28 Feb, 2016
1 commit
-
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
Signed-off-by: Alex Williamson
28 Jan, 2016
1 commit
-
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
Reviewed-by: Alexey Kardashevskiy
Tested-by: Alexey Kardashevskiy
Tested-by: Anatoly Burakov
Tested-by: Santosh Shukla
Fixes: 03a76b60f8ba ("vfio: Include No-IOMMU mode")
Signed-off-by: Alex Williamson
05 Jan, 2016
1 commit
-
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
Signed-off-by: Alex Williamson
22 Dec, 2015
2 commits
-
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
Acked-by: Michael S. Tsirkin -
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: 0990822c9866 ('VFIO: platform: reset: AMD xgbe reset module')
Signed-off-by: Dan Carpenter
Reviewed-by: Eric Auger
Signed-off-by: Alex Williamson
04 Dec, 2015
1 commit
-
Revert commit 033291eccbdb ("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
21 Nov, 2015
2 commits
-
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
Signed-off-by: Alex Williamson -
request_module already takes format strings, so no need to duplicate
the effort.Signed-off-by: Kees Cook
Signed-off-by: Alex Williamson
20 Nov, 2015
2 commits
-
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
Signed-off-by: Alex Williamson -
platform_driver does not need to set an owner because
platform_driver_register() will set it.Signed-off-by: Krzysztof Kozlowski
Acked-by: Baptiste Reynal
Signed-off-by: Alex Williamson
14 Nov, 2015
1 commit
-
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
09 Nov, 2015
1 commit
-
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
Signed-off-by: Alex Williamson
05 Nov, 2015
2 commits
-
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
Acked-by: Michael S. Tsirkin -
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:
[] ? vfio_group_fops_unl_ioctl+0x253/0x410 [vfio]
[] do_vfs_ioctl+0x2cd/0x4c0
[] ? __fget+0x77/0xb0
[] SyS_ioctl+0x79/0x90
[] ? syscall_return_slowpath+0x50/0x130
[] entry_SYSCALL_64_fastpath+0x16/0x75Fix 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: 4bc94d5dc95d ("vfio: Fix lockdep issue")
Signed-off-by: Joerg Roedel
Signed-off-by: Alex Williamson
04 Nov, 2015
11 commits
-
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 MACThose tiny pieces of code are inherited from the native xgbe driver.
Signed-off-by: Eric Auger
Reviewed-by: Arnd Bergmann
Signed-off-by: Alex Williamson -
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
Signed-off-by: Alex Williamson -
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
Signed-off-by: Alex Williamson -
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
Reported-by: Arnd Bergmann
Reviewed-by: Arnd Bergmann
Signed-off-by: Alex Williamson -
Let's retrieve the compatibility string on probe and store it
in the vfio_platform_device structSigned-off-by: Eric Auger
Signed-off-by: Alex Williamson -
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
Reviewed-by: Arnd Bergmann
Signed-off-by: Alex Williamson -
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
Reviewed-by: Arnd Bergmann
Signed-off-by: Alex Williamson -
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
Reviewed-by: Arnd Bergmann
Signed-off-by: Alex Williamson -
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
Suggested-by: Arnd Bergmann
Reviewed-by: Arnd Bergmann
Signed-off-by: Alex Williamson -
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: 6e3f26456009 "vfio/platform: read and write support for the device fd"
Signed-off-by: James Morse
Acked-by: Baptiste Reynal
Tested-by: Baptiste Reynal
Signed-off-by: Alex Williamson -
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
Acked-by: Will Deacon
Signed-off-by: Alex Williamson
28 Oct, 2015
3 commits
-
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
Signed-off-by: Alex Williamson -
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 932c435caba8 ("PCI: Add
dev_flags bit to access VPD through function 0") and 7aa6ca4d39ed
("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
Acked-by: Mark Rustad -
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
01 Oct, 2015
1 commit
-
This patch adds the registration/unregistration of an
irq_bypass_producer for MSI/MSIx on vfio pci devices.Acked-by: Alex Williamson
Signed-off-by: Feng Wu
Signed-off-by: Paolo Bonzini
25 Jul, 2015
1 commit
-
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
Fixes: 20f300175a1e ("vfio/pci: Fix racy vfio_device_get_from_dev() call")
Reported-by: Joerg Roedel
Tested-by: Joerg Roedel
29 Jun, 2015
1 commit
-
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
24 Jun, 2015
1 commit
-
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
...
22 Jun, 2015
4 commits
-
This patch enables building VFIO platform and derivatives on ARM64.
Signed-off-by: Eric Auger
Acked-by: Baptiste Reynal
Tested-by: Baptiste Reynal
Signed-off-by: Alex Williamson -
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
Acked-by: Baptiste Reynal
Tested-by: Baptiste Reynal
Signed-off-by: Alex Williamson -
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
Acked-by: Baptiste Reynal
Tested-by: Baptiste Reynal
Signed-off-by: Alex Williamson -
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
Acked-by: Baptiste Reynal
Tested-by: Baptiste Reynal
Signed-off-by: Alex Williamson
18 Jun, 2015
1 commit
-
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
Acked-by: Baptiste Reynal
Tested-by: Baptiste Reynal
Signed-off-by: Alex Williamson
11 Jun, 2015
3 commits
-
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
[aw: for the vfio related changes]
Acked-by: Alex Williamson
Reviewed-by: David Gibson
Signed-off-by: Michael Ellerman -
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
[aw: for the vfio related changes]
Acked-by: Alex Williamson
Reviewed-by: David Gibson
Signed-off-by: Michael Ellerman -
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
[aw: for the vfio related changes]
Acked-by: Alex Williamson
Reviewed-by: David Gibson
Signed-off-by: Michael Ellerman
