IOMMU superpages enabled is effectively unchanged.

Unfortunately the same algorithm does not work well on IOMMUs with
fine-grained superpages, like AMD-Vi, costing about 25% extra since
the IOMMU will automatically unmap any power-of-two contiguous
mapping we've provided it.  We add a routine and a domain flag to
detect this feature, leaving AMD-Vi unaffected by this unmap
optimization.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2015-02-06 10:58:56 -07:00