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The vfio-pci huge_fault handler doesn't make any attempt to insert a
mapping containing the faulting address, it only inserts mappings if the
faulting address and resulting pfn are aligned. This works in a lot of
cases, particularly in conjunction with QEMU where DMA mappings linearly
fault the mmap. However, there are configurations where we don't get
that linear faulting and pages are faulted on-demand.
The scenario reported in the bug below is such a case, where the physical
address width of the CPU is greater than that of the IOMMU, resulting in a
VM where guest firmware has mapped device MMIO beyond the address width of
the IOMMU. In this configuration, the MMIO is faulted on demand and
tracing indicates that occasionally the faults generate a VM_FAULT_OOM.
Given the use case, this results in a "error: kvm run failed Bad address",
killing the VM.
The host is not under memory pressure in this test, therefore it's
suspected that VM_FAULT_OOM is actually the result of a NULL return from
__pte_offset_map_lock() in the get_locked_pte() path from insert_pfn().
This suggests a potential race inserting a pte concurrent to a pmd, and
maybe indicates some deficiency in the mm layer properly handling such a
case.
Nevertheless, Peter noted the inconsistency of vfio-pci's huge_fault
handler where our mapping granularity depends on the alignment of the
faulting address relative to the order rather than aligning the faulting
address to the order to more consistently insert huge mappings. This
change not only uses the page tables more consistently and efficiently, but
as any fault to an aligned page results in the same mapping, the race
condition suspected in the VM_FAULT_OOM is avoided.
Reported-by: Adolfo <adolfotregosa@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220057
Fixes: 09dfc8a5f2ce ("vfio/pci: Fallback huge faults for unaligned pfn")
Cc: stable@vger.kernel.org
Tested-by: Adolfo <adolfotregosa@gmail.com>
Co-developed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20250502224035.3183451-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Pull VFIO updates from Alex Williamson:
- Relax IGD support code to match display class device rather than
specifically requiring a VGA device (Tomita Moeko)
- Accelerate DMA mapping of device MMIO by iterating at PMD and PUD
levels to take advantage of huge pfnmap support added in v6.12
(Alex Williamson)
- Extend virtio vfio-pci variant driver to include migration support
for block devices where enabled by the PF (Yishai Hadas)
- Virtualize INTx PIN register for devices where the platform does not
route legacy PCI interrupts for the device and the interrupt is
reported as IRQ_NOTCONNECTED (Alex Williamson)
* tag 'vfio-v6.15-rc1' of https://github.com/awilliam/linux-vfio:
vfio/pci: Handle INTx IRQ_NOTCONNECTED
vfio/virtio: Enable support for virtio-block live migration
vfio/type1: Use mapping page mask for pfnmaps
mm: Provide address mask in struct follow_pfnmap_args
vfio/type1: Use consistent types for page counts
vfio/type1: Use vfio_batch for vaddr_get_pfns()
vfio/type1: Convert all vaddr_get_pfns() callers to use vfio_batch
vfio/type1: Catch zero from pin_user_pages_remote()
vfio/pci: match IGD devices in display controller class
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The ability to map PCI resources to user-space is controlled by global
defines. For vfio there is VFIO_PCI_MMAP which is only disabled on s390 and
controls mapping of PCI resources using vfio-pci with a fallback option via
the pread()/pwrite() interface.
For the PCI core there is ARCH_GENERIC_PCI_MMAP_RESOURCE which enables a
generic implementation for mapping PCI resources plus the newer sysfs
interface. Then there is HAVE_PCI_MMAP which can be used with custom
definitions of pci_mmap_resource_range() and the historical /proc/bus/pci
interface. Both mechanisms are all or nothing.
For s390 mapping PCI resources is possible and useful for testing and
certain applications such as QEMU's vfio-pci based user-space NVMe driver.
For certain devices, however access to PCI resources via mappings to
user-space is not possible and these must be excluded from the general PCI
resource mapping mechanisms.
Introduce pdev->non_mappable_bars to indicate that a PCI device's BARs can
not be accessed via mappings to user-space. In the future this enables
per-device restrictions of PCI resource mapping.
For now, set this flag for all PCI devices on s390 in line with the
existing, general disable of PCI resource mapping. As s390 is the only user
of the VFI_PCI_MMAP Kconfig options this can already be replaced with a
check of this new flag. Also add similar checks in the other code protected
by HAVE_PCI_MMAP respectively ARCH_GENERIC_PCI_MMAP in preparation for
enabling these for supported devices.
Link: https://lore.kernel.org/lkml/20250212132808.08dcf03c.alex.williamson@redhat.com/
Link: https://lore.kernel.org/r/20250226-vfio_pci_mmap-v7-2-c5c0f1d26efd@linux.ibm.com
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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Some systems report INTx as not routed by setting pdev->irq to
IRQ_NOTCONNECTED, resulting in a -ENOTCONN error when trying to
setup eventfd signaling. Include this in the set of conditions
for which the PIN register is virtualized to zero.
Additionally consolidate vfio_pci_get_irq_count() to use this
virtualized value in reporting INTx support via ioctl and sanity
checking ioctl paths since pdev->irq is re-used when the device
is in MSI mode.
The combination of these results in both the config space of the
device and the ioctl interface behaving as if the device does not
support INTx.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20250311230623.1264283-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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If ROM bar is missing for any reason, we can fallback to using pdev->rom
to expose the ROM content to the guest. This fixes some passthrough use
cases where the upstream bridge does not have enough address window.
Signed-off-by: Yunxiang Li <Yunxiang.Li@amd.com>
Link: https://lore.kernel.org/r/20250102185013.15082-3-Yunxiang.Li@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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After commit 0c0e0736acad ("PCI: Set ROM shadow location in arch code,
not in PCI core"), the shadow ROM works the same as regular ROM BARs so
these code paths are no longer needed.
Signed-off-by: Yunxiang Li <Yunxiang.Li@amd.com>
Link: https://lore.kernel.org/r/20250102185013.15082-2-Yunxiang.Li@amd.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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The PFN must also be aligned to the fault order to insert a huge
pfnmap. Test the alignment and fallback when unaligned.
Fixes: f9e54c3a2f5b ("vfio/pci: implement huge_fault support")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219619
Reported-by: Athul Krishna <athul.krishna.kr@protonmail.com>
Reported-by: Precific <precification@posteo.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Precific <precification@posteo.de>
Link: https://lore.kernel.org/r/20250102183416.1841878-1-alex.williamson@redhat.com
Cc: stable@vger.kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Pull VFIO updates from Alex Williamson:
"Just a few cleanups this cycle:
- Remove several unused structure and function declarations, and
unused variables (Dr. David Alan Gilbert, Yue Haibing, Zhang Zekun)
- Constify unmodified structure in mdev (Hongbo Li)
- Convert to unsigned type to catch overflow with less fanfare than
passing a negative value to kcalloc() (Dan Carpenter)"
* tag 'vfio-v6.12-rc1' of https://github.com/awilliam/linux-vfio:
vfio/pci: clean up a type in vfio_pci_ioctl_pci_hot_reset_groups()
vfio/mdev: Constify struct kobj_type
vfio: mdev: Remove unused function declarations
vfio/fsl-mc: Remove unused variable 'hwirq'
vfio/pci: Remove unused struct 'vfio_pci_mmap_vma'
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With the addition of pfnmap support in vmf_insert_pfn_{pmd,pud}() we can
take advantage of PMD and PUD faults to PCI BAR mmaps and create more
efficient mappings. PCI BARs are always a power of two and will typically
get at least PMD alignment without userspace even trying. Userspace
alignment for PUD mappings is also not too difficult.
Consolidate faults through a single handler with a new wrapper for
standard single page faults. The pre-faulting behavior of commit
d71a989cf5d9 ("vfio/pci: Insert full vma on mmap'd MMIO fault") is removed
in this refactoring since huge_fault will cover the bulk of the faults and
results in more efficient page table usage. We also want to avoid that
pre-faulted single page mappings preempt huge page mappings.
Link: https://lkml.kernel.org/r/20240826204353.2228736-20-peterx@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The "array_count" value comes from the copy_from_user() in
vfio_pci_ioctl_pci_hot_reset(). If the user passes a value larger than
INT_MAX then we'll pass a negative value to kcalloc() which triggers an
allocation failure and a stack trace.
It's better to make the type unsigned so that if (array_count > count)
returns -EINVAL instead.
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/262ada03-d848-4369-9c37-81edeeed2da2@stanley.mountain
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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'vfio_pci_mmap_vma' has been unused since
commit aac6db75a9fc ("vfio/pci: Use unmap_mapping_range()")
Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240727160307.1000476-1-linux@treblig.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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The count variable is used without initialization, it results in mistakes
in the device counting and crashes the userspace if the get hot reset info
path is triggered.
Fixes: f6944d4a0b87 ("vfio/pci: Collect hot-reset devices to local buffer")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=219010
Reported-by: Žilvinas Žaltiena <zaltys@natrix.lt>
Cc: Beld Zhang <beldzhang@gmail.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240710004150.319105-1-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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In order to improve performance of typical scenarios we can try to insert
the entire vma on fault. This accelerates typical cases, such as when
the MMIO region is DMA mapped by QEMU. The vfio_iommu_type1 driver will
fault in the entire DMA mapped range through fixup_user_fault().
In synthetic testing, this improves the time required to walk a PCI BAR
mapping from userspace by roughly 1/3rd.
This is likely an interim solution until vmf_insert_pfn_{pmd,pud}() gain
support for pfnmaps.
Suggested-by: Yan Zhao <yan.y.zhao@intel.com>
Link: https://lore.kernel.org/all/Zl6XdUkt%2FzMMGOLF@yzhao56-desk.sh.intel.com/
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Link: https://lore.kernel.org/r/20240607035213.2054226-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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With the vfio device fd tied to the address space of the pseudo fs
inode, we can use the mm to track all vmas that might be mmap'ing
device BARs, which removes our vma_list and all the complicated lock
ordering necessary to manually zap each related vma.
Note that we can no longer store the pfn in vm_pgoff if we want to use
unmap_mapping_range() to zap a selective portion of the device fd
corresponding to BAR mappings.
This also converts our mmap fault handler to use vmf_insert_pfn()
because we no longer have a vma_list to avoid the concurrency problem
with io_remap_pfn_range(). The goal is to eventually use the vm_ops
huge_fault handler to avoid the additional faulting overhead, but
vmf_insert_pfn_{pmd,pud}() need to learn about pfnmaps first.
Also, Jason notes that a race exists between unmap_mapping_range() and
the fops mmap callback if we were to call io_remap_pfn_range() to
populate the vma on mmap. Specifically, mmap_region() does call_mmap()
before it does vma_link_file() which gives a window where the vma is
populated but invisible to unmap_mapping_range().
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240530045236.1005864-3-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Yi notes relative to commit f6944d4a0b87 ("vfio/pci: Collect hot-reset
devices to local buffer") that we previously tested the resulting
device count with a WARN_ON, which was removed when we switched to
the in-loop user copy in commit b56b7aabcf3c ("vfio/pci: Copy hot-reset
device info to userspace in the devices loop"). Finding no devices in
the bus/slot would be an unexpected condition, so let's restore the
warning and trigger a -ERANGE error here as success with no devices
would be an unexpected result to userspace as well.
Suggested-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20240516174831.2257970-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Lockdep reports the below circular locking dependency issue. The
mmap_lock acquisition while holding pci_bus_sem is due to the use of
copy_to_user() from within a pci_walk_bus() callback.
Building the devices array directly into the user buffer is only for
convenience. Instead we can allocate a local buffer for the array,
bounded by the number of devices on the bus/slot, fill the device
information into this local buffer, then copy it into the user buffer
outside the bus walk callback.
======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc5+ #39 Not tainted
------------------------------------------------------
CPU 0/KVM/4113 is trying to acquire lock:
ffff99a609ee18a8 (&vdev->vma_lock){+.+.}-{4:4}, at: vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
but task is already holding lock:
ffff99a243a052a0 (&mm->mmap_lock){++++}-{4:4}, at: vaddr_get_pfns+0x3f/0x170 [vfio_iommu_type1]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&mm->mmap_lock){++++}-{4:4}:
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
__might_fault+0x5c/0x80
_copy_to_user+0x1e/0x60
vfio_pci_fill_devs+0x9f/0x130 [vfio_pci_core]
vfio_pci_walk_wrapper+0x45/0x60 [vfio_pci_core]
__pci_walk_bus+0x6b/0xb0
vfio_pci_ioctl_get_pci_hot_reset_info+0x10b/0x1d0 [vfio_pci_core]
vfio_pci_core_ioctl+0x1cb/0x400 [vfio_pci_core]
vfio_device_fops_unl_ioctl+0x7e/0x140 [vfio]
__x64_sys_ioctl+0x8a/0xc0
do_syscall_64+0x8d/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #2 (pci_bus_sem){++++}-{4:4}:
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
down_read+0x3e/0x160
pci_bridge_wait_for_secondary_bus.part.0+0x33/0x2d0
pci_reset_bus+0xdd/0x160
vfio_pci_dev_set_hot_reset+0x256/0x270 [vfio_pci_core]
vfio_pci_ioctl_pci_hot_reset_groups+0x1a3/0x280 [vfio_pci_core]
vfio_pci_core_ioctl+0x3b5/0x400 [vfio_pci_core]
vfio_device_fops_unl_ioctl+0x7e/0x140 [vfio]
__x64_sys_ioctl+0x8a/0xc0
do_syscall_64+0x8d/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #1 (&vdev->memory_lock){+.+.}-{4:4}:
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
down_write+0x3b/0xc0
vfio_pci_zap_and_down_write_memory_lock+0x1c/0x30 [vfio_pci_core]
vfio_basic_config_write+0x281/0x340 [vfio_pci_core]
vfio_config_do_rw+0x1fa/0x300 [vfio_pci_core]
vfio_pci_config_rw+0x75/0xe50 [vfio_pci_core]
vfio_pci_rw+0xea/0x1a0 [vfio_pci_core]
vfs_write+0xea/0x520
__x64_sys_pwrite64+0x90/0xc0
do_syscall_64+0x8d/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
-> #0 (&vdev->vma_lock){+.+.}-{4:4}:
check_prev_add+0xeb/0xcc0
validate_chain+0x465/0x530
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
__mutex_lock+0x97/0xde0
vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
__do_fault+0x31/0x160
do_pte_missing+0x65/0x3b0
__handle_mm_fault+0x303/0x720
handle_mm_fault+0x10f/0x460
fixup_user_fault+0x7f/0x1f0
follow_fault_pfn+0x66/0x1c0 [vfio_iommu_type1]
vaddr_get_pfns+0xf2/0x170 [vfio_iommu_type1]
vfio_pin_pages_remote+0x348/0x4e0 [vfio_iommu_type1]
vfio_pin_map_dma+0xd2/0x330 [vfio_iommu_type1]
vfio_dma_do_map+0x2c0/0x440 [vfio_iommu_type1]
vfio_iommu_type1_ioctl+0xc5/0x1d0 [vfio_iommu_type1]
__x64_sys_ioctl+0x8a/0xc0
do_syscall_64+0x8d/0x170
entry_SYSCALL_64_after_hwframe+0x76/0x7e
other info that might help us debug this:
Chain exists of:
&vdev->vma_lock --> pci_bus_sem --> &mm->mmap_lock
Possible unsafe locking scenario:
block dm-0: the capability attribute has been deprecated.
CPU0 CPU1
---- ----
rlock(&mm->mmap_lock);
lock(pci_bus_sem);
lock(&mm->mmap_lock);
lock(&vdev->vma_lock);
*** DEADLOCK ***
2 locks held by CPU 0/KVM/4113:
#0: ffff99a25f294888 (&iommu->lock#2){+.+.}-{4:4}, at: vfio_dma_do_map+0x60/0x440 [vfio_iommu_type1]
#1: ffff99a243a052a0 (&mm->mmap_lock){++++}-{4:4}, at: vaddr_get_pfns+0x3f/0x170 [vfio_iommu_type1]
stack backtrace:
CPU: 1 PID: 4113 Comm: CPU 0/KVM Not tainted 6.9.0-rc5+ #39
Hardware name: Dell Inc. PowerEdge T640/04WYPY, BIOS 2.15.1 06/16/2022
Call Trace:
<TASK>
dump_stack_lvl+0x64/0xa0
check_noncircular+0x131/0x150
check_prev_add+0xeb/0xcc0
? add_chain_cache+0x10a/0x2f0
? __lock_acquire+0x4e4/0xb90
validate_chain+0x465/0x530
__lock_acquire+0x4e4/0xb90
lock_acquire+0xbc/0x2d0
? vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
? lock_is_held_type+0x9a/0x110
__mutex_lock+0x97/0xde0
? vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
? lock_acquire+0xbc/0x2d0
? vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
? find_held_lock+0x2b/0x80
? vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
vfio_pci_mmap_fault+0x35/0x1a0 [vfio_pci_core]
__do_fault+0x31/0x160
do_pte_missing+0x65/0x3b0
__handle_mm_fault+0x303/0x720
handle_mm_fault+0x10f/0x460
fixup_user_fault+0x7f/0x1f0
follow_fault_pfn+0x66/0x1c0 [vfio_iommu_type1]
vaddr_get_pfns+0xf2/0x170 [vfio_iommu_type1]
vfio_pin_pages_remote+0x348/0x4e0 [vfio_iommu_type1]
vfio_pin_map_dma+0xd2/0x330 [vfio_iommu_type1]
vfio_dma_do_map+0x2c0/0x440 [vfio_iommu_type1]
vfio_iommu_type1_ioctl+0xc5/0x1d0 [vfio_iommu_type1]
__x64_sys_ioctl+0x8a/0xc0
do_syscall_64+0x8d/0x170
? rcu_core+0x8d/0x250
? __lock_release+0x5e/0x160
? rcu_core+0x8d/0x250
? lock_release+0x5f/0x120
? sched_clock+0xc/0x30
? sched_clock_cpu+0xb/0x190
? irqtime_account_irq+0x40/0xc0
? __local_bh_enable+0x54/0x60
? __do_softirq+0x315/0x3ca
? lockdep_hardirqs_on_prepare.part.0+0x97/0x140
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f8300d0357b
Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 75 68 0f 00 f7 d8 64 89 01 48
RSP: 002b:00007f82ef3fb948 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8300d0357b
RDX: 00007f82ef3fb990 RSI: 0000000000003b71 RDI: 0000000000000023
RBP: 00007f82ef3fb9c0 R08: 0000000000000000 R09: 0000561b7e0bcac2
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000200000000 R14: 0000381800000000 R15: 0000000000000000
</TASK>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240503143138.3562116-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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https://git.kernel.org/pub/scm/linux/kernel/git/oupton/linux into v6.9/vfio/next
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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>
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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>
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Ever since the eventfd type was introduced back in 2007 in commit
e1ad7468c77d ("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>
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The VFIO_DEVICE_GET_INFO, VFIO_DEVICE_GET_REGION_INFO, and
VFIO_IOMMU_GET_INFO ioctls fill in an info struct followed by capability
structs:
+------+---------+---------+-----+
| info | caps[0] | caps[1] | ... |
+------+---------+---------+-----+
Both the info and capability struct sizes are not always multiples of
sizeof(u64), leaving u64 fields in later capability structs misaligned.
Userspace applications currently need to handle misalignment manually in
order to support CPU architectures and programming languages with strict
alignment requirements.
Make life easier for userspace by ensuring alignment in the kernel. This
is done by padding info struct definitions and by copying out zeroes
after capability structs that are not aligned.
The new layout is as follows:
+------+---------+---+---------+-----+
| info | caps[0] | 0 | caps[1] | ... |
+------+---------+---+---------+-----+
In this example caps[0] has a size that is not multiples of sizeof(u64),
so zero padding is added to align the subsequent structure.
Adding zero padding between structs does not break the uapi. The memory
layout is specified by the info.cap_offset and caps[i].next fields
filled in by the kernel. Applications use these field values to locate
structs and are therefore unaffected by the addition of zero padding.
Note that code that copies out info structs with padding is updated to
always zero the struct and copy out as many bytes as userspace
requested. This makes the code shorter and avoids potential information
leaks by ensuring padding is initialized.
Originally-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230809203144.2880050-1-stefanha@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This is the way user to invoke hot-reset for the devices opened by cdev
interface. User should check the flag VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED
in the output of VFIO_DEVICE_GET_PCI_HOT_RESET_INFO ioctl before doing
hot-reset for cdev devices.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718105542.4138-11-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This copies the vfio_pci_dependent_device to userspace during looping each
affected device for reporting vfio_pci_hot_reset_info. This avoids counting
the affected devices and allocating a potential large buffer to store the
vfio_pci_dependent_device of all the affected devices before copying them
to userspace.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230718105542.4138-10-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This allows VFIO_DEVICE_GET_PCI_HOT_RESET_INFO ioctl use the iommufd_ctx
of the cdev device to check the ownership of the other affected devices.
When VFIO_DEVICE_GET_PCI_HOT_RESET_INFO is called on an IOMMUFD managed
device, the new flag VFIO_PCI_HOT_RESET_FLAG_DEV_ID is reported to indicate
the values returned are IOMMUFD devids rather than group IDs as used when
accessing vfio devices through the conventional vfio group interface.
Additionally the flag VFIO_PCI_HOT_RESET_FLAG_DEV_ID_OWNED will be reported
in this mode if all of the devices affected by the hot-reset are owned by
either virtue of being directly bound to the same iommufd context as the
calling device, or implicitly owned via a shared IOMMU group.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718105542.4138-9-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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There are drivers that need to search vfio_device within a given dev_set.
e.g. vfio-pci. So add a helper.
vfio_pci_is_device_in_set() now returns -EBUSY in commit a882c16a2b7e
("vfio/pci: Change vfio_pci_try_bus_reset() to use the dev_set") where
it was trying to preserve the return of vfio_pci_try_zap_and_vma_lock_cb().
However, it makes more sense to return -ENODEV.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718105542.4138-8-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This prepares to add another method for hot reset. The major hot reset logic
are moved to vfio_pci_ioctl_pci_hot_reset_groups().
No functional change is intended.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Tested-by: Terrence Xu <terrence.xu@intel.com>
Tested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718105542.4138-3-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This suits more on what the code does.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Yanting Jiang <yanting.jiang@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718105542.4138-2-yi.l.liu@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Test and enable PCIe AtomicOp completer support of various widths and
report via device-info capability to userspace.
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Robin Voetter <robin@streamhpc.com>
Tested-by: Robin Voetter <robin@streamhpc.com>
Link: https://lore.kernel.org/r/20230519214748.402003-1-alex.williamson@redhat.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Dynamic MSI-X is supported. Clear VFIO_IRQ_INFO_NORESIZE
to provide guidance to user space.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/fd1ef2bf6ae972da8e2805bc95d5155af5a8fb0a.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Not all MSI-X devices support dynamic MSI-X allocation. Whether
a device supports dynamic MSI-X should be queried using
pci_msix_can_alloc_dyn().
Instead of scattering code with pci_msix_can_alloc_dyn(),
probe this ability once and store it as a property of the
virtual device.
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/f1ae022c060ecb7e527f4f53c8ccafe80768da47.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Interrupt context is statically allocated at the time interrupts
are allocated. Following allocation, the context is managed by
directly accessing the elements of the array using the vector
as index. The storage is released when interrupts are disabled.
It is possible to dynamically allocate a single MSI-X interrupt
after MSI-X is enabled. A dynamic storage for interrupt context
is needed to support this. Replace the interrupt context array with an
xarray (similar to what the core uses as store for MSI descriptors)
that can support the dynamic expansion while maintaining the
custom that uses the vector as index.
With a dynamic storage it is no longer required to pre-allocate
interrupt contexts at the time the interrupts are allocated.
MSI and MSI-X interrupt contexts are only used when interrupts are
enabled. Their allocation can thus be delayed until interrupt enabling.
Only enabled interrupts will have associated interrupt contexts.
Whether an interrupt has been allocated (a Linux irq number exists
for it) becomes the criteria for whether an interrupt can be enabled.
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/lkml/20230404122444.59e36a99.alex.williamson@redhat.com/
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/40e235f38d427aff79ae35eda0ced42502aa0937.1683740667.git.reinette.chatre@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Pull VFIO updates from Alex Williamson:
- Remove redundant resource check in vfio-platform (Angus Chen)
- Use GFP_KERNEL_ACCOUNT for persistent userspace allocations, allowing
removal of arbitrary kernel limits in favor of cgroup control (Yishai
Hadas)
- mdev tidy-ups, including removing the module-only build restriction
for sample drivers, Kconfig changes to select mdev support,
documentation movement to keep sample driver usage instructions with
sample drivers rather than with API docs, remove references to
out-of-tree drivers in docs (Christoph Hellwig)
- Fix collateral breakages from mdev Kconfig changes (Arnd Bergmann)
- Make mlx5 migration support match device support, improve source and
target flows to improve pre-copy support and reduce downtime (Yishai
Hadas)
- Convert additional mdev sysfs case to use sysfs_emit() (Bo Liu)
- Resolve copy-paste error in mdev mbochs sample driver Kconfig (Ye
Xingchen)
- Avoid propagating missing reset error in vfio-platform if reset
requirement is relaxed by module option (Tomasz Duszynski)
- Range size fixes in mlx5 variant driver for missed last byte and
stricter range calculation (Yishai Hadas)
- Fixes to suspended vaddr support and locked_vm accounting, excluding
mdev configurations from the former due to potential to indefinitely
block kernel threads, fix underflow and restore locked_vm on new mm
(Steve Sistare)
- Update outdated vfio documentation due to new IOMMUFD interfaces in
recent kernels (Yi Liu)
- Resolve deadlock between group_lock and kvm_lock, finally (Matthew
Rosato)
- Fix NULL pointer in group initialization error path with IOMMUFD (Yan
Zhao)
* tag 'vfio-v6.3-rc1' of https://github.com/awilliam/linux-vfio: (32 commits)
vfio: Fix NULL pointer dereference caused by uninitialized group->iommufd
docs: vfio: Update vfio.rst per latest interfaces
vfio: Update the kdoc for vfio_device_ops
vfio/mlx5: Fix range size calculation upon tracker creation
vfio: no need to pass kvm pointer during device open
vfio: fix deadlock between group lock and kvm lock
vfio: revert "iommu driver notify callback"
vfio/type1: revert "implement notify callback"
vfio/type1: revert "block on invalid vaddr"
vfio/type1: restore locked_vm
vfio/type1: track locked_vm per dma
vfio/type1: prevent underflow of locked_vm via exec()
vfio/type1: exclude mdevs from VFIO_UPDATE_VADDR
vfio: platform: ignore missing reset if disabled at module init
vfio/mlx5: Improve the target side flow to reduce downtime
vfio/mlx5: Improve the source side flow upon pre_copy
vfio/mlx5: Check whether VF is migratable
samples: fix the prompt about SAMPLE_VFIO_MDEV_MBOCHS
vfio/mdev: Use sysfs_emit() to instead of sprintf()
vfio-mdev: add back CONFIG_VFIO dependency
...
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Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.
[akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo]
Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Use GFP_KERNEL_ACCOUNT for userspace persistent allocations.
The GFP_KERNEL_ACCOUNT option lets the memory allocator know that this
is untrusted allocation triggered from userspace and should be a subject
of kmem accounting, and as such it is controlled by the cgroup
mechanism.
The way to find the relevant allocations was for example to look at the
close_device function and trace back all the kfrees to their
allocations.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230108154427.32609-4-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Pull VFIO updates from Alex Williamson:
- Replace deprecated git://github.com link in MAINTAINERS (Palmer
Dabbelt)
- Simplify vfio/mlx5 with module_pci_driver() helper (Shang XiaoJing)
- Drop unnecessary buffer from ACPI call (Rafael Mendonca)
- Correct latent missing include issue in iova-bitmap and fix support
for unaligned bitmaps. Follow-up with better fix through refactor
(Joao Martins)
- Rework ccw mdev driver to split private data from parent structure,
better aligning with the mdev lifecycle and allowing us to remove a
temporary workaround (Eric Farman)
- Add an interface to get an estimated migration data size for a
device, allowing userspace to make informed decisions, ex. more
accurately predicting VM downtime (Yishai Hadas)
- Fix minor typo in vfio/mlx5 array declaration (Yishai Hadas)
- Simplify module and Kconfig through consolidating SPAPR/EEH code and
config options and folding virqfd module into main vfio module (Jason
Gunthorpe)
- Fix error path from device_register() across all vfio mdev and sample
drivers (Alex Williamson)
- Define migration pre-copy interface and implement for vfio/mlx5
devices, allowing portions of the device state to be saved while the
device continues operation, towards reducing the stop-copy state size
(Jason Gunthorpe, Yishai Hadas, Shay Drory)
- Implement pre-copy for hisi_acc devices (Shameer Kolothum)
- Fixes to mdpy mdev driver remove path and error path on probe (Shang
XiaoJing)
- vfio/mlx5 fixes for incorrect return after copy_to_user() fault and
incorrect buffer freeing (Dan Carpenter)
* tag 'vfio-v6.2-rc1' of https://github.com/awilliam/linux-vfio: (42 commits)
vfio/mlx5: error pointer dereference in error handling
vfio/mlx5: fix error code in mlx5vf_precopy_ioctl()
samples: vfio-mdev: Fix missing pci_disable_device() in mdpy_fb_probe()
hisi_acc_vfio_pci: Enable PRE_COPY flag
hisi_acc_vfio_pci: Move the dev compatibility tests for early check
hisi_acc_vfio_pci: Introduce support for PRE_COPY state transitions
hisi_acc_vfio_pci: Add support for precopy IOCTL
vfio/mlx5: Enable MIGRATION_PRE_COPY flag
vfio/mlx5: Fallback to STOP_COPY upon specific PRE_COPY error
vfio/mlx5: Introduce multiple loads
vfio/mlx5: Consider temporary end of stream as part of PRE_COPY
vfio/mlx5: Introduce vfio precopy ioctl implementation
vfio/mlx5: Introduce SW headers for migration states
vfio/mlx5: Introduce device transitions of PRE_COPY
vfio/mlx5: Refactor to use queue based data chunks
vfio/mlx5: Refactor migration file state
vfio/mlx5: Refactor MKEY usage
vfio/mlx5: Refactor PD usage
vfio/mlx5: Enforce a single SAVE command at a time
vfio: Extend the device migration protocol with PRE_COPY
...
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We don't need a kconfig symbol for this, just directly test CONFIG_EEH in
the few places that need it.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v5-fc5346cacfd4+4c482-vfio_modules_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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The vfio_spapr_pci_eeh_open/release() functions are one line wrappers
around an arch function. Just call them directly. This eliminates some
weird exported symbols that don't need to exist.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/1-v5-fc5346cacfd4+4c482-vfio_modules_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Add an option to get migration data size by introducing a new migration
feature named VFIO_DEVICE_FEATURE_MIG_DATA_SIZE.
Upon VFIO_DEVICE_FEATURE_GET the estimated data length that will be
required to complete STOP_COPY is returned.
This option may better enable user space to consider before moving to
STOP_COPY whether it can meet the downtime SLA based on the returned
data.
The patch also includes the implementation for mlx5 and hisi for this
new option to make it feature complete for the existing drivers in this
area.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Longfang Liu <liulongfang@huawei.com>
Link: https://lore.kernel.org/r/20221106174630.25909-2-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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vfio_pci_dev_set_needs_reset() inspects the open_count of every device
in the set to determine whether a reset is allowed. The current device
always has open_count == 1 within vfio_pci_core_disable(), effectively
disabling the reset logic. This field is also documented as private in
vfio_device, so it should not be used to determine whether other devices
in the set are open.
Checking for vfio_device_set_open_count() > 1 on the device set fixes
both issues.
After commit 2cd8b14aaa66 ("vfio/pci: Move to the device set
infrastructure"), failure to create a new file for a device would cause
the reset to be skipped due to open_count being decremented after
calling close_device() in the error path.
After commit eadd86f835c6 ("vfio: Remove calls to
vfio_group_add_container_user()"), releasing a device would always skip
the reset due to an ordering change in vfio_device_fops_release().
Failing to reset the device leaves it in an unknown state, potentially
causing errors when it is accessed later or bound to a different driver.
This issue was observed with a Radeon RX Vega 56 [1002:687f] (rev c3)
assigned to a Windows guest. After shutting down the guest, unbinding
the device from vfio-pci, and binding the device to amdgpu:
[ 548.007102] [drm:psp_hw_start [amdgpu]] *ERROR* PSP create ring failed!
[ 548.027174] [drm:psp_hw_init [amdgpu]] *ERROR* PSP firmware loading failed
[ 548.027242] [drm:amdgpu_device_fw_loading [amdgpu]] *ERROR* hw_init of IP block <psp> failed -22
[ 548.027306] amdgpu 0000:0a:00.0: amdgpu: amdgpu_device_ip_init failed
[ 548.027308] amdgpu 0000:0a:00.0: amdgpu: Fatal error during GPU init
Fixes: 2cd8b14aaa66 ("vfio/pci: Move to the device set infrastructure")
Fixes: eadd86f835c6 ("vfio: Remove calls to vfio_group_add_container_user()")
Signed-off-by: Anthony DeRossi <ajderossi@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20221110014027.28780-4-ajderossi@gmail.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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With the "mess" sorted out, we should be able to inline the
vfio_free_device call introduced by commit cb9ff3f3b84c
("vfio: Add helpers for unifying vfio_device life cycle")
and remove them from driver release callbacks.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com> # vfio-ap part
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-8-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This replaces uses of vfio_file_iommu_group() which were only detecting if
the file is a VFIO file with no interest in the actual group.
The only remaning user of vfio_file_iommu_group() is in KVM for the SPAPR
stuff. It passes the iommu_group into the arch code through kvm for some
reason.
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Eric Farman <farman@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/1-v2-15417f29324e+1c-vfio_group_disassociate_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Tidy up @probe so all migration specific initialization logic is moved
to migration specific @init callback.
Remove vfio_pci_core_{un}init_device() given no user now.
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20220921104401.38898-5-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Also introduce two pci core helpers as @init/@release for pci drivers:
- vfio_pci_core_init_dev()
- vfio_pci_core_release_dev()
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20220921104401.38898-3-kevin.tian@intel.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Introduce the DMA logging feature support in the vfio core layer.
It includes the processing of the device start/stop/report DMA logging
UAPIs and calling the relevant driver 'op' to do the work.
Specifically,
Upon start, the core translates the given input ranges into an interval
tree, checks for unexpected overlapping, non aligned ranges and then
pass the translated input to the driver for start tracking the given
ranges.
Upon report, the core translates the given input user space bitmap and
page size into an IOVA kernel bitmap iterator. Then it iterates it and
call the driver to set the corresponding bits for the dirtied pages in a
specific IOVA range.
Upon stop, the driver is called to stop the previous started tracking.
The next patches from the series will introduce the mlx5 driver
implementation for the logging ops.
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/20220908183448.195262-6-yishaih@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This patch implements VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY_WITH_WAKEUP
device feature. In the VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY, if there is
any access for the VFIO device on the host side, then the device will
be moved out of the low power state without the user's guest driver
involvement. Once the device access has been finished, then the host
can move the device again into low power state. With the low power
entry happened through VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY_WITH_WAKEUP,
the device will not be moved back into the low power state and
a notification will be sent to the user by triggering wakeup eventfd.
vfio_pci_core_pm_entry() will be called for both the variants of low
power feature entry so add an extra argument for wakeup eventfd context
and store locally in 'struct vfio_pci_core_device'.
For the entry happened without wakeup eventfd, all the exit related
handling will be done by the LOW_POWER_EXIT device feature only.
When the LOW_POWER_EXIT will be called, then the vfio core layer
vfio_device_pm_runtime_get() will increment the usage count and will
resume the device. In the driver runtime_resume callback, the
'pm_wake_eventfd_ctx' will be NULL. Then vfio_pci_core_pm_exit()
will call vfio_pci_runtime_pm_exit() and all the exit related handling
will be done.
For the entry happened with wakeup eventfd, in the driver resume
callback, eventfd will be triggered and all the exit related handling will
be done. When vfio_pci_runtime_pm_exit() will be called by
vfio_pci_core_pm_exit(), then it will return early.
But if the runtime suspend has not happened on the host side, then
all the exit related handling will be done in vfio_pci_core_pm_exit()
only.
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220829114850.4341-6-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Currently, if the runtime power management is enabled for vfio-pci
based devices in the guest OS, then the guest OS will do the register
write for PCI_PM_CTRL register. This write request will be handled in
vfio_pm_config_write() where it will do the actual register write of
PCI_PM_CTRL register. With this, the maximum D3hot state can be
achieved for low power. If we can use the runtime PM framework, then
we can achieve the D3cold state (on the supported systems) which will
help in saving maximum power.
1. D3cold state can't be achieved by writing PCI standard
PM config registers. This patch implements the following
newly added low power related device features:
- VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY
- VFIO_DEVICE_FEATURE_LOW_POWER_EXIT
The VFIO_DEVICE_FEATURE_LOW_POWER_ENTRY feature will allow the
device to make use of low power platform states on the host
while the VFIO_DEVICE_FEATURE_LOW_POWER_EXIT will prevent
further use of those power states.
2. The vfio-pci driver uses runtime PM framework for low power entry and
exit. On the platforms where D3cold state is supported, the runtime
PM framework will put the device into D3cold otherwise, D3hot or some
other power state will be used.
There are various cases where the device will not go into the runtime
suspended state. For example,
- The runtime power management is disabled on the host side for
the device.
- The user keeps the device busy after calling LOW_POWER_ENTRY.
- There are dependent devices that are still in runtime active state.
For these cases, the device will be in the same power state that has
been configured by the user through PCI_PM_CTRL register.
3. The hypervisors can implement virtual ACPI methods. For example,
in guest linux OS if PCI device ACPI node has _PR3 and _PR0 power
resources with _ON/_OFF method, then guest linux OS invokes
the _OFF method during D3cold transition and then _ON during D0
transition. The hypervisor can tap these virtual ACPI calls and then
call the low power device feature IOCTL.
4. The 'pm_runtime_engaged' flag tracks the entry and exit to
runtime PM. This flag is protected with 'memory_lock' semaphore.
5. All the config and other region access are wrapped under
pm_runtime_resume_and_get() and pm_runtime_put(). So, if any
device access happens while the device is in the runtime suspended
state, then the device will be resumed first before access. Once the
access has been finished, then the device will again go into the
runtime suspended state.
6. The memory region access through mmap will not be allowed in the low
power state. Since __vfio_pci_memory_enabled() is a common function,
so check for 'pm_runtime_engaged' has been added explicitly in
vfio_pci_mmap_fault() to block only mmap'ed access.
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220829114850.4341-5-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This patch adds INTx handling during runtime suspend/resume.
All the suspend/resume related code for the user to put the device
into the low power state will be added in subsequent patches.
The INTx lines may be shared among devices. Whenever any INTx
interrupt comes for the VFIO devices, then vfio_intx_handler() will be
called for each device sharing the interrupt. Inside vfio_intx_handler(),
it calls pci_check_and_mask_intx() and checks if the interrupt has
been generated for the current device. Now, if the device is already
in the D3cold state, then the config space can not be read. Attempt
to read config space in D3cold state can cause system unresponsiveness
in a few systems. To prevent this, mask INTx in runtime suspend callback,
and unmask the same in runtime resume callback. If INTx has been already
masked, then no handling is needed in runtime suspend/resume callbacks.
'pm_intx_masked' tracks this, and vfio_pci_intx_mask() has been updated
to return true if the INTx vfio_pci_irq_ctx.masked value is changed
inside this function.
For the runtime suspend which is triggered for the no user of VFIO
device, the 'irq_type' will be VFIO_PCI_NUM_IRQS and these
callbacks won't do anything.
The MSI/MSI-X are not shared so similar handling should not be
needed for MSI/MSI-X. vfio_msihandler() triggers eventfd_signal()
without doing any device-specific config access. When the user performs
any config access or IOCTL after receiving the eventfd notification,
then the device will be moved to the D0 state first before
servicing any request.
Another option was to check this flag 'pm_intx_masked' inside
vfio_intx_handler() instead of masking the interrupts. This flag
is being set inside the runtime_suspend callback but the device
can be in non-D3cold state (for example, if the user has disabled D3cold
explicitly by sysfs, the D3cold is not supported in the platform, etc.).
Also, in D3cold supported case, the device will be in D0 till the
PCI core moves the device into D3cold. In this case, there is
a possibility that the device can generate an interrupt. Adding check
in the IRQ handler will not clear the IRQ status and the interrupt
line will still be asserted. This can cause interrupt flooding.
Signed-off-by: Abhishek Sahu <abhsahu@nvidia.com>
Link: https://lore.kernel.org/r/20220829114850.4341-4-abhsahu@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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This makes the code clearer and replaces a few places trying to access a
flex array with an actual flex array.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Done mechanically with:
$ git clang-format-14 -i --lines 675:1210 drivers/vfio/pci/vfio_pci_core.c
And manually reflow the multi-line comments clang-format doesn't fix.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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500 lines is a bit long for a single function, move the bodies of each
ioctl into separate functions and leave behind a switch statement to
dispatch them. This patch just adds the function declarations and does not
fix the indenting. The next patch will restore the indenting.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/2-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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