mirror of
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185a4caeec
4320 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Jaehoon Kim
|
9972befc3e |
KVM: s390: Fall back to short-term pinning in MAP ioctl
FOLL_LONGTERM pinning fails for some memory types, such as file-backed
guest memory. As a result, kvm_s390_adapter_map() returns -EINVAL and
irqfd adapter registration fails even though interrupt delivery could
still work via the existing non-atomic path.
When FOLL_LONGTERM pinning fails, verify that the page is accessible
using a short-term pin instead. If the short-term pin succeeds, unpin
the page and add a map entry with pinned=false to preserve MAP/UNMAP
symmetry. The non-atomic irqfd path already performs short-term pinning
for interrupt delivery, so this restores the previous behavior for
memory that cannot be pinned long-term.
get_map_info() is updated to return NULL for unpinned entries so that
the atomic irqfd fast path falls back to the non-atomic path.
kvm_s390_adapter_unmap() and kvm_s390_unmap_all_adapters() skip dirty
marking and unpin for unpinned entries.
Update Documentation/virt/kvm/devices/s390_flic.rst to reflect the
new MAP/UNMAP behavior.
Fixes:
|
||
|
Uwe Kleine-König (The Capable Hub)
|
ecca1d63c1 |
Replace <linux/mod_devicetable.h> by more specific <linux/device-id/*.h> (headers)
<linux/mod_devicetable.h> is included in a many files:
$ git grep '<linux/mod_devicetable.h>'
|
||
|
Linus Torvalds
|
c75597caad |
s390:
* Fix S390_USER_OPEREXEC so it can now be enabled regardless of other
unrelated capabilities
* Fix handling of the _PAGE_UNUSED pte bit that could lead to guest
memory corruption in some scenarios
* A bunch of misc gmap fixes (locking, behaviour under memory pressure)
* Fix CMMA dirty tracking
x86:
* Tidy up some WARN_ON() and BUG_ON(), replacing them with WARN_ON_ONCE()
or KVM_BUG_ON(). All of these have obviously never triggered, or
somebody would have been annoyed earlier, but still.
* Fix missing interrupt due to stale CR8 intercept
* Add a statistic that can come in handy to debug leaks as well as the
vulnerability to a class of recently-discovered issues.
* Do not ask arch/x86/kernel to export default_cpu_present_to_apicid()
just for KVM.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"s390:
- Fix S390_USER_OPEREXEC so it can now be enabled regardless of other
unrelated capabilities
- Fix handling of the _PAGE_UNUSED pte bit that could lead to guest
memory corruption in some scenarios
- A bunch of misc gmap fixes (locking, behaviour under memory
pressure)
- Fix CMMA dirty tracking
x86:
- Tidy up some WARN_ON() and BUG_ON(), replacing them with
WARN_ON_ONCE() or KVM_BUG_ON(). All of these have obviously never
triggered, or somebody would have been annoyed earlier, but still...
- Fix missing interrupt due to stale CR8 intercept
- Add a statistic that can come in handy to debug leaks as well as
the vulnerability to a class of recently-discovered issues
- Do not ask arch/x86/kernel to export
default_cpu_present_to_apicid() just for KVM"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits)
x86/apic: KVM: Use cpu_physical_id() to get APIC ID of running vCPU for AVIC
KVM: x86/mmu: Expose number of shadow MMU shadow pages as a stat
KVM: x86: Unconditionally recompute CR8 intercept on PPR update
KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode
KVM: x86: WARN (once) if RTC pending EOI tracking goes off the rails
KVM: x86: WARN and fail kvm_set_irq() if a PIC or I/O APIC vector is invalid
KVM: x86: Bug the VM, not the kernel, if the ISR count {under,over}flows
KVM: x86/mmu: Bug the VM, not the host kernel, if KVM write-protects upper SPTEs
KVM: x86: Replace BUG_ON() with WARN_ON_ONCE() on "bad" nested GPA translation
KVM: Replace guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned()
KVM: s390: Return failure in case of failure in kvm_s390_set_cmma_bits()
KVM: s390: selftests: Fix cmma selftest
KVM: s390: Fix cmma dirty tracking
KVM: s390: Fix locking in kvm_s390_set_mem_control()
KVM: s390: Fix handle_{sske,pfmf} under memory pressure
KVM: s390: Fix code typo in gmap_protect_asce_top_level()
KVM: s390: Do not set special large pages dirty
KVM: s390: Fix dat_peek_cmma() overflow
s390/mm: Fix handling of _PAGE_UNUSED pte bit
KVM: s390: Fix typo in UCONTROL documentation
...
|
||
|
Paolo Bonzini
|
91b16b53a0 |
KVM: s390: Fix S390_USER_OPEREXEC and more gmap fixes
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||
|
Claudio Imbrenda
|
d4bb00704a |
s390/mm: Fix handling of _PAGE_UNUSED pte bit
The _PAGE_UNUSED softbit should not really be lying around. Its sole
purpose is to signal to try_to_unmap_one() and try_to_migrate_one()
that the page can be discarded instead of being moved / swapped.
KVM has no way to know why a page is being unmapped, so it sets the bit
on userspace ptes corresponding to unused guest pages every time they
get unmapped. KVM has no reasonable way to clear the bit once the page
is in use again.
While set_ptes() checks and clears the bit, other paths that set new
ptes did not. This led to used pages being thrown out as if they were
unused, causing guest corruption.
Fix the issue by clearing the _PAGE_UNUSED bit for present ptes in
set_pte(), i.e. whenever a present pte is getting set. The check in
set_ptes() is then redundant and can be removed.
Also fix gmap_helper_try_set_pte_unused() to only set the bit if the
pte is present; the _PAGE_UNUSED bit is only defined for present ptes
and thus should not be set for non-present ptes.
Fixes:
|
||
|
Linus Torvalds
|
2580f89860 |
more s390 updates for 7.2 merge window
- consolidate s390 idle time accounting by moving all CPU time tracking to the architecture backend and eliminate the mix of architecture- specific and common code accounting - Add missing EXPORT_SYMBOL_GPL() to kcpustat_field_idle() and kcpustat_field_iowait() functions - Finalize ptep_get() conversion by replacing direct page table entry dereferencing with proper accessors (ptep_get(), pmdp_get(), etc.) - Explicitly check the buffer length in PKEY_VERIFYPROTK ioctl and pkey_pckmo implementations and fail if the length is exceeded -----BEGIN PGP SIGNATURE----- iI0EABYKADUWIQQrtrZiYVkVzKQcYivNdxKlNrRb8AUCajlD5xccYWdvcmRlZXZA bGludXguaWJtLmNvbQAKCRDNdxKlNrRb8K6cAP48oh4X6XLdK3Eohkm9WjkI0mxZ Qh/tkI1o1GcckwU/zAD+O0LKfJIcb4mo0cH7FgTOJTUCbmPBX711zjom2t9Bvww= =BTXg -----END PGP SIGNATURE----- Merge tag 's390-7.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Alexander Gordeev: - consolidate s390 idle time accounting by moving all CPU time tracking to the architecture backend and eliminate the mix of architecture- specific and common code accounting - Add missing EXPORT_SYMBOL_GPL() to kcpustat_field_idle() and kcpustat_field_iowait() functions - Finalize ptep_get() conversion by replacing direct page table entry dereferencing with proper accessors (ptep_get(), pmdp_get(), etc.) - Explicitly check the buffer length in PKEY_VERIFYPROTK ioctl and pkey_pckmo implementations and fail if the length is exceeded * tag 's390-7.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/pkey: Check length in pkey_pckmo handler implementation s390/pkey: Check length in PKEY_VERIFYPROTK ioctl s390/idle: Add missing EXPORT_SYMBOL_GPL() s390/mm: Complete ptep_get() conversion s390/idle: Remove idle time and count sysfs files s390/idle: Provide arch specific kcpustat_field_idle()/kcpustat_field_iowait() s390/irq/idle: Use stcke instead of stckf for time stamps s390/timex: Move union tod_clock type to separate header |
||
|
Linus Torvalds
|
2e05544060 |
mm.git review status for mm-hotfixes-stable..mm-nonmm-stable
Everything:
Total patches: 108
Reviews/patch: 0.84
Reviewed rate: 75%
Patch series in this merge:
- The 2 patch series "taskstats: fix TGID dead-thread stat retention"
from Yiyang Chen fixes a taskstats TGID aggregation bug where fields
added in the TGID query path were not preserved after thread exit, and
adds a kselftest covering the regression.
- The 2 patch series "lib/tests: string_helpers: Slight improvements"
from Andy Shevchenko improves lib/tests/string_helpers_kunit.c a little.
- The 2 patch series "lib/base64: decode fixes" from Josh Law addreesses
minor issues in lib/base64.c.
- The 3 patch series "selftests/filelock: Make output more kselftestish"
from Mark Brown makes the output from the ofdlocks test a bit easier for
tooling to work with, and also ignores the generated file.
- The 3 patch series "uaccess: unify inline vs outline
copy_{from,to}_user() selection" from Yury Norov simplifies the usercopy
code by removing the selectability of inlining copy_{from,to}_user().
- The 5 patch series "ocfs2: validate inline xattr header consumers"
from ZhengYuan Huang fixes a number of possible issues in the ocfs2
xattr code.
- The 8 patch series "lib and lib/cmdline enhancements" from Dmitry
Antipov provides additional robustness checking in the cmdline handling
code and its in-kernel testing and selftests.
- The 18 patch series "cleanup the RAID6 P/Q library" from Christoph
Hellwig cleans up the RAID6 P/Q library to match the recent updates to
the RAID 5 XOR library and other CRC/crypto libraries.
- The 3 patch series "ocfs2: harden inode validators against forged
metadata" from Michael Bommarito adds three structural checks to OCFS2
dinode validation so malformed on-disk fields are rejected before
ocfs2_populate_inode() copies them into the in-core inode.
- The 2 patch series "lib/raid: replace __get_free_pages() call with
kmalloc()" from Mike Rapoport cleans up the lib/raid code by using
kmalloc() in more places.
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Merge tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
- "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen)
Fix a taskstats TGID aggregation bug where fields added in the TGID
query path were not preserved after thread exit, and adds a kselftest
covering the regression.
- "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko)
Improve lib/tests/string_helpers_kunit.c a little
- "lib/base64: decode fixes" (Josh Law)
Address minor issues in lib/base64.c
- "selftests/filelock: Make output more kselftestish" (Mark Brown)
Make the output from the ofdlocks test a bit easier for tooling to
work with. Also ignore the generated file
- "uaccess: unify inline vs outline copy_{from,to}_user() selection"
(Yury Norov)
Simplify the usercopy code by removing the selectability of inlining
copy_{from,to}_user().
- "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang)
Fix a number of possible issues in the ocfs2 xattr code
- "lib and lib/cmdline enhancements" (Dmitry Antipov)
Provide additional robustness checking in the cmdline handling code
and its in-kernel testing and selftests
- "cleanup the RAID6 P/Q library" (Christoph Hellwig)
Clean up the RAID6 P/Q library to match the recent updates to the
RAID 5 XOR library and other CRC/crypto libraries
- "ocfs2: harden inode validators against forged metadata" (Michael
Bommarito)
Add three structural checks to OCFS2 dinode validation so malformed
on-disk fields are rejected before ocfs2_populate_inode() copies them
into the in-core inode
- "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike
Rapoport)
Clean up the lib/raid code by using kmalloc() in more places
* tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits)
ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write
ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
lib: interval_tree_test: validate benchmark parameters
ocfs2: avoid moving extents to occupied clusters
treewide: fix transposed "sign" typos and update spelling.txt
ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
fat: reject BPB volumes whose data area starts beyond total sectors
selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems
lib/test_firmware: allocate the configured into_buf size
fs: efs: remove unneeded debug prints
checkpatch: cuppress warnings when Reported-by: is followed by Link:
MAINTAINERS: add Alexander as a kcov reviewer
mailmap: update Alexander Sverdlin's Email addresses
fs: fat: inode: replace sprintf() with scnprintf()
ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent
ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()
ocfs2/dlm: require a ref for locking_state debugfs open
ocfs2: reject FITRIM ranges shorter than a cluster
ocfs2: validate fast symlink target during inode read
ocfs2: add journal NULL check in ocfs2_checkpoint_inode()
...
|
||
|
Linus Torvalds
|
c98d767b34 |
Arm:
"This is a bit of an odd merge window on the KVM/arm64 front. There is
absolutely no new feature in the pull request. It is purely fixes,
because it is simply becoming too hard to review new stuff when so
many AI-fuelled fixes hit the list".
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime.
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed
as well.
- Large set of pKVM fixes, mostly addressing recurring issues
around hypervisor tracking of donated pages in obscure cases
where the donation could fail and leave things in a bizarre
state.
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned
out to be far more invasive than initially expected...
- Reduce the overhead of L1/L2 context switch by not touching
the FP registers.
- Fix the way non-implemented page sizes are dealt with when
a guest insist on using them for S2 translation.
- The usual set of low-impact fixes and cleanups all over the map.
Loongarch:
- On a request for lazy FPU load, load all FPU state that the VM
supports instead of enabling only the part (FPU, LSX or LASX)
that caused the FPU load request.
- Some enhancements about interrupt injection.
- Some bug fixes and other small changes.
RISC-V:
- Batch G-stage TLB flushes for GPA range based page table updates
- Convert HGEI line management to fully per-HART
- Fix missing CSR dirty marking when FWFT state updated via ONE_REG
- Fix stale FWFT feature exposure to Guest/VM
- Speed up dirty logging write faults using MMU rwlock and atomic
PTE updates using cmpxchg() for permission-only changes
- Use flexible array for APLIC IRQ state
- Use kvm_slot_dirty_track_enabled() for logging enable check on
a memslot
- Avoid skipping valid pages in kvm_riscv_gstage_wp_range()
- Avoid skipping valid pages in kvm_riscv_gstage_unmap_range()
- Use endian-specific __lelong for NACL shared memory
S390:
- KVM_PRE_FAULT_MEMORY support
- Support for 2G hugepages
- Support for the ASTFLEIE 2 facility
- Support for fast inject using kvm_arch_set_irq_inatomic
- Fix potential leak of uninitialized bytes
- A few more misc gmap fixes.
x86:
- Generic support for the more granular permissions allowed by EPT,
namely "read" (which was previously usurping the U bit) and
separate execution bits for kernel and userspace.
- Do not assume that all page tables start with U=1/W=1/NX=0 at the
root, as AMD GMET needs to have U=0 at the root.
- Introduce common assembly macros for use within Intel and AMD
vendor-specific vmentry code. This touches the SPEC_CTRL handling,
which is now entirely done in assembly for Intel (by reusing the
AMD code that already existed), and register save/restore which
uses some macro magic to compute the offsets in the struct. Both
of these are preparatory changes for upcoming APX support.
- Clean up KVM's register tracking and storage, primarily to prepare for
APX support, which expands the maximum number of GPRs from 16 to 32.
- Keep a single copy of the PDPTRs rather than two, since architecturally
there is just one.
- Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor code
gets a chance to handle things like reaping the PML buffer.
- Update KVM's view of PV async enabling if and only if the MSR write fully
succeeds.
- Fix a variety of issues where the emulator doesn't honor guest-debug state,
and clean up related code along the way.
- Synthesize EPT Violation and #NPF "error code" bits when injecting faults
into L1 that didn't originate in hardware (in which case the VMCS/VMCB
doesn't hold relevant information).
- Add support for virtualizing (well, emulating) AMD's flavor of CPL>0 CPUID
faulting.
- Clean up the GPR APIs so that KVM's use of "raw" is consistent, and fix a
variety of minor bugs along the way.
- Fix an OOB memory access due to not checking the VP ID when handling a
Hyper-V PV TLB flush for L2.
- Fix a bug in the mediated PMU's handling of fixed counters that allowed the
guest to bypass the PMU event filter.
- Allow userspace to return EAGAIN when handling SNP and TDX hypercalls, so
the KVM can forward a "retry" status code to the guest, and reserve all
unused error codes for future usage.
- Overhaul the TDP MMU => S-EPT code to move as much S-EPT specific logic as
possible into the TDX code, and to funnel (almost) all S-EPT updates into
a single chokepoint. The motivation is largely to prepare for upcoming
Dynamic PAMT support, but the cleanups are nice to have on their own.
- Plug a hole in shadow page table handling, where KVM fails to recursively
zap nested EPT/NPT shadow page tables when the nested hypervisor tears
down its own EPT/NPT page tables from the bottom up
x86 (Intel):
- Support for nested MBEC (Mode-Based Execute Control), see above in the
generic section; also run with MBEC enabled even for non-nested mode.
- Use the kernel's "enum pg_level" in the TDX APIs instead of the TDX-Module's
level definitions (which are 0-based).
- Rework the TDX memory APIs to not require/assume that guest memory is
backed by "struct page" (in prepartion for guest_memfd hugepage support).
- Fix a largely benign bug where KVM TDX would incorrectly state it could
emulate several x2APIC MSRs.
- Use the "safe" WRMSR API when proxying LBR MSR writes as the to-be-written
value is guest controlled and completely unvalidated.
x86 (AMD):
- Support for nested GMET (Guest Mode Execution Trap), see above in the
generic section; also run with GMET enabled even for non-nested mode.
- Fixes and minor cleanups to GHCB handling, on top of the earlier work
already merged into 7.1-rc.
- Ensure KVM's copy of CR0 and CR3 are up-to-date prior to invoking
fastpath handlers.
- Add support for virtualizing gPAT (KVM previously just used L1's PAT when
running L2).
- Fix goofs where KVM mishandles side effects (e.g. single-step and PMC
updates) when emulating VMRUN.
- Fix a variety of bugs in AVIC's handling of x2APIC MSR interception, most
notably where KVM didn't disable interception of IRR, ISR, and TMR regs.
- Add support for virtualizing Host-Only/Guest-Only bits in the mediated PMU.
- Don't advertise support for unusable VM types, and account for VM types
that are disabled by firmware, e.g. to mitigate security vulnerabilities.
- Rewrite the SEV {en,de}crypt debug ioctls as they were riddle with bugs and
unnecessarily complicated, and add comprehensive tests.
- Clean up and deduplicate the SEV page pinning code.
- Fix minor goofs related to writing back CPUID information after firmware
rejects a CPUID page for an SNP vCPU.
Generic:
- Rename invalidate_begin() to invalidate_start() throughout KVM to follow
the kernel's nomenclature, e.g. for mmu_notifiers.
- Use guard() to cleanup up various KVM+VFIO flows.
- Minor cleanups.
guest_memfd:
- Return -EEXIST instead of -EINVAL if userspace attempts to bind a gmem
range to multiple memslots, and fix the test that was supposed to ensure
KVM returns -EEXIST.
- Treat memslot binding offsets and sizes as unsigned values to fix a bug
where KVM interprets a large "offset + size" as a negative value and allows
a nonsensical offset.
- Use the inode number instead of the page offset for the NUMA interleaving
index to fix a bug where the effective index would jump by two for
consecutive pages (the caller also adds in the page offset).
Selftests:
- Randomize the dirty log test's delay when reaping the bitmap on the first
pass, as always waiting only 1ms hid a KVM RISC-V bug as the test reaped the
bitmap before KVM could build up enough state to hit the bug.
- A pile of one-off fixes and cleanups.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"arm64:
This is a bit of an odd merge window on the KVM/arm64 front. There
is absolutely no new feature in the pull request. It is purely
fixes, because it is simply becoming too hard to review new stuff
when so many AI-fuelled fixes hit the list.
- Significant cleanup of the vgic-v5 PPI support which was merged in
7.1. This makes the code more maintainable, and squashes a couple
of bugs in the meantime
- Set of fixes for the handling of the MMU in an NV context,
particularly VNCR-triggered faults. S1POE support is fixed as well
- Large set of pKVM fixes, mostly addressing recurring issues around
hypervisor tracking of donated pages in obscure cases where the
donation could fail and leave things in a bizarre state
- Fixes for the so-called "lazy vgic init", which resulted in
sleeping operations in non-preemptible sections. This turned out to
be far more invasive than initially expected..
- Reduce the overhead of L1/L2 context switch by not touching the FP
registers
- Fix the way non-implemented page sizes are dealt with when a guest
insist on using them for S2 translation
- The usual set of low-impact fixes and cleanups all over the map
Loongarch:
- On a request for lazy FPU load, load all FPU state that the VM
supports instead of enabling only the part (FPU, LSX or LASX) that
caused the FPU load request
- Some enhancements about interrupt injection
- Some bug fixes and other small changes
RISC-V:
- Batch G-stage TLB flushes for GPA range based page table updates
- Convert HGEI line management to fully per-HART
- Fix missing CSR dirty marking when FWFT state updated via ONE_REG
- Fix stale FWFT feature exposure to Guest/VM
- Speed up dirty logging write faults using MMU rwlock and atomic PTE
updates using cmpxchg() for permission-only changes
- Use flexible array for APLIC IRQ state
- Use kvm_slot_dirty_track_enabled() for logging enable check on a
memslot
- Avoid skipping valid pages in kvm_riscv_gstage_wp_range()
- Avoid skipping valid pages in kvm_riscv_gstage_unmap_range()
- Use endian-specific __lelong for NACL shared memory
S390:
- KVM_PRE_FAULT_MEMORY support
- Support for 2G hugepages
- Support for the ASTFLEIE 2 facility
- Support for fast inject using kvm_arch_set_irq_inatomic
- Fix potential leak of uninitialized bytes
- A few more misc gmap fixes
x86:
- Generic support for the more granular permissions allowed by EPT,
namely "read" (which was previously usurping the U bit) and
separate execution bits for kernel and userspace
- Do not assume that all page tables start with U=1/W=1/NX=0 at the
root, as AMD GMET needs to have U=0 at the root
- Introduce common assembly macros for use within Intel and AMD
vendor-specific vmentry code. This touches the SPEC_CTRL handling,
which is now entirely done in assembly for Intel (by reusing the
AMD code that already existed), and register save/restore which
uses some macro magic to compute the offsets in the struct. Both of
these are preparatory changes for upcoming APX support
- Clean up KVM's register tracking and storage, primarily to prepare
for APX support, which expands the maximum number of GPRs from 16
to 32
- Keep a single copy of the PDPTRs rather than two, since
architecturally there is just one
- Handle EXIT_FASTPATH_EXIT_USERSPACE in vendor code to ensure vendor
code gets a chance to handle things like reaping the PML buffer
- Update KVM's view of PV async enabling if and only if the MSR write
fully succeeds
- Fix a variety of issues where the emulator doesn't honor
guest-debug state, and clean up related code along the way
- Synthesize EPT Violation and #NPF "error code" bits when injecting
faults into L1 that didn't originate in hardware (in which case the
VMCS/VMCB doesn't hold relevant information)
- Add support for virtualizing (well, emulating) AMD's flavor of
CPL>0 CPUID faulting
- Clean up the GPR APIs so that KVM's use of "raw" is consistent, and
fix a variety of minor bugs along the way
- Fix an OOB memory access due to not checking the VP ID when
handling a Hyper-V PV TLB flush for L2
- Fix a bug in the mediated PMU's handling of fixed counters that
allowed the guest to bypass the PMU event filter
- Allow userspace to return EAGAIN when handling SNP and TDX
hypercalls, so the KVM can forward a "retry" status code to the
guest, and reserve all unused error codes for future usage
- Overhaul the TDP MMU => S-EPT code to move as much S-EPT specific
logic as possible into the TDX code, and to funnel (almost) all
S-EPT updates into a single chokepoint. The motivation is largely
to prepare for upcoming Dynamic PAMT support, but the cleanups are
nice to have on their own
- Plug a hole in shadow page table handling, where KVM fails to
recursively zap nested EPT/NPT shadow page tables when the nested
hypervisor tears down its own EPT/NPT page tables from the bottom
up
x86 (Intel):
- Support for nested MBEC (Mode-Based Execute Control), see above in
the generic section; also run with MBEC enabled even for non-nested
mode
- Use the kernel's "enum pg_level" in the TDX APIs instead of the
TDX-Module's level definitions (which are 0-based)
- Rework the TDX memory APIs to not require/assume that guest memory
is backed by "struct page" (in prepartion for guest_memfd hugepage
support)
- Fix a largely benign bug where KVM TDX would incorrectly state it
could emulate several x2APIC MSRs
- Use the "safe" WRMSR API when proxying LBR MSR writes as the
to-be-written value is guest controlled and completely unvalidated
x86 (AMD):
- Support for nested GMET (Guest Mode Execution Trap), see above in
the generic section; also run with GMET enabled even for non-nested
mode
- Fixes and minor cleanups to GHCB handling, on top of the earlier
work already merged into 7.1-rc
- Ensure KVM's copy of CR0 and CR3 are up-to-date prior to invoking
fastpath handlers
- Add support for virtualizing gPAT (KVM previously just used L1's
PAT when running L2)
- Fix goofs where KVM mishandles side effects (e.g. single-step and
PMC updates) when emulating VMRUN
- Fix a variety of bugs in AVIC's handling of x2APIC MSR
interception, most notably where KVM didn't disable interception of
IRR, ISR, and TMR regs
- Add support for virtualizing Host-Only/Guest-Only bits in the
mediated PMU
- Don't advertise support for unusable VM types, and account for VM
types that are disabled by firmware, e.g. to mitigate security
vulnerabilities
- Rewrite the SEV {en,de}crypt debug ioctls as they were riddle with
bugs and unnecessarily complicated, and add comprehensive tests
- Clean up and deduplicate the SEV page pinning code
- Fix minor goofs related to writing back CPUID information after
firmware rejects a CPUID page for an SNP vCPU
Generic:
- Rename invalidate_begin() to invalidate_start() throughout KVM to
follow the kernel's nomenclature, e.g. for mmu_notifiers
- Use guard() to cleanup up various KVM+VFIO flows
- Minor cleanups
guest_memfd:
- Return -EEXIST instead of -EINVAL if userspace attempts to bind a
gmem range to multiple memslots, and fix the test that was supposed
to ensure KVM returns -EEXIST
- Treat memslot binding offsets and sizes as unsigned values to fix a
bug where KVM interprets a large "offset + size" as a negative
value and allows a nonsensical offset
- Use the inode number instead of the page offset for the NUMA
interleaving index to fix a bug where the effective index would
jump by two for consecutive pages (the caller also adds in the page
offset)
Selftests:
- Randomize the dirty log test's delay when reaping the bitmap on the
first pass, as always waiting only 1ms hid a KVM RISC-V bug as the
test reaped the bitmap before KVM could build up enough state to
hit the bug
- A pile of one-off fixes and cleanups"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (326 commits)
KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level
KVM: x86: Fix shadow paging use-after-free due to unexpected role
KVM: s390: Introducing kvm_arch_set_irq_inatomic fast inject
KVM: s390: Enable adapter_indicators_set to use mapped pages
KVM: s390: Add map/unmap ioctl and clean mappings post-guest
riscv: kvm: Use endian-specific __lelong for NACL shared memory
KVM: selftests: access_tracking_perf_test: bump number of NUMA nodes to 32
KVM: s390: vsie: Implement ASTFLEIE facility 2
KVM: s390: vsie: Refactor handle_stfle
s390/sclp: Detect ASTFLEIE 2 facility
KVM: s390: Minor refactor of base/ext facility lists
KVM: x86/mmu: move pdptrs out of the MMU
KVM: x86: check that kvm_handle_invpcid is only invoked with shadow paging
KVM: nSVM: invalidate cached PDPTRs across nested NPT transitions
KVM: nVMX: remove unnecessary code in prepare_vmcs02_rare
KVM: x86: remove nested_mmu from mmu_is_nested()
KVM: arm64: vgic-its: Make ABI commit helpers return void
KVM: s390: Initialize KVM_S390_GET_CMMA_BITS memory
LoongArch: KVM: Add missing slots_lock for device register/unregister
LoongArch: KVM: Validate irqchip index in irqfd routing
...
|
||
|
Alexander Gordeev
|
28da1cce9e |
s390/mm: Complete ptep_get() conversion
Finalize commit
|
||
|
Alexander Gordeev
|
9fb519794e |
Merge branch 'idle-time-acc' into features
Heiko Carstens says: =================== This is supposed to improve s390 idle time accounting, and brings it back to the state it was before arch_cpu_idle_time() was removed from s390 [3]. In result all cpu time accounting is done by the s390 architecture backend again, instead of having a mix of architecure specific and common code accounting (common code: idle, s390 architecture: everything else). =================== Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
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Linus Torvalds
|
25a01b5155 |
s390 updates for 7.2 merge window
- Use CIO device online variable instead of the internal FSM state to determine device availability during purge operations - Remove extra check of task_stack_page() because try_get_task_stack() already takes care of that when reading /proc/<pid>/wchan - Allow user-space to use the new SCLP action qualifier 4 for to provide NVMe SMART log data to the platform. - Send AP CHANGE uevents on successful bind and successful association to notify user-space about SE operations on AP queue devices - Add an s390dbf kernel parameter to configure debug log levels and area sizes during early boot - On arm64 the empty zero page is going to be mapped read-only. Do the same for s390 with an explicit set_memory_ro() call - Improve s390-specific bcr_serialize() and cpu_relax() implementations - Remove all unused variables to avoid allmodconfig W=1 build fails with latest clang-23 - Cleanup default Kconfig values for s390 selftests - Add a s390-tod trace clock to allow comparing trace timestamps between different systems or virtual machines on s390 - Remove the s390 implementation of strlcat() in favor of the generic variant - Make consistent the calling order between page_table_check_pte_clear() and secure page conversion across all code paths - Rearrange some fields within AP and zcrypt structs to reduce memory consumption and unused holes - Shorten GR_NUM and VX_NUM macros and move them to a separate header - Replace __get_free_page() with kmalloc() in few sources - Introduce an infrastructure for more efficient this_cpu operations. Eliminate conditional branches when PREEMPT_NONE is removed - Enable Rust support - Use z10 as minimum architecture level, similar to the boot code, to enforce a defined architecture level set - Improve and convert various mem*() helper functions to C. For that add .noinstr.text section to avoid orphaned warnings from the linker - Fix the function pointer type in __ret_from_fork() to correct the indirect call to match kernel thread return type of int - Revert support for DCACHE_WORD_ACCESS to avoid an endless exception loop on read from donated Ultravisor pages at unaligned addresses -----BEGIN PGP SIGNATURE----- iI0EABYKADUWIQQrtrZiYVkVzKQcYivNdxKlNrRb8AUCai/rTRccYWdvcmRlZXZA bGludXguaWJtLmNvbQAKCRDNdxKlNrRb8KNOAPwMpGVtXcKF4HftCv49X0WpqKbU tdYO9hbq9wanIGpgIgEAk5vggxe74pj+palTbtCDteVjDpnSp811x8gfmLlPrgU= =qzZ2 -----END PGP SIGNATURE----- Merge tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux Pull s390 updates from Alexander Gordeev: - Use CIO device online variable instead of the internal FSM state to determine device availability during purge operations - Remove extra check of task_stack_page() because try_get_task_stack() already takes care of that when reading /proc/<pid>/wchan - Allow user-space to use the new SCLP action qualifier 4 for to provide NVMe SMART log data to the platform. - Send AP CHANGE uevents on successful bind and successful association to notify user-space about SE operations on AP queue devices - Add an s390dbf kernel parameter to configure debug log levels and area sizes during early boot - On arm64 the empty zero page is going to be mapped read-only. Do the same for s390 with an explicit set_memory_ro() call - Improve s390-specific bcr_serialize() and cpu_relax() implementations - Remove all unused variables to avoid allmodconfig W=1 build fails with latest clang-23 - Cleanup default Kconfig values for s390 selftests - Add a s390-tod trace clock to allow comparing trace timestamps between different systems or virtual machines on s390 - Remove the s390 implementation of strlcat() in favor of the generic variant - Make consistent the calling order between page_table_check_pte_clear() and secure page conversion across all code paths - Rearrange some fields within AP and zcrypt structs to reduce memory consumption and unused holes - Shorten GR_NUM and VX_NUM macros and move them to a separate header - Replace __get_free_page() with kmalloc() in few sources - Introduce an infrastructure for more efficient this_cpu operations. Eliminate conditional branches when PREEMPT_NONE is removed - Enable Rust support - Use z10 as minimum architecture level, similar to the boot code, to enforce a defined architecture level set - Improve and convert various mem*() helper functions to C. For that add .noinstr.text section to avoid orphaned warnings from the linker - Fix the function pointer type in __ret_from_fork() to correct the indirect call to match kernel thread return type of int - Revert support for DCACHE_WORD_ACCESS to avoid an endless exception loop on read from donated Ultravisor pages at unaligned addresses * tag 's390-7.2-1' of gitolite.kernel.org:pub/scm/linux/kernel/git/s390/linux: (52 commits) s390: Revert support for DCACHE_WORD_ACCESS s390/process: Fix kernel thread function pointer type s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C s390/memmove: Optimize backward copy case s390/string: Convert memset(16|32|64)() to C s390/string: Convert memcpy() to C s390/string: Convert memset() to C s390/string: Convert memmove() to C s390/string: Add -ffreestanding compile option to string.o s390: Add .noinstr.text to boot and purgatory linker scripts s390/purgatory: Enforce z10 minimum architecture level s390: Enable Rust support s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers rust: helpers: Add memchr wrapper for string operations rust/bindgen_parameters: Mark s390 types as opaque to prevent repr conflicts s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support s390/ap: Fix locking issue in SE bind and associate sysfs functions s390/percpu: Provide arch_this_cpu_write() implementation s390/percpu: Provide arch_this_cpu_read() implementation ... |
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Heiko Carstens
|
968ec3f960 |
s390/idle: Remove idle time and count sysfs files
Remove the s390 specific idle_time_us and idle_count per cpu sysfs files. They do not provide any additional value. The risk that there are existing applications which rely on these architecture specific files should be very low. However if it turns out such applications exist, this can be easily reverted. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
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Heiko Carstens
|
670e057744 |
s390/idle: Provide arch specific kcpustat_field_idle()/kcpustat_field_iowait()
The former s390 specific arch_cpu_idle_time() implementation was removed, since its implementation was racy and reported idle time could go backwards [1]. However this removal was not necessary, since independently of the s390 architecture specific races there exists the iowait counter update race, which can also lead to reported idle time going backwards [2]. With Frederic Weisbecker's recent cpu idle time accounting refactoring kernel_cpustat got a sequence counter. Use this to implement s390 specific variants of kcpustat_field_idle() and kcpustat_field_iowait(). This is logically a revert of [1] and moves cpu idle time accounting back into s390 architecture code, which is also more precise than the dyntick idle time accounting by nohz/scheduler. For comparing cross cpu time stamps it is necessary to use the stcke instead of the stckf instruction in irq entry path. Furthermore this open-codes a sequence lock in assembler and C code, which is required to update the irq entry time stamp to the per cpu idle_data structure in a race free manner. [1] commit |
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Heiko Carstens
|
4fe307f0f5 |
s390/irq/idle: Use stcke instead of stckf for time stamps
The upcoming cpu idle time accounting rework involves comparing and subtracting cross cpu time stamps. Time stamps created with the stckf instruction monotonic with respect to the local cpu. For cross cpu monotonic time stamps the slightly slower stcke instruction has to be used [1]. Convert the idle time accounting relevant usages of stckf to stcke. [1] Principles of Operation - Setting and Inspecting the Clock Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
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Heiko Carstens
|
fe47b8b1c0 |
s390/timex: Move union tod_clock type to separate header
Move union tod_clock type to separate header file. This is preparation for upcoming changes in order to avoid header dependency problems. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
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|
Paolo Bonzini
|
4dffb0a5d1 |
KVM: s390: New features for 7.2
New features for 7.2 for KVM/s390: * KVM_PRE_FAULT_MEMORY support * Support for 2G hugepages * Support for the ASTFLEIE 2 facility * kvm_arch_set_irq_inatomic Fast Inject * Fix potential leak of uninitialized bytes -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEoWuZBM6M3lCBSfTnuARItAMU6BMFAmov7sIACgkQuARItAMU 6BNlChAArkYNfy+aHUKDV+fTbYobSaCLPTTEXtDwkykPIC4CQa55kc/rcXWPxtw8 C9YupDZ/LFsfbP/bUKXssPcU5fOt2K4BMJOiB/3J4MrfCdEM50KEOGb20f7TRf2Y CYVOFEjHum2nA3N7p13VLbUGj+yCzisMCejeVXDQY5nStn+4pcE1S1CZKuZ2k7Vz a72CGg6CUs5Ee4yRlsqoUzpqtEIGbOWVbJKVjf7pRSqBgYQQrrpJ0ImleujrAsSA eKWnAKUJ/JxpnRRZtudl663v+YXZs2q4cHsKACZ0eugSQIKEU1RYaobz6/e2D7g6 AOxKurd0YPCrtEulZzwQT+uY3KJXVt8J6KBHEeJiTLeG2Dmm7/dL6t4Y9CNqpGK/ nx/U05tGqcJ2cvWGAB3NXVj3n1ocrgy9+OUCbLw9YaxeqEAdPKTeRqE4nl6+mla6 F0t1dEEqJNbm44rcH9sHLzJiOZh4ziKnLT0VwJFGwUDMcNsl+uNqZtl4tjWfD3+t 15nwUoOiVWPGKqSnXVl8QRCQvAmQ3wK7ThIR2MOCYM4y2sfdF+c5QjX1uznQHc5j 1o4oSjN1hDNxvjMzGOM2Xn3swtCPhCAzQZCr3JtZkB5je5jtV047uRJTYjqiXgKD FnQ7VQzDFTEDhhLWgJJNgjUrKScKfMSrQpapgu0LWSjqisjToHg= =GOQC -----END PGP SIGNATURE----- Merge tag 'kvm-s390-next-7.2-1' of https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD KVM: s390: New features for 7.2 New features for 7.2 for KVM/s390: * KVM_PRE_FAULT_MEMORY support * Support for 2G hugepages * Support for the ASTFLEIE 2 facility * kvm_arch_set_irq_inatomic Fast Inject * Fix potential leak of uninitialized bytes |
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|
Douglas Freimuth
|
a868b30492 |
KVM: s390: Introducing kvm_arch_set_irq_inatomic fast inject
s390 needs a fast path for irq injection, and along those lines we introduce kvm_arch_set_irq_inatomic. Instead of placing all interrupts on the global work queue as it does today, this patch provides a fast path for irq injection. The inatomic fast path cannot lose control since it is running with interrupts disabled. This meant making the following changes that exist on the slow path today. First, the adapter_indicators page needs to be mapped since it is accessed with interrupts disabled, so we added map/unmap functions. Second, access to shared resources between the fast and slow paths needed to be changed from mutex and semaphores to spin_lock's. Finally, the memory allocation on the slow path utilizes GFP_KERNEL_ACCOUNT but we had to implement the fast path with GFP_ATOMIC allocation. Each of these enhancements were required to prevent blocking on the fast inject path. Fencing of Fast Inject in Secure Execution environments is enabled in the patch series by not mapping adapter indicator pages. In Secure Execution environments the path of execution available before this patch is followed. Statistical counters have been added to enable analysis of irq injection on the fast path and slow path including io_390_inatomic, io_flic_inject_airq, io_set_adapter_int and io_390_inatomic_no_inject. The no inject counter captures adapter masked, coalesced and suppressed interrupts. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Douglas Freimuth <freimuth@linux.ibm.com> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260604192755.203143-4-freimuth@linux.ibm.com> |
||
|
Douglas Freimuth
|
c9a5688380 |
KVM: s390: Add map/unmap ioctl and clean mappings post-guest
s390 needs map/unmap ioctls, which map the adapter set indicator pages, so the pages can be accessed when interrupts are disabled. The mappings are cleaned up when the guest is removed. pin_user_pages_remote is used for both the ioctl as well as the pin-on-demand logic in adapter_indicators_set(). Map/Unmap ioctls are fenced in order to avoid the longterm pinning in Secure Execution environments. In Secure Execution environments the path of execution available before this patch is followed. Statistical counters to count map/unmap functions for adapter indicator pages are added. The counters can be used to analyze map/unmap functions in non-Secure Execution environments and similarly can be used to analyze Secure Execution environments where the counters will not be incremented as the adapter indicator pages are not mapped. Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Douglas Freimuth <freimuth@linux.ibm.com> Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260604192755.203143-2-freimuth@linux.ibm.com> |
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|
Linus Torvalds
|
a53fcff8fc |
Updates for the NOHZ subsystem:
- Fix a long standing TOCTOU in get_cpu_sleep_time_us()
- Make the CPU offline NOHZ handling more robust by disabling NOHZ on the
outgoing CPU early instead of creating unneeded state which needs to be
undone.
- Unify idle CPU time accounting instead of having two different
accounting mechanisms. These two different mechanisms are not really
independent, but the different properties can in the worst case cause
that gloabl idle time can be observed going backwards.
- Consolidate the idle/iowait time retrieval interfaces instead of
converting back and forth between them.
- Make idle interrupt time accounting more robust. The original code
assumes that interrupt time accouting is enabled and therefore stops
elapsing idle time while an interrupt is handled in NOHZ dyntick
state. That assumption is not correct as interrupt time accounting can
be disabled at compile and runtime.
- Fix an accounting error between dyntick idle time and dyntick idle
steal time. The stolen time is not accounted and therefore idle time
becomes inaccurate. The stolen time is now accounted after the fact as
there is no way to predict the steal time upfront.
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Merge tag 'timers-nohz-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip
Pull NOHZ updates from Thomas Gleixner:
- Fix a long standing TOCTOU in get_cpu_sleep_time_us()
- Make the CPU offline NOHZ handling more robust by disabling NOHZ on
the outgoing CPU early instead of creating unneeded state which needs
to be undone.
- Unify idle CPU time accounting instead of having two different
accounting mechanisms. These two different mechanisms are not really
independent, but the different properties can in the worst case cause
that gloabl idle time can be observed going backwards.
- Consolidate the idle/iowait time retrieval interfaces instead of
converting back and forth between them.
- Make idle interrupt time accounting more robust. The original code
assumes that interrupt time accouting is enabled and therefore stops
elapsing idle time while an interrupt is handled in NOHZ dyntick
state. That assumption is not correct as interrupt time accounting
can be disabled at compile and runtime.
- Fix an accounting error between dyntick idle time and dyntick idle
steal time. The stolen time is not accounted and therefore idle time
becomes inaccurate. The stolen time is now accounted after the fact
as there is no way to predict the steal time upfront.
* tag 'timers-nohz-2026-06-13' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip:
sched/cputime: Handle dyntick-idle steal time correctly
sched/cputime: Handle idle irqtime gracefully
sched/cputime: Provide get_cpu_[idle|iowait]_time_us() off-case
tick/sched: Consolidate idle time fetching APIs
tick/sched: Account tickless idle cputime only when tick is stopped
tick/sched: Remove unused fields
tick/sched: Move dyntick-idle cputime accounting to cputime code
tick/sched: Remove nohz disabled special case in cputime fetch
tick/sched: Unify idle cputime accounting
s390/time: Prepare to stop elapsing in dynticks-idle
powerpc/time: Prepare to stop elapsing in dynticks-idle
sched/cputime: Correctly support generic vtime idle time
sched/cputime: Remove superfluous and error prone kcpustat_field() parameter
sched/idle: Handle offlining first in idle loop
tick/sched: Fix TOCTOU in nohz idle time fetch
|
||
|
Nina Schoetterl-Glausch
|
0e9704f1bc |
KVM: s390: vsie: Implement ASTFLEIE facility 2
Implement shadowing of format-2 facility list when running in VSIE. ASTFLEIE2 is available since IBM z16. To function G1 has to run this KVM code and G1 and G2 have to run QEMU with ASTFLEIE2 support. Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Co-developed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> [imbrenda@linux.ibm.com: Fix typo in comment] Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260612-vsie-alter-stfle-fac-v4-4-74f0e1559929@linux.ibm.com> |
||
|
Nina Schoetterl-Glausch
|
bf8f3cec93 |
KVM: s390: vsie: Refactor handle_stfle
Use switch case in anticipation of handling format-1 and format-2 facility list designations in the future. As the alternate STFLE facilities are not enabled, only case 0 is possible. No functional change intended. Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Co-developed-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260612-vsie-alter-stfle-fac-v4-3-74f0e1559929@linux.ibm.com> |
||
|
Nina Schoetterl-Glausch
|
a8ceca7d8c |
s390/sclp: Detect ASTFLEIE 2 facility
Detect alternate STFLE interpretive execution facility 2. Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com> Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Message-ID: <20260612-vsie-alter-stfle-fac-v4-2-74f0e1559929@linux.ibm.com> |
||
|
Heiko Carstens
|
37540b8c28 |
s390: Revert support for DCACHE_WORD_ACCESS
load_unaligned_zeropad() reads eight bytes from unaligned addresses and may cross page boundaries. It handles exceptions which may happen if reading from the second page results in an exception. For pages which are donated to the Ultravisor for secure execution purposes the do_secure_storage_access() exception handler however does not handle such exceptions correctly. Such an exception may result in an endless exception loop which will never be resolved. An attempt to fix this [1] turned out to be not sufficient. For now revert load_unaligned_zeropad() until this problem has been resolved in a proper way. Note that the implementation of load_unaligned_zeropad() itself is correct. The revert is just a temporary workaround until there is complete fix for secure storage access exceptions. [1] commit |
||
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Heiko Carstens
|
51746fc082 |
s390/tishift: Convert __ashlti3(), __ashrti3(), __lshrti3() to C
There is no reason to have __ashlti3(), __ashrti3(), and __lshrti3() implemented in assembler. Convert them all to C, which allows the compiler to optimize the code if newer instructions allow that. Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
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Alexander Gordeev
|
982c89c9b9 |
Merge branch 'rust-for-s390' into features
Jan Polensky says: =================== Rust support on s390 requires a small set of architecture-specific pieces before the generic Rust kernel infrastructure can be used. The series wires up s390 as a Rust-capable 64-bit architecture, adds the missing assembly interfaces needed by Rust for WARN/BUG reporting and for static branches, adjusts bindgen parameters to avoid repr layout conflicts caused by packed and aligned s390 structures, and fixes issues discovered during testing. s390 currently requires rustc with support for -Zpacked-stack, and the minimum tool version gating is adjusted accordingly. Link: https://github.com/Rust-for-Linux/linux/issues/2 Tested against: rustc 1.96.0 (ac68faa20 2026-05-25) =================== Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
|
Jan Polensky
|
a423d94fa1 |
s390/cmpxchg: Fix KASAN stack-out-of-bounds in atomic helpers
The __arch_cmpxchg1, __arch_cmpxchg2, __arch_xchg1, and __arch_xchg2 functions emulate 1-byte and 2-byte atomic operations using 4-byte cmpxchg instructions, since s390 lacks native 1/2-byte cmpxchg support. When KASAN is enabled, the READ_ONCE() operations in these functions trigger stack-out-of-bounds warnings because they perform 4-byte reads when only 1 or 2 bytes should be accessed. Mark these functions as __no_sanitize_or_inline to prevent KASAN instrumentation while maintaining correct functionality. This resolves the following KASAN error during rust_atomics KUnit tests: BUG: KASAN: stack-out-of-bounds in rust_helper_atomic_i8_xchg+0xb2/0xc0 Read of size 4 at addr 001bff7ffdbefcf0 by task kunit_try_catch/142 Reported-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Link: https://lore.kernel.org/rust-for-linux/CANiq72m4GVWFYqnxNtCHTPu7XcGewHB5LNwOoayTfnXs9pPbNg@mail.gmail.com/ Suggested-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/rust-for-linux/DITFTAVVHTNQ.380OHUHGTOI6M@garyguo.net/ Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Gary Guo <gary@garyguo.net> Signed-off-by: Jan Polensky <japo@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
|
Jan Polensky
|
6900bec59d |
s390/jump_label: Implement ARCH_STATIC_BRANCH_JUMP_ASM and ARCH_STATIC_BRANCH_ASM macros
Rust static branch support needs the s390 jump label instruction sequence and __jump_table emission in a reusable form. The current implementation embeds the sequence directly in the C asm goto blocks, which cannot be shared with Rust. Introduce ARCH_STATIC_BRANCH_ASM and ARCH_STATIC_BRANCH_JUMP_ASM to describe the brcl sequences for the likely-false and likely-true cases and to emit the same __jump_table entries as before. Switch the existing C helpers to use the new macros to avoid duplication without changing the generated code. Acked-by: Gary Guo <gary@garyguo.net> Acked-by: Miguel Ojeda <ojeda@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Jan Polensky <japo@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
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Jan Polensky
|
184b8dc879 |
s390/bug: Provide ARCH_WARN_ASM for Rust WARN/BUG support
Rust WARN and BUG support relies on ARCH_WARN_ASM to emit __bug_table entries. On s390 the macro is missing, so Rust code cannot generate proper WARN/BUG metadata for the kernel's bug reporting infrastructure. Define ARCH_WARN_ASM to produce the same assembly sequence and __bug_table entry format as the existing s390 BUG handling, including the monitor call. Define ARCH_WARN_REACHABLE as empty since s390 does not provide reachability analysis for warning paths. Acked-by: Gary Guo <gary@garyguo.net> Acked-by: Miguel Ojeda <ojeda@kernel.org> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jan Polensky <japo@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
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Linus Torvalds
|
95b78879a8 |
Arm:
- Correctly drop the ITS translation cache reference when it actually
gets invalidated
- Take the SRCU lock for SW page table walks
- Restore POR_EL0 access to host EL0, avoiding POR_EL0 becoming
inaccessible from EL0 after running a guest
- Reassign nested_mmus array behind mmu_lock, ensuring that vcpu init
and MMU notifiers are mutually exclusive
- Correctly handle FEAT_XNX at stage-2
s390:
- More fixes for the new page table management and nested virtualization
x86:
- More fixes for GHCB issues
- Read start/end indices of page size change requests exactly one per vmexit
- Unmap and unpin the GHCB as needed on vCPU free
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"arm64:
- Correctly drop the ITS translation cache reference when it actually
gets invalidated
- Take the SRCU lock for SW page table walks
- Restore POR_EL0 access to host EL0, avoiding POR_EL0 becoming
inaccessible from EL0 after running a guest
- Reassign nested_mmus array behind mmu_lock, ensuring that vcpu init
and MMU notifiers are mutually exclusive
- Correctly handle FEAT_XNX at stage-2
s390:
- More fixes for the new page table management and nested
virtualization
x86:
- More fixes for GHCB issues:
- Read start/end indices of page size change requests exactly once
per vmexit
- Unmap and unpin the GHCB as needed on vCPU free"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (23 commits)
KVM: arm64: Correctly identify executable PTEs at stage-2
KVM: arm64: nv: Fix handling of XN[0] when !FEAT_XNX
KVM: arm64: Reassign nested_mmus array behind mmu_lock
KVM: arm64: Restore POR_EL0 access to host EL0
KVM: arm64: Take the SRCU lock for page table walks in fault injection and AT emulation
KVM: arm64: vgic-its: Drop the translation cache reference only for the erased entry
KVM: SEV: Unmap and unpin the GHCB as needed on vCPU free
KVM: SEV: Decouple the need to sync the GHCB SA from the need to free the SA
KVM: SEV: Move sev_free_vcpu() down below sev_es_unmap_ghcb()
KVM: Don't WARN if memory is dirtied without a vCPU when the VM is dying
KVM: SEV: Read start/end indices of PSC requests exactly once per #VMGEXIT
KVM: SEV: Add an anonymous "psc" struct to track current PSC metadata
KVM: SEV: Make it more obvious when KVM is writing back the current PSC index
KVM: s390: Remove ptep_zap_softleaf_entry()
KVM: s390: Fix possible reference leak in fault-in code
KVM: s390: Prevent memslots outside the ASCE range
KVM: s390: Lock pte when making page secure
KVM: s390: Fix fault-in code
KVM: s390: vsie: Fix rmap handling in _do_shadow_crste()
KVM: s390: Fix guest / virtual address confusion in _essa_clear_cbrl()
...
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Linus Torvalds
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6a08076f00 |
s390 updates for 7.1-rc7
- Enable IOMMUFD and VFIO cdev such that PCI pass-through to QEMU/KVM can optionally utilize native IOMMUFD - With HAVE_ARCH_BUG_FORMAT enabled the BUG infrastructure might misinterpret flags or fault. Fix this by moving the "format" field emission into __BUG_ENTRY() - The generic version of _THIS_IP_ is known to be brittle and may break with current and future GCC and Clang optimizations. Fix it by overriding _THIS_IP_ -----BEGIN PGP SIGNATURE----- iI0EABYKADUWIQQrtrZiYVkVzKQcYivNdxKlNrRb8AUCaiEazRccYWdvcmRlZXZA bGludXguaWJtLmNvbQAKCRDNdxKlNrRb8KNjAP4/q8Q7AW6/lj5MDaOBXzJ+FkEB 3ZJjgWOSvaXRS2fjTAD/cxOnhZELxZ98XcYbF+KrCBbMSUec7zoYzMsGbO0oegQ= =5yIB -----END PGP SIGNATURE----- Merge tag 's390-7.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Alexander Gordeev: - Enable IOMMUFD and VFIO cdev such that PCI pass-through to QEMU/KVM can optionally utilize native IOMMUFD - With HAVE_ARCH_BUG_FORMAT enabled the BUG infrastructure might misinterpret flags or fault. Fix this by moving the "format" field emission into __BUG_ENTRY() - The generic version of _THIS_IP_ is known to be brittle and may break with current and future GCC and Clang optimizations. Fix it by overriding _THIS_IP_ * tag 's390-7.1-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390: Implement _THIS_IP_ using inline asm s390/bug: Always emit format word in __BUG_ENTRY s390/configs: Enable IOMMUFD and VFIO cdev in defconfigs |
||
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Heiko Carstens
|
4a9d66c670 |
s390/percpu: Provide arch_this_cpu_write() implementation
Provide an s390 specific implementation of arch_this_cpu_write() instead of the generic variant. The generic variant uses a quite expensive raw_local_irq_save() / raw_local_irq_restore() pair. Get rid of this by providing an own variant which makes use of the new percpu code section infrastructure. With this the text size of the kernel image is reduced by ~1k (defconfig). Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
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Heiko Carstens
|
9858c19a66 |
s390/percpu: Provide arch_this_cpu_read() implementation
Provide an s390 specific implementation of arch_this_cpu_read() instead of the generic variant. The generic variant uses preempt_disable() / preempt_enable() pair and READ_ONCE(). Get rid of the preempt_disable() / preempt_enable() pairs by providing an own variant which makes use of the new percpu code section infrastructure. With this the text size of the kernel image is reduced by ~1k (defconfig). Also 87 generated preempt_schedule_notrace() function calls within the kernel image (modules not counted) are removed. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
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Heiko Carstens
|
ee8cefbfb0 |
s390/percpu: Use new percpu code section for arch_this_cpu_[and|or]()
Convert arch_this_cpu_[and|or]() to make use of the new percpu code section infrastructure. There is no user of this_cpu_and() and only one user of this_cpu_or() within the kernel. Therefore this conversion has hardly any effect, and also removes only preempt_schedule_notrace() function call. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
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Heiko Carstens
|
593f1aac97 |
s390/percpu: Use new percpu code section for arch_this_cpu_add_return()
Convert arch_this_cpu_add_return() to make use of the new percpu code section infrastructure. With this the text size of the kernel image is reduced by ~4k (defconfig). Also 66 generated preempt_schedule_notrace() function calls within the kernel image (modules not counted) are removed. Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
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Heiko Carstens
|
18ec6c5d7e |
s390/percpu: Use new percpu code section for arch_this_cpu_add()
Convert arch_this_cpu_add() to make use of the new percpu code section
infrastructure.
With this the text size of the kernel image is reduced by ~76kb
(defconfig). Also more than 5300 generated preempt_schedule_notrace()
function calls within the kernel image (modules not counted) are removed.
With:
DEFINE_PER_CPU(long, foo);
void bar(long a) { this_cpu_add(foo, a); }
Old arch_this_cpu_add() looks like this:
00000000000000c0 <bar>:
c0: c0 04 00 00 00 00 jgnop c0 <bar>
c6: eb 01 03 a8 00 6a asi 936,1
cc: c4 18 00 00 00 00 lgrl %r1,cc <bar+0xc>
ce: R_390_GOTENT foo+0x2
d2: e3 10 03 b8 00 08 ag %r1,952
d8: eb 22 10 00 00 e8 laag %r2,%r2,0(%r1)
de: eb ff 03 a8 00 6e alsi 936,-1
e4: a7 a4 00 05 jhe ee <bar+0x2e>
e8: c0 f4 00 00 00 00 jg e8 <bar+0x28>
ea: R_390_PC32DBL __s390_indirect_jump_r14+0x2
ee: c0 f4 00 00 00 00 jg ee <bar+0x2e>
f0: R_390_PLT32DBL preempt_schedule_notrace+0x2
New arch_this_cpu_add() looks like this:
00000000000000c0 <bar>:
c0: c0 04 00 00 00 00 jgnop c0 <bar>
c6: c4 38 00 00 00 00 lgrl %r3,c6 <bar+0x6>
c8: R_390_GOTENT foo+0x2
cc: b9 04 00 43 lgr %r4,%r3
d0: eb 00 43 c0 00 52 mviy 960(%r0),4
d6: e3 40 03 b8 00 08 ag %r4,952
dc: eb 52 40 00 00 e8 laag %r5,%r2,0(%r4)
e2: eb 00 03 c0 00 52 mviy 960,0
e8: c0 f4 00 00 00 00 jg e8 <bar+0x28>
ea: R_390_PC32DBL __s390_indirect_jump_r14+0x2
Note that the conditional function call is removed.
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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||
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Heiko Carstens
|
b50403d4f3 |
s390/percpu: Add missing do { } while (0) constructs
Add missing do { } while (0) constructs in order to avoid potential
build failures.
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260319120503.4046659-1-hca%40linux.ibm.com
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
||
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Heiko Carstens
|
a737737cdb |
s390/percpu: Infrastructure for more efficient this_cpu operations
With the intended removal of PREEMPT_NONE this_cpu operations based on
atomic instructions, guarded with preempt_disable()/preempt_enable() pairs
become more expensive: the preempt_disable() / preempt_enable() pairs are
not optimized away anymore during compile time.
In particular the conditional call to preempt_schedule_notrace() after
preempt_enable() adds additional code and register pressure.
E.g. this simple C code sequence
DEFINE_PER_CPU(long, foo);
long bar(long a) { return this_cpu_add_return(foo, a); }
generates this code:
11a976: eb af f0 68 00 24 stmg %r10,%r15,104(%r15)
11a97c: b9 04 00 ef lgr %r14,%r15
11a980: b9 04 00 b2 lgr %r11,%r2
11a984: e3 f0 ff c8 ff 71 lay %r15,-56(%r15)
11a98a: e3 e0 f0 98 00 24 stg %r14,152(%r15)
11a990: eb 01 03 a8 00 6a asi 936,1 <- __preempt_count_add(1)
11a996: c0 10 00 d2 ac b5 larl %r1,1b70300 <- address of percpu var
11a9a0: e3 10 23 b8 00 08 ag %r1,952 <- add percpu offset
11a9a6: eb ab 10 00 00 e8 laag %r10,%r11,0(%r1) <- atomic op
11a9ac: eb ff 03 a8 00 6e alsi 936,-1 <- __preempt_count_dec_and_test()
11a9b2: a7 54 00 05 jnhe 11a9bc <bar+0x4c>
11a9b6: c0 e5 00 76 d1 bd brasl %r14,ff4d30 <preempt_schedule_notrace>
11a9bc: b9 e8 b0 2a agrk %r2,%r10,%r11
11a9c0: eb af f0 a0 00 04 lmg %r10,%r15,160(%r15)
11a9c6 07 fe br %r14
Even though the above example is more or less the worst case, since the
branch to preempt_schedule_notrace() requires a stackframe, which
otherwise wouldn't be necessary, there is also the conditional jnhe branch
instruction.
Get rid of the conditional branch with the following code sequence:
11a8e6: c0 30 00 d0 c5 0d larl %r3,1b33300
11a8ec: b9 04 00 43 lgr %r4,%r3
11a8f0: eb 00 43 c0 00 52 mviy 960,4
11a8f6: e3 40 03 b8 00 08 ag %r4,952
11a8fc: eb 52 40 00 00 e8 laag %r5,%r2,0(%r4)
11a902: eb 00 03 c0 00 52 mviy 960,0
11a908: b9 08 00 25 agr %r2,%r5
11a90c 07 fe br %r14
The general idea is that this_cpu operations based on atomic instructions
are guarded with mviy instructions:
- The first mviy instruction writes the register number, which contains
the percpu address variable to lowcore. This also indicates that a
percpu code section is executed.
- The first instruction following the mviy instruction must be the ag
instruction which adds the percpu offset to the percpu address register.
- Afterwards the atomic percpu operation follows.
- Then a second mviy instruction writes a zero to lowcore, which indicates
the end of the percpu code section.
- In case of an interrupt/exception/nmi the register number which was
written to lowcore is copied to the exception frame (pt_regs), and a zero
is written to lowcore.
- On return to the previous context it is checked if a percpu code section
was executed (saved register number not zero), and if the process was
migrated to a different cpu. If the percpu offset was already added to
the percpu address register (instruction address does _not_ point to the
ag instruction) the content of the percpu address register is adjusted so
it points to percpu variable of the new cpu.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
||
|
Heiko Carstens
|
495bc70aa3 |
s390/fpu: Move GR_NUM / VX_NUM macros to separate header file
Move GR_NUM / VX_NUM macros to separate insn-common-asm.h header file so they can be reused for non-fpu insn constructs. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
|
Heiko Carstens
|
b8288a3bd6 |
s390/fpu: Shorten GR_NUM / VX_NUM macros
Use the ".irp" directive to get rid of all the repeated ".ifc" usages in fpu-insn-asm.h. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Steffen Eiden <seiden@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
||
|
Frederic Weisbecker
|
ad5a9e14ec |
s390/time: Prepare to stop elapsing in dynticks-idle
Currently the tick subsystem stores the idle cputime accounting in private
fields, allowing cohabitation with architecture idle vtime accounting. The
former is fetched on online CPUs, the latter on offline CPUs.
For consolidation purposes, architecture vtime accounting will continue to
account the cputime but will make a break when the idle tick is
stopped. The dyntick cputime accounting will then be relayed by the tick
subsystem so that the idle cputime is still seen advancing coherently even
when the tick isn't there to flush the idle vtime.
Prepare for that and introduce three new APIs which will be used in
subsequent patches:
- vtime_dynticks_start() is deemed to be called when idle enters in
dyntick mode. The idle cputime that elapsed so far is accumulated
and accounted. Also idle time accounting is ignored.
- vtime_dynticks_stop() is deemed to be called when idle exits from
dyntick mode. The vtime entry clocks are fast-forward to current time
so that idle accounting restarts elapsing from now. Also idle time
accounting is resumed.
- vtime_reset() is deemed to be called from dynticks idle IRQ entry to
fast-forward the clock to current time so that the IRQ time is still
accounted by vtime while nohz cputime is paused.
Also accumulated vtime won't be flushed from dyntick-idle ticks to avoid
accounting twice the idle cputime, along with nohz accounting.
Co-developed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Link: https://patch.msgid.link/20260508131647.43868-7-frederic@kernel.org
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Claudio Imbrenda
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89fa757931 |
KVM: s390: Avoid potentially sleeping while atomic when zapping pages
Factor out try_get_locked_pte(), which behaves similarly to
get_locked_pte(), but does not attempt to allocate missing tables and
performs a spin_trylock() instead of blocking.
The new function is also exported, since it will be used in other
patches.
If intermediate entries are missing, there can be no pte swap entry to
free, so it's safe to ignore them.
This avoids potentially sleeping while atomic.
Fixes:
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Alexander Gordeev
|
670a7eaf88 |
s390/mm: Make PTC and UV call order consistent
In various code paths, page_table_check_pte_clear() is called before converting a secure page, while in others it is called after. Make this consistent and always perform the conversion after the PTC hook has been called. Also make all conversion‑ eligibility condition checks look the same, and rework the one in ptep_get_and_clear_full() slightly. Acked-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
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Heiko Carstens
|
6a312165f7 |
s390/string: Remove strlcat() implementation
strlcat() shouldn't be used anymore (see fortify-string.h), and will be deprecated / removed sooner or later [1]. Therefore remove the s390 implementation of strlcat() in favor of the generic variant. [1] https://lore.kernel.org/all/20260514160719.105084-3-manuelebner@mailbox.org/ Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
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Marco Elver
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7c6535c37d |
s390: Implement _THIS_IP_ using inline asm
Both GCC [1] and Clang [2] consider the generic version of _THIS_IP_ to
be broken:
#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
In particular, the address of a label is only expected to be used with a
computed goto.
While the generic version more or less works today, it is known to be
brittle and may break with current and future optimizations. For
example, Clang -O2 always returns 1 when this function is inlined:
static inline unsigned long get_ip(void)
{ return ({ __label__ __here; __here: (unsigned long)&&__here; }); }
Fix it by overriding _THIS_IP_ in <asm/linkage.h> (which is included by
<linux/instruction_pointer.h>) using an architecture-specific inline asm
version. Additionally, avoiding taking the address of a label prevents
compilers from emitting spurious indirect branch targets (e.g. ENDBR or
BTI) under control-flow integrity schemes.
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120071 [1]
Link: https://github.com/llvm/llvm-project/issues/138272 [2]
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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Yury Norov
|
c02be2ad2b |
uaccess: unify inline vs outline copy_{from,to}_user() selection
The kernel allows arches to select between inline and outline
implementations of the copy_{from,to}_user() by defining individual
INLINE_COPY_FROM_USER and INLINE_COPY_TO_USER, correspondingly. However,
all arches enable or disable them always together.
Without the real use-case for one helper being inlined while the other
outlined, having independent controls is excessive and error prone.
Switch the codebase to the single unified INLINE_COPY_USER control.
Link: https://lore.kernel.org/20260425020857.356850-3-ynorov@nvidia.com
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Viktor Malik <vmalik@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
Jan Polensky
|
3daad7f60a |
s390/bug: Always emit format word in __BUG_ENTRY
When CONFIG_DEBUG_BUGVERBOSE is disabled, the s390 __BUG_ENTRY() macro
omits the format string pointer, so the generated __bug_table entry no
longer matches struct bug_entry.
With HAVE_ARCH_BUG_FORMAT enabled, the generic BUG infrastructure reads
bug_entry::format via bug_get_format(). If the format word is missing,
subsequent fields are read from the wrong offset, which may:
- Misinterpret flags (BUG vs WARN classification errors)
- Fault when dereferencing a misread format pointer
The root cause is that __BUG_ENTRY() delegates format word emission to
__BUG_ENTRY_VERBOSE(), which is conditional on CONFIG_DEBUG_BUGVERBOSE.
Fix this by moving the format field emission directly into __BUG_ENTRY()
so it is always emitted unconditionally. Remove the format parameter from
__BUG_ENTRY_VERBOSE() and keep only file/line emission conditional on
CONFIG_DEBUG_BUGVERBOSE.
Fixes:
|
||
|
Sven Schnelle
|
29eb8a7b6e |
s390/tracing: Add s390-tod clock
In order to allow comparing trace timestamps between different systems or virtual machines on s390, add a s390-tod trace clock. This clock just uses the returned TOD clock value from stcke directly. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |
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|
Masami Hiramatsu (Google)
|
a494d3c8d5 |
ring-buffer: Flush and stop persistent ring buffer on panic
On real hardware, panic and machine reboot may not flush hardware cache
to memory. This means the persistent ring buffer, which relies on a
coherent state of memory, may not have its events written to the buffer
and they may be lost. Moreover, there may be inconsistency with the
counters which are used for validation of the integrity of the
persistent ring buffer which may cause all data to be discarded.
To avoid this issue, stop recording of the ring buffer on panic and
flush the cache of the ring buffer's memory.
Fixes:
|
||
|
Heiko Carstens
|
44e5edace5 |
s390/processor: Implement cpu_relax() with cpu serialization
There are many loops in the form of
while (READ_ONCE(*somelocation))
cpu_relax();
Strictly speaking the architecture requires serialization instead of only a
compiler barrier in the loop so the READ_ONCE() will see an updated value.
However real hardware does not require this (see IBM z Systems Processor
Optimization Primer - FAQ [1]), but it is still recommended to add
serialization. Given that cpu_relax() is doing nothing useful, it does
not hurt to add the single and fast instruction which makes sure that
serialization happens, and such loops may be left a bit faster.
[1] https://community.ibm.com/community/user/viewdocument/microprocessor-optimization-primer
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
|
||
|
Heiko Carstens
|
24b3afcff4 |
s390/processor: Remove duplicated cpu_relax() define
cpu_relax() is defined identically at two different locations. Just like most other architectures remove the implementation at asm/processor.h and only use the one at asm/vdso/processor.h, avoiding code duplication. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> |