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git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:
- Update to documents and code comments (Michael Kelley)
- Harden Vmbus (Kameron Carr)
- Rework MSHV driver page deposit logic (Mukesh Rathor)
- Vmbus kexec bug fix (Shradha Gupta)
- Miscellaneous bug fixes (Daehyeon Ko, Jiale Yao, Sasha Levin)
* tag 'hyperv-next-signed-20261028' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
Drivers: hv: Remove leftover support for old Hyper-V versions
mshv: Remove unused *_old memory deposit functions
mshv: Redesign hypervisor memory deposit logic
mshv: Rename memory deposit memory functions to _old
mshv_vtl: reject poll files with multiple waitqueues
mshv_vtl: detach poll waiter on POLLFREE
mshv_vtl: initialize poll file mutex before device registration
Documentation: hyperv: Update information on guest CPU offlining
Documentation: hyperv: Remove support for guests on Hyper-V 2012/2012R2
Drivers: hv: Run VMBus kexec cleanup from syscore shutdown
kexec: Add helper to report an active kexec reboot
tools: hv: remove unused rte_smp_mb()
Documentation: hyperv: Update documentation for sending VMBus packets
Drivers: hv: vmbus: Check ACPI companion before use
Documentation: hyperv: Describe validation of the ring buffer indices
Drivers: hv: vmbus: Keep the ring byte counts sane for a bad index
Drivers: hv: vmbus: Compute ring byte counts from a caller-held snapshot
Drivers: hv: vmbus: Use *_ONCE() to access shared ring buffer indices
Drivers: hv: vmbus: Bounds check the shared ring buffer indices
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When removing support for running Linux guests on Windows Server
2008/2008R2 and Windows 7, one area was missed due to the code
comment spelling "2012" incorrectly. Remove that functionality now.
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux
Pull IOMMU updates from Joerg Roedel:
"Core:
- Detect scatterlist length overflows and finalize deferred domain
attachments before mapping MSI pages
- Consolidate x86 MSI reserved-region handling and clean up internal
DMA and SVA helpers
AMD IOMMU:
- Add IOMMU PerfOpt support, enabled by amdgpu for supported
integrated GPUs in identity domains
- Restrict forced identity mapping to GPUs that require it
- Fix kdump device-table allocation and reuse, ATS configuration
error handling, and an interrupt-remapping allocation leak
- Clean up device probing and initialization
- Add Vasant Hegde as an AMD IOMMU maintainer
ARM SMMUv2:
- Device-tree binding updates for Qualcomm Maili and Nord SoCs
ARM SMMUv3:
- Work around hardware integration issue on Google Tensor G5 SoCs
where all DMA transactions appear as instruction fetches
- Allow command queue size to be configured on the kernel
command-line
- Reduce queue sizes when running as a kdump kernel
- Fix some pre-existing issues in the driver and kunit tests reported
by Sashiko
- Fix handling of Arm hardware errata relating to the contiguous hint
when using SVA
- Rework the TLB invalidation logic in preparation for enabling
iommu-pt in future
- Minor cleanups in preparation for improving support for kdump
Apple DART:
- Support device-tree DMA aperture specifications
Broadcom:
- Add BCM2712 IOMMU support for Raspberry Pi 5 display and multimedia
devices, including the generic page-table format and shared TLB
cache management
Hyper-V:
- Add a para-virtualized guest IOMMU driver with guest-managed
stage-1 page tables and page-selective IOTLB invalidation
Intel VT-d:
- Enhanced IQE fault handling for batched multiple descriptors,
- Optimization of page-table level calculation in
compute_vasz_lg2_ss(),
- Fixes for several pre-existing issues reported by Sashiko,
- General cleanup and refinement
RISC-V:
- Report cache-coherency capability for coherent devices, enabling
VFIO/iommufd use
Samsung Exynos:
- Support SysMMUs without BLOCK mode, fixing their enable sequence
and TLB invalidation
- Improve v7 fault diagnostics with transaction information"
* tag 'iommu-updates-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux: (69 commits)
MAINTAINERS: Make Vasant Hegde AMD IOMMU maintainer
iommu/hyperv: Make hv_iommu_device static
iommu/hyperv: Add missing PCI dependency for the guest IOMMU driver
iommu/amd: Don't allocate kdump device table from DMA32
iommu/amd: Program device table when kdump reuse fails
iommu/dma: Clean up redundant MSI cookie check
iommu/dma: Catch scatterlist length overflows
iommu/hyperv: Add page-selective IOTLB flush support
iommu/hyperv: Add para-virtualized IOMMU support for Hyper-V guest
iommu/x86: Add architectural MSI reserved region helper
Drivers: hv: Add logical device ID registry for vPCI devices
hyperv: Introduce new hypercall interfaces used by Hyper-V guest IOMMU
iommu: Make iommu-dma helpers private
iommu/arm-smmu-v3: Don't rb_erase() a never-inserted stream node
iommu/arm-smmu-v3: Add Q_POS() macro
iommu/arm-smmu-v3: Add arm_smmu_attach_release()
iommu/arm-smmu-v3: Disable the impl before disabling the SMMU on shutdown
iommu/arm-smmu-v3: Populate the tlbi at the top of the call chain
iommu/arm-smmu-v3: Precompute the invalidation commands
iommu/arm-smmu-v3: Keep track in arm_smmu_invs if range invalidation is used
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Remove the renamed *_old functions, done for ease of review.
Signed-off-by: Mukesh R <mrathor@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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The current memory deposit implementation has a few issues and bugs:
o It is very slow: one of the main contributions to slow VM creations
and boot is many hypercalls repeatedly coming back with insufficient
memory. On Hyper-V, a hypercall returns with such status whenever it
cannot complete due to lack of memory in the hypervisor and needs more.
o Contiguous range requirement is broken, and is critical bug
o An incorrect assumption is made that contiguous memory size would
always be power of 2.
o Two pages are allocated, only one is really needed. Extra alloc adds
to the overhead.
o For a 512 page deposit, the allocation is split into two: one for 511
and second for 1. Thus, an order 9 allocation never happens. A
contiguous 2M range, if possible, greatly improves performance
in the hypervisor as it can be mapped as large page whenever possible.
Also, removing extra allocation reduces overhead in linux.
o Since a page is already allocated to collect the frames, there is
not really a need to use per cpu input page, and hence avoid local
irq disable.
o In hv_call_deposit_pages(), in case of error, under err_free_allocations
label, all pages are freed without checking status to see if some pages
were deposited. This is a critical bug as it would free pages that hyp
may be using.
All of above is addressed by:
o Allocate 2M by default, this is the recommendation from the hypervisor
team, and greatly improves performance. Depositing one or few pages
at a time results in lot of insufficient memory returns from hypercalls.
o Always start with a full 2M range allocation, thus getting contiguous if
available. In cases where possible, the deposits are much faster.
o Allocate only one page in the deposit function and collect 511 pfns
there. Just use a local variable for last pfn.
o Use the page as input to hypercall. Since this page is locally allocated,
irq disable can be avoided helping speed up the deposit.
o Fix the physical contiguous memory enforcement..
o Lastly, remove pre-deposits hv_call_create_vp() and
hv_call_initialize_partition() as they were removed internally while
ago, most likely because they didn't help much.
Signed-off-by: Mukesh R <mrathor@linux.microsoft.com>
Reviewed-by: Souradeep Chakrabarti <schakrabarti@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Rename hv_call_deposit_pages() and hv_deposit_memory_node() to _old
to make reviewing the new functions much easier.
Signed-off-by: Mukesh R <mrathor@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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MSHV_SET_POLL_FILE invokes a file descriptor poll callback with a poll
table backed by a single embedded wait entry. A poll callback may,
however, register the table with more than one waitqueue. pipe_poll()
does this naturally for an O_RDWR FIFO.
The second registration currently warns but then inserts the same list
node into another list. The new insertion overwrites the entry links while
the first waitqueue still points at it, corrupting the first waitqueue and
causing an invalid callback traversal when that queue wakes.
Reject a second distinct waitqueue, remove the first registration through
the common removal helper, and return -EINVAL from the ioctl. Repeated
registration of the same waitqueue is treated as a no-op. A rejected
replacement leaves the CPU slot unregistered, consistent with the existing
remove-before-register ordering. Single-waitqueue users such as the OpenHCL
io_uring poll file keep their existing behavior.
An LLM assisted the source audit, fix development, and validation of this
issue.
Fixes: 7bfe3b8ea6e3 ("Drivers: hv: Introduce mshv_vtl driver")
Cc: stable@vger.kernel.org
Signed-off-by: Daehyeon Ko <4ncienth@gmail.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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MSHV_SET_POLL_FILE keeps a poll wait entry after the ioctl returns. A
file reference does not always pin the registered waitqueue:
signalfd_poll() uses current->sighand->signalfd_wqh, whose lifetime is
tied to the task.
signalfd_cleanup() sends POLLFREE before the sighand is freed. The MSHV
callback currently leaves its entry linked, so __wake_up_pollfree()
warns and a later replacement calls remove_wait_queue() through a stale
wqh pointer. A source-equivalent KASAN run reproduced:
BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave
_raw_spin_lock_irqsave
remove_wait_queue
harness_ioctl [mshv_pollfree_harness]
The object belonged to sighand_cache and had been released through
slab_free_after_rcu_debug() after __cleanup_sighand().
On POLLFREE, unlink the entry under the provider waitqueue lock. Preserve
the existing CPU cancellation before publishing a NULL wqh, since a NULL
load lets a racing replacement reuse the persistent poll state. Use a
matching acquire load under RCU when removing a normal registration.
The callback takes no mutex and does not sleep, so the existing
mutex-to-waitqueue-lock order is unchanged.
An LLM assisted the source audit, fix development, and validation of this
issue.
Fixes: 7bfe3b8ea6e3 ("Drivers: hv: Introduce mshv_vtl driver")
Cc: stable@vger.kernel.org
Signed-off-by: Daehyeon Ko <4ncienth@gmail.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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mshv_vtl_init() registers /dev/mshv before initializing the poll file
mutex. A concurrent MSHV_SET_POLL_FILE ioctl can therefore attempt to lock
an uninitialized mutex while module initialization is still in progress.
Initialize the file-scope mutex statically so it is ready before the misc
device becomes visible.
Fixes: 7bfe3b8ea6e3 ("Drivers: hv: Introduce mshv_vtl driver")
Signed-off-by: Jiale Yao <yaojiale02@163.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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ARM64 Hyper-V guests do not run the VMBus kexec cleanup before
secondary CPUs are stopped. Consequently, the old VMBus connection
and SynIC state remain active when the kexec kernel starts.
Run the VMBus kexec handler from the existing VMBus syscore shutdown
callback. syscore_shutdown() runs after device shutdown and before
machine shutdown, while all CPUs needed by the SynIC CPU hotplug
teardown are still available. Guard the callback with
kexec_is_in_progress() so normal restart, halt, and poweroff paths are
unchanged.
Use the same path on x86 and remove the architecture-specific handler
pointer and the weak setup/remove interfaces. VMBus teardown now
precedes hv_stimer_global_cleanup() on x86.
The new x86 ordering relies on commit be0cfab740e5 ("clocksource:
hyper-v: Remove support for stimer interrupts in message mode"), which
removed the synthetic timer's dependency on VMBus message delivery.
Older kernels that retain message-mode stimer interrupts must preserve
the existing x86 ordering and therefore require an ARM64-specific
backport.
Document the VMBus cleanup path and its position in shutdown ordering.
Fixes: 9bbb888824e3 ("arm64: hyperv: Initialize hypervisor on boot")
Link: https://lore.kernel.org/all/20260814093133.3191250-1-shradhagupta@linux.microsoft.com/
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Suggested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Shradha Gupta <shradhagupta@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Bradley Morgan <brads@mainlining.org>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Platform drivers can be forced to bind to devices outside their match
tables through driver_override. vmbus_acpi_add() assumes that every bound
device has an ACPI companion and dereferences it without checking.
Return -ENODEV when the companion is absent to avoid a NULL pointer
dereference.
Signed-off-by: Jiale Yao <yaojiale02@163.com>
Fixes: 9c8434238041 ("Drivers: hv: vmbus: Convert acpi_device to more generic platform_device")
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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The remaining users of the shared indices can't cause a bad memory
access with the channels a CoCo VM accepts today, but an out-of-range
index gives them a nonsense byte count. Give them defined behavior
instead.
hv_pkt_iter_first() bounds its memcpy() by hv_pkt_iter_avail(), which
is derived from write_index, and by pkt_buffer_size, which comes from
max_pkt_size and can exceed ring_datasize. A bad write index can then
make it read past the end of the ring. Only KVP has such a max_pkt_size
(16K on a 12K ring with 4K pages), and vmbus_is_valid_offer() rejects
it in isolated VMs, so this is latent. hv_pkt_iter_avail() now reports
an empty ring for a bad write index and logs it, rate-limited like
hv_ringbuffer_write(). It takes the channel instead of the ring so the
message can include the relid.
hv_get_bytes_to_read() and hv_get_bytes_to_write() now return 0 for a
bad index, so callers see nothing to read and no room to write. This
also stops hv_end_read() from reporting data that hv_pkt_iter_first()
won't return, which would keep a channel rescheduling its callback.
hv_pkt_iter_close() only uses the indices to decide whether to signal
the host, so skip the signal if either is out of range.
Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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hv_get_ringbuffer_availbytes() reads the indices directly, so a caller
that also wants the index values has to read them a second time. The
host can change them in between, resulting in the byte counts and the
indices reflecting two different states of the ring.
Replace it with hv_ringbuffer_avail_write() and
hv_ringbuffer_avail_read(), which take the indices as arguments and
return a single count. They are separate because most callers want only
one of the two values. Use them in hv_ringbuffer_write() in place of the
open-coded equivalent. hv_get_bytes_to_read(), hv_get_bytes_to_write()
and hv_pkt_iter_avail() duplicated the same arithmetic, so put the
helpers in include/linux/hyperv.h and use them there too.
Add a hv_ringbuffer_indices_invalid() helper that bounds checks a pair
of read and write indices, and use it for the check in
hv_ringbuffer_write(). Convert the remaining callers to use a single
snapshot:
- hv_ringbuffer_get_debuginfo() now reports the indices and the
computed byte counts from the same snapshot.
- hv_pkt_iter_close() computes the free space from priv_read_index
instead of re-reading the shared read index. The two agree unless a
misbehaving host has rewritten the value.
No functional change intended for a well-behaved host.
Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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The ring buffer read/write indices live in a page shared with the host,
so the compiler must not split, merge or refetch accesses to them. Add
READ_ONCE()/WRITE_ONCE() in hv_set_next_write_location(),
hv_pkt_iter_close(), hv_get_bytes_to_read() and hv_get_bytes_to_write().
The accesses in hv_ringbuffer_get_debuginfo() are left to the next
patch.
Drop hv_get_ring_bufferindices(). It has one caller and is a one-line
expression on the write index. Inlining it moves the access to the call
site, so hv_ringbuffer_write() can reuse its validated snapshot of that
index, old_write, rather than reading the shared memory a second time.
No functional change intended for a well-behaved host.
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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In a CoCo VM the host is untrusted. Since the VMBus ring buffer read and
write indices live in shared memory, the guest has to treat both as
potentially malicious.
hv_ringbuffer_write() copies into the ring at write_index with no bounds
checking, so the host can make the guest write packet data at any offset
up to 4 GiB past the start of the ring buffer. read_index matters too:
the available space derived from both indices is the only bound on how
much is copied, and an out-of-range index can make it far larger than
the ring.
The fix is to validate both indices before use and to use the validated
snapshot instead of re-accessing. For invalid indices,
hv_ringbuffer_write() logs and returns -EIO.
One re-read of write_index is left unchecked in this patch:
hv_get_ring_bufferindices() fetches it again for the prev_indices
trailer. The value is only returned to the host and is not used as an
offset or length for indexing. Since this is not a security issue, it is
addressed later in the series.
Open-coding the bytes available arithmetic keeps the fix free of
prerequisites; a later patch refactors it into a helper function.
Fixes: 3e7ee4902fe6 ("Staging: hv: add the Hyper-V virtual bus")
Cc: stable@vger.kernel.org # 5.15.x
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
"Here are the arm64 updates for 7.4.
The more interesting bits are the removal of big-endian kernel support
(already marked BROKEN for some time), preemptible this_cpu_*()
operations and MPAM support for the firmware-backed (Fb) interface.
CCA (Arm's confidential compute) is slowly trickling in with host RMI
(Realm Management Interface) support and some refactoring, including a
dedicated SMCCC bus to advertise firmware services. There are also the
usual PMU updates for new hardware and a few fixes/cleanups.
Core features:
- Remove big-endian kernel support: CONFIG_CPU_BIG_ENDIAN has
depended on BROKEN for a while, so drop the remaining code (BE
hypervisor object, BPF JIT, assembly/crypto/library routines,
endianness helper macros, selftests) and force a little-endian
build
- Add preemptible this_cpu_*() operations (read/write, RMW, xchg,
cmpxchg and cmpxchg128) that no longer need to disable preemption
around the per-CPU address generation and access
- Preparation patches for implementing CONFIG_HOTPLUG_PARALLEL on
arm64
Memory management:
- Treat faults taken by EFI runtime firmware as kernel faults
- Clear PTE_WRITE for EFI_MEMORY_RO mappings (with hardware dirty
state management enabled, this is not truly read-only)
- Raise the default ARCH_MMAP_RND_BITS for 48-bit and 52-bit VA
configurations (28/26/24 bits for 4K/16K/64K pages)
- Implement clear_page[s]() using memset()
- Enable BBML2 no-abort (a.k.a. BBML3) for the NVIDIA Rigel CPU
Perf and PMU:
- Support for HiSilicon's ITS PMU
- Add support for some new events: INST_SIMD_ALU_VEC for Apple PMUs
and a cycle counter for the latest version of HiSilicon's MN PMU
hardware
- A bunch of fixes to the CXL PMU driver to address pre-existing
issues from Sashiko
- Fix generation of PERF_RECORD_ITRACE_START records for SPE and ETM
drivers
- Reduce excessive stack consumption in the Marvell DDR PMU driver
- Minor driver updates and cleanups all over
Arm Confidential Compute Architecture (CCA):
- Add an Arm SMCCC bus for firmware services discovered through SMCCC
and move the TRNG and CCA guest (TSM provider) drivers onto it,
removing the dummy CCA platform device and adding a sysfs ABI for
Realm guests
- Move the Realm Service Interface (RSI) code out of arch/arm64/ into
drivers/firmware/arm_rmm/
- Add the host side of the Realm Management Interface (RMI): detect,
configure and activate the RMM, add SRO support and wrappers for
the Realm RMI commands
- Block hibernation (new arch hook in the PM core) and kexec while
the RMM is active. To be revisited in the future with proper
support for deactivation
- Handle Granule Protection Faults (GPFs) taken by the host, caused
by accesses to memory delegated to the RMM. In a future patch, the
exception table lookup will be limited to is_kdump_kernel() cases
MPAM (Memory Partitioning And Monitoring):
- Add support for the MPAM firmware-backed (Fb) interface, allowing
MSC accesses to be mediated by firmware
- Fix a list of theoretical issues with the driver (MSC access error
propagation, MBWU monitor save/restore and locking, resctrl class
handling, error interrupt restore, maximum number of PARTIDs)
- Add the mailing list and a missing file to the MAINTAINERS entry
- Document when to set arm64.nompam
Errata and CPU features:
- Add the NXP i.MX8QM/8QP workaround for the Cortex-A53 cache
coherency issue (ERR050104), using a new ARM64_CPUCAP_SOC_ERRATUM
capability type for SoC-level errata
Miscellaneous:
- Mask debug exceptions (DAIF) around the hardware breakpoint
register manipulations when called from generic kernel code
- Don't zero the SVE state buffer when the SVE state is live
- Return -EPERM instead of -EBUSY from the GCS prctl() locking
failures (matching x86), with the selftest updated. Slight ABI
change but no software deployment yet
- kselftest: fix unsound MTE fault skipping by introducing MTE-safe
memory accessors, avoid copying each signal test binary more than
once
- Update sysreg definitions (fix three enum values and two field
names, mark architecturally dropped fields as RES0) and remove the
TME transaction state check from the BRBE driver
- Fix the description of ARM64_HAS_LPA2 and remove a redundant
ID_AA64MMFR0 define"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (144 commits)
arm64: cpufeature: Enable BBML2 for NVIDIA Rigel
arm64: cputype: Add NVIDIA Rigel definitions
arm64: raise default ARCH_MMAP_RND_BITS for 48-bit and 52-bit VA
arm64/debug: mask debug exceptions when called from common code
kselftest/arm64: signal: copy each test binary only once
kselftest/arm64: Check for -EPERM not -EBUSY in the locking test
arm64: gcs: Return -EPERM not -EBUSY for prctl() locking failures
perf: arm_brbe: Remove the check for TME transaction states
arm64: sysreg: Mark fields the architecture dropped as RES0
arm64: sysreg: Fix the names of two misspelt fields
arm64: sysreg: Fix three incorrect enum values
arm64: smp: Defer RCU registration during secondary CPU bringup
arm64: smp: Don't bother printing the I-cache policy for each CPU
arm64: smp: Defer update of secondary CPU capabilities
arm64: smp: Tidy up cpuinfo init and cpufeature updates
arm64: smp: Tidy up smp_prepare_cpus()
arm64: cpufeature: Store every ID register with its overrides applied
arm64: cpufeature: Read MPAMIDR_EL1 in __cpuinfo_store_cpu()
arm64: cpufeature: Add read_cpuid_with_overrides()
arm64: cpufeature: Check arm64_ftr_regs[] before the first store
...
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'hyper-v', 'samsung/exynos', 'riscv', 'broadcom', 'intel/vt-d', 'amd/amd-vi' and 'core' into next
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Hyper-V identifies each PCI pass-thru device by a logical device ID in
its hypercall interface. This ID consists of a per-bus prefix, derived
from the VMBus device instance GUID, combined with the PCI function
number of the endpoint device.
Add a registry in hv_common.c that maps a PCI domain number to its
logical device ID prefix. The vPCI bus driver (pci-hyperv) registers the
prefix when a bus is probed and unregisters it when the bus is removed.
Consumers such as the para-virtualized IOMMU driver look up the prefix
by PCI domain number and combine it with the function number to form the
complete logical device ID for hypercalls.
Use rhashtable for the sparse exact-match mapping. Lookups copy the
prefix while holding the RCU read lock, and removal defers freeing the
entry until existing readers have completed.
The prefix construction is shared via hv_build_logical_dev_id_prefix() so
that pci-hyperv's interrupt retargeting path and the registry use exactly
the same byte layout. It is derived on demand from the constant hv_device
instance GUID rather than cached in struct hv_pcibus_device, which is
private to the pci-hyperv module; this keeps the interface narrow and
avoids depending on pci-hyperv internals.
Co-developed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Signed-off-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Signed-off-by: Yu Zhang <zhangyu1@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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Hyper-V guest IOMMU is a para-virtualized IOMMU based on hypercalls.
Introduce the hypercalls used by the child partition to interact with
this facility.
These hypercalls fall into below categories:
- Detection and capability: HVCALL_GET_IOMMU_CAPABILITIES is used to
detect the existence and capabilities of the guest IOMMU.
- Device management: HVCALL_GET_LOGICAL_DEVICE_PROPERTY is used to
check whether an endpoint device is managed by the guest IOMMU.
- Domain management: A set of hypercalls is provided to handle the
creation, configuration, and deletion of guest domains, as well as
the attachment/detachment of endpoint devices to/from those domains.
- IOTLB flushing: HVCALL_FLUSH_DEVICE_DOMAIN is used to ask Hyper-V
for a domain-selective IOTLB flush (which in its handler may flush
the device TLB as well).
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Co-developed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Signed-off-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Co-developed-by: Yu Zhang <zhangyu1@linux.microsoft.com>
Signed-off-by: Yu Zhang <zhangyu1@linux.microsoft.com>
Reviewed-by: Jacob Pan <jacob.pan@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
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Now that arm64 no longer supports a big-endian kernel, simplify some
driver Kconfig entries so that the dependency on a little-endian kernel
no longer needs to be called out explicitly.
Reviewed-by: Michael Kelley <mhklinux@outlook.com> # Hyper-V
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Will Deacon <will@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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Register-page setup is optional for each CPU. If allocation or
registration fails, mshv_vtl_configure_reg_page() warns and leaves that
CPU's reg_page NULL, but initial context setup continues successfully.
Meanwhile, successful setup on another CPU sets the global
mshv_has_reg_page flag.
mshv_vtl_fault() checks this global flag before selecting the requested
CPU's register page. With mixed setup results across online CPUs, the
check passes even for a CPU with no register page, reaching
get_page(NULL) when userspace faults in that mapping.
Check the selected per-CPU register page before taking its reference and
return VM_FAULT_SIGBUS if it is absent.
Fixes: 7bfe3b8ea6e3 ("Drivers: hv: Introduce mshv_vtl driver")
Cc: stable@vger.kernel.org
Signed-off-by: Hardik Garg <hargar@linux.microsoft.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Correct "substract" to "subtract".
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Hemanth Selam <hemanth.selam@gmail.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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In two places, current code forces vmbus_connection.conn_state to
DISCONNECTED prior to calling vmbus_disconnect(). But vmbus_disconnect()
calls vmbus_initiate_unload(), which unloads the VMBus connection
only if the conn_state is CONNECTED. Consequently, the connection
remains and the Hyper-V host might continue to send messages or post
VMBus interrupts.
The problem was introduced in commit 74347a99e73ae ("x86/Hyper-V:
Unload vmbus channel in hv panic callback"), in that
vmbus_initiate_unload() started checking the current connection
state before doing the unload. This commit removed some occurrences
where conn_state was forced to DISCONNECTED, but these two remained,
apparently due to an oversight at the time.
Fix this by not forcing conn_state to DISCONNECTED during VMBus exit,
or if a failure occurs when establishing the connection in the first
place. Whatever value conn_state has at the time is then read by
vmbus_initiate_unload() to determine if there is a connection to
be unloaded.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/linux-hyperv/20260805205806.B5AC31F000E9@smtp.kernel.org/
Fixes: 74347a99e73ae ("x86/Hyper-V: Unload vmbus channel in hv panic callback")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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The removal of stimer message mode in commit be0cfab740e5 ("clocksource:
hyper-v: Remove support for stimer interrupts in message mode") left a
few comments out of date. hv_stimer_setup_percpu_clockev() picked up two
typos ("afters", "to allows"), and the hv_synic_suspend() comment still
references the deleted hv_stimer_legacy_cleanup(), the legacy non-Direct
Mode configuration, and clockevents_unbind_device(), which is no longer
on the cleanup path.
Update the typos and rewrite the hv_synic_suspend() comment to describe
the current Direct Mode path: non-boot CPU stimers are cleaned up via
the cpuhp teardown callback hv_stimer_cleanup(), and CPU0's stimer is
left alone because it is harmless (interrupts stay disabled across the
suspend/resume window) and is shut down later by the timekeeping code.
Signed-off-by: Jiangshan Yi <yijiangshan@kylinos.cn>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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There is a retry loop in init_vp_index() where the CPUs from a certain
node are stripped out if they have already been in the allocated cpumask
or not in HK_TYPE_MANAGED_IRQ housekeeping cpumask. If there is no
CPU left, the allocated cpumask is ignored and the process is retried
again. However, if the HK_TYPE_MANAGED_IRQ housekeeping cpumask turns
out not to contain any CPU in that particular node, that will become an
infinite retry loop. This particular problem was reported by sashiko
[1]. This should rarely happen, but we still need to guard against this.
Fix this infinite loop problem by also skipping NUMA node that has no
housekeeping CPU in the inner while loop of init_vp_index(). Also update
the early abort check to check for the absence of online housekeeping
CPUs instead of just the emptiness of the cpumask. As the outer for
loop will only be reached if the housekeeping cpumask has at least one
online CPU, a NUMA node with housekeeping CPUs will eventually be found.
Link: https://sashiko.dev/#/message/20260422030903.E1BFCC2BCB0%40smtp.kernel.org [1]
Fixes: 6640b5df1a38 ("Drivers: hv: vmbus: Don't assign VMbus channel interrupts to isolated CPUs")
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michael Kelley <mhkelley@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci
This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.
Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.
Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <kees+treewide@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:
- Decrypt netvsc buffer on contiguous direct-map addresses (Kameron
Carr)
- Drop WS2012/2012R2 & Win8/8.1 Hyper-V support (Michael Kelley)
- Use more meaningful errnos for hypercall status code (Hardik Garg)
- Fix lost interrupts on CPU hot-unplug for Hyper-V PCI/MSI (Naman
Jain)
- Reserve more MSHV vectors for Linux root partition (Wei Liu)
* tag 'hyperv-next-signed-20260826' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
clocksource: hyper-v: Remove support for stimer interrupts in message mode
scsi: storvsc: Remove support for storvsc protocol of old Hyper-V hosts
hv_netvsc: Remove GPADL teardown special case for old Hyper-V hosts
hv_sock: Remove check for old Hyper-V hosts
Drivers: hv: Remove support for WS2012/2012R2 & Win8/8.1 version of Hyper-V
hv_netvsc: Allocate send/receive buffers using vmbus_alloc_buffer()
Drivers: hv: vmbus: Add vmbus_alloc_buffer()/vmbus_free_buffer() for CoCo VMs
Drivers: hv: vmbus: add vmbus_establish_gpadl_caller_decrypted()
Drivers: hv: vmbus: Skip VMBus module cleanup for non-nested root partition
x86/hyperv: reserve more vectors
PCI: hv: Set irq_retrigger callback for the Hyper-V PCI MSI irqchip
Drivers: hv: Use meaningful errnos for hypercall status codes
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In Hyper-V versions prior to WS2016/Win10, Hyper-V synthetic timers
interrupt the guest by delivering a message that is initially handled
by the Linux VMBus driver. Starting with WS2016/Win10, Hyper-V can
deliver stimer interrupts directly to an assigned interrupt vector
without involving the VMBus driver. This is called "Direct Mode".
With the overall removal of Linux support for running on Hyper-V
hosts earlier than WS2016 and Windows 10, it's no longer necessary
to support the legacy message-based delivery. Remove that delivery
mechanism and always use Direct Mode. If for some reason, the
Hyper-V host does not enumerate Direct Mode, output an error
message but continue to run using the LAPIC timer instead of an
stimer.
With these changes, the VMBus driver no longer calls the stimer
interrupt service routine. This removal has a broader benefit in
unblocking the disentangling of VMBus code and stimer code, as
they should be independent of each other. The final disentangling
will come as a follow-on patch set.
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Linux code for running as a Hyper-V guest includes special cases for
running on Hyper-V in WS2012/2012R2 and Windows 8/8.1. These versions
were initially released 14 years ago, and official support ended in 2023
(unless a customer has contracted for extended security updates). Given
the release of subsequent versions with improved functionality, there's
no need to continue to support the latest Linux kernels on these versions
of Hyper-V. If someone is running Linux on one of these older Hyper-V
versions and doesn't want to upgrade, they can continue to do so as
presumably they don't want upgrade the Linux version either.
Simplify Linux code by removing special cases for running on these
old versions of Hyper-V. Remove the negotiation of the VMBus protocol
versions for WS2012/Win8, and remove special case code based on those
VMBus protocol versions. Also update the balloon and snapshot drivers
to no longer negotiate driver-specific protocol versions for these
older Hyper-V versions, and remove any related special cases.
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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On CoCo VMs without confidential VMBus, the netvsc send and receive buffers
must be made host-visible by decrypting them. These buffers are vmalloc'ed,
but set_memory_decrypted()/encrypted() do not work on vmalloc'ed memory.
This use case is (so far) unique to netvsc, so solve it locally rather than
changing the set_memory() or allocation APIs.
Add vmbus_alloc_buffer()/vmbus_free_buffer() to the VMBus core. When the
guest's isolation model requires it, allocate the buffer as a list of
physically-contiguous chunks via alloc_pages_node(), starting at
MAX_PAGE_ORDER and falling back to smaller orders so the allocation still
succeeds under memory fragmentation. Each chunk is decrypted in place via
set_memory_decrypted() on its direct-map address, and the chunks are then
stitched into a single virtually-contiguous range with vmap(). Buffers that
do not need decryption keep using vzalloc().
To free the buffer, vmbus_free_buffer() calls vunmap() on the range then
re-encrypts and frees each chunk individually; any chunk that fails
re-encryption is leaked to prevent accidentally freeing decrypted memory.
This approach minimizes scattering of decrypted 4 KiB pages through the
kernel direct map and the resulting shattering of large page mappings.
Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Add a new vmbus_establish_gpadl_caller_decrypted() for callers that want to
decrypt their own buffers. Add a new hv_gpadl_type,
HV_GPADL_BUFFER_DECRYPTED, to communicate the decryption status of the
buffer.
No functional change for existing callers.
Signed-off-by: Kameron Carr <kameroncarr@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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The VMBus module initialization function, hv_acpi_init(), currently
does nothing when running in the root partition and root is not nested
in another VM. But the initialization function reports success, so the
VMBus module is indeed loaded. VMBus functionality is not actually
needed, but the VMBus module must be loaded so that hv_vmbus_exists()
can answer correctly. Furthermore, the mshv_root dependency on the
VMBus module is needed as described in the commit message for
840b740a35bf ("mshv: Add conditional VMBus dependency").
Loading the VMBus module without actually initializing it causes
failures if the module should later be unloaded. The module unload code
tries to clean up things that were never initialized, resulting in
memory faults and a panic.
Fix this by having VMBus module exit function perform the same
check for non-nested root partition, and do nothing in such a
case, just like hv_acpi_init().
In the long run, the code that manages the Hyper-V provided SynIC
should be refactored to better coordinate the requirements of
root partition scenarios and normal VM scenarios, and to hopefully
remove the hv_vmbus_exists() dependnecy between mshv_root and
VMBus modules. Preventing the current unload failure scenario is
an expediency until such a refactoring is done.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/linux-hyperv/20260721154943.A09BD1F00A3D@smtp.kernel.org/
Fixes: 7e279d78664aa ("Drivers: hv: vmbus: skip VMBus initialization if Linux is root")
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Commit 3817854ba892 ("hyperv: Log hypercall status codes as strings")
converted hv_result_to_errno() from a switch to a table and added status
codes used for string logging. Statuses without an existing specific
mapping were assigned the generic -EIO fallback even when a more specific
errno was available.
Map HV_STATUS_ACCESS_DENIED and HV_STATUS_OPERATION_DENIED to -EACCES,
HV_STATUS_UNKNOWN_PROPERTY and HV_STATUS_PROPERTY_VALUE_OUT_OF_RANGE to
-EINVAL, and HV_STATUS_PROCESSOR_FEATURE_NOT_SUPPORTED to -EOPNOTSUPP.
This lets callers distinguish permission, argument, and capability
failures from generic I/O errors.
The table conversion also added duplicate HV_STATUS_INVALID_LP_INDEX and
HV_STATUS_INVALID_REGISTER_VALUE entries. Remove the later -EIO entries,
which are unreachable because find_hv_status_info() returns the first
match.
Signed-off-by: Hardik Garg <hargar@linux.microsoft.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm: drop "sub" prefix from various places" (Dev Jain)
page->folio conversion and a naming cleanup
- "mm/kasan: remove redundant initialization for kasan_flag_write_only"
(Igor Putko)
KASAN cleanup work
- "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)
Small speedup in the pagecaache read code
- "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)
Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
allocations when the caller asked for GFP_NOFS or GFP_NOIO
- "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
Leitao)
Avoid a soft lockup watchdog trigger from the kmemleak scanning code
in extreme situations
- "mm/page_owner: misc cleanups" (Ye Liu)
Cleanups to the page_owner code. For some reason lots of people have
been working on the page_owner code this cycle.
- "mm: convert to walk_page_range_vma() to eliminate find_vma()"
(Kefeng Wang)
Simplify and accelerate the page walking library function
- "mm/migrate: preparatory cleanups for batch copy and offload"
(Shivank Garg)
Cleanups in the migration code
- "mm/page_owner: add per-fd filter infrastructure for print_mode and
NUMA filtering" (Zhen Ni)
Per-fd filtering to page_owner in order to reduce the sometimes vast
amount of output it can produce
- "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)
Fixes and preparatory cleanups around bootmem HugeTLB handling,
sparse initialization ordering, and related vmemmap setup
- "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)
Reduce lock contention in zs_free(), which dominates the unmap path
under memory pressure on Android (LMK kills) and on x86 servers
running zswap-heavy workloads.
Up to 1.83x improvement in microbenchmarking.
- "move alloc_tag.c file under mm/" (Suren Baghdasaryan)
- "samples/damon: handle damon_{start,stop}() failures" (SJ Park)
Fix improper handling of damon_start(), damon_stop(), and
damon_call() failures across DAMON sample modules to prevent
potential memory leaks, operation disruptions and use-after-free
bugs
- "mm/damon/sysfs: kobject_del() directories that users can
create/remove" (SJ Park)
Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
causeing creation failures due to duplicate directory names by adding
missing kobject_del() calls before creating new directories
- "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)
Clean up the core pte handling code
- "selftests/damon: misc fixes for test bugs" (Kunwu Chan)
Fix several bugs in the DAMON selftests
- "selftests/damon: fix memcg_path staging handling" (Cheng Nie)
Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
add a test case for it in sysfs.py.
- "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)
Selftest coverage for DAMON's refresh_ms sysfs feature by updating
the test control module and verifying that scheme stats update
automatically without manual intervention
- "mm/damon: five misc fixups" (Akinobu Mita)
Miscellaneous DAMON fixups.
- "mm/damon/core: detect internal variation above max_nr_regions/2"
(Jiayuan Chen)
Fix DAMON's region splitting behavior when region counts exceed half
the maximum budget by dynamically scaling down the split fraction as
the limit approaches, preventing large regions from staying un-split,
and add corresponding KUnit test coverage
- "mm: preparatory patches for PMD level swap entries" (Usama Arif)
Refactor and clean up PMD softleaf helpers, call sites, and
architecture flags to lay the groundwork for a follow-up series that
introduces PMD page table swap entries
- "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
Park)
Update DAMON design and ABI documentation, expands unit and selftest
coverage, optimize damon_commit_target_regions(), and clean up
recently added sysfs interface code for better readability
- "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
(Usama Arif)
Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
userspace event notifications and refactor v1-only eventfd handling
into mm/memcontrol-v1.c to reduce memory overhead and code complexity
- "selftests/mm: refactor pkey helpers and fix mmap error handling"
(Hongfu Li)
Refactor pkeys shared tracing and assertion helpers into a common
file, unify protection key selftests to use consistent diagnostic
logging and assertions, and enforce standardized MAP_FAILED return
checks for mmap() calls across the tests
- "mm/damon: optimize out nr_accesses_bp" (SJ Park)
Replace the error-prone, continuously updated nr_accesses_bp field in
damon_region with an on-demand moving sum function, reducing
structure memory overhead and avoiding state corruption bugs
- "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)
Decouple HugeTLB folio allocation from VMA dependencies by
introducing hugetlb_alloc_folio(), enabling subsystems like
guest_memfd to allocate HugeTLB folios without standard VMA
reservations or pseudo-VMAs
- "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)
Integrate DAMON's probe_hits attribute counter into the pseudo moving
sum infrastructure, enabling real-time, online monitoring without
waiting for full aggregation intervals
- "mm: Some cleanups for page allocator APIs" (Brendan Jackman)
Simplify and refactor the page allocator entry points and flags by
unifying allocation paths, adding internal alloc_flags arguments, and
eliminating redundant __ prefixed alloc_pages variants.
- "Fix incorrect access of hugetlb pte entries" (Dev Jain)
Enforce the consistent use of huge_ptep_get() instead of ptep_get()
for HugeTLB entries and fixes an unaligned address issue in arm64's
huge_ptep_get() implementation
- "mm/damon: validate all parameters in the core" (SJ Park)
Consolidate parameter validation into the DAMON core specifically
within damon_start() and damon_commit_ctx() to centralize error
checking, eliminate caller-side redundant checks and to improve
maintenance efficiency
- "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
Chen)
Rename is_need() to filter_record() for clearer return semantics, fix
per-record allocation memory leaks and bound output copies in
search_pattern() to address an existing buffer issue
- "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)
Mitigate a system-wide stall which occurs when a cgroup is removed
while one of its memory control files is doing synchronous reclaim
- "mm/memory-failure: add panic option for unrecoverable pages" (Breno
Leitao)
Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
that immediately panics the kernel on unrecoverable memory errors in
kernel-owned pages to preserve error context and prevent delayed,
silent data corruption
- "mm/damon: refactor damon_{start,stop,commit}() for simple error
handling" (SJ Park)
Refactor the DAMON core API functions to guarantee that all contexts
are fully stopped when damon_start(), damon_stop(), or damon_commit()
fail, eliminating the need for complex and error-prone caller-side
cleanup code
- "Keep tail page private zero at free and folio split" (Zi Yan)
Add checks to ensure tail_page->private is zero when freeing compound
or high-order pages and when promoting tail pages during large folio
splits. By validating these fields at free and split time, it allows
the removal of redundant private field clearing inside
prep_compound_tail()
- "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
Song)
Eliminate redundant lru_add_drain() calls in
wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
contention and system overhead
By validating folio refcounts against the LRU cache before draining
and removing unnecessary drains in the swap path, it achieves up to a
30.5% reduction in drain calls during heavy swap workloads
- "mm: clean up folio LRU and swap declarations" (Jianyue Wu)
Reorganize folio LRU and swap code by relocating page-cluster state
to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
MM-internal reclaim declarations into mm/internal.h.
- "userfaultfd: working set tracking for VM guest memory" (Kiryl
Shutsemau)
Add userfaultfd support for tracking the working set of VM guest
memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
Hildenbrand)
Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
performing some smaller cleanups around freeing of reserved vmemmap
pages on the way.
- "mm/damon: update probe hits for runtime parameter commits" (SJ Park)
Ensure that DAMON's probe_hits attribute counter is properly updated
when monitoring intervals are changed at runtime, matching the
behavior of nr_accesses. To achieve this, it refactors and renames
existing helper functions for shared use, applies the updates to
probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
maintain measurement accuracy.
- "KSM: performance optimizations for rmap_walk_ksm" (xu xin)
Resolve a severe KSM reverse-mapping performance bottleneck where
thousands of split VMAs sharing a single anon_vma cause extended lock
contention.
By adding an interval-filtering check during the rmap walk, it
reduces worst-case anon_vma lock hold times from over 500ms down to
under 2ms, preventing application freezes and latency spikes under
memory pressure.
- "mm: split a couple of headers from internal.h" (Mike Rapoport)
Split declarations related to mm_init, memblock, vmalloc and sparse
into new headers
- "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)
Apply the interval tree optimization from rmap_walk_ksm() to
collect_procs_ksm() to avoid iterating over non-matching VMAs during
KSM memory error handling.
It hoists loop-invariant address initialization and restricts the
anon_vma_interval_tree_foreach walk to a targeted page offset range,
reducing redundant checks and improving lookup efficiency.
- "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
Patil)
Fix issues in the hugetlb and KSM MM selftest categories that can
report failures when the prerequisites for the tests are not
satisfied
- "mm/damon: introduce data attributes only monitoring" (SJ Park)
Introduce attribute-weighted region management in DAMON, allowing
users to prioritize specific data attributes (such as page sizes or
cgroups) over or instead of access monitoring.
By assigning weights to attribute probes, DAMON can completely
disable access tracking and adjust monitoring regions based on
weighted probe-hit counters to optimize monitoring quality for
attribute-focused workloads.
- "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
(Stanislav Kinsburskii)
Extend hmm_range_fault() to support userfaultfd-backed regions by
allowing the mmap lock to be dropped during fault handling via a new
hmm_range_fault_locked() helper.
By accepting a locked pointer and signaling retry status when lock
release occurs, it enables page fault resolution in userfaultfd
regions while preserving backward compatibility for existing callers.
- "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)
Clean up and standardize how vma->vm_pgoff is accessed and
manipulated across file-backed and anonymous mappings in the kernel
It introduces dedicated helper functions such as vma_start_pgoff(),
vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
renaming rmap interval tree helpers to better reflect their
functionality.
These changes establish a cleaner foundation for future work that
will unify virtual page offset indexing for all anonymous and CoW'd
folios.
- "mm: handle device-private PMDs in walk callbacks" (Usama Arif)
Address kernel panics and state corruption caused by MM walk
callbacks reaching non-present device-private PMD swap entries
created during HMM migrations
It ensures that functions which acquire pmd_trans_huge_lock()
properly recognize device-private PMDs instead of assuming a present
THP or a standard migration entry.
- "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)
Refactor try_to_unmap_one by modularizing Hugetlb,
anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
functions, laying the structural groundwork for batched anonymous
large folio unmapping.
- "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)
Fix typos and fills in missing entries in the DAMON sysfs ABI
document
- "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)
Introduce an atomic sysfs state attribute and supporting DAX/MM
infrastructure to prevent userland races when offlining and removing
entire memory regions
By adding an unplugged state alongside standard online modes, it
enables whole-device atomic hotplug control while preserving backward
compatibility.
- "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)
Continue transitioning the kernel from the deprecated vm_flags_t type
to vma_flags_t across core memory management infrastructure.
It replaces legacy type usage in core functions such as do_mmap(),
unmapped area allocation, mm->def_vma_flags, and VMA operations like
mlock, mprotect, and mremap.
- "Two small patches to clean up mm/mm_slot.h" (xu xin)
Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
slot deletion sequences in khugepaged and KSM. It also adds code
documentation explaining why mm_slot_lookup and mm_slot_insert must
remain as preprocessor macros rather than static inline functions.
- "mm/damon/core: hide core-private struct fields" (SJ Park)
Clean up DAMON core structures by consistently marking internal-only
fields with private: comment tags to prevent improper direct access
from outer layers.
It enforces encapsulation across core structures including
damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
interact through approved access APIs instead of exposing raw struct
members.
- "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
(SJ Park)
Address potential infinite loops, NULL dereferences, and race
conditions identified in DAMON
It fixes an infinite loop triggered by extreme user configurations, a
NULL pointer dereference within unit tests and minor monitoring
accuracy degradation caused by subtle runtime races.
- "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
Jackman)
Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
via non-PCP or isolated migration paths.
It also resolves potential kernel crashes and privilege escalation
risks triggered when BPF tracing runs in NMI context alongside memory
hotplug or large allocation frees.
- "mm/page_alloc: couple of followups for recent cleanups" (Brendan
Jackman)
Clean up and update page allocator nomenclature, documentation, and
debug assertions.
It aligns internal FPI_ flags with the public "nolock" naming
convention, removes outdated internal implementation details from
high-level page allocator comments, and eliminates obsolete
VM_BUG_ON() assertions in allocation paths.
- "mm/mseal: further cleanups" (Lorenzo Stoakes)
Refactor and simplify the mseal implementation by clarifying API
boundaries and removing unnecessary code complexity.
It replaces generic do_mseal() usage outside the syscall with a
dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
eliminates mm_struct parameters to enforce that sealing applies only
to current->mm, and streamlines overall logic and comments with no
functional changes intended.
- "mm/vmscan: fix swappiness=max and clean up per-node proactive
reclaim" (Ridong Chen)
Resolve reclaim behavior bugs and clean up function parameters across
memory reclaim paths
It fixes swappiness=max in both standard reclaim and MGLRU so
unswappable anonymous memory no longer falls back to evicting page
cache, ensures reclaim_store() returns accurate error codes instead
of collapsing all failures into -EAGAIN, and removes the obsolete
gfp_mask parameter from __node_reclaim().
- "mm: mincore: misc cleanups" (Kefeng Wang)
Clean up and simplifies the mincore code. Most importantly, it
removes the historical special behavior that always reports VM_PFNMAP
pages as non-resident.
- "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)
Two trivial cleanups in the folio split API
- "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
bugs" (SJ Park)
Resolve minor operational and testing bugs in DAMON identified by
Sashiko. It initializes the damos->last_applied field to prevent
occasional efficiency degradation and fixes invalid memory accesses
in DAMON KUnit tests during test failure handling.
- "cleanup for stable_page_flags()" (Jinjiang Tu)
Clean up and refactor stable_page_flags() used by /proc/kpageflags
without altering functionality.
It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
bits, converts folio-specific flag checks to standard folio_test_*()
helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
- "Batch unmap of uffd-wp file folios" (Dev Jain)
Extend batched folio unmapping support to file folios within
userfaultfd write-protect (uffd-wp) VMAs by adding batching
capabilities to pte_install_uffd_wp_if_needed().
This removes special-case restrictions on uffd-wp VMAs in
try_to_unmap_one(), significantly simplifying the function's control
flow and complexity.
- "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
(Sang-Heon Jeon)
Clarify and clean up the architecture-specific usage of
__late_set_fixmap() and __late_clear_fixmap() after
early_ioremap_reset()
It adds explicit documentation regarding when early_ioremap_reset()
must be called and removes redundant macro definitions and reset
calls in the RISC-V and ARM64 architectures.
- "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)
Address severe performance regressions, swap storms, and spurious
OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
production
It updates the page allocator slowpath so non-movable allocation
requests actively trigger direct reclaim and direct compaction at
pageblock_order scale, allowing them to claim whole pageblocks rather
than spinning unproductively.
- "zram: lockmap tweaks" (Sebastian Siewior)
Optimize and fix lockdep tracking for zram devices by consolidating
per-entry lockmaps and isolate lock classes across multiple instances
This reduces memory overhead by replacing per-entry lockdep_map
instances with a single map per struct zram, and assigns a dynamic
lock_class_key to each instance to prevent false deadlock reports
when different zram devices are backed by distinct filesystems.
* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
selftests/mm: unpoison pages in memory-failure teardown
mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
mm/zsmalloc: fix release order of locks in zs_page_migrate()
Documentation: zram: remove sections numbering
ksm: stop iterating VMAs when ksm_test_exit returns true
mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
zram: use a custom key for each zram object
zram: move lockmap to be per-zram instead per table
selftests/mm: fix gup_longterm EINVAL error message
mm: page_alloc: fix non-movable reclaim storm in defrag_mode
mm: page_alloc: move capture_control to the page allocator
mm: compaction: support non-movable compaction for pageblock requests
mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
hugetlb: evaluate subpool free state while locked
mm/damon: remove trailing semicolons after function definitions
mm/damon/ops-common: prevent migration fallback to non-target nodes
mm/damon: update outdated comment about DAMOS filter handling
...
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MSHV currently faults movable memory regions by taking mmap_read_lock()
around hmm_range_fault(). That prevents the fault path from handling VMAs
whose fault handlers need to drop mmap_lock, such as userfaultfd-backed
mappings.
Use hmm_range_fault_unlocked_timeout() instead. Passing a timeout of 0
preserves MSHV's existing unbounded retry behavior while letting the HMM
helper own mmap_lock acquisition and refresh range->notifier_seq
internally before walking the range. After the fault succeeds, MSHV still
takes mreg_mutex and checks mmu_interval_read_retry() before installing
the pages into the region, so the existing invalidation synchronization is
preserved.
Fold the small fault-and-lock helper into mshv_region_range_fault(), since
the remaining retry path is just the standard "fault, take the driver
lock, check the interval notifier sequence" pattern.
Link: https://lore.kernel.org/20260723-hmm-v10-v11-4-c55b003a4b61@gmail.com
Signed-off-by: Stanislav Kinsburskii <skinsburskii@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lizhi Hou <lizhi.hou@amd.com>
Cc: Long Li <longli@microsoft.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Lyude <lyude@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oded Gabbay <ogabbay@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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cpu is taken from pgoff & 0xffff. cpu_online() does not reject cpu >=
nr_cpu_ids, and per_cpu_ptr() can then walk off __per_cpu_offset.
Signed-off-by: Yi Xie <xieyi@kylinos.cn>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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mshv_partition_ioctl_create_vp() called anon_inode_getfd() before
publishing the new VP into partition->pt_vp_array. anon_inode_getfd()
includes fd_install(), so the fd was live in current->files before the
publish ran.
A concurrent MSHV_RUN_VP ioctl on that fd does not serialise against the
in-progress MSHV_CREATE_VP — it takes vp->vp_mutex, not the partition
mutex. Once the VP starts running and traps, mshv_intercept_isr() can look
up partition->pt_vp_array[vp_index] and observe NULL, silently dropping the
intercept message.
Split the fd creation: reserve an fd with get_unused_fd_flags(), create the
file with anon_inode_getfile(), publish the VP via smp_store_release(), and
finally call fd_install() as the userspace-visibility commit point.
Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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VMBus sends CHANNELMSG_INITIATE_CONTACT through a Hyper-V message
connection ID. Older protocol versions use VMBUS_MESSAGE_CONNECTION_ID,
while protocol version 5.0 and newer normally use
VMBUS_MESSAGE_CONNECTION_ID_4.
For a VTL2 kernel using VMBus protocol 5.0 or newer, the host
may expect INITIATE_CONTACT on either the redirect connection ID or
VMBUS_MESSAGE_CONNECTION_ID_4. There is no capability indication that
identifies which ID is active, so the driver must determine it at runtime.
During VMBus negotiation, the redirect ID is tried first because it is
used by VTL2 configurations with VMBus redirection enabled. If the
redirect ID is unavailable, the host rejects it synchronously with
HV_STATUS_INVALID_CONNECTION_ID, allowing fallback to the standard ID.
Return a distinct error for an invalid Initiate Contact connection ID so
this fallback does not mask other post-message failures or
protocol-version rejections. Preserve the existing connection ID
selection for older protocol versions or when running below VTL2.
Signed-off-by: Hardik Garg <hargar@linux.microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Reviewed-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Naman Jain <namjain@linux.microsoft.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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mshv_partition_ioctl_create_vp() initialises a VP struct (allocations,
mutex_init, init_waitqueue_head, page mappings) and then publishes the
pointer into partition->pt_vp_array. Several ISR paths read this array
locklessly: the intercept ISR, the two scheduler ISRs, and
mshv_try_assert_irq_fast() on the irqfd fast path.
Of these, only mshv_try_assert_irq_fast() can structurally race the
publish. It runs from an eventfd waker without holding pt_mutex, and
MSHV_IRQFD does not require the target lapic_apic_id (== vp_index) to
refer to an existing VP at registration time. A user can therefore
register an irqfd targeting a yet-to-be-created VP, then trigger
mshv_try_assert_irq_fast() concurrently with MSHV_CREATE_VP for the
same index. On weakly-ordered architectures the reader can observe a
non-NULL pointer in pt_vp_array before the initialising stores to the
VP struct become visible, leading to use of partially-initialised
fields (e.g. vp_register_page).
The other ISR readers cannot reach this race: the hypervisor will not
generate intercept or scheduler messages for a VP that has never been
told to run, and the user can only call MSHV_RUN_VP on the VP fd
returned by MSHV_CREATE_VP, which by construction is returned after
the publish. Leave those readers as plain loads.
Use smp_store_release() in mshv_partition_ioctl_create_vp() to publish
the pointer, and pair it with smp_load_acquire() in
mshv_try_assert_irq_fast(). On x86 these compile to plain accesses
under TSO; on ARM64 they emit one-instruction acquire/release barriers,
acceptable on this fast path.
The destroy-side path (destroy_partition() clearing pt_vp_array[i] to
NULL after kfree(vp)) has a separate ordering and lifetime concern
that is out of scope here.
Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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In mshv_partition_ioctl_create_vp(), when kzalloc for the VP struct
fails, the code jumps to the cleanup path without setting ret. At that
point ret is 0 from the preceding successful mshv_vp_stats_map() call,
so the function returns success to userspace despite having failed to
create the VP. No fd is installed and no VP is registered in pt_vp_array,
but userspace has no way to know the operation failed.
Set ret to -ENOMEM before jumping to the cleanup path.
Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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In mshv_irqfd_assign(), the level-triggered validation for resample
irqfds checks irqfd_lapic_irq.lapic_control.level_triggered before
mshv_irqfd_update() has populated the field. Since the irqfd struct is
zero-allocated, level_triggered is always 0 at that point, causing the
check to always reject resample irqfds with -EINVAL. This makes
level-triggered interrupt resampling — used to avoid interrupt storms
with assigned devices — completely non-functional.
Move the check after the mshv_irqfd_update() call, which resolves the
IRQ routing entry and populates irqfd_lapic_irq with the actual trigger
mode.
Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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mshv_irqfd_deactivate() and the hlist traversal of pt_irqfds_list
require pt->pt_irqfds_lock to be held, but mshv_irqfd_deassign()
omits it. This races with the EPOLLHUP path in mshv_irqfd_wakeup(),
which does take the lock before calling mshv_irqfd_deactivate().
Additionally, mshv_irqfd_deactivate() uses hlist_del() which poisons
the node pointers rather than resetting them. Since
mshv_irqfd_is_active() relies on hlist_unhashed() (checks pprev ==
NULL), a poisoned node still appears active. If a concurrent path calls
mshv_irqfd_deactivate() again on the same irqfd, the guard fails to
prevent a double hlist_del() on poisoned pointers.
Fix both issues:
- Add the missing spin_lock_irq/spin_unlock_irq around the list
traversal in mshv_irqfd_deassign(), matching mshv_irqfd_release().
- Use hlist_del_init() instead of hlist_del() so the node is properly
marked as unhashed after removal, making the is_active guard reliable.
Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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mshv_portid_free() uses synchronize_rcu() followed by kfree() to
reclaim port table entries. This blocks the caller until a full RCU
grace period elapses, which is unnecessary since the same module already
uses the non-blocking kfree_rcu() pattern in mshv_port_table_fini().
Replace with kfree_rcu() to avoid the blocking wait and keep the
reclamation strategy consistent across the file.
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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idr_alloc() is called with GFP_KERNEL inside idr_lock(), which holds a
spinlock. GFP_KERNEL allows the allocator to sleep, triggering a
sleeping-while-atomic bug.
Fix by using idr_preload(GFP_KERNEL) before taking the lock to
pre-allocate memory in a sleepable context, then idr_alloc() with
GFP_NOWAIT inside the spinlock-protected section.
Fixes: 621191d709b1 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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The duplicate routing entry check in mshv_update_routing_table() uses
guest_irq_num != 0 to detect whether a GSI slot is already occupied.
This fails for GSI 0 because its guest_irq_num is 0 both when the slot
is unused (zero-initialized) and when legitimately assigned. As a
result, duplicate entries for GSI 0 are silently accepted, with the
second entry overwriting the first — corrupting the routing table
without any error reported to userspace.
While GSI 0 (legacy timer) is unlikely to appear in MSI-based routing
in practice, the check is semantically wrong — it conflates
"uninitialized" with "GSI number 0." Use girq_entry_valid instead,
which is explicitly set to true when an entry is populated and remains
zero for unused slots regardless of the GSI number.
Fixes: 621191d709b14 ("Drivers: hv: Introduce mshv_root module to expose /dev/mshv to VMMs")
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Reviewed-by: Anirudh Rayabharam (Microsoft) <anirudh@anirudhrb.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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vmbus_irq_initialized is only true if the registration of the per-CPU
threads succeeded. If it failed, the whole registration aborts and the
vmbus_exit() path is never called.
Remove vmbus_irq_initialized.
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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lockdep_hardirq_threaded() is supposed to be used within IRQ core code
and not within drivers. It is not obvious from within the driver, that
this is the only interrupt service routing and that it is not shared
handler.
Replace lockdep_hardirq_threaded() with a lockdep annotation limiting
threaded context on PREEMPT_RT to __vmbus_isr().
Fixes: f8e6343b7a89c ("Drivers: hv: vmbus: Use kthread for vmbus interrupts on PREEMPT_RT")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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put_unused_fd() if anon_inode_getfile() fails.
Fixes: 7bfe3b8ea6e30 ("Drivers: hv: Introduce mshv_vtl driver")
Signed-off-by: Yi Xie <xieyi@kylinos.cn>
Reviewed-by: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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mshv_vtl_hvcall_call() copies output_size bytes to userspace.
The output page is freshly allocated. Userspace chooses the copyout length.
If the hypercall writes less, the tail can contain stale page data.
Clear the copied range before issuing the hypercall.
Also check both bounce page allocations before either page is used.
Signed-off-by: Yousef Alhouseen <alhouseenyousef@gmail.com>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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In current code, the coherent_dma_mask for VMBus devices is not set, so
it has the default value of 0, which essentially means "invalid". Because
drivers for VMBus devices do not use dma_alloc_*() functions, the usual
use of the coherent mask does not occur, and no errors result.
However, a valid coherent_dma_mask may be needed even though the drivers
don't use dma_alloc_*() functions. In a CoCo VM, the VMBus storvsc and
netvsc drivers must bounce buffer DMA operations through the swiotlb
because the Hyper-V host can't DMA into encrypted guest memory. If the
kernel is built with CONFIG_SWIOTLB_DYNAMIC and the initial swiotlb size
is small, swiotlb code may need to grow the swiotlb in response to a DMA
mapping request. That growth first allocates a transient pool while the
swiotlb is expanded in the background. The transient pool memory is
allocated from the DMA atomic pools, and the allocation code checks for
a valid coherent_dma_mask. With current code, this check fails, then the
DMA mapping request from the storvsc or netvsc driver fails, and finally
an I/O error occurs.
Fix this problem by setting coherent_dma_mask for VMBus devices at the
same time that dma_mask is set. Being a synthetic bus, VMBus does not
have any restrictions on coherent DMA, so the coherent mask is set to
the full 64 bits for all VMBus devices, just like with dma_mask.
Signed-off-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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