Ever since the eventfd type was introduced back in 2007 in commit
e1ad7468c7 ("signal/timer/event: eventfd core") the eventfd_signal()
function only ever passed 1 as a value for @n. There's no point in
keeping that additional argument.
Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-2-bd549b14ce0c@kernel.org
Acked-by: Xu Yilun <yilun.xu@intel.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com> # ocxl
Acked-by: Eric Farman <farman@linux.ibm.com> # s390
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
pci_msix_alloc_irq_at() enables an individual MSI-X interrupt to be
allocated after MSI-X enabling.
Use dynamic MSI-X (if supported by the device) to allocate an interrupt
after MSI-X is enabled. An MSI-X interrupt is dynamically allocated at
the time a valid eventfd is assigned. This is different behavior from
a range provided during MSI-X enabling where interrupts are allocated
for the entire range whether a valid eventfd is provided for each
interrupt or not.
The PCI-MSIX API requires that some number of irqs are allocated for
an initial set of vectors when enabling MSI-X on the device. When
dynamic MSIX allocation is not supported, the vector table, and thus
the allocated irq set can only be resized by disabling and re-enabling
MSI-X with a different range. In that case the irq allocation is
essentially a cache for configuring vectors within the previously
allocated vector range. When dynamic MSI-X allocation is supported,
the API still requires some initial set of irqs to be allocated, but
also supports allocating and freeing specific irq vectors both
within and beyond the initially allocated range.
For consistency between modes, as well as to reduce latency and improve
reliability of allocations, and also simplicity, this implementation
only releases irqs via pci_free_irq_vectors() when either the interrupt
mode changes or the device is released.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/lkml/20230403211841.0e206b67.alex.williamson@redhat.com/
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/956c47057ae9fd45591feaa82e9ae20929889249.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
In preparation for surrounding code change it is helpful to
ensure that existing comments are accurate.
Remove inaccurate comment about direct access and update
the rest of the comment to reflect the purpose of writing
the cached MSI message to the device.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/lkml/20230330164050.0069e2a5.alex.williamson@redhat.com/
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/5b605ce7dcdab5a5dfef19cec4d73ae2fdad3ae1.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
struct vfio_pci_core_device::num_ctx counts how many interrupt
contexts have been allocated. When all interrupt contexts are
allocated simultaneously num_ctx provides the upper bound of all
vectors that can be used as indices into the interrupt context
array.
With the upcoming support for dynamic MSI-X the number of
interrupt contexts does not necessarily span the range of allocated
interrupts. Consequently, num_ctx is no longer a trusted upper bound
for valid indices.
Stop using num_ctx to determine if a provided vector is valid. Use
the existence of allocated interrupt.
This changes behavior on the error path when user space provides
an invalid vector range. Behavior changes from early exit without
any modifications to possible modifications to valid vectors within
the invalid range. This is acceptable considering that an invalid
range is not a valid scenario, see link to discussion.
The checks that ensure that user space provides a range of vectors
that is valid for the device are untouched.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/lkml/20230316155646.07ae266f.alex.williamson@redhat.com/
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/e27d350f02a65b8cbacd409b4321f5ce35b3186d.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Interrupt context is statically allocated at the time interrupts
are allocated. Following allocation, the context is managed by
directly accessing the elements of the array using the vector
as index. The storage is released when interrupts are disabled.
It is possible to dynamically allocate a single MSI-X interrupt
after MSI-X is enabled. A dynamic storage for interrupt context
is needed to support this. Replace the interrupt context array with an
xarray (similar to what the core uses as store for MSI descriptors)
that can support the dynamic expansion while maintaining the
custom that uses the vector as index.
With a dynamic storage it is no longer required to pre-allocate
interrupt contexts at the time the interrupts are allocated.
MSI and MSI-X interrupt contexts are only used when interrupts are
enabled. Their allocation can thus be delayed until interrupt enabling.
Only enabled interrupts will have associated interrupt contexts.
Whether an interrupt has been allocated (a Linux irq number exists
for it) becomes the criteria for whether an interrupt can be enabled.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/lkml/20230404122444.59e36a99.alex.williamson@redhat.com/
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/40e235f38d427aff79ae35eda0ced42502aa0937.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Enabling and disabling of an interrupt involves several steps
that can fail. Cleanup after failure is done when the error
is encountered, resulting in some repetitive code.
Support for dynamic contexts will introduce more steps during
interrupt enabling and disabling.
Transition to centralized exit path in preparation for dynamic
contexts to eliminate duplicate error handling code.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/72dddae8aa710ce522a74130120733af61cffe4d.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Interrupt context storage is statically allocated at the time
interrupts are allocated. Following allocation, the interrupt
context is managed by directly accessing the elements of the
array using the vector as index.
It is possible to allocate additional MSI-X vectors after
MSI-X has been enabled. Dynamic storage of interrupt context
is needed to support adding new MSI-X vectors after initial
allocation.
Replace direct access of array elements with pointers to the
array elements. Doing so reduces impact of moving to a new data
structure. Move interactions with the array to helpers to
mostly contain changes needed to transition to a dynamic
data structure.
No functional change intended.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/eab289693c8325ede9aba99380f8b8d5143980a4.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
User space provides the vector as an unsigned int that is checked
early for validity (vfio_set_irqs_validate_and_prepare()).
A later negative check of the provided vector is not necessary.
Remove the negative check and ensure the type used
for the vector is consistent as an unsigned int.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/28521e1b0b091849952b0ecb8c118729fc8cdc4f.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfio_msi_disable() releases all previously allocated state
associated with each interrupt before disabling MSI/MSI-X.
vfio_msi_disable() iterates twice over the interrupt state:
first directly with a for loop to do virqfd cleanup, followed
by another for loop within vfio_msi_set_block() that removes
the interrupt handler and its associated state using
vfio_msi_set_vector_signal().
Simplify interrupt cleanup by iterating over allocated interrupts
once.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/837acb8cbe86a258a50da05e56a1f17c1a19abbe.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Use GFP_KERNEL_ACCOUNT for userspace persistent allocations.
The GFP_KERNEL_ACCOUNT option lets the memory allocator know that this
is untrusted allocation triggered from userspace and should be a subject
of kmem accounting, and as such it is controlled by the cgroup
mechanism.
The way to find the relevant allocations was for example to look at the
close_device function and trace back all the kfrees to their
allocations.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230108154427.32609-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This patch adds INTx handling during runtime suspend/resume.
All the suspend/resume related code for the user to put the device
into the low power state will be added in subsequent patches.
The INTx lines may be shared among devices. Whenever any INTx
interrupt comes for the VFIO devices, then vfio_intx_handler() will be
called for each device sharing the interrupt. Inside vfio_intx_handler(),
it calls pci_check_and_mask_intx() and checks if the interrupt has
been generated for the current device. Now, if the device is already
in the D3cold state, then the config space can not be read. Attempt
to read config space in D3cold state can cause system unresponsiveness
in a few systems. To prevent this, mask INTx in runtime suspend callback,
and unmask the same in runtime resume callback. If INTx has been already
masked, then no handling is needed in runtime suspend/resume callbacks.
'pm_intx_masked' tracks this, and vfio_pci_intx_mask() has been updated
to return true if the INTx vfio_pci_irq_ctx.masked value is changed
inside this function.
For the runtime suspend which is triggered for the no user of VFIO
device, the 'irq_type' will be VFIO_PCI_NUM_IRQS and these
callbacks won't do anything.
The MSI/MSI-X are not shared so similar handling should not be
needed for MSI/MSI-X. vfio_msihandler() triggers eventfd_signal()
without doing any device-specific config access. When the user performs
any config access or IOCTL after receiving the eventfd notification,
then the device will be moved to the D0 state first before
servicing any request.
Another option was to check this flag 'pm_intx_masked' inside
vfio_intx_handler() instead of masking the interrupts. This flag
is being set inside the runtime_suspend callback but the device
can be in non-D3cold state (for example, if the user has disabled D3cold
explicitly by sysfs, the D3cold is not supported in the platform, etc.).
Also, in D3cold supported case, the device will be in D0 till the
PCI core moves the device into D3cold. In this case, there is
a possibility that the device can generate an interrupt. Adding check
in the IRQ handler will not clear the IRQ status and the interrupt
line will still be asserted. This can cause interrupt flooding.
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220829114850.4341-4-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Only three of these are actually used, simplify to three inline functions,
and open code the if statement in vfio_pci_config.c.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/3-v2-1bd95d72f298+e0e-vfio_pci_priv_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The header in include/linux should have only the exported interface for
other vfio_pci modules to use. Internal definitions for vfio_pci.ko
should be in a "priv" header along side the .c files.
Move the internal declarations out of vfio_pci_core.h. They either move to
vfio_pci_priv.h or to the C file that is the only user.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/1-v2-1bd95d72f298+e0e-vfio_pci_priv_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Now that vfio_pci has been split into two source modules, one focusing on
the "struct pci_driver" (vfio_pci.c) and a toolbox library of code
(vfio_pci_core.c), complete the split and move them into two different
kernel modules.
As before vfio_pci.ko continues to present the same interface under sysfs
and this change will have no functional impact.
Splitting into another module and adding exports allows creating new HW
specific VFIO PCI drivers that can implement device specific
functionality, such as VFIO migration interfaces or specialized device
requirements.
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20210826103912.128972-14-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This is a preparation patch for separating the vfio_pci driver to a
subsystem driver and a generic pci driver. This patch doesn't change any
logic.
The new vfio_pci_core_device structure will be the main structure of the
core driver and later on vfio_pci_device structure will be the main
structure of the generic vfio_pci driver.
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20210826103912.128972-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This is a preparation patch for separating the vfio_pci driver to a
subsystem driver and a generic pci driver. This patch doesn't change any
logic.
Signed-off-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20210826103912.128972-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The eventfd context is used as our irqbypass token, therefore if an
eventfd is re-used, our token is the same. The irqbypass code will
return an -EBUSY in this case, but we'll still attempt to unregister
the producer, where if that duplicate token still exists, results in
removing the wrong object. Clear the token of failed producers so
that they harmlessly fall out when unregistered.
Fixes: 6d7425f109 ("vfio: Register/unregister irq_bypass_producer")
Reported-by: guomin chen <guomin_chen@sina.com>
Tested-by: guomin chen <guomin_chen@sina.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Accessing the disabled memory space of a PCI device would typically
result in a master abort response on conventional PCI, or an
unsupported request on PCI express. The user would generally see
these as a -1 response for the read return data and the write would be
silently discarded, possibly with an uncorrected, non-fatal AER error
triggered on the host. Some systems however take it upon themselves
to bring down the entire system when they see something that might
indicate a loss of data, such as this discarded write to a disabled
memory space.
To avoid this, we want to try to block the user from accessing memory
spaces while they're disabled. We start with a semaphore around the
memory enable bit, where writers modify the memory enable state and
must be serialized, while readers make use of the memory region and
can access in parallel. Writers include both direct manipulation via
the command register, as well as any reset path where the internal
mechanics of the reset may both explicitly and implicitly disable
memory access, and manipulation of the MSI-X configuration, where the
MSI-X vector table resides in MMIO space of the device. Readers
include the read and write file ops to access the vfio device fd
offsets as well as memory mapped access. In the latter case, we make
use of our new vma list support to zap, or invalidate, those memory
mappings in order to force them to be faulted back in on access.
Our semaphore usage will stall user access to MMIO spaces across
internal operations like reset, but the user might experience new
behavior when trying to access the MMIO space while disabled via the
PCI command register. Access via read or write while disabled will
return -EIO and access via memory maps will result in a SIGBUS. This
is expected to be compatible with known use cases and potentially
provides better error handling capabilities than present in the
hardware, while avoiding the more readily accessible and severe
platform error responses that might otherwise occur.
Fixes: CVE-2020-12888
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Since irq_bypass_register_producer() is called after request_irq(), we
should do tear-down in reverse order: irq_bypass_unregister_producer()
then free_irq().
Specifically free_irq() may release resources required by the
irqbypass del_producer() callback. Notably an example provided by
Marc Zyngier on arm64 with GICv4 that he indicates has the potential
to wedge the hardware:
free_irq(irq)
__free_irq(irq)
irq_domain_deactivate_irq(irq)
its_irq_domain_deactivate()
[unmap the VLPI from the ITS]
kvm_arch_irq_bypass_del_producer(cons, prod)
kvm_vgic_v4_unset_forwarding(kvm, irq, ...)
its_unmap_vlpi(irq)
[Unmap the VLPI from the ITS (again), remap the original LPI]
Signed-off-by: Jiang Yi <giangyi@amazon.com>
Cc: stable@vger.kernel.org # v4.4+
Fixes: 6d7425f109 ("vfio: Register/unregister irq_bypass_producer")
Link: https://lore.kernel.org/kvm/20191127164910.15888-1-giangyi@amazon.com
Reviewed-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
[aw: commit log]
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Rename write_msi_msg() to pci_write_msi_msg() to mark it as PCI
specific.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The MSIx vector table lives in device memory, which may be cleared as
part of a backdoor device reset. This is the case on the IBM IPR HBA
when the BIST is run on the device. When assigned to a QEMU guest,
the guest driver does a pci_save_state(), issues a BIST, then does a
pci_restore_state(). The BIST clears the MSIx vector table, but due
to the way interrupts are configured the pci_restore_state() does not
restore the vector table as expected. Eventually this results in an
EEH error on Power platforms when the device attempts to signal an
interrupt with the zero'd table entry.
Fix the problem by restoring the host cached MSI message prior to
enabling each vector.
Reported-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
pci_enable_msix() and pci_enable_msi_block() have been deprecated; use
pci_enable_msix_range() and pci_enable_msi_range() instead.
[bhelgaas: changelog]
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
device_lock is much too prone to lockups. For instance if we have a
pending .remove then device_lock is already held. If userspace
attempts to modify AER signaling after that point, a deadlock occurs.
eventfd setup/teardown is already protected in vfio with the igate
mutex. AER is not a high performance interrupt, so we can also use
the same mutex to protect signaling versus setup races.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
eventfd_fget() tests to see whether the file is an eventfd file, which
we then immediately pass to eventfd_ctx_fileget(), which again tests
whether the file is an eventfd file. Simplify slightly by using
fdget() so that we only test that we're looking at an eventfd once.
fget() could also be used, but fdget() makes use of fget_light() for
another slight optimization.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Changes include extension to support PCI AER notification to userspace, byte granularity of PCI config space and access to unarchitected PCI config space, better protection around IOMMU driver accesses, default file mode fix, and a few misc cleanups.
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Merge tag 'vfio-for-v3.10' of git://github.com/awilliam/linux-vfio
Pull vfio updates from Alex Williamson:
"Changes include extension to support PCI AER notification to
userspace, byte granularity of PCI config space and access to
unarchitected PCI config space, better protection around IOMMU driver
accesses, default file mode fix, and a few misc cleanups."
* tag 'vfio-for-v3.10' of git://github.com/awilliam/linux-vfio:
vfio: Set container device mode
vfio: Use down_reads to protect iommu disconnects
vfio: Convert container->group_lock to rwsem
PCI/VFIO: use pcie_flags_reg instead of access PCI-E Capabilities Register
vfio-pci: Enable raw access to unassigned config space
vfio-pci: Use byte granularity in config map
vfio: make local function vfio_pci_intx_unmask_handler() static
VFIO-AER: Vfio-pci driver changes for supporting AER
VFIO: Wrapper for getting reference to vfio_device
vfio_pci_intx_unmask_handler() was not declared. It should be static.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The vfio drivers call kmalloc or kzalloc, but do not
include <linux/slab.h>, which causes build errors on
ARM.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: kvm@vger.kernel.org
- New VFIO_SET_IRQ ioctl option to pass the eventfd that is signaled when
an error occurs in the vfio_pci_device
- Register pci_error_handler for the vfio_pci driver
- When the device encounters an error, the error handler registered by
the vfio_pci driver gets invoked by the AER infrastructure
- In the error handler, signal the eventfd registered for the device.
- This results in the qemu eventfd handler getting invoked and
appropriate action taken for the guest.
Signed-off-by: Vijay Mohan Pandarathil <vijaymohan.pandarathil@hp.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The virq_disabled flag tracks the userspace view of INTx masking
across interrupt mode changes, but we're not consistently applying
this to the interrupt and masking handler notion of the device.
Currently if the user sets DisINTx while in MSI or MSIX mode, then
returns to INTx mode (ex. rebooting a qemu guest), the hardware has
DisINTx+, but the management of INTx thinks it's enabled, making it
impossible to actually clear DisINTx. Fix this by updating the
handler state when INTx is re-enabled.
Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
We need to be ready to recieve an interrupt as soon as we call
request_irq, so our eventfd context setting needs to be moved
earlier. Without this, an interrupt from our device or one
sharing the interrupt line can pass a NULL into eventfd_signal
and oops.
Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
vfoi-pci supports a mechanism like KVM's irqfd for unmasking an
interrupt through an eventfd. There are two ways to shutdown this
interface: 1) close the eventfd, 2) ioctl (such as disabling the
interrupt). Both of these do the release through a workqueue,
which can result in a segfault if two jobs get queued for the same
virqfd.
Fix this by protecting the pointer to these virqfds by a spinlock.
The vfio pci device will therefore no longer have a reference to it
once the release job is queued under lock. On the ioctl side, we
still flush the workqueue to ensure that any outstanding releases
are completed.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add PCI device support for VFIO. PCI devices expose regions
for accessing config space, I/O port space, and MMIO areas
of the device. PCI config access is virtualized in the kernel,
allowing us to ensure the integrity of the system, by preventing
various accesses while reducing duplicate support across various
userspace drivers. I/O port supports read/write access while
MMIO also supports mmap of sufficiently sized regions. Support
for INTx, MSI, and MSI-X interrupts are provided using eventfds to
userspace.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Christian Brauner