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>
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>
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>
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>
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>
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>
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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
- 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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Current vfio-pci just supports normal pci device, so vfio_pci_probe() will
return if the pci device is not a normal device. While current code makes a
mistake. PCI_HEADER_TYPE is the offset in configuration space of the device
type, but we use this value to mask the type value.
This patch fixs this by do the check directly on the pci_dev->hdr_type.
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org # v3.6+
- s390 support (Frank Blaschka)
- Enable iommu-type1 for ARM SMMU (Will Deacon)
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Merge tag 'vfio-v3.19-rc1' of git://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- s390 support (Frank Blaschka)
- Enable iommu-type1 for ARM SMMU (Will Deacon)
* tag 'vfio-v3.19-rc1' of git://github.com/awilliam/linux-vfio:
drivers/vfio: allow type-1 IOMMU instantiation on top of an ARM SMMU
vfio: make vfio run on s390
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>
add Kconfig switch to hide INTx
add Kconfig switch to let vfio announce PCI BARs are not mapable
Signed-off-by: Frank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Locking both the remove() and release() path results in a deadlock
that should have been obvious. To fix this we can get and hold the
vfio_device reference as we evaluate whether to do a bus/slot reset.
This will automatically block any remove() calls, allowing us to
remove the explict lock. Fixes 61d792562b.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org [3.17]
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>
In PCIe r1.0, sec 5.10.2, bit 0 of the Uncorrectable Error Status, Mask,
and Severity Registers was for "Training Error." In PCIe r1.1, sec 7.10.2,
bit 0 was redefined to be "Undefined."
Rename PCI_ERR_UNC_TRAIN to PCI_ERR_UNC_UND to reflect this change.
No functional change.
[bhelgaas: changelog]
Signed-off-by: Chen, Gong <gong.chen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The existing vfio_pci_open() fails upon error returned from
vfio_spapr_pci_eeh_open(), which breaks POWER7's P5IOC2 PHB
support which this patch brings back.
The patch fixes the issue by dropping the return value of
vfio_spapr_pci_eeh_open().
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Each time a device is released, mark whether a local reset was
successful or whether a bus/slot reset is needed. If a reset is
needed and all of the affected devices are bound to vfio-pci and
unused, allow the reset. This is most useful when the userspace
driver is killed and releases all the devices in an unclean state,
such as when a QEMU VM quits.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Serializing open/release allows us to fix a refcnt error if we fail
to enable the device and lets us prevent devices from being unbound
or opened, giving us an opportunity to do bus resets on release. No
restriction added to serialize binding devices to vfio-pci while the
mutex is held though.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Our current open/release path looks like this:
vfio_pci_open
vfio_pci_enable
pci_enable_device
pci_save_state
pci_store_saved_state
vfio_pci_release
vfio_pci_disable
pci_disable_device
pci_restore_state
pci_enable_device() doesn't modify PCI_COMMAND_MASTER, so if a device
comes to us with it enabled, it persists through the open and gets
stored as part of the device saved state. We then restore that saved
state when released, which can allow the device to attempt to continue
to do DMA. When the group is disconnected from the domain, this will
get caught by the IOMMU, but if there are other devices in the group,
the device may continue running and interfere with the user. Even in
the former case, IOMMUs don't necessarily behave well and a stream of
blocked DMA can result in unpleasant behavior on the host.
Explicitly disable Bus Master as we're enabling the device and
slightly re-work release to make sure that pci_disable_device() is
the last thing that touches the device.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The patch adds new IOCTL commands for sPAPR VFIO container device
to support EEH functionality for PCI devices, which have been passed
through from host to somebody else via VFIO.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Alexander Graf <agraf@suse.de>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
According PCI local bus specification, the register of Message
Control for MSI (offset: 2, length: 2) has bit#0 to enable or
disable MSI logic and it shouldn't be part contributing to the
calculation of MSI interrupt count. The patch fixes the issue.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
There's nothing we can do different if pci_load_and_free_saved_state()
fails, other than maybe print some log message, but the actual re-load
of the state is an unnecessary step here since we've only just saved
it. We can cleanup a coverity warning and eliminate the unnecessary
step by freeing the state ourselves.
Detected by Coverity: CID 753101
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
When sizing the TPH capability we store the register containing the
table size into the 'dword' variable, but then use the uninitialized
'byte' variable to analyze the size. The table size is also actually
reported as an N-1 value, so correct sizing to account for this.
The round_up() for both TPH and DPA is unnecessary, remove it.
Detected by Coverity: CID 714665 & 715156
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>
- Remove unnecessary and dangerous use of device_lock
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Merge tag 'vfio-v3.14-rc1' of git://github.com/awilliam/linux-vfio
Pull vfio update from Alex Williamson:
- convert to misc driver to support module auto loading
- remove unnecessary and dangerous use of device_lock
* tag 'vfio-v3.14-rc1' of git://github.com/awilliam/linux-vfio:
vfio-pci: Don't use device_lock around AER interrupt setup
vfio: Convert control interface to misc driver
misc: Reserve minor for VFIO
PCI resets will attempt to take the device_lock for any device to be
reset. This is a problem if that lock is already held, for instance
in the device remove path. It's not sufficient to simply kill the
user process or skip the reset if called after .remove as a race could
result in the same deadlock. Instead, we handle all resets as "best
effort" using the PCI "try" reset interfaces. This prevents the user
from being able to induce a deadlock by triggering a reset.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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>
These are set of two capability registers, it's pretty much given that
they're registers, so reflect their purpose in the name.
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
The current VFIO_DEVICE_RESET interface only maps to PCI use cases
where we can isolate the reset to the individual PCI function. This
means the device must support FLR (PCIe or AF), PM reset on D3hot->D0
transition, device specific reset, or be a singleton device on a bus
for a secondary bus reset. FLR does not have widespread support,
PM reset is not very reliable, and bus topology is dictated by the
system and device design. We need to provide a means for a user to
induce a bus reset in cases where the existing mechanisms are not
available or not reliable.
This device specific extension to VFIO provides the user with this
ability. Two new ioctls are introduced:
- VFIO_DEVICE_PCI_GET_HOT_RESET_INFO
- VFIO_DEVICE_PCI_HOT_RESET
The first provides the user with information about the extent of
devices affected by a hot reset. This is essentially a list of
devices and the IOMMU groups they belong to. The user may then
initiate a hot reset by calling the second ioctl. We must be
careful that the user has ownership of all the affected devices
found via the first ioctl, so the second ioctl takes a list of file
descriptors for the VFIO groups affected by the reset. Each group
must have IOMMU protection established for the ioctl to succeed.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Having PCIe/PCI-X capability isn't enough to assume that there are
extended capabilities. Both specs define that the first capability
header is all zero if there are no extended capabilities. Testing
for this avoids an erroneous message about hiding capability 0x0 at
offset 0x100.
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>
If an attempt is made to unbind a device from vfio-pci while that
device is in use, the request is blocked until the device becomes
unused. Unfortunately, that unbind path still grabs the device_lock,
which certain things like __pci_reset_function() also want to take.
This means we need to try to acquire the locks ourselves and use the
pre-locked version, __pci_reset_function_locked().
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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
We now cache the MSI/MSI-X capability offsets in the struct pci_dev,
so no need to find the capabilities again.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
PCI_MSIX_FLAGS_BIRMASK is mis-named because the BIR mask is in the
Table Offset register, not the flags ("Message Control" per spec)
register.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Currently, we use pcie_flags_reg to cache PCI-E Capabilities Register,
because PCI-E Capabilities Register bits are almost read-only. This patch
use pcie_caps_reg() instead of another access PCI-E Capabilities Register.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Devices like be2net hide registers between the gaps in capabilities
and architected regions of PCI config space. Our choices to support
such devices is to either build an ever growing and unmanageable white
list or rely on hardware isolation to protect us. These registers are
really no different than MMIO or I/O port space registers, which we
don't attempt to regulate, so treat PCI config space in the same way.
Reported-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Gavin Shan <shangw@linux.vnet.ibm.com>
The config map previously used a byte per dword to map regions of
config space to capabilities. Modulo a bug where we round the length
of capabilities down instead of up, this theoretically works well and
saves space so long as devices don't try to hide registers in the gaps
between capabilities. Unfortunately they do exactly that so we need
byte granularity on our config space map. Increase the allocation of
the config map and split accesses at capability region boundaries.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Gavin Shan <shangw@linux.vnet.ibm.com>
The VFIO_DEVICE_SET_IRQS ioctl takes a start and count parameter, both
of which are unsigned. We attempt to bounds check these, but fail to
account for the case where start is a very large number, allowing
start + count to wrap back into the valid range. Bounds check both
start and start + count.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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 CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
PCI defines display class VGA regions at I/O port address 0x3b0, 0x3c0
and MMIO address 0xa0000. As these are non-overlapping, we can ignore
the I/O port vs MMIO difference and expose them both in a single
region. We make use of the VGA arbiter around each access to
configure chipset access as necessary.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
We give the user access to change the power state of the device but
certain transitions result in an uninitialized state which the user
cannot resolve. To fix this we need to mark the PowerState field of
the PMCSR register read-only and effect the requested change on behalf
of the user. This has the added benefit that pdev->current_state
remains accurate while controlled by the user.
The primary example of this bug is a QEMU guest doing a reboot where
the device it put into D3 on shutdown and becomes unusable on the next
boot because the device did a soft reset on D3->D0 (NoSoftRst-).
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
We can actually handle MMIO and I/O port from the same access function
since PCI already does abstraction of this. The ROM BAR only requires
a minor difference, so it gets included too. vfio_pci_config_readwrite
gets renamed for consistency.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The read and write functions are nearly identical, combine them
and convert to a switch statement. This also makes it easy to
narrow the scope of when we use the io/mem accessors in case new
regions are added.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
A read from a range hidden from the user (ex. MSI-X vector table)
attempts to fill the user buffer up to the end of the excluded range
instead of up to the requested count. Fix it.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Cc: stable@vger.kernel.org
Devices making use of PM reset are getting incorrectly identified as
not supporting reset because pci_pm_reset() fails unless the device is
in D0 power state. When first attached to vfio_pci devices are
typically in an unknown power state. We can fix this by explicitly
setting the power state or simply calling pci_enable_device() before
attempting a pci_reset_function(). We need to enable the device
anyway, so move this up in our vfio_pci_enable() function, which also
simplifies the error path a bit.
Note that pci_disable_device() does not explicitly set the power
state, so there's no need to re-order vfio_pci_disable().
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The two labels for error recovery in function vfio_pci_init() is out of
order, so fix it.
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Move the device reset to the end of our disable path, the device
should already be stopped from pci_disable_device(). This also allows
us to manipulate the save/restore to avoid the save/reset/restore +
save/restore that we had before.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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>
Our mmap path mistakely relied on vma->vm_pgoff to get set in
remap_pfn_range. After b3b9c293, that path only applies to
copy-on-write mappings. Set it in our own code.
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The VM_RESERVED flag was killed off in commit 314e51b985 ("mm: kill
vma flag VM_RESERVED and mm->reserved_vm counter"), and replaced by the
proper semantic flags (eg "don't core-dump" etc). But there was a new
use of VM_RESERVED that got missed by the merge.
Fix the remaining use of VM_RESERVED in the vfio_pci driver, replacing
the VM_RESERVED flag with VM_DONTEXPAND | VM_DONTDUMP.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation,org>
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>
Yongji Xie