[ Upstream commit 87d0f901a9 ]
Explicitly set/clear CR8 write interception when AVIC is (de)activated to
fix a bug where KVM leaves the interception enabled after AVIC is
activated. E.g. if KVM emulates INIT=>WFS while AVIC is deactivated, CR8
will remain intercepted in perpetuity.
On its own, the dangling CR8 intercept is "just" a performance issue, but
combined with the TPR sync bug fixed by commit d02e48830e ("KVM: SVM:
Sync TPR from LAPIC into VMCB::V_TPR even if AVIC is active"), the danging
intercept is fatal to Windows guests as the TPR seen by hardware gets
wildly out of sync with reality.
Note, VMX isn't affected by the bug as TPR_THRESHOLD is explicitly ignored
when Virtual Interrupt Delivery is enabled, i.e. when APICv is active in
KVM's world. I.e. there's no need to trigger update_cr8_intercept(), this
is firmly an SVM implementation flaw/detail.
WARN if KVM gets a CR8 write #VMEXIT while AVIC is active, as KVM should
never enter the guest with AVIC enabled and CR8 writes intercepted.
Fixes: 3bbf3565f4 ("svm: Do not intercept CR8 when enable AVIC")
Cc: stable@vger.kernel.org
Cc: Jim Mattson <jmattson@google.com>
Cc: Naveen N Rao (AMD) <naveen@kernel.org>
Cc: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Reviewed-by: Naveen N Rao (AMD) <naveen@kernel.org>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260203190711.458413-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
[Squash fix to avic_deactivate_vmcb. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f2f6e67a56 ]
To help with a future change, add a helper to look up the maximum
physical ID depending on the vCPU AVIC mode. No functional change
intended.
Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Naveen N Rao (AMD) <naveen@kernel.org>
Link: https://lore.kernel.org/r/0ab9bf5e20a3463a4aa3a5ea9bbbac66beedf1d1.1757009416.git.naveen@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Stable-dep-of: 87d0f901a9 ("KVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 574ef752d4 ]
KVM allows VMMs to specify the maximum possible APIC ID for a virtual
machine through KVM_CAP_MAX_VCPU_ID capability so as to limit data
structures related to APIC/x2APIC. Utilize the same to set the AVIC
physical max index in the VMCB, similar to VMX. This helps hardware
limit the number of entries to be scanned in the physical APIC ID table
speeding up IPI broadcasts for virtual machines with smaller number of
vCPUs.
Unlike VMX, SVM AVIC requires a single page to be allocated for the
Physical APIC ID table and the Logical APIC ID table, so retain the
existing approach of allocating those during VM init.
Signed-off-by: Naveen N Rao (AMD) <naveen@kernel.org>
Link: https://lore.kernel.org/r/adb07ccdb3394cd79cb372ba6bcc69a4e4d4ef54.1757009416.git.naveen@kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Stable-dep-of: 87d0f901a9 ("KVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9435c1e143 ]
Different GIC types require the private IRQs to be initialised
differently. GICv5 is the culprit as it supports both a different
number of private IRQs, and all of these are PPIs (there are no
SGIs). Moreover, as GICv5 uses the top bits of the interrupt ID to
encode the type, the intid also needs to computed differently.
Up until now, the GIC model has been set after initialising the
private IRQs for a VCPU. Move this earlier to ensure that the GIC
model is available when configuring the private IRQs. While we're at
it, also move the setting of the in_kernel flag and implementation
revision to keep them grouped together as before.
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260128175919.3828384-7-sascha.bischoff@arm.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Stable-dep-of: ac6769c8f9 ("KVM: arm64: Eagerly init vgic dist/redist on vgic creation")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8cc7dd77a1 upstream.
When resuming from s2ram, firmware may re-enable x2apic mode, which may have
been disabled by the kernel during boot either because it doesn't support IRQ
remapping or for other reasons. This causes the kernel to continue using the
xapic interface, while the hardware is in x2apic mode, which causes hangs.
This happens on defconfig + bare metal + s2ram.
Fix this in lapic_resume() by disabling x2apic if the kernel expects it to be
disabled, i.e. when x2apic_mode = 0.
The ACPI v6.6 spec, Section 16.3 [1] says firmware restores either the
pre-sleep configuration or initial boot configuration for each CPU, including
MSR state:
When executing from the power-on reset vector as a result of waking from an
S2 or S3 sleep state, the platform firmware performs only the hardware
initialization required to restore the system to either the state the
platform was in prior to the initial operating system boot, or to the
pre-sleep configuration state. In multiprocessor systems, non-boot
processors should be placed in the same state as prior to the initial
operating system boot.
(further ahead)
If this is an S2 or S3 wake, then the platform runtime firmware restores
minimum context of the system before jumping to the waking vector. This
includes:
CPU configuration. Platform runtime firmware restores the pre-sleep
configuration or initial boot configuration of each CPU (MSR, MTRR,
firmware update, SMBase, and so on). Interrupts must be disabled (for
IA-32 processors, disabled by CLI instruction).
(and other things)
So at least as per the spec, re-enablement of x2apic by the firmware is
allowed if "x2apic on" is a part of the initial boot configuration.
[1] https://uefi.org/specs/ACPI/6.6/16_Waking_and_Sleeping.html#initialization
[ bp: Massage. ]
Fixes: 6e1cb38a2a ("x64, x2apic/intr-remap: add x2apic support, including enabling interrupt-remapping")
Co-developed-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Rahul Bukte <rahul.bukte@sony.com>
Signed-off-by: Shashank Balaji <shashank.mahadasyam@sony.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260306-x2apic-fix-v2-1-bee99c12efa3@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 157820264a upstream.
bpf_get_func_ip() helper function returns the address of the traced
function. It relies on the IP address stored at ctx - 16 by the bpf
trampoline. On 64-bit powerpc, this address is recovered from LR
accounting for OOL trampoline. But the address stored here was off
by 4-bytes. Ensure the address is the actual start of the traced
function.
Reported-by: Abhishek Dubey <adubey@linux.ibm.com>
Fixes: d243b62b7b ("powerpc64/bpf: Add support for bpf trampolines")
Cc: stable@vger.kernel.org
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303181031.390073-3-hbathini@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 01b6ac7272 upstream.
Commit 61688a82e0 ("powerpc/bpf: enable kfunc call") inadvertently
enabled kfunc call support for 32-bit powerpc but that support will
not be possible until ABI mismatch between 32-bit powerpc and eBPF is
handled in 32-bit powerpc JIT code. Till then, advertise support only
for 64-bit powerpc. Also, in powerpc ABI, caller needs to extend the
arguments properly based on signedness. The JIT code is responsible
for handling this explicitly for kfunc calls as verifier can't handle
this for each architecture-specific ABI needs. But this was not taken
care of while kfunc call support was enabled for powerpc. Fix it by
handling this with bpf_jit_find_kfunc_model() and using zero_extend()
& sign_extend() helper functions.
Fixes: 61688a82e0 ("powerpc/bpf: enable kfunc call")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303181031.390073-7-hbathini@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 35e4f2a17e upstream.
The per-device MSI allocation calculation in pseries_irq_domain_alloc()
is clearly wrong. It can still happen to work when nr_irqs is 1.
Correct it.
Fixes: c0215e2d72 ("powerpc/pseries: Fix MSI-X allocation failure when quota is exceeded")
Cc: stable@vger.kernel.org
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
[maddy: Fixed Nilay's reviewed-by tag]
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260302003948.1452016-1-namcao@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5f25805303 upstream.
xor_xc_5() contains a larl 1,2f that is not used by the asm and is not
declared as a clobber. This can corrupt a compiler-allocated value in %r1
and lead to miscompilation. Remove the instruction.
Fixes: 745600ed69 ("s390/lib: Use exrl instead of ex in xor functions")
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Christ <jchrist@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f775276edc upstream.
The inline assembly constraints for xor_xc_2() are incorrect. "bytes",
"p1", and "p2" are input operands, while all three of them are modified
within the inline assembly. Given that the function consists only of this
inline assembly it seems unlikely that this may cause any problems, however
fix this in any case.
Fixes: 2cfc5f9ce7 ("s390/xor: optimized xor routing using the XC instruction")
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20260302133500.1560531-2-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 674c5ff0f4 upstream.
The __stackleak_poison() inline assembly comes with a "count" operand where
the "d" constraint is used. "count" is used with the exrl instruction and
"d" means that the compiler may allocate any register from 0 to 15.
If the compiler would allocate register 0 then the exrl instruction would
not or the value of "count" into the executed instruction - resulting in a
stackframe which is only partially poisoned.
Use the correct "a" constraint, which excludes register 0 from register
allocation.
Fixes: 2a405f6bb3 ("s390/stackleak: provide fast __stackleak_poison() implementation")
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20260302133500.1560531-4-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 17c144f110 upstream.
The check if the initial mapping is sufficient needs to happen much
earlier during bootup. Move this test directly to the start_parisc()
function and use native PDC iodc functions to print the warning, because
panic() and printk() are not functional yet.
This fixes boot when enabling various KALLSYSMS options which need
much more space.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v6.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 97c5550b76 upstream.
contpte_ptep_set_access_flags() compared the gathered ptep_get() value
against the requested entry to detect no-ops. ptep_get() ORs AF/dirty
from all sub-PTEs in the CONT block, so a dirty sibling can make the
target appear already-dirty. When the gathered value matches entry, the
function returns 0 even though the target sub-PTE still has PTE_RDONLY
set in hardware.
For a CPU with FEAT_HAFDBS this gathered view is fine, since hardware may
set AF/dirty on any sub-PTE and CPU TLB behavior is effectively gathered
across the CONT range. But page-table walkers that evaluate each
descriptor individually (e.g. a CPU without DBM support, or an SMMU
without HTTU, or with HA/HD disabled in CD.TCR) can keep faulting on the
unchanged target sub-PTE, causing an infinite fault loop.
Gathering can therefore cause false no-ops when only a sibling has been
updated:
- write faults: target still has PTE_RDONLY (needs PTE_RDONLY cleared)
- read faults: target still lacks PTE_AF
Fix by checking each sub-PTE against the requested AF/dirty/write state
(the same bits consumed by __ptep_set_access_flags()), using raw
per-PTE values rather than the gathered ptep_get() view, before
returning no-op. Keep using the raw target PTE for the write-bit unfold
decision.
Per Arm ARM (DDI 0487) D8.7.1 ("The Contiguous bit"), any sub-PTE in a CONT
range may become the effective cached translation and software must
maintain consistent attributes across the range.
Fixes: 4602e5757b ("arm64/mm: wire up PTE_CONT for user mappings")
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: stable@vger.kernel.org
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: James Houghton <jthoughton@google.com>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Piotr Jaroszynski <pjaroszynski@nvidia.com>
Acked-by: Balbir Singh <balbirs@nvidia.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8475d8fe21 upstream.
The KERNEL_INITIAL_ORDER value defines the initial size (usually 32 or
64 MB) of the page table during bootup. Up until now the whole area was
initialized with PTE entries, but there was no check if we filled too
many entries. Change the code to fill up with so many entries that the
"_end" symbol can be reached by the kernel, but not more entries than
actually fit into the initial PTE tables.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v6.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c25c4aa3f7 upstream.
Commit 143937ca51 ("arm64, mm: avoid always making PTE dirty in
pte_mkwrite()") changed pte_mkwrite_novma() to only clear PTE_RDONLY
when PTE_DIRTY is set. This was to allow writable-clean PTEs for swap
pages that haven't actually been written.
However, this broke kexec and hibernation for some platforms. Both go
through trans_pgd_create_copy() -> _copy_pte(), which calls
pte_mkwrite_novma() to make the temporary linear-map copy fully
writable. With the updated pte_mkwrite_novma(), read-only kernel pages
(without PTE_DIRTY) remain read-only in the temporary mapping.
While such behaviour is fine for user pages where hardware DBM or
trapping will make them writeable, subsequent in-kernel writes by the
kexec relocation code will fault.
Add PTE_DIRTY back to all _PAGE_KERNEL* protection definitions. This was
the case prior to 5.4, commit aa57157be6 ("arm64: Ensure
VM_WRITE|VM_SHARED ptes are clean by default"). With the kernel
linear-map PTEs always having PTE_DIRTY set, pte_mkwrite_novma()
correctly clears PTE_RDONLY.
Fixes: 143937ca51 ("arm64, mm: avoid always making PTE dirty in pte_mkwrite()")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: stable@vger.kernel.org
Reported-by: Jianpeng Chang <jianpeng.chang.cn@windriver.com>
Link: https://lore.kernel.org/r/20251204062722.3367201-1-jianpeng.chang.cn@windriver.com
Cc: Will Deacon <will@kernel.org>
Cc: Huang, Ying <ying.huang@linux.alibaba.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8e732934fb upstream.
The 32MB initial kernel mapping can become too small when CONFIG_KALLSYMS
is used. Increase the mapping to 64 MB in this case.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v6.0+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 47a8aad135 upstream.
vm_get_page_prot() short-circuits the protection_map[] lookup for a
VM_SHADOW_STACK mapping since it uses a different PIE index from the
typical read/write/exec permissions. However, the side effect is that it
also ignores mprotect(PROT_NONE) by creating an accessible PTE.
Special-case the !(vm_flags & VM_ACCESS_FLAGS) flags to use the
protection_map[VM_NONE] permissions instead. No GCS attributes are
required for an inaccessible PTE.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 6497b66ba6 ("arm64/mm: Map pages for guarded control stack")
Cc: stable@vger.kernel.org
Cc: Mark Brown <broonie@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d879ac6756 upstream.
When Linux is running as guest, runs a user space process and the
user space process accesses a page that the host has paged out,
the guest gets a pfault interrupt and schedules a different process.
Without this mechanism the host would have to suspend the whole
virtual CPU until the page has been paged in.
To setup the pfault interrupt the real address of parameter list
should be passed to DIAGNOSE 0x258, but a virtual address is passed
instead.
That has a performance impact, since the pfault setup never succeeds,
the interrupt is never delivered to a guest and the whole virtual CPU
is suspended as result.
Cc: stable@vger.kernel.org
Fixes: c98d2ecae0 ("s390/mm: Uncouple physical vs virtual address spaces")
Reported-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit e9bbfb4bfa ]
It may happen that mm is already released, which leads to kernel panic.
This adds the NULL check for current->mm, similarly to
commit 20afc60f89 ("x86, perf: Check that current->mm is alive before getting user callchain").
I was getting this panic when running a profiling BPF program
(profile.py from bcc-tools):
[26215.051935] Kernel attempted to read user page (588) - exploit attempt? (uid: 0)
[26215.051950] BUG: Kernel NULL pointer dereference on read at 0x00000588
[26215.051952] Faulting instruction address: 0xc00000000020fac0
[26215.051957] Oops: Kernel access of bad area, sig: 11 [#1]
[...]
[26215.052049] Call Trace:
[26215.052050] [c000000061da6d30] [c00000000020fc10] perf_callchain_user_64+0x2d0/0x490 (unreliable)
[26215.052054] [c000000061da6dc0] [c00000000020f92c] perf_callchain_user+0x1c/0x30
[26215.052057] [c000000061da6de0] [c0000000005ab2a0] get_perf_callchain+0x100/0x360
[26215.052063] [c000000061da6e70] [c000000000573bc8] bpf_get_stackid+0x88/0xf0
[26215.052067] [c000000061da6ea0] [c008000000042258] bpf_prog_16d4ab9ab662f669_do_perf_event+0xf8/0x274
[...]
In addition, move storing the top-level stack entry to generic
perf_callchain_user to make sure the top-evel entry is always captured,
even if current->mm is NULL.
Fixes: 20002ded4d ("perf_counter: powerpc: Add callchain support")
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Tested-by: Qiao Zhao <qzhao@redhat.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Reviewed-by: Saket Kumar Bhaskar <skb99@linux.ibm.com>
[Maddy: fixed message to avoid checkpatch format style error]
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260309144045.169427-1-vmalik@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8531d5a83d upstream.
If, for any odd reason, we cannot converge to mapping size that is
completely contained in a memblock region, we fail to install a S2
mapping and go back to the faulting instruction. Rince, repeat.
This happens when faulting in regions that are smaller than a page
or that do not have PAGE_SIZE-aligned boundaries (as witnessed on
an O6 board that refuses to boot in protected mode).
In this situation, fallback to using a PAGE_SIZE mapping anyway --
it isn't like we can go any lower.
Fixes: e728e70580 ("KVM: arm64: Adjust range correctly during host stage-2 faults")
Link: https://lore.kernel.org/r/86wlzr77cn.wl-maz@kernel.org
Cc: stable@vger.kernel.org
Cc: Quentin Perret <qperret@google.com>
Reviewed-by: Quentin Perret <qperret@google.com>
Link: https://patch.msgid.link/20260305132751.2928138-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3989a6d036 upstream.
Initialize all per-vCPU AVIC control fields in the VMCB if AVIC is enabled
in KVM and the VM has an in-kernel local APIC, i.e. if it's _possible_ the
vCPU could activate AVIC at any point in its lifecycle. Configuring the
VMCB if and only if AVIC is active "works" purely because of optimizations
in kvm_create_lapic() to speculatively set apicv_active if AVIC is enabled
*and* to defer updates until the first KVM_RUN. In quotes because KVM
likely won't do the right thing if kvm_apicv_activated() is false, i.e. if
a vCPU is created while APICv is inhibited at the VM level for whatever
reason. E.g. if the inhibit is *removed* before KVM_REQ_APICV_UPDATE is
handled in KVM_RUN, then __kvm_vcpu_update_apicv() will elide calls to
vendor code due to seeing "apicv_active == activate".
Cleaning up the initialization code will also allow fixing a bug where KVM
incorrectly leaves CR8 interception enabled when AVIC is activated without
creating a mess with respect to whether AVIC is activated or not.
Cc: stable@vger.kernel.org
Fixes: 67034bb9dd ("KVM: SVM: Add irqchip_split() checks before enabling AVIC")
Fixes: 6c3e4422dd ("svm: Add support for dynamic APICv")
Reviewed-by: Naveen N Rao (AMD) <naveen@kernel.org>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260203190711.458413-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e2ffe85b6d upstream.
Add KVM_X86_QUIRK_VMCS12_ALLOW_FREEZE_IN_SMM to allow L1 to set
FREEZE_IN_SMM in vmcs12's GUEST_IA32_DEBUGCTL field, as permitted
prior to commit 6b1dd26544 ("KVM: VMX: Preserve host's
DEBUGCTLMSR_FREEZE_IN_SMM while running the guest"). Enable the quirk
by default for backwards compatibility (like all quirks); userspace
can disable it via KVM_CAP_DISABLE_QUIRKS2 for consistency with the
constraints on WRMSR(IA32_DEBUGCTL).
Note that the quirk only bypasses the consistency check. The vmcs02 bit is
still owned by the host, and PMCs are not frozen during virtualized SMM.
In particular, if a host administrator decides that PMCs should not be
frozen during physical SMM, then L1 has no say in the matter.
Fixes: 095686e6fc ("KVM: nVMX: Check vmcs12->guest_ia32_debugctl on nested VM-Enter")
Cc: stable@vger.kernel.org
Signed-off-by: Jim Mattson <jmattson@google.com>
Link: https://patch.msgid.link/20260205231537.1278753-1-jmattson@google.com
[sean: tag for stable@, clean-up and fix goofs in the comment and docs]
Signed-off-by: Sean Christopherson <seanjc@google.com>
[Rename quirk. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 08f97454b7 upstream.
Since 3669ddd8fa ("KVM: arm64: Add a range to pkvm_mappings"),
pKVM tracks the memory that has been mapped into a guest in a
side data structure. Crucially, it uses it to find out whether
a page has already been mapped, and therefore refuses to map it
twice. So far, so good.
However, this very patch completely breaks non-4kB page support,
with guests being unable to boot. The most obvious symptom is that
we take the same fault repeatedly, and not making forward progress.
A quick investigation shows that this is because of the above
rejection code.
As it turns out, there are multiple issues at play:
- while the HPFAR_EL2 register gives you the faulting IPA minus
the bottom 12 bits, it will still give you the extra bits that
are part of the page offset for anything larger than 4kB,
even for a level-3 mapping
- pkvm_pgtable_stage2_map() assumes that the address passed as
a parameter is aligned to the size of the intended mapping
- the faulting address is only aligned for a non-page mapping
When the planets are suitably aligned (pun intended), the guest
faults on a page by accessing it past the bottom 4kB, and extra bits
get set in the HPFAR_EL2 register. If this results in a page mapping
(which is likely with large granule sizes), nothing aligns it further
down, and pkvm_mapping_iter_first() finds an intersection that
doesn't really exist. We assume this is a spurious fault and return
-EAGAIN. And again...
This doesn't hit outside of the protected code, as the page table
code always aligns the IPA down to a page boundary, hiding the issue
for everyone else.
Fix it by always forcing the alignment on vma_pagesize, irrespective
of the value of vma_pagesize.
Fixes: 3669ddd8fa ("KVM: arm64: Add a range to pkvm_mappings")
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://https://patch.msgid.link/20260222141000.3084258-1-maz@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 691417ffe7 ]
When kmeter.c was refactored into km83xx.c in 2011, the "keymile" vendor
prefix was changed to upper-case "Keymile". The devicetree at
arch/powerpc/boot/dts/kmeter1.dts never underwent the same change,
suggesting that this was simply a mistake.
Fixes: 93e2b95c81 ("powerpc/83xx: rename and update kmeter1")
Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Reviewed-by: Heiko Schocher <hs@nabladev.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260303-keymile-v1-1-463a11e71702@posteo.net
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 04e707cb77 ]
With crash hotplug support enabled, additional memory is allocated to
the elfcorehdr kexec segment to accommodate resources added during
memory hotplug events. However, the kdump FDT is not updated with the
same size, which can result in elfcorehdr corruption in the kdump
kernel.
Update elf_headers_sz (the kimage member representing the size of the
elfcorehdr kexec segment) to reflect the total memory allocated for the
elfcorehdr segment instead of the elfcorehdr buffer size at the time of
kdump load. This allows of_kexec_alloc_and_setup_fdt() to reserve the
full elfcorehdr memory in the kdump FDT and prevents elfcorehdr
corruption.
Fixes: 849599b702 ("powerpc/crash: add crash memory hotplug support")
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260227171801.2238847-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 38c64dfe0a ]
Certain versions of kexec don't even work without kernel-end being
added to the device-tree. Add it even if crash-kernel is disabled.
Signed-off-by: Ben Collins <bcollins@kernel.org>
Reviewed-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/2025042122-inescapable-mandrill-8a5ff2@boujee-and-buff
Stable-dep-of: 20197b967a ("powerpc/kexec/core: use big-endian types for crash variables")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0ee95a1d45 ]
Test robot reports the following error with clang-16.0.6:
In file included from kernel/rseq.c:75:
include/linux/rseq_entry.h:141:3: error: invalid operand for instruction
unsafe_get_user(offset, &ucs->post_commit_offset, efault);
^
include/linux/uaccess.h:608:2: note: expanded from macro 'unsafe_get_user'
arch_unsafe_get_user(x, ptr, local_label); \
^
arch/powerpc/include/asm/uaccess.h:518:2: note: expanded from macro 'arch_unsafe_get_user'
__get_user_size_goto(__gu_val, __gu_addr, sizeof(*(p)), e); \
^
arch/powerpc/include/asm/uaccess.h:284:2: note: expanded from macro '__get_user_size_goto'
__get_user_size_allowed(x, ptr, size, __gus_retval); \
^
arch/powerpc/include/asm/uaccess.h:275:10: note: expanded from macro '__get_user_size_allowed'
case 8: __get_user_asm2(x, (u64 __user *)ptr, retval); break; \
^
arch/powerpc/include/asm/uaccess.h:258:4: note: expanded from macro '__get_user_asm2'
" li %1+1,0\n" \
^
<inline asm>:7:5: note: instantiated into assembly here
li 31+1,0
^
1 error generated.
On PPC32, for 64 bits vars a pair of registers is used. Usually the
lower register in the pair is the high part and the higher register is
the low part. GCC uses r3/r4 ... r11/r12 ... r14/r15 ... r30/r31
In older kernel code inline assembly was using %1 and %1+1 to represent
64 bits values. However here it looks like clang uses r31 as high part,
allthough r32 doesn't exist hence the error.
Allthoug %1+1 should work, most places now use %L1 instead of %1+1, so
let's do the same here.
With that change, the build doesn't fail anymore and a disassembly shows
clang uses r17/r18 and r31/r14 pair when GCC would have used r16/r17 and
r30/r31:
Disassembly of section .fixup:
00000000 <.fixup>:
0: 38 a0 ff f2 li r5,-14
4: 3a 20 00 00 li r17,0
8: 3a 40 00 00 li r18,0
c: 48 00 00 00 b c <.fixup+0xc>
c: R_PPC_REL24 .text+0xbc
10: 38 a0 ff f2 li r5,-14
14: 3b e0 00 00 li r31,0
18: 39 c0 00 00 li r14,0
1c: 48 00 00 00 b 1c <.fixup+0x1c>
1c: R_PPC_REL24 .text+0x144
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202602021825.otcItxGi-lkp@intel.com/
Fixes: c20beffeec ("powerpc/uaccess: Use flexible addressing with __put_user()/__get_user()")
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
Acked-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/8ca3a657a650e497a96bfe7acde2f637dadab344.1770103646.git.chleroy@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 8678591b47 upstream.
Commit 3e86e4d74c ("kbuild: keep .modinfo section in
vmlinux.unstripped") added .modinfo to ELF_DETAILS while removing it
from COMMON_DISCARDS, as it was needed in vmlinux.unstripped and
ELF_DETAILS was present in all architecture specific vmlinux linker
scripts. While this shuffle is fine for vmlinux, ELF_DETAILS and
COMMON_DISCARDS may be used by other linker scripts, such as the s390
and x86 compressed boot images, which may not expect to have a .modinfo
section. In certain circumstances, this could result in a bootloader
failing to load the compressed kernel [1].
Commit ddc6cbef3e ("s390/boot/vmlinux.lds.S: Ensure bzImage ends with
SecureBoot trailer") recently addressed this for the s390 bzImage but
the same bug remains for arm, parisc, and x86. The presence of .modinfo
in the x86 bzImage was the root cause of the issue worked around with
commit d50f210913 ("kbuild: align modinfo section for Secureboot
Authenticode EDK2 compat"). misc.c in arch/x86/boot/compressed includes
lib/decompress_unzstd.c, which in turn includes lib/xxhash.c and its
MODULE_LICENSE / MODULE_DESCRIPTION macros due to the STATIC definition.
Split .modinfo out from ELF_DETAILS into its own macro and handle it in
all vmlinux linker scripts. Discard .modinfo in the places where it was
previously being discarded from being in COMMON_DISCARDS, as it has
never been necessary in those uses.
Cc: stable@vger.kernel.org
Fixes: 3e86e4d74c ("kbuild: keep .modinfo section in vmlinux.unstripped")
Reported-by: Ed W <lists@wildgooses.com>
Closes: https://lore.kernel.org/587f25e0-a80e-46a5-9f01-87cb40cfa377@wildgooses.com/ [1]
Tested-by: Ed W <lists@wildgooses.com> # x86_64
Link: https://patch.msgid.link/20260225-separate-modinfo-from-elf-details-v1-1-387ced6baf4b@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4ca191cec1 upstream.
As part of the work to remove the dependency on calling into the decompressor
code (startup_64()) for a UEFI boot, a call to rmpadjust() was removed from
sev_enable() in favor of checking the value of the snp_vmpl variable.
When booting through a non-UEFI path and calling startup_64(), the call to
sev_enable() is performed before the BSS section is zeroed. With the removal
of the rmpadjust() call and the corresponding check of the return code, the
snp_vmpl variable is checked.
Since the kernel is running at VMPL0, the snp_vmpl variable will not have been
set and should be the default value of 0. However, since the call occurs
before the BSS is zeroed, the snp_vmpl variable may not actually be zero,
which will cause the guest boot to fail.
Since the decompressor relocates itself, the BSS would need to be cleared both
before and after the relocation, but this would, in effect, cause all of the
changes to BSS variables before relocation to be lost after relocation.
Instead, move the snp_vmpl variable into the .data section so that it is
initialized and the value made safe during relocation. As a pre-caution
against future changes, move other SEV-related decompressor variables into the
.data section, too.
Fixes: 68a501d7fd ("x86/boot: Drop redundant RMPADJUST in SEV SVSM presence check")
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Changyuan Lyu <changyuanl@google.com>
Tested-by: Kevin Hui <kevinhui@meta.com>
Tested-by: Changyuan Lyu <changyuanl@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/5648b7de5b0a5d0dfef3785f9582b718678c6448.1770217260.git.thomas.lendacky@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9073428bb2 upstream.
The SEV-SNP IBPB-on-Entry feature does not require a guest-side
implementation. It was added in Zen5 h/w, after the first SNP Zen
implementation, and thus was not accounted for when the initial set of SNP
features were added to the kernel.
In its abundant precaution, commit
8c29f01654 ("x86/sev: Add SEV-SNP guest feature negotiation support")
included SEV_STATUS' IBPB-on-Entry bit as a reserved bit, thereby masking
guests from using the feature.
Allow guests to make use of IBPB-on-Entry when supported by the hypervisor, as
the bit is now architecturally defined and safe to expose.
Fixes: 8c29f01654 ("x86/sev: Add SEV-SNP guest feature negotiation support")
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikunj A Dadhania <nikunj@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: stable@kernel.org
Link: https://patch.msgid.link/20260203222405.4065706-2-kim.phillips@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3d1973a0c7 upstream.
CONFIG_EFI_SBAT_FILE can be a relative path. When compiling using a different
output directory (O=) the build currently fails because it can't find the
filename set in CONFIG_EFI_SBAT_FILE:
arch/x86/boot/compressed/sbat.S: Assembler messages:
arch/x86/boot/compressed/sbat.S:6: Error: file not found: kernel.sbat
Add $(srctree) as include dir for sbat.o.
[ bp: Massage commit message. ]
Fixes: 61b57d3539 ("x86/efi: Implement support for embedding SBAT data for x86")
Signed-off-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: <stable@kernel.org>
Link: https://patch.msgid.link/f4eda155b0cef91d4d316b4e92f5771cb0aa7187.1772047658.git.jstancek@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6a8a48644c upstream.
IMC on SPR and EMR does not support sub-channels. In contrast, CPUs
that use gnr_uncores[] (e.g. Granite Rapids and Sierra Forest)
implement two command schedulers (SCH0/SCH1) per memory channel,
providing logically independent command and data paths.
Do not reuse the spr_uncore_imc[] configuration for these CPUs.
Instead, introduce a dedicated gnr_uncore_imc[] with per-scheduler
events, so userspace can monitor SCH0 and SCH1 independently.
On these CPUs, replace cas_count_{read,write} with
cas_count_{read,write}_sch{0,1}. This may break existing userspace
that relies on cas_count_{read,write}, prompting it to switch to the
per-scheduler events, as the legacy event reports only partial
traffic (SCH0).
Fixes: 632c4bf6d0 ("perf/x86/intel/uncore: Support Granite Rapids")
Fixes: cb4a6ccf35 ("perf/x86/intel/uncore: Support Sierra Forest and Grand Ridge")
Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260210005225.20311-1-zide.chen@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a4b0bf6a40 upstream.
efi_free_boot_services() frees memory occupied by EFI_BOOT_SERVICES_CODE
and EFI_BOOT_SERVICES_DATA using memblock_free_late().
There are two issue with that: memblock_free_late() should be used for
memory allocated with memblock_alloc() while the memory reserved with
memblock_reserve() should be freed with free_reserved_area().
More acutely, with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
efi_free_boot_services() is called before deferred initialization of the
memory map is complete.
Benjamin Herrenschmidt reports that this causes a leak of ~140MB of
RAM on EC2 t3a.nano instances which only have 512MB or RAM.
If the freed memory resides in the areas that memory map for them is
still uninitialized, they won't be actually freed because
memblock_free_late() calls memblock_free_pages() and the latter skips
uninitialized pages.
Using free_reserved_area() at this point is also problematic because
__free_page() accesses the buddy of the freed page and that again might
end up in uninitialized part of the memory map.
Delaying the entire efi_free_boot_services() could be problematic
because in addition to freeing boot services memory it updates
efi.memmap without any synchronization and that's undesirable late in
boot when there is concurrency.
More robust approach is to only defer freeing of the EFI boot services
memory.
Split efi_free_boot_services() in two. First efi_unmap_boot_services()
collects ranges that should be freed into an array then
efi_free_boot_services() later frees them after deferred init is complete.
Link: https://lore.kernel.org/all/ec2aaef14783869b3be6e3c253b2dcbf67dbc12a.camel@kernel.crashing.org
Fixes: 916f676f8d ("x86, efi: Retain boot service code until after switching to virtual mode")
Cc: <stable@vger.kernel.org>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0e6f596d6a ]
There are declarations of the variable "eentry", "pcpu_handlers[]" and
"exception_handlers[]" in asm/setup.h, the source files already include
this header file directly or indirectly, so no need to declare them in
the source files, just remove the code.
Cc: stable@vger.kernel.org
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 055c7e7519 ]
After commit 4cd641a79e ("LoongArch: Remove unnecessary checks for ORC
unwinder"), the system can not boot normally under some configs (such as
enable KASAN), there are many error messages "cannot find unwind pc".
The kernel boots normally with the defconfig, so no problem found out at
the first time. Here is one way to reproduce:
cd linux
make mrproper defconfig -j"$(nproc)"
scripts/config -e KASAN
make olddefconfig all -j"$(nproc)"
sudo make modules_install
sudo make install
sudo reboot
The address that can not unwind is not a valid kernel address which is
between "pcpu_handlers[cpu]" and "pcpu_handlers[cpu] + vec_sz" due to
the code of eentry was copied to the new area of pcpu_handlers[cpu] in
setup_tlb_handler(), handle this special case to get the valid address
to unwind normally.
Cc: stable@vger.kernel.org
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4cd641a79e ]
According to the following function definitions, __kernel_text_address()
already checks __module_text_address(), so it should remove the check of
__module_text_address() in bt_address() at least.
int __kernel_text_address(unsigned long addr)
{
if (kernel_text_address(addr))
return 1;
...
return 0;
}
int kernel_text_address(unsigned long addr)
{
bool no_rcu;
int ret = 1;
...
if (is_module_text_address(addr))
goto out;
...
return ret;
}
bool is_module_text_address(unsigned long addr)
{
guard(rcu)();
return __module_text_address(addr) != NULL;
}
Furthermore, there are two checks of __kernel_text_address(), one is in
bt_address() and the other is after calling bt_address(), it looks like
redundant.
Handle the exception address first and then use __kernel_text_address()
to validate the calculated address for exception or the normal address
in bt_address(), then it can remove the check of __kernel_text_address()
after calling bt_address().
Just remove unnecessary checks, no functional changes intended.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Stable-dep-of: 055c7e7519 ("LoongArch: Handle percpu handler address for ORC unwinder")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6517dfbcc9 ]
Add two flags for KVM_CAP_X2APIC_API to allow userspace to control support
for Suppress EOI Broadcasts when using a split IRQCHIP (I/O APIC emulated
by userspace), which KVM completely mishandles. When x2APIC support was
first added, KVM incorrectly advertised and "enabled" Suppress EOI
Broadcast, without fully supporting the I/O APIC side of the equation,
i.e. without adding directed EOI to KVM's in-kernel I/O APIC.
That flaw was carried over to split IRQCHIP support, i.e. KVM advertised
support for Suppress EOI Broadcasts irrespective of whether or not the
userspace I/O APIC implementation supported directed EOIs. Even worse,
KVM didn't actually suppress EOI broadcasts, i.e. userspace VMMs without
support for directed EOI came to rely on the "spurious" broadcasts.
KVM "fixed" the in-kernel I/O APIC implementation by completely disabling
support for Suppress EOI Broadcasts in commit 0bcc3fb95b ("KVM: lapic:
stop advertising DIRECTED_EOI when in-kernel IOAPIC is in use"), but
didn't do anything to remedy userspace I/O APIC implementations.
KVM's bogus handling of Suppress EOI Broadcast is problematic when the
guest relies on interrupts being masked in the I/O APIC until well after
the initial local APIC EOI. E.g. Windows with Credential Guard enabled
handles interrupts in the following order:
1. Interrupt for L2 arrives.
2. L1 APIC EOIs the interrupt.
3. L1 resumes L2 and injects the interrupt.
4. L2 EOIs after servicing.
5. L1 performs the I/O APIC EOI.
Because KVM EOIs the I/O APIC at step #2, the guest can get an interrupt
storm, e.g. if the IRQ line is still asserted and userspace reacts to the
EOI by re-injecting the IRQ, because the guest doesn't de-assert the line
until step #4, and doesn't expect the interrupt to be re-enabled until
step #5.
Unfortunately, simply "fixing" the bug isn't an option, as KVM has no way
of knowing if the userspace I/O APIC supports directed EOIs, i.e.
suppressing EOI broadcasts would result in interrupts being stuck masked
in the userspace I/O APIC due to step #5 being ignored by userspace. And
fully disabling support for Suppress EOI Broadcast is also undesirable, as
picking up the fix would require a guest reboot, *and* more importantly
would change the virtual CPU model exposed to the guest without any buy-in
from userspace.
Add KVM_X2APIC_ENABLE_SUPPRESS_EOI_BROADCAST and
KVM_X2APIC_DISABLE_SUPPRESS_EOI_BROADCAST flags to allow userspace to
explicitly enable or disable support for Suppress EOI Broadcasts. This
gives userspace control over the virtual CPU model exposed to the guest,
as KVM should never have enabled support for Suppress EOI Broadcast without
userspace opt-in. Not setting either flag will result in legacy quirky
behavior for backward compatibility.
Disallow fully enabling SUPPRESS_EOI_BROADCAST when using an in-kernel
I/O APIC, as KVM's history/support is just as tragic. E.g. it's not clear
that commit c806a6ad35 ("KVM: x86: call irq notifiers with directed EOI")
was entirely correct, i.e. it may have simply papered over the lack of
Directed EOI emulation in the I/O APIC.
Note, Suppress EOI Broadcasts is defined only in Intel's SDM, not in AMD's
APM. But the bit is writable on some AMD CPUs, e.g. Turin, and KVM's ABI
is to support Directed EOI (KVM's name) irrespective of guest CPU vendor.
Fixes: 7543a635aa ("KVM: x86: Add KVM exit for IOAPIC EOIs")
Closes: https://lore.kernel.org/kvm/7D497EF1-607D-4D37-98E7-DAF95F099342@nutanix.com
Cc: stable@vger.kernel.org
Suggested-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Khushit Shah <khushit.shah@nutanix.com>
Link: https://patch.msgid.link/20260123125657.3384063-1-khushit.shah@nutanix.com
[sean: clean up minor formatting goofs and fix a comment typo]
Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit faa6baa364 ]
Replace verbatim license text with a `SPDX-License-Identifier`.
The comment header mis-attributes this license to be "X11", but the
license text does not include the last line "Except as contained in this
notice, the name of the X Consortium shall not be used in advertising or
otherwise to promote the sale, use or other dealings in this Software
without prior written authorization from the X Consortium.". Therefore,
this license is actually equivalent to the SPDX "MIT" license (confirmed
by text diffing).
Cc: Andrej Rosano <andrej@inversepath.com>
Signed-off-by: Bence Csókás <csokas.bence@prolan.hu>
Acked-by: Andrej Rosano <andrej.rosano@reversec.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Stable-dep-of: 43d67ec26b ("PCI: dwc: ep: Fix resizable BAR support for multi-PF configurations")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 46c56b7371 ]
The pcie bus address should be mapped 1:1 to the cpu side MMIO address, so
that there is no same address allocated from normal system memory. Otherwise
it's broken if the same address assigned to the EP for DMA purpose.Fix it to
sync with the vendor BSP.
Fixes: 0acf4fa7f1 ("arm64: dts: rockchip: add PCIe3 support for rk3588")
Fixes: 8d81b77f4c ("arm64: dts: rockchip: add rk3588 PCIe2 support")
Cc: stable@vger.kernel.org
Cc: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Link: https://patch.msgid.link/1767600929-195341-2-git-send-email-shawn.lin@rock-chips.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f63ea193a4 ]
The pcie bus address should be mapped 1:1 to the cpu side MMIO address, so
that there is no same address allocated from normal system memory. Otherwise
it's broken if the same address assigned to the EP for DMA purpose.Fix it to
sync with the vendor BSP.
Fixes: 568a67e742 ("arm64: dts: rockchip: Fix rk356x PCIe register and range mappings")
Fixes: 66b51ea7d7 ("arm64: dts: rockchip: Add rk3568 PCIe2x1 controller")
Cc: stable@vger.kernel.org
Cc: Andrew Powers-Holmes <aholmes@omnom.net>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Link: https://patch.msgid.link/1767600929-195341-1-git-send-email-shawn.lin@rock-chips.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d55c571e43 ]
This script
#!/usr/bin/bash
echo 0 > /proc/sys/kernel/randomize_va_space
echo 'void main(void) {}' > TEST.c
# -fcf-protection to ensure that the 1st endbr32 insn can't be emulated
gcc -m32 -fcf-protection=branch TEST.c -o test
bpftrace -e 'uprobe:./test:main {}' -c ./test
"hangs", the probed ./test task enters an endless loop.
The problem is that with randomize_va_space == 0
get_unmapped_area(TASK_SIZE - PAGE_SIZE) called by xol_add_vma() can not
just return the "addr == TASK_SIZE - PAGE_SIZE" hint, this addr is used
by the stack vma.
arch_get_unmapped_area_topdown() doesn't take TIF_ADDR32 into account and
in_32bit_syscall() is false, this leads to info.high_limit > TASK_SIZE.
vm_unmapped_area() happily returns the high address > TASK_SIZE and then
get_unmapped_area() returns -ENOMEM after the "if (addr > TASK_SIZE - len)"
check.
handle_swbp() doesn't report this failure (probably it should) and silently
restarts the probed insn. Endless loop.
I think that the right fix should change the x86 get_unmapped_area() paths
to rely on TIF_ADDR32 rather than in_32bit_syscall(). Note also that if
CONFIG_X86_X32_ABI=y, in_x32_syscall() falsely returns true in this case
because ->orig_ax = -1.
But we need a simple fix for -stable, so this patch just sets TS_COMPAT if
the probed task is 32-bit to make in_ia32_syscall() true.
Fixes: 1b028f784e ("x86/mm: Introduce mmap_compat_base() for 32-bit mmap()")
Reported-by: Paulo Andrade <pandrade@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/all/aV5uldEvV7pb4RA8@redhat.com/
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/aWO7Fdxn39piQnxu@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ae25884ad7 ]
When userspace is interrupted at the start of a function, before we
get a chance to complete the frame, unwind will miss one caller.
X86 has a uprobe specific fixup for this, add bits to the generic
unwinder to support this.
Suggested-by: Jens Remus <jremus@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251024145156.GM4068168@noisy.programming.kicks-ass.net
Stable-dep-of: d55c571e43 ("x86/uprobes: Fix XOL allocation failure for 32-bit tasks")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 49cf34c081 ]
Use ARCH_INIT_USER_FP_FRAME to describe how frame pointers are unwound
on x86, and enable CONFIG_HAVE_UNWIND_USER_FP accordingly so the
unwind_user interfaces can be used.
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20250827193828.347397433@kernel.org
Stable-dep-of: d55c571e43 ("x86/uprobes: Fix XOL allocation failure for 32-bit tasks")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ead63640d4 ]
Ignore -EBUSY when checking nested events after exiting a blocking state
while L2 is active, as exiting to userspace will generate a spurious
userspace exit, usually with KVM_EXIT_UNKNOWN, and likely lead to the VM's
demise. Continuing with the wakeup isn't perfect either, as *something*
has gone sideways if a vCPU is awakened in L2 with an injected event (or
worse, a nested run pending), but continuing on gives the VM a decent
chance of surviving without any major side effects.
As explained in the Fixes commits, it _should_ be impossible for a vCPU to
be put into a blocking state with an already-injected event (exception,
IRQ, or NMI). Unfortunately, userspace can stuff MP_STATE and/or injected
events, and thus put the vCPU into what should be an impossible state.
Don't bother trying to preserve the WARN, e.g. with an anti-syzkaller
Kconfig, as WARNs can (hopefully) be added in paths where _KVM_ would be
violating x86 architecture, e.g. by WARNing if KVM attempts to inject an
exception or interrupt while the vCPU isn't running.
Cc: Alessandro Ratti <alessandro@0x65c.net>
Cc: stable@vger.kernel.org
Fixes: 26844fee6a ("KVM: x86: never write to memory from kvm_vcpu_check_block()")
Fixes: 45405155d8 ("KVM: x86: WARN if a vCPU gets a valid wakeup that KVM can't yet inject")
Link: https://syzkaller.appspot.com/text?tag=ReproC&x=10d4261a580000
Reported-by: syzbot+1522459a74d26b0ac33a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/671bc7a7.050a0220.455e8.022a.GAE@google.com
Link: https://patch.msgid.link/20260109030657.994759-1-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit adbf61cc47 ]
ACPI v6.3 defined a new "Online Capable" MADT LAPIC flag. This bit is
used in conjunction with the "Enabled" MADT LAPIC flag to determine if
a CPU can be enabled/hotplugged by the OS after boot.
Before the new bit was defined, the "Enabled" bit was explicitly
described like this (ACPI v6.0 wording provided):
"If zero, this processor is unusable, and the operating system
support will not attempt to use it"
This means that CPU hotplug (based on MADT) is not possible. Many BIOS
implementations follow this guidance. They may include LAPIC entries in
MADT for unavailable CPUs, but since these entries are marked with
"Enabled=0" it is expected that the OS will completely ignore these
entries.
However, QEMU will do the same (include entries with "Enabled=0") for
the purpose of allowing CPU hotplug within the guest.
Comment from QEMU function pc_madt_cpu_entry():
/* ACPI spec says that LAPIC entry for non present
* CPU may be omitted from MADT or it must be marked
* as disabled. However omitting non present CPU from
* MADT breaks hotplug on linux. So possible CPUs
* should be put in MADT but kept disabled.
*/
Recent Linux topology changes broke the QEMU use case. A following fix
for the QEMU use case broke bare metal topology enumeration.
Rework the Linux MADT LAPIC flags check to allow the QEMU use case only
for guests and to maintain the ACPI spec behavior for bare metal.
Remove an unnecessary check added to fix a bare metal case introduced by
the QEMU "fix".
[ bp: Change logic as Michal suggested. ]
[ mingo: Removed misapplied -stable tag. ]
Fixes: fed8d8773b ("x86/acpi/boot: Correct acpi_is_processor_usable() check")
Fixes: f0551af021 ("x86/topology: Ignore non-present APIC IDs in a present package")
Closes: https://lore.kernel.org/r/20251024204658.3da9bf3f.michal.pecio@gmail.com
Reported-by: Michal Pecio <michal.pecio@gmail.com>
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Michal Pecio <michal.pecio@gmail.com>
Tested-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Link: https://lore.kernel.org/20251111145357.4031846-1-yazen.ghannam@amd.com
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ef06fd16d4 ]
struct bpf_plt contains a u64 target field. Currently, the BPF JIT
allocator requests an alignment of 4 bytes (sizeof(u32)) for the JIT
buffer.
Because the base address of the JIT buffer can be 4-byte aligned (e.g.,
ending in 0x4 or 0xc), the relative padding logic in build_plt() fails
to ensure that target lands on an 8-byte boundary.
This leads to two issues:
1. UBSAN reports misaligned-access warnings when dereferencing the
structure.
2. More critically, target is updated concurrently via WRITE_ONCE() in
bpf_arch_text_poke() while the JIT'd code executes ldr. On arm64,
64-bit loads/stores are only guaranteed to be single-copy atomic if
they are 64-bit aligned. A misaligned target risks a torn read,
causing the JIT to jump to a corrupted address.
Fix this by increasing the allocation alignment requirement to 8 bytes
(sizeof(u64)) in bpf_jit_binary_pack_alloc(). This anchors the base of
the JIT buffer to an 8-byte boundary, allowing the relative padding math
in build_plt() to correctly align the target field.
Fixes: b2ad54e153 ("bpf, arm64: Implement bpf_arch_text_poke() for arm64")
Signed-off-by: Fuad Tabba <tabba@google.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20260226075525.233321-1-tabba@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
