KVM Dirty Ring changes for 6.17
Fix issues with dirty ring harvesting where KVM doesn't bound the processing
of entries in any way, which allows userspace to keep KVM in a tight loop
indefinitely. Clean up code and comments along the way.
KVM generic changes for 6.17
- Add a tracepoint for KVM_SET_MEMORY_ATTRIBUTES to help debug issues related
to private <=> shared memory conversions.
- Drop guest_memfd's .getattr() implementation as the VFS layer will call
generic_fillattr() if inode_operations.getattr is NULL.
KVM MMIO Stale Data mitigation cleanup for 6.17
Rework KVM's mitigation for the MMIO State Data vulnerability to track
whether or not a vCPU has access to (host) MMIO based on the MMU that will be
used when running in the guest. The current approach doesn't actually detect
whether or not a guest has access to MMIO, and is prone to false negatives (and
to a lesser extent, false positives), as KVM_DEV_VFIO_FILE_ADD is optional, and
obviously only covers VFIO devices.
KVM IRQ changes for 6.17
- Rework irqbypass to track/match producers and consumers via an xarray
instead of a linked list. Using a linked list leads to O(n^2) insertion
times, which is hugely problematic for use cases that create large numbers
of VMs. Such use cases typically don't actually use irqbypass, but
eliminating the pointless registration is a future problem to solve as it
likely requires new uAPI.
- Track irqbypass's "token" as "struct eventfd_ctx *" instead of a "void *",
to avoid making a simple concept unnecessarily difficult to understand.
- Add CONFIG_KVM_IOAPIC for x86 to allow disabling support for I/O APIC, PIC,
and PIT emulation at compile time.
- Drop x86's irq_comm.c, and move a pile of IRQ related code into irq.c.
- Fix a variety of flaws and bugs in the AVIC device posted IRQ code.
- Inhibited AVIC if a vCPU's ID is too big (relative to what hardware
supports) instead of rejecting vCPU creation.
- Extend enable_ipiv module param support to SVM, by simply leaving IsRunning
clear in the vCPU's physical ID table entry.
- Disable IPI virtualization, via enable_ipiv, if the CPU is affected by
erratum #1235, to allow (safely) enabling AVIC on such CPUs.
- Dedup x86's device posted IRQ code, as the vast majority of functionality
can be shared verbatime between SVM and VMX.
- Harden the device posted IRQ code against bugs and runtime errors.
- Use vcpu_idx, not vcpu_id, for GA log tag/metadata, to make lookups O(1)
instead of O(n).
- Generate GA Log interrupts if and only if the target vCPU is blocking, i.e.
only if KVM needs a notification in order to wake the vCPU.
- Decouple device posted IRQs from VFIO device assignment, as binding a VM to
a VFIO group is not a requirement for enabling device posted IRQs.
- Clean up and document/comment the irqfd assignment code.
- Disallow binding multiple irqfds to an eventfd with a priority waiter, i.e.
ensure an eventfd is bound to at most one irqfd through the entire host,
and add a selftest to verify eventfd:irqfd bindings are globally unique.
Enable ring-based dirty memory tracking on riscv:
- Enable CONFIG_HAVE_KVM_DIRTY_RING_ACQ_REL as riscv is weakly
ordered.
- Set KVM_DIRTY_LOG_PAGE_OFFSET for the ring buffer's physical page
offset.
- Add a check to kvm_vcpu_kvm_riscv_check_vcpu_requests for checking
whether the dirty ring is soft full.
To handle vCPU requests that cause exits to userspace, modified the
`kvm_riscv_check_vcpu_requests` to return a value (currently only
returns 0 or 1).
Signed-off-by: Quan Zhou <zhouquan@iscas.ac.cn>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20e116efb1f7aff211dd8e3cf8990c5521ed5f34.1749810735.git.zhouquan@iscas.ac.cn
Signed-off-by: Anup Patel <anup@brainfault.org>
The Smnpm extension requires special handling because the guest ISA
extension maps to a different extension (Ssnpm) on the host side.
commit 1851e78362 ("RISC-V: KVM: Allow Smnpm and Ssnpm extensions for
guests") missed that the vcpu->arch.isa bit is based only on the host
extension, so currently both KVM_RISCV_ISA_EXT_{SMNPM,SSNPM} map to
vcpu->arch.isa[RISCV_ISA_EXT_SSNPM]. This does not cause any problems
for the guest, because both extensions are force-enabled anyway when the
host supports Ssnpm, but prevents checking for (guest) Smnpm in the SBI
FWFT logic.
Redefine kvm_isa_ext_arr to look up the guest extension, since only the
guest -> host mapping is unambiguous. Factor out the logic for checking
for host support of an extension, so this special case only needs to be
handled in one place, and be explicit about which variables hold a host
vs a guest ISA extension.
Fixes: 1851e78362 ("RISC-V: KVM: Allow Smnpm and Ssnpm extensions for guests")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20250111004702.2813013-2-samuel.holland@sifive.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Delegate illegal instruction fault to VS mode by default to avoid such
exceptions being trapped to HS and redirected back to VS.
The delegation of illegal instruction fault is particularly important
to guest applications that use vector instructions frequently. In such
cases, an illegal instruction fault will be raised when guest user thread
uses vector instruction the first time and then guest kernel will enable
user thread to execute following vector instructions.
The fw pmu event counter remains undeleted so that guest can still query
illegal instruction events via sbi call. Guest will only see zero count
on illegal instruction faults and know 'firmware' has delegated it.
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Xu Lu <luxu.kernel@bytedance.com>
Link: https://lore.kernel.org/r/20250714094554.89151-1-luxu.kernel@bytedance.com
Signed-off-by: Anup Patel <anup@brainfault.org>
Pull timer fix from Thomas Gleixner:
"A single fix for the PTP systemcounter mechanism:
The rework of this mechanism added a 'use_nsec' member to struct
system_counterval. get_device_system_crosststamp() instantiates that
struct on the stack and hands a pointer to the driver callback.
Only the drivers which set use_nsec to true, initialize that field,
but all others ignore it. As get_device_system_crosststamp() does not
initialize the struct, the use_nsec field contains random stack
content in those cases. That causes a miscalulation usually resulting
in a failing range check in the best case.
Initialize the structure before handing it to the drivers to cure
that"
* tag 'timers-urgent-2025-07-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Zero initialize system_counterval when querying time from phc drivers
Pull spi fix from Mark Brown:
"One last fix for v6.16, removing some hard coding to avoid data
corruption on some NAND devices in the QPIC driver"
* tag 'spi-fix-v6.16-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: spi-qpic-snand: don't hardcode ECC steps
Pull i2c fixes from Wolfram Sang:
- qup: avoid potential hang when waiting for bus idle
- tegra: improve ACPI reset error handling
- virtio: use interruptible wait to prevent hang during transfer
* tag 'i2c-for-6.16-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: qup: jump out of the loop in case of timeout
i2c: virtio: Avoid hang by using interruptible completion wait
i2c: tegra: Fix reset error handling with ACPI
Pull clk fixes from Stephen Boyd:
"A few Allwinner clk driver fixes:
- Mark Allwinner A523 MBUS clock as critical to avoid
system stalls
- Fix names of CSI related clocks on Allwinner V3s. This
includes changes to the driver, DT bindings and DT files.
- Fix parents of TCON clock on Allwinner V3s"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: sunxi-ng: v3s: Fix TCON clock parents
clk: sunxi-ng: v3s: Fix CSI1 MCLK clock name
clk: sunxi-ng: v3s: Fix CSI SCLK clock name
clk: sunxi-ng: a523: Mark MBUS clock as critical
Pull ARM fixes from Russell King:
- use an absolute path for asm/unified.h in KBUILD_AFLAGS to solve a
regression caused by commit d5c8d6e0fa ("kbuild: Update assembler
calls to use proper flags and language target")
- fix dead code elimination binutils version check again
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rmk/linux:
ARM: 9450/1: Fix allowing linker DCE with binutils < 2.36
ARM: 9448/1: Use an absolute path to unified.h in KBUILD_AFLAGS
Pull SoC fixes from Arnd Bergmann:
"These are two fixes that came in late, one addresses a regression on a
rockchips based board, the other is for ensuring a consistent dt
binding for a device added in 6.16 before the incorrect one makes it
into a release"
* tag 'soc-fixes-6.16-3' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
arm64: dts: rockchip: Drop netdev led-triggers on NanoPi R5S
arm64: dts: allwinner: a523: Rename emac0 to gmac0
i2c-host-fixes for v6.16-rc8
qup: avoid potential hang when waiting for bus idle
tegra: improve ACPI reset error handling
virtio: use interruptible wait to prevent hang during transfer
Pull drm fixes (part 2) from Dave Airlie:
"Just the follow up fixes for i915 and xe, all pretty minor.
i915:
- Fix DP 2.7 Gbps DP_LINK_BW value on g4x
- Fix return value on intel_atomic_commit_fence_wait
xe:
- Fix build without debugfs"
* tag 'drm-fixes-2025-07-26' of https://gitlab.freedesktop.org/drm/kernel:
drm/xe: Fix build without debugfs
drm/i915/display: Fix dma_fence_wait_timeout() return value handling
drm/i915/dp: Fix 2.7 Gbps DP_LINK_BW value on g4x
Pull block fix from Jens Axboe:
"Just a single fix for regression in this release, where a module
reference could be leaked"
* tag 'block-6.16-20250725' of git://git.kernel.dk/linux:
block: fix module reference leak in mq-deadline I/O scheduler
Pull vfs fixes from Christian Brauner:
"Two last-minute fixes for this cycle:
- Set afs vllist to NULL if addr parsing fails
- Add a missing check for reaching the end of the string in afs"
* tag 'vfs-6.16-rc8.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
afs: Set vllist to NULL if addr parsing fails
afs: Fix check for NULL terminator
Pull bcachefs fixes from Kent Overstreet:
"User reported fixes:
- Fix btree node scan on encrypted filesystems by not using btree
node header fields encrypted
- Fix a race in btree write buffer flush; this caused EROs primarily
during fsck for some people"
* tag 'bcachefs-2025-07-24' of git://evilpiepirate.org/bcachefs:
bcachefs: Add missing snapshots_seen_add_inorder()
bcachefs: Fix write buffer flushing from open journal entry
bcachefs: btree_node_scan: don't re-read before initializing found_btree_node
After commit d5c8d6e0fa ("kbuild: Update assembler calls to use proper
flags and language target"), which updated as-instr to use the
'assembler-with-cpp' language option, the Kbuild version of as-instr
always fails internally for arch/arm with
<command-line>: fatal error: asm/unified.h: No such file or directory
compilation terminated.
because '-include' flags are now taken into account by the compiler
driver and as-instr does not have '$(LINUXINCLUDE)', so unified.h is not
found.
This went unnoticed at the time of the Kbuild change because the last
use of as-instr in Kbuild that arch/arm could reach was removed in 5.7
by commit 541ad0150c ("arm: Remove 32bit KVM host support") but a
stable backport of the Kbuild change to before that point exposed this
potential issue if one were to be reintroduced.
Follow the general pattern of '-include' paths throughout the tree and
make unified.h absolute using '$(srctree)' to ensure KBUILD_AFLAGS can
be used independently.
Closes: https://lore.kernel.org/CACo-S-1qbCX4WAVFA63dWfHtrRHZBTyyr2js8Lx=Az03XHTTHg@mail.gmail.com/
Cc: stable@vger.kernel.org
Fixes: d5c8d6e0fa ("kbuild: Update assembler calls to use proper flags and language target")
Reported-by: KernelCI bot <bot@kernelci.org>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
This fixes an infinite loop when repairing "extent past end of inode",
when the extent is an older snapshot than the inode that needs repair.
Without the snaphsots_seen_add_inorder() we keep trying to delete the
same extent, even though it's no longer visible in the inode's snapshot.
Fixes: 63d6e93119 ("bcachefs: bch2_fpunch_snapshot()")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When flushing the btree write buffer, we pull write buffer keys directly
from the journal instead of letting the journal write path copy them to
the write buffer.
When flushing from the currently open journal buffer, we have to block
new reservations and wait for outstanding reservations to complete.
Recheck the reservation state after blocking new reservations:
previously, we were checking the reservation count from before calling
__journal_block().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Pull misc fixes from Andrew Morton:
"11 hotfixes. 9 are cc:stable and the remainder address post-6.15
issues or aren't considered necessary for -stable kernels.
7 are for MM"
* tag 'mm-hotfixes-stable-2025-07-24-18-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
sprintf.h requires stdarg.h
resource: fix false warning in __request_region()
mm/damon/core: commit damos_quota_goal->nid
kasan: use vmalloc_dump_obj() for vmalloc error reports
mm/ksm: fix -Wsometimes-uninitialized from clang-21 in advisor_mode_show()
mm: update MAINTAINERS entry for HMM
nilfs2: reject invalid file types when reading inodes
selftests/mm: fix split_huge_page_test for folio_split() tests
mailmap: add entry for Senozhatsky
mm/zsmalloc: do not pass __GFP_MOVABLE if CONFIG_COMPACTION=n
mm/vmscan: fix hwpoisoned large folio handling in shrink_folio_list
A warning is raised when __request_region() detects a conflict with a
resource whose resource.desc is IORES_DESC_DEVICE_PRIVATE_MEMORY.
But this warning is only valid for iomem_resources.
The hmem device resource uses resource.desc as the numa node id, which can
cause spurious warnings.
This warning appeared on a machine with multiple cxl memory expanders.
One of the NUMA node id is 6, which is the same as the value of
IORES_DESC_DEVICE_PRIVATE_MEMORY.
In this environment it was just a spurious warning, but when I saw the
warning I suspected a real problem so it's better to fix it.
This change fixes this by restricting the warning to only iomem_resource.
This also adds a missing new line to the warning message.
Link: https://lkml.kernel.org/r/20250719112604.25500-1-akinobu.mita@gmail.com
Fixes: 7dab174e2e ("dax/hmem: Move hmem device registration to dax_hmem.ko")
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Pull pci fix from Bjorn Helgaas:
- Create pwrctrl devices only when we need them, i.e., when
CONFIG_PCI_PWRCTRL is enabled.
This allows brcmstb to work around a pwrctrl regression by
disabling CONFIG_PCI_PWRCTRL (Manivannan Sadhasivam)
* tag 'pci-v6.16-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/pci/pci:
PCI/pwrctrl: Create pwrctrl devices only when CONFIG_PCI_PWRCTRL is enabled
Pull sound fixes from Takashi Iwai:
"Some last-minute fixes. All changes are device-specific small fixes or
quirks, safe to apply"
* tag 'sound-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ASoC: mediatek: common: fix device and OF node leak
ALSA: hda/realtek: Fix mute LED mask on HP OMEN 16 laptop
ALSA: usb-audio: qcom: Adjust mutex unlock order
ASoC: SDCA: correct the calculation of the maximum init table size
ASoC: rt5650: Eliminate the high frequency glitch
ASoC: SOF: Intel: PTL: Add the sdw_process_wakeen op
ALSA: hda/realtek - Add mute LED support for HP Pavilion 15-eg0xxx
ALSA: hda/realtek - Add mute LED support for HP Victus 15-fa0xxx
ASoC: mediatek: mt8365-dai-i2s: pass correct size to mt8365_dai_set_priv
Pull arm64 fixes from Will Deacon:
"Two important arm64 fixes ahead of the 6.16 release.
The first fixes a regression introduced during the merge window where
the KVM UUID (which is used to advertise KVM-specific hypercalls for
things like time synchronisation in the guest) was corrupted thanks to
an endianness bug introduced when converting the code to use the
UUID_INIT() helper.
The second fixes a stack-pointer corruption issue during
context-switch which has been observed in the wild when taking a
pseudo-NMI with shadow call stack enabled.
Summary:
- Fix broken UUID value for the KVM/arm64 hypervisor SMCCC interface
- Fix stack corruption on context-switch, primarily seen on (but not
limited to) configurations with both pNMI and SCS enabled"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64/entry: Mask DAIF in cpu_switch_to(), call_on_irq_stack()
arm64: kvm, smccc: Fix vendor uuid
Pull networking fixes from Paolo Abeni:
"Including fixes from can and xfrm.
The TI regression notified last week is actually on our net-next tree,
it does not affect 6.16.
We are investigating a virtio regression which is quite hard to
reproduce - currently only our CI sporadically hits it. Hopefully it
should not be critical, and I'm not sure that an additional week would
be enough to solve it.
Current release - fix to a fix:
- sched: sch_qfq: avoid sleeping in atomic context in qfq_delete_class
Previous releases - regressions:
- xfrm:
- set transport header to fix UDP GRO handling
- delete x->tunnel as we delete x
- eth:
- mlx5: fix memory leak in cmd_exec()
- i40e: when removing VF MAC filters, avoid losing PF-set MAC
- gve: fix stuck TX queue for DQ queue format
Previous releases - always broken:
- can: fix NULL pointer deref of struct can_priv::do_set_mode
- eth:
- ice: fix a null pointer dereference in ice_copy_and_init_pkg()
- ism: fix concurrency management in ism_cmd()
- dpaa2: fix device reference count leak in MAC endpoint handling
- icssg-prueth: fix buffer allocation for ICSSG
Misc:
- selftests: mptcp: increase code coverage"
* tag 'net-6.16-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (34 commits)
net: hns3: default enable tx bounce buffer when smmu enabled
net: hns3: fixed vf get max channels bug
net: hns3: disable interrupt when ptp init failed
net: hns3: fix concurrent setting vlan filter issue
s390/ism: fix concurrency management in ism_cmd()
selftests: drv-net: wait for iperf client to stop sending
MAINTAINERS: Add in6.h to MAINTAINERS
selftests: netfilter: tone-down conntrack clash test
can: netlink: can_changelink(): fix NULL pointer deref of struct can_priv::do_set_mode
net/sched: sch_qfq: Avoid triggering might_sleep in atomic context in qfq_delete_class
gve: Fix stuck TX queue for DQ queue format
net: appletalk: Fix use-after-free in AARP proxy probe
net: bcmasp: Restore programming of TX map vector register
selftests: mptcp: connect: also cover checksum
selftests: mptcp: connect: also cover alt modes
e1000e: ignore uninitialized checksum word on tgp
e1000e: disregard NVM checksum on tgp when valid checksum bit is not set
ice: Fix a null pointer dereference in ice_copy_and_init_pkg()
i40e: When removing VF MAC filters, only check PF-set MAC
i40e: report VF tx_dropped with tx_errors instead of tx_discards
...
