- Add warning in unlikely case that device is not captured with
driver_override. (Kunwu Chan)
- Error handling improvements in mlx5-vfio-pci to detect firmware
tracking object error states, logging of firmware error syndrom,
and releasing of firmware resources in aborted migration sequence.
(Yishai Hadas)
- Correct an un-alphabetized VFIO MAINTAINERS entry.
(Alex Williamson)
- Make the mdev_bus_type const and also make the class struct const
for a couple of the vfio-mdev sample drivers. (Ricardo B. Marliere)
- Addition of a new vfio-pci variant driver for the GPU of NVIDIA's
Grace-Hopper superchip. During initialization of the chip-to-chip
interconnect in this hardware module, the PCI BARs of the device
become unused in favor of a faster, coherent mechanism for exposing
device memory. This driver primarily changes the VFIO
representation of the device to masquerade this coherent aperture
to replace the physical PCI BARs for userspace drivers. This also
incorporates use of a new vma flag allowing KVM to use write
combining attributes for uncached device memory. (Ankit Agrawal)
- Reset fixes and cleanups for the pds-vfio-pci driver. Save and
restore files were previously leaked if the device didn't pass
through an error state, this is resolved and later re-fixed to
prevent access to the now freed files. Reset handling is also
refactored to remove the complicated deferred reset mechanism.
(Brett Creeley)
- Remove some references to pl330 in the vfio-platform amba
driver. (Geert Uytterhoeven)
- Remove twice redundant and ugly code to unpin incidental pins
of the zero-page. (Alex Williamson)
- Deferred reset logic is also removed from the hisi-acc-vfio-pci
driver as a simplification. (Shameer Kolothum)
- Enforce that mlx5-vfio-pci devices must support PRE_COPY and
remove resulting unnecessary code. There is no device firmware
that has been available publicly without this support.
(Yishai Hadas)
- Switch over to using the .remove_new callback for vfio-platform
in support of the broader transition for a void remove function.
(Uwe Kleine-König)
- Resolve multiple issues in interrupt code for VFIO bus drivers
that allow calling eventfd_signal() on a NULL context. This
also remove a potential race in INTx setup on certain hardware
for vfio-pci, races with various mechanisms to mask INTx, and
leaked virqfds in vfio-platform. (Alex Williamson)
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Merge tag 'vfio-v6.9-rc1' of https://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- Add warning in unlikely case that device is not captured with
driver_override (Kunwu Chan)
- Error handling improvements in mlx5-vfio-pci to detect firmware
tracking object error states, logging of firmware error syndrom, and
releasing of firmware resources in aborted migration sequence (Yishai
Hadas)
- Correct an un-alphabetized VFIO MAINTAINERS entry (Alex Williamson)
- Make the mdev_bus_type const and also make the class struct const for
a couple of the vfio-mdev sample drivers (Ricardo B. Marliere)
- Addition of a new vfio-pci variant driver for the GPU of NVIDIA's
Grace-Hopper superchip. During initialization of the chip-to-chip
interconnect in this hardware module, the PCI BARs of the device
become unused in favor of a faster, coherent mechanism for exposing
device memory. This driver primarily changes the VFIO representation
of the device to masquerade this coherent aperture to replace the
physical PCI BARs for userspace drivers. This also incorporates use
of a new vma flag allowing KVM to use write combining attributes for
uncached device memory (Ankit Agrawal)
- Reset fixes and cleanups for the pds-vfio-pci driver. Save and
restore files were previously leaked if the device didn't pass
through an error state, this is resolved and later re-fixed to
prevent access to the now freed files. Reset handling is also
refactored to remove the complicated deferred reset mechanism (Brett
Creeley)
- Remove some references to pl330 in the vfio-platform amba driver
(Geert Uytterhoeven)
- Remove twice redundant and ugly code to unpin incidental pins of the
zero-page (Alex Williamson)
- Deferred reset logic is also removed from the hisi-acc-vfio-pci
driver as a simplification (Shameer Kolothum)
- Enforce that mlx5-vfio-pci devices must support PRE_COPY and remove
resulting unnecessary code. There is no device firmware that has been
available publicly without this support (Yishai Hadas)
- Switch over to using the .remove_new callback for vfio-platform in
support of the broader transition for a void remove function (Uwe
Kleine-König)
- Resolve multiple issues in interrupt code for VFIO bus drivers that
allow calling eventfd_signal() on a NULL context. This also remove a
potential race in INTx setup on certain hardware for vfio-pci, races
with various mechanisms to mask INTx, and leaked virqfds in
vfio-platform (Alex Williamson)
* tag 'vfio-v6.9-rc1' of https://github.com/awilliam/linux-vfio: (29 commits)
vfio/fsl-mc: Block calling interrupt handler without trigger
vfio/platform: Create persistent IRQ handlers
vfio/platform: Disable virqfds on cleanup
vfio/pci: Create persistent INTx handler
vfio: Introduce interface to flush virqfd inject workqueue
vfio/pci: Lock external INTx masking ops
vfio/pci: Disable auto-enable of exclusive INTx IRQ
vfio/pds: Refactor/simplify reset logic
vfio/pds: Make sure migration file isn't accessed after reset
vfio/platform: Convert to platform remove callback returning void
vfio/mlx5: Enforce PRE_COPY support
vfio/mbochs: make mbochs_class constant
vfio/mdpy: make mdpy_class constant
hisi_acc_vfio_pci: Remove the deferred_reset logic
Revert "vfio/type1: Unpin zero pages"
vfio/nvgrace-gpu: Convey kvm to map device memory region as noncached
vfio: amba: Rename pl330_ids[] to vfio_amba_ids[]
vfio/pds: Always clear the save/restore FDs on reset
vfio/nvgrace-gpu: Add vfio pci variant module for grace hopper
vfio/pci: rename and export range_intersect_range
...
The eventfd_ctx trigger pointer of the vfio_fsl_mc_irq object is
initially NULL and may become NULL if the user sets the trigger
eventfd to -1. The interrupt handler itself is guaranteed that
trigger is always valid between request_irq() and free_irq(), but
the loopback testing mechanisms to invoke the handler function
need to test the trigger. The triggering and setting ioctl paths
both make use of igate and are therefore mutually exclusive.
The vfio-fsl-mc driver does not make use of irqfds, nor does it
support any sort of masking operations, therefore unlike vfio-pci
and vfio-platform, the flow can remain essentially unchanged.
Cc: Diana Craciun <diana.craciun@oss.nxp.com>
Cc: <stable@vger.kernel.org>
Fixes: cc0ee20bd9 ("vfio/fsl-mc: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-8-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The vfio-platform SET_IRQS ioctl currently allows loopback triggering of
an interrupt before a signaling eventfd has been configured by the user,
which thereby allows a NULL pointer dereference.
Rather than register the IRQ relative to a valid trigger, register all
IRQs in a disabled state in the device open path. This allows mask
operations on the IRQ to nest within the overall enable state governed
by a valid eventfd signal. This decouples @masked, protected by the
@locked spinlock from @trigger, protected via the @igate mutex.
In doing so, it's guaranteed that changes to @trigger cannot race the
IRQ handlers because the IRQ handler is synchronously disabled before
modifying the trigger, and loopback triggering of the IRQ via ioctl is
safe due to serialization with trigger changes via igate.
For compatibility, request_irq() failures are maintained to be local to
the SET_IRQS ioctl rather than a fatal error in the open device path.
This allows, for example, a userspace driver with polling mode support
to continue to work regardless of moving the request_irq() call site.
This necessarily blocks all SET_IRQS access to the failed index.
Cc: Eric Auger <eric.auger@redhat.com>
Cc: <stable@vger.kernel.org>
Fixes: 57f972e2b3 ("vfio/platform: trigger an interrupt via eventfd")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-7-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
irqfds for mask and unmask that are not specifically disabled by the
user are leaked. Remove any irqfds during cleanup
Cc: Eric Auger <eric.auger@redhat.com>
Cc: <stable@vger.kernel.org>
Fixes: a7fa7c77cf ("vfio/platform: implement IRQ masking/unmasking via an eventfd")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-6-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
A vulnerability exists where the eventfd for INTx signaling can be
deconfigured, which unregisters the IRQ handler but still allows
eventfds to be signaled with a NULL context through the SET_IRQS ioctl
or through unmask irqfd if the device interrupt is pending.
Ideally this could be solved with some additional locking; the igate
mutex serializes the ioctl and config space accesses, and the interrupt
handler is unregistered relative to the trigger, but the irqfd path
runs asynchronous to those. The igate mutex cannot be acquired from the
atomic context of the eventfd wake function. Disabling the irqfd
relative to the eventfd registration is potentially incompatible with
existing userspace.
As a result, the solution implemented here moves configuration of the
INTx interrupt handler to track the lifetime of the INTx context object
and irq_type configuration, rather than registration of a particular
trigger eventfd. Synchronization is added between the ioctl path and
eventfd_signal() wrapper such that the eventfd trigger can be
dynamically updated relative to in-flight interrupts or irqfd callbacks.
Cc: <stable@vger.kernel.org>
Fixes: 89e1f7d4c6 ("vfio: Add PCI device driver")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-5-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
In order to synchronize changes that can affect the thread callback,
introduce an interface to force a flush of the inject workqueue. The
irqfd pointer is only valid under spinlock, but the workqueue cannot
be flushed under spinlock. Therefore the flush work for the irqfd is
queued under spinlock. The vfio_irqfd_cleanup_wq workqueue is re-used
for queuing this work such that flushing the workqueue is also ordered
relative to shutdown.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-4-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Mask operations through config space changes to DisINTx may race INTx
configuration changes via ioctl. Create wrappers that add locking for
paths outside of the core interrupt code.
In particular, irq_type is updated holding igate, therefore testing
is_intx() requires holding igate. For example clearing DisINTx from
config space can otherwise race changes of the interrupt configuration.
This aligns interfaces which may trigger the INTx eventfd into two
camps, one side serialized by igate and the other only enabled while
INTx is configured. A subsequent patch introduces synchronization for
the latter flows.
Cc: <stable@vger.kernel.org>
Fixes: 89e1f7d4c6 ("vfio: Add PCI device driver")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-3-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Currently for devices requiring masking at the irqchip for INTx, ie.
devices without DisINTx support, the IRQ is enabled in request_irq()
and subsequently disabled as necessary to align with the masked status
flag. This presents a window where the interrupt could fire between
these events, resulting in the IRQ incrementing the disable depth twice.
This would be unrecoverable for a user since the masked flag prevents
nested enables through vfio.
Instead, invert the logic using IRQF_NO_AUTOEN such that exclusive INTx
is never auto-enabled, then unmask as required.
Cc: <stable@vger.kernel.org>
Fixes: 89e1f7d4c6 ("vfio: Add PCI device driver")
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20240308230557.805580-2-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The current logic for handling resets is more complicated than it needs
to be. The deferred_reset flag is used to indicate a reset is needed
and the deferred_reset_state is the requested, post-reset, state.
Also, the deferred_reset logic was added to vfio migration drivers to
prevent a circular locking dependency with respect to mm_lock and state
mutex. This is mainly because of the copy_to/from_user() functions(which
takes mm_lock) invoked under state mutex.
Remove all of the deferred reset logic and just pass the requested
next state to pds_vfio_reset() so it can be used for VMM and DSC
initiated resets.
This removes the need for pds_vfio_state_mutex_lock(), so remove that
and replace its use with a simple mutex_unlock().
Also, remove the reset_mutex as it's no longer needed since the
state_mutex can be the driver's primary protector.
Suggested-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Link: https://lore.kernel.org/r/20240308182149.22036-3-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
It's possible the migration file is accessed after reset when it has
been cleaned up, especially when it's initiated by the device. This is
because the driver doesn't rip out the filep when cleaning up it only
frees the related page structures and sets its local struct
pds_vfio_lm_file pointer to NULL. This can cause a NULL pointer
dereference, which is shown in the example below during a restore after
a device initiated reset:
BUG: kernel NULL pointer dereference, address: 000000000000000c
PF: supervisor read access in kernel mode
PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:pds_vfio_get_file_page+0x5d/0xf0 [pds_vfio_pci]
[...]
Call Trace:
<TASK>
pds_vfio_restore_write+0xf6/0x160 [pds_vfio_pci]
vfs_write+0xc9/0x3f0
? __fget_light+0xc9/0x110
ksys_write+0xb5/0xf0
__x64_sys_write+0x1a/0x20
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
[...]
Add a disabled flag to the driver's struct pds_vfio_lm_file that gets
set during cleanup. Then make sure to check the flag when the migration
file is accessed via its file_operations. By default this flag will be
false as the memory for struct pds_vfio_lm_file is kzalloc'd, which means
the struct pds_vfio_lm_file is enabled and accessible. Also, since the
file_operations and driver's migration file cleanup happen under the
protection of the same pds_vfio_lm_file.lock, using this flag is thread
safe.
Fixes: 8512ed2563 ("vfio/pds: Always clear the save/restore FDs on reset")
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Link: https://lore.kernel.org/r/20240308182149.22036-2-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/79d3df42fe5b359a05b8061631e72e5ed249b234.1709886922.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Enable live migration only once the firmware supports PRE_COPY.
PRE_COPY has been supported by the firmware for a long time already [1]
and is required to achieve a low downtime upon live migration.
This lets us clean up some old code that is not applicable those days
while PRE_COPY is fully supported by the firmware.
[1] The minimum firmware version that supports PRE_COPY is 28.36.1010,
it was released in January 2023.
No firmware without PRE_COPY support ever available to users.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20240306105624.114830-1-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
- Infrastructure for building KVM's trap configuration based on the
architectural features (or lack thereof) advertised in the VM's ID
registers
- Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to
x86's WC) at stage-2, improving the performance of interacting with
assigned devices that can tolerate it
- Conversion of KVM's representation of LPIs to an xarray, utilized to
address serialization some of the serialization on the LPI injection
path
- Support for _architectural_ VHE-only systems, advertised through the
absence of FEAT_E2H0 in the CPU's ID register
- Miscellaneous cleanups, fixes, and spelling corrections to KVM and
selftests
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Merge tag 'kvmarm-6.9' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for 6.9
- Infrastructure for building KVM's trap configuration based on the
architectural features (or lack thereof) advertised in the VM's ID
registers
- Support for mapping vfio-pci BARs as Normal-NC (vaguely similar to
x86's WC) at stage-2, improving the performance of interacting with
assigned devices that can tolerate it
- Conversion of KVM's representation of LPIs to an xarray, utilized to
address serialization some of the serialization on the LPI injection
path
- Support for _architectural_ VHE-only systems, advertised through the
absence of FEAT_E2H0 in the CPU's ID register
- Miscellaneous cleanups, fixes, and spelling corrections to KVM and
selftests
The deferred_reset logic was added to vfio migration drivers to prevent
a circular locking dependency with respect to mm_lock and state mutex.
This is mainly because of the copy_to/from_user() functions(which takes
mm_lock) invoked under state mutex. But for HiSilicon driver, the only
place where we now hold the state mutex for copy_to_user is during the
PRE_COPY IOCTL. So for pre_copy, release the lock as soon as we have
updated the data and perform copy_to_user without state mutex. By this,
we can get rid of the deferred_reset logic.
Link: https://lore.kernel.org/kvm/20240220132459.GM13330@nvidia.com/
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240229091152.56664-1-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This reverts commit 873aefb376.
This was a heinous workaround and it turns out it's been fixed in mm
twice since it was introduced. Most recently, commit c8070b7875
("mm: Don't pin ZERO_PAGE in pin_user_pages()") would have prevented
running up the zeropage refcount, but even before that commit
84209e87c6 ("mm/gup: reliable R/O long-term pinning in COW mappings")
avoids the vfio use case from pinning the zeropage at all, instead
replacing it with exclusive anonymous pages.
Remove this now useless overhead.
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240229223544.257207-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The NVIDIA Grace Hopper GPUs have device memory that is supposed to be
used as a regular RAM. It is accessible through CPU-GPU chip-to-chip
cache coherent interconnect and is present in the system physical
address space. The device memory is split into two regions - termed
as usemem and resmem - in the system physical address space,
with each region mapped and exposed to the VM as a separate fake
device BAR [1].
Owing to a hardware defect for Multi-Instance GPU (MIG) feature [2],
there is a requirement - as a workaround - for the resmem BAR to
display uncached memory characteristics. Based on [3], on system with
FWB enabled such as Grace Hopper, the requisite properties
(uncached, unaligned access) can be achieved through a VM mapping (S1)
of NORMAL_NC and host mapping (S2) of MT_S2_FWB_NORMAL_NC.
KVM currently maps the MMIO region in S2 as MT_S2_FWB_DEVICE_nGnRE by
default. The fake device BARs thus displays DEVICE_nGnRE behavior in the
VM.
The following table summarizes the behavior for the various S1 and S2
mapping combinations for systems with FWB enabled [3].
S1 | S2 | Result
NORMAL_NC | NORMAL_NC | NORMAL_NC
NORMAL_NC | DEVICE_nGnRE | DEVICE_nGnRE
Recently a change was added that modifies this default behavior and
make KVM map MMIO as MT_S2_FWB_NORMAL_NC when a VMA flag
VM_ALLOW_ANY_UNCACHED is set [4]. Setting S2 as MT_S2_FWB_NORMAL_NC
provides the desired behavior (uncached, unaligned access) for resmem.
To use VM_ALLOW_ANY_UNCACHED flag, the platform must guarantee that
no action taken on the MMIO mapping can trigger an uncontained
failure. The Grace Hopper satisfies this requirement. So set
the VM_ALLOW_ANY_UNCACHED flag in the VMA.
Applied over next-20240227.
base-commit: 22ba90670a51
Link: https://lore.kernel.org/all/20240220115055.23546-4-ankita@nvidia.com/ [1]
Link: https://www.nvidia.com/en-in/technologies/multi-instance-gpu/ [2]
Link: https://developer.arm.com/documentation/ddi0487/latest/ section D8.5.5 [3]
Link: https://lore.kernel.org/all/20240224150546.368-1-ankita@nvidia.com/ [4]
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Vikram Sethi <vsethi@nvidia.com>
Cc: Zhi Wang <zhiw@nvidia.com>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240229193934.2417-1-ankita@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Obviously drivers/vfio/platform/vfio_amba.c started its life as a
simplified copy of drivers/dma/pl330.c, but not all variable names were
updated.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1d1b873b59b208547439225aee1f24d6f2512a1f.1708945194.git.geert+renesas@glider.be
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
After reset the VFIO device state will always be put in
VFIO_DEVICE_STATE_RUNNING, but the save/restore files will only be
cleared if the previous state was VFIO_DEVICE_STATE_ERROR. This
can/will cause the restore/save files to be leaked if/when the
migration state machine transitions through the states that
re-allocates these files. Fix this by always clearing the
restore/save files for resets.
Fixes: 7dabb1bcd1 ("vfio/pds: Add support for firmware recovery")
Cc: stable@vger.kernel.org
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240228003205.47311-2-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The VM_ALLOW_ANY_UNCACHED flag is implemented for ARM64,
allowing KVM stage 2 device mapping attributes to use Normal-NC
rather than DEVICE_nGnRE, which allows guest mappings supporting
write-combining attributes (WC). ARM does not architecturally
guarantee this is safe, and indeed some MMIO regions like the GICv2
VCPU interface can trigger uncontained faults if Normal-NC is used.
To safely use VFIO in KVM the platform must guarantee full safety
in the guest where no action taken against a MMIO mapping can
trigger an uncontained failure. The expectation is that most VFIO PCI
platforms support this for both mapping types, at least in common
flows, based on some expectations of how PCI IP is integrated. So
make vfio-pci set the VM_ALLOW_ANY_UNCACHED flag.
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20240224150546.368-5-ankita@nvidia.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
NVIDIA's upcoming Grace Hopper Superchip provides a PCI-like device
for the on-chip GPU that is the logical OS representation of the
internal proprietary chip-to-chip cache coherent interconnect.
The device is peculiar compared to a real PCI device in that whilst
there is a real 64b PCI BAR1 (comprising region 2 & region 3) on the
device, it is not used to access device memory once the faster
chip-to-chip interconnect is initialized (occurs at the time of host
system boot). The device memory is accessed instead using the chip-to-chip
interconnect that is exposed as a contiguous physically addressable
region on the host. This device memory aperture can be obtained from host
ACPI table using device_property_read_u64(), according to the FW
specification. Since the device memory is cache coherent with the CPU,
it can be mmap into the user VMA with a cacheable mapping using
remap_pfn_range() and used like a regular RAM. The device memory
is not added to the host kernel, but mapped directly as this reduces
memory wastage due to struct pages.
There is also a requirement of a minimum reserved 1G uncached region
(termed as resmem) to support the Multi-Instance GPU (MIG) feature [1].
This is to work around a HW defect. Based on [2], the requisite properties
(uncached, unaligned access) can be achieved through a VM mapping (S1)
of NORMAL_NC and host (S2) mapping with MemAttr[2:0]=0b101. To provide
a different non-cached property to the reserved 1G region, it needs to
be carved out from the device memory and mapped as a separate region
in Qemu VMA with pgprot_writecombine(). pgprot_writecombine() sets the
Qemu VMA page properties (pgprot) as NORMAL_NC.
Provide a VFIO PCI variant driver that adapts the unique device memory
representation into a more standard PCI representation facing userspace.
The variant driver exposes these two regions - the non-cached reserved
(resmem) and the cached rest of the device memory (termed as usemem) as
separate VFIO 64b BAR regions. This is divergent from the baremetal
approach, where the device memory is exposed as a device memory region.
The decision for a different approach was taken in view of the fact that
it would necessiate additional code in Qemu to discover and insert those
regions in the VM IPA, along with the additional VM ACPI DSDT changes to
communicate the device memory region IPA to the VM workloads. Moreover,
this behavior would have to be added to a variety of emulators (beyond
top of tree Qemu) out there desiring grace hopper support.
Since the device implements 64-bit BAR0, the VFIO PCI variant driver
maps the uncached carved out region to the next available PCI BAR (i.e.
comprising of region 2 and 3). The cached device memory aperture is
assigned BAR region 4 and 5. Qemu will then naturally generate a PCI
device in the VM with the uncached aperture reported as BAR2 region,
the cacheable as BAR4. The variant driver provides emulation for these
fake BARs' PCI config space offset registers.
The hardware ensures that the system does not crash when the memory
is accessed with the memory enable turned off. It synthesis ~0 reads
and dropped writes on such access. So there is no need to support the
disablement/enablement of BAR through PCI_COMMAND config space register.
The memory layout on the host looks like the following:
devmem (memlength)
|--------------------------------------------------|
|-------------cached------------------------|--NC--|
| |
usemem.memphys resmem.memphys
PCI BARs need to be aligned to the power-of-2, but the actual memory on the
device may not. A read or write access to the physical address from the
last device PFN up to the next power-of-2 aligned physical address
results in reading ~0 and dropped writes. Note that the GPU device
driver [6] is capable of knowing the exact device memory size through
separate means. The device memory size is primarily kept in the system
ACPI tables for use by the VFIO PCI variant module.
Note that the usemem memory is added by the VM Nvidia device driver [5]
to the VM kernel as memblocks. Hence make the usable memory size memblock
(MEMBLK_SIZE) aligned. This is a hardwired ABI value between the GPU FW and
VFIO driver. The VM device driver make use of the same value for its
calculation to determine USEMEM size.
Currently there is no provision in KVM for a S2 mapping with
MemAttr[2:0]=0b101, but there is an ongoing effort to provide the same [3].
As previously mentioned, resmem is mapped pgprot_writecombine(), that
sets the Qemu VMA page properties (pgprot) as NORMAL_NC. Using the
proposed changes in [3] and [4], KVM marks the region with
MemAttr[2:0]=0b101 in S2.
If the device memory properties are not present, the driver registers the
vfio-pci-core function pointers. Since there are no ACPI memory properties
generated for the VM, the variant driver inside the VM will only use
the vfio-pci-core ops and hence try to map the BARs as non cached. This
is not a problem as the CPUs have FWB enabled which blocks the VM
mapping's ability to override the cacheability set by the host mapping.
This goes along with a qemu series [6] to provides the necessary
implementation of the Grace Hopper Superchip firmware specification so
that the guest operating system can see the correct ACPI modeling for
the coherent GPU device. Verified with the CUDA workload in the VM.
[1] https://www.nvidia.com/en-in/technologies/multi-instance-gpu/
[2] section D8.5.5 of https://developer.arm.com/documentation/ddi0487/latest/
[3] https://lore.kernel.org/all/20240211174705.31992-1-ankita@nvidia.com/
[4] https://lore.kernel.org/all/20230907181459.18145-2-ankita@nvidia.com/
[5] https://github.com/NVIDIA/open-gpu-kernel-modules
[6] https://lore.kernel.org/all/20231203060245.31593-1-ankita@nvidia.com/
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Zhi Wang <zhi.wang.linux@gmail.com>
Signed-off-by: Aniket Agashe <aniketa@nvidia.com>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20240220115055.23546-4-ankita@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
range_intersect_range determines an overlap between two ranges. If an
overlap, the helper function returns the overlapping offset and size.
The VFIO PCI variant driver emulates the PCI config space BAR offset
registers. These offset may be accessed for read/write with a variety
of lengths including sub-word sizes from sub-word offsets. The driver
makes use of this helper function to read/write the targeted part of
the emulated register.
Make this a vfio_pci_core function, rename and export as GPL. Also
update references in virtio driver.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20240220115055.23546-3-ankita@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
do_io_rw() is used to read/write to the device MMIO. The grace hopper
VFIO PCI variant driver require this functionality to read/write to
its memory.
Rename this as vfio_pci_core functions and export as GPL.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20240220115055.23546-2-ankita@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Now that the driver core can properly handle constant struct bus_type,
move the mdev_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kirti Wankhede <kwankhede@nvidia.com>
Link: https://lore.kernel.org/r/20240208-bus_cleanup-vfio-v1-1-ed5da3019949@marliere.net
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Let firmware knows upon leaving PRE_COPY back to RUNNING as of some
error in the target/migration cancellation.
This will let firmware cleaning its internal resources that were turned
on upon PRE_COPY.
The flow is based on the device specification in this area.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20240205124828.232701-6-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Block incremental query which is state-dependent once the migration file
was previously marked with state error.
This may prevent redundant calls to firmware upon PRE_COPY which will
end-up with a failure and a syndrome printed in dmesg.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20240205124828.232701-5-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The SAVE command uses the async command interface over the PF.
Upon a failure in the firmware -EREMOTEIO is returned.
In that case call mlx5_cmd_out_err() to let it print the command failure
details including the firmware syndrome.
Note:
The other commands in the driver use the sync command interface in a way
that a firmware syndrome is printed upon an error inside mlx5_core.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20240205124828.232701-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Add support for tracker object change event by referring to its
MLX5_EVENT_TYPE_OBJECT_CHANGE event when occurs.
This lets the driver recognize whether the firmware moved the tracker
object to an error state.
In that case, the driver will skip/block any usage of that object
including an early exit in case the object was previously marked with an
error.
This functionality also covers the case when no CQE is delivered as of
the error state.
The driver was adapted to the device specification to handle the above.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Leon Romanovsky <leon@kernel.org>
Link: https://lore.kernel.org/r/20240205124828.232701-3-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
kasprintf() returns a pointer to dynamically allocated memory
which can be NULL upon failure.
This is a blocking notifier callback, so errno isn't a proper return
value. Use WARN_ON to small allocation failures.
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Link: https://lore.kernel.org/r/20240115063434.20278-1-chentao@kylinos.cn
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
It is more accurate to Check if KVM is enabled, instead of having the
architecture say so. Architectures always "have" KVM, so for example
checking CONFIG_HAVE_KVM in vfio code is pointless, but if KVM is disabled
in a specific build, there is no need for support code.
Alternatively, the #ifdefs could simply be deleted. However, this
would add dead code. For example, when KVM is disabled, there is no
need to include code in VFIO that uses symbol_get, as that symbol_get
would always fail.
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: x86@kernel.org
Cc: kbingham@kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Add debugfs support, initially used for reporting device migration
state. (Longfang Liu)
- Fixes and support for migration dirty tracking across multiple IOVA
regions in the pds-vfio-pci driver. (Brett Creeley)
- Improved IOMMU allocation accounting visibility. (Pasha Tatashin)
- Virtio infrastructure and a new virtio-vfio-pci variant driver, which
provides emulation of a legacy virtio interfaces on modern virtio
hardware for virtio-net VF devices where the PF driver exposes
support for legacy admin queues, ie. an emulated IO BAR on an SR-IOV
VF to provide driver ABI compatibility to legacy devices.
(Yishai Hadas & Feng Liu)
- Migration fixes for the hisi-acc-vfio-pci variant driver.
(Shameer Kolothum)
- Kconfig dependency fix for new virtio-vfio-pci variant driver.
(Arnd Bergmann)
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Merge tag 'vfio-v6.8-rc1' of https://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson:
- Add debugfs support, initially used for reporting device migration
state (Longfang Liu)
- Fixes and support for migration dirty tracking across multiple IOVA
regions in the pds-vfio-pci driver (Brett Creeley)
- Improved IOMMU allocation accounting visibility (Pasha Tatashin)
- Virtio infrastructure and a new virtio-vfio-pci variant driver, which
provides emulation of a legacy virtio interfaces on modern virtio
hardware for virtio-net VF devices where the PF driver exposes
support for legacy admin queues, ie. an emulated IO BAR on an SR-IOV
VF to provide driver ABI compatibility to legacy devices (Yishai
Hadas & Feng Liu)
- Migration fixes for the hisi-acc-vfio-pci variant driver (Shameer
Kolothum)
- Kconfig dependency fix for new virtio-vfio-pci variant driver (Arnd
Bergmann)
* tag 'vfio-v6.8-rc1' of https://github.com/awilliam/linux-vfio: (22 commits)
vfio/virtio: fix virtio-pci dependency
hisi_acc_vfio_pci: Update migration data pointer correctly on saving/resume
vfio/virtio: Declare virtiovf_pci_aer_reset_done() static
vfio/virtio: Introduce a vfio driver over virtio devices
vfio/pci: Expose vfio_pci_core_iowrite/read##size()
vfio/pci: Expose vfio_pci_core_setup_barmap()
virtio-pci: Introduce APIs to execute legacy IO admin commands
virtio-pci: Initialize the supported admin commands
virtio-pci: Introduce admin commands
virtio-pci: Introduce admin command sending function
virtio-pci: Introduce admin virtqueue
virtio: Define feature bit for administration virtqueue
vfio/type1: account iommu allocations
vfio/pds: Add multi-region support
vfio/pds: Move seq/ack bitmaps into region struct
vfio/pds: Pass region info to relevant functions
vfio/pds: Move and rename region specific info
vfio/pds: Only use a single SGL for both seq and ack
vfio/pds: Fix calculations in pds_vfio_dirty_sync
MAINTAINERS: Add vfio debugfs interface doc link
...
The new vfio-virtio driver already has a dependency on VIRTIO_PCI_ADMIN_LEGACY,
but that is a bool symbol and allows vfio-virtio to be built-in even if
virtio-pci itself is a loadable module. This leads to a link failure:
aarch64-linux-ld: drivers/vfio/pci/virtio/main.o: in function `virtiovf_pci_probe':
main.c:(.text+0xec): undefined reference to `virtio_pci_admin_has_legacy_io'
aarch64-linux-ld: drivers/vfio/pci/virtio/main.o: in function `virtiovf_pci_init_device':
main.c:(.text+0x260): undefined reference to `virtio_pci_admin_legacy_io_notify_info'
aarch64-linux-ld: drivers/vfio/pci/virtio/main.o: in function `virtiovf_pci_bar0_rw':
main.c:(.text+0x6ec): undefined reference to `virtio_pci_admin_legacy_common_io_read'
aarch64-linux-ld: main.c:(.text+0x6f4): undefined reference to `virtio_pci_admin_legacy_device_io_read'
aarch64-linux-ld: main.c:(.text+0x7f0): undefined reference to `virtio_pci_admin_legacy_common_io_write'
aarch64-linux-ld: main.c:(.text+0x7f8): undefined reference to `virtio_pci_admin_legacy_device_io_write'
Add another explicit dependency on the tristate symbol.
Fixes: eb61eca0e8 ("vfio/virtio: Introduce a vfio driver over virtio devices")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240109075731.2726731-1-arnd@kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Merge tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual miscellaneous features, cleanups, and fixes
for vfs and individual fses.
Features:
- Add Jan Kara as VFS reviewer
- Show correct device and inode numbers in proc/<pid>/maps for vma
files on stacked filesystems. This is now easily doable thanks to
the backing file work from the last cycles. This comes with
selftests
Cleanups:
- Remove a redundant might_sleep() from wait_on_inode()
- Initialize pointer with NULL, not 0
- Clarify comment on access_override_creds()
- Rework and simplify eventfd_signal() and eventfd_signal_mask()
helpers
- Process aio completions in batches to avoid needless wakeups
- Completely decouple struct mnt_idmap from namespaces. We now only
keep the actual idmapping around and don't stash references to
namespaces
- Reformat maintainer entries to indicate that a given subsystem
belongs to fs/
- Simplify fput() for files that were never opened
- Get rid of various pointless file helpers
- Rename various file helpers
- Rename struct file members after SLAB_TYPESAFE_BY_RCU switch from
last cycle
- Make relatime_need_update() return bool
- Use GFP_KERNEL instead of GFP_USER when allocating superblocks
- Replace deprecated ida_simple_*() calls with their current ida_*()
counterparts
Fixes:
- Fix comments on user namespace id mapping helpers. They aren't
kernel doc comments so they shouldn't be using /**
- s/Retuns/Returns/g in various places
- Add missing parameter documentation on can_move_mount_beneath()
- Rename i_mapping->private_data to i_mapping->i_private_data
- Fix a false-positive lockdep warning in pipe_write() for watch
queues
- Improve __fget_files_rcu() code generation to improve performance
- Only notify writer that pipe resizing has finished after setting
pipe->max_usage otherwise writers are never notified that the pipe
has been resized and hang
- Fix some kernel docs in hfsplus
- s/passs/pass/g in various places
- Fix kernel docs in ntfs
- Fix kcalloc() arguments order reported by gcc 14
- Fix uninitialized value in reiserfs"
* tag 'vfs-6.8.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (36 commits)
reiserfs: fix uninit-value in comp_keys
watch_queue: fix kcalloc() arguments order
ntfs: dir.c: fix kernel-doc function parameter warnings
fs: fix doc comment typo fs tree wide
selftests/overlayfs: verify device and inode numbers in /proc/pid/maps
fs/proc: show correct device and inode numbers in /proc/pid/maps
eventfd: Remove usage of the deprecated ida_simple_xx() API
fs: super: use GFP_KERNEL instead of GFP_USER for super block allocation
fs/hfsplus: wrapper.c: fix kernel-doc warnings
fs: add Jan Kara as reviewer
fs/inode: Make relatime_need_update return bool
pipe: wakeup wr_wait after setting max_usage
file: remove __receive_fd()
file: stop exposing receive_fd_user()
fs: replace f_rcuhead with f_task_work
file: remove pointless wrapper
file: s/close_fd_get_file()/file_close_fd()/g
Improve __fget_files_rcu() code generation (and thus __fget_light())
file: massage cleanup of files that failed to open
fs/pipe: Fix lockdep false-positive in watchqueue pipe_write()
...
When the optional PRE_COPY support was added to speed up the device
compatibility check, it failed to update the saving/resuming data
pointers based on the fd offset. This results in migration data
corruption and when the device gets started on the destination the
following error is reported in some cases,
[ 478.907684] arm-smmu-v3 arm-smmu-v3.2.auto: event 0x10 received:
[ 478.913691] arm-smmu-v3 arm-smmu-v3.2.auto: 0x0000310200000010
[ 478.919603] arm-smmu-v3 arm-smmu-v3.2.auto: 0x000002088000007f
[ 478.925515] arm-smmu-v3 arm-smmu-v3.2.auto: 0x0000000000000000
[ 478.931425] arm-smmu-v3 arm-smmu-v3.2.auto: 0x0000000000000000
[ 478.947552] hisi_zip 0000:31:00.0: qm_axi_rresp [error status=0x1] found
[ 478.955930] hisi_zip 0000:31:00.0: qm_db_timeout [error status=0x400] found
[ 478.955944] hisi_zip 0000:31:00.0: qm sq doorbell timeout in function 2
Fixes: d9a871e4a1 ("hisi_acc_vfio_pci: Introduce support for PRE_COPY state transitions")
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20231120091406.780-1-shameerali.kolothum.thodi@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Introduce a vfio driver over virtio devices to support the legacy
interface functionality for VFs.
Background, from the virtio spec [1].
--------------------------------------------------------------------
In some systems, there is a need to support a virtio legacy driver with
a device that does not directly support the legacy interface. In such
scenarios, a group owner device can provide the legacy interface
functionality for the group member devices. The driver of the owner
device can then access the legacy interface of a member device on behalf
of the legacy member device driver.
For example, with the SR-IOV group type, group members (VFs) can not
present the legacy interface in an I/O BAR in BAR0 as expected by the
legacy pci driver. If the legacy driver is running inside a virtual
machine, the hypervisor executing the virtual machine can present a
virtual device with an I/O BAR in BAR0. The hypervisor intercepts the
legacy driver accesses to this I/O BAR and forwards them to the group
owner device (PF) using group administration commands.
--------------------------------------------------------------------
Specifically, this driver adds support for a virtio-net VF to be exposed
as a transitional device to a guest driver and allows the legacy IO BAR
functionality on top.
This allows a VM which uses a legacy virtio-net driver in the guest to
work transparently over a VF which its driver in the host is that new
driver.
The driver can be extended easily to support some other types of virtio
devices (e.g virtio-blk), by adding in a few places the specific type
properties as was done for virtio-net.
For now, only the virtio-net use case was tested and as such we introduce
the support only for such a device.
Practically,
Upon probing a VF for a virtio-net device, in case its PF supports
legacy access over the virtio admin commands and the VF doesn't have BAR
0, we set some specific 'vfio_device_ops' to be able to simulate in SW a
transitional device with I/O BAR in BAR 0.
The existence of the simulated I/O bar is reported later on by
overwriting the VFIO_DEVICE_GET_REGION_INFO command and the device
exposes itself as a transitional device by overwriting some properties
upon reading its config space.
Once we report the existence of I/O BAR as BAR 0 a legacy driver in the
guest may use it via read/write calls according to the virtio
specification.
Any read/write towards the control parts of the BAR will be captured by
the new driver and will be translated into admin commands towards the
device.
In addition, any data path read/write access (i.e. virtio driver
notifications) will be captured by the driver and forwarded to the
physical BAR which its properties were supplied by the admin command
VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO upon the probing/init flow.
With that code in place a legacy driver in the guest has the look and
feel as if having a transitional device with legacy support for both its
control and data path flows.
[1]
03c2d32e50
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20231219093247.170936-10-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Expose vfio_pci_core_iowrite/read##size() to let it be used by drivers.
This functionality is needed to enable direct access to some physical
BAR of the device with the proper locks/checks in place.
The next patches from this series will use this functionality on a data
path flow when a direct access to the BAR is needed.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20231219093247.170936-9-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Expose vfio_pci_core_setup_barmap() to be used by drivers.
This will let drivers to mmap a BAR and re-use it from both vfio and the
driver when it's applicable.
This API will be used in the next patches by the vfio/virtio coming
driver.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20231219093247.170936-8-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
iommu allocations should be accounted in order to allow admins to
monitor and limit the amount of iommu memory.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20231130200900.2320829-1-pasha.tatashin@soleen.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Only supporting a single region/range is limiting,
wasteful, and in some cases broken (i.e. when there
are large gaps in the iova memory ranges). Fix this
by adding support for multiple regions based on
what the device tells the driver it can support.
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-7-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Since the host seq/ack bitmaps are part of a region
move them into struct pds_vfio_region. Also, make use
of the bmp_bytes value for validation purposes.
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-6-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
A later patch in the series implements multi-region
support. That will require specific regions to be
passed to relevant functions. Prepare for that change
by passing the region structure to relevant functions.
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-5-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
An upcoming change in this series will add support
for multiple regions. To prepare for that, move
region specific information into struct pds_vfio_region
and rename the members for readability. This will
reduce the size of the patch that actually implements
multiple region support.
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-4-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Since the seq/ack operations never happen in parallel there
is no need for multiple scatter gather lists per region.
The current implementation is wasting memory. Fix this by
only using a single scatter-gather list for both the seq
and ack operations.
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-3-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
The incorrect check is being done for comparing the
iova/length being requested to sync. This can cause
the dirty sync operation to fail. Fix this by making
sure the iova offset added to the requested sync
length doesn't exceed the region_size.
Also, the region_start is assumed to always be at 0.
This can cause dirty tracking to fail because the
device/driver bitmap offset always starts at 0,
however, the region_start/iova may not. Fix this by
determining the iova offset from region_start to
determine the bitmap offset.
Fixes: f232836a91 ("vfio/pds: Add support for dirty page tracking")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231117001207.2793-2-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
There are multiple devices, software and operational steps involved
in the process of live migration. An error occurred on any node may
cause the live migration operation to fail.
This complex process makes it very difficult to locate and analyze
the cause when the function fails.
In order to quickly locate the cause of the problem when the
live migration fails, I added a set of debugfs to the vfio
live migration driver.
+-------------------------------------------+
| |
| |
| QEMU |
| |
| |
+---+----------------------------+----------+
| ^ | ^
| | | |
| | | |
v | v |
+---------+--+ +---------+--+
|src vfio_dev| |dst vfio_dev|
+--+---------+ +--+---------+
| ^ | ^
| | | |
v | | |
+-----------+----+ +-----------+----+
|src dev debugfs | |dst dev debugfs |
+----------------+ +----------------+
The entire debugfs directory will be based on the definition of
the CONFIG_DEBUG_FS macro. If this macro is not enabled, the
interfaces in vfio.h will be empty definitions, and the creation
and initialization of the debugfs directory will not be executed.
vfio
|
+---<dev_name1>
| +---migration
| +--state
|
+---<dev_name2>
+---migration
+--state
debugfs will create a public root directory "vfio" file.
then create a dev_name() file for each live migration device.
First, create a unified state acquisition file of "migration"
in this device directory.
Then, create a public live migration state lookup file "state".
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/r/20231106072225.28577-2-liulongfang@huawei.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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>
The driver could possibly sleep while in atomic context resulting
in the following call trace while CONFIG_DEBUG_ATOMIC_SLEEP=y is
set:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2817, name: bash
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
Call Trace:
<TASK>
dump_stack_lvl+0x36/0x50
__might_resched+0x123/0x170
mutex_lock+0x1e/0x50
pds_vfio_put_lm_file+0x1e/0xa0 [pds_vfio_pci]
pds_vfio_put_save_file+0x19/0x30 [pds_vfio_pci]
pds_vfio_state_mutex_unlock+0x2e/0x80 [pds_vfio_pci]
pci_reset_function+0x4b/0x70
reset_store+0x5b/0xa0
kernfs_fop_write_iter+0x137/0x1d0
vfs_write+0x2de/0x410
ksys_write+0x5d/0xd0
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
This can happen if pds_vfio_put_restore_file() and/or
pds_vfio_put_save_file() grab the mutex_lock(&lm_file->lock)
while the spin_lock(&pds_vfio->reset_lock) is held, which can
happen during while calling pds_vfio_state_mutex_unlock().
Fix this by changing the reset_lock to reset_mutex so there are no such
conerns. Also, make sure to destroy the reset_mutex in the driver specific
VFIO device release function.
This also fixes a spinlock bad magic BUG that was caused
by not calling spinlock_init() on the reset_lock. Since, the lock is
being changed to a mutex, make sure to call mutex_init() on it.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/kvm/1f9bc27b-3de9-4891-9687-ba2820c1b390@moroto.mountain/
Fixes: bb500dbe2a ("vfio/pds: Add VFIO live migration support")
Signed-off-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Shannon Nelson <shannon.nelson@amd.com>
Link: https://lore.kernel.org/r/20231122192532.25791-3-brett.creeley@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
