kernel/arch/x86/kvm/i8254.c, branch linux-rolling-stable

Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-08-03T23:23:09Z

Pull non-MM updates from Andrew Morton: "Significant patch series in this pull request: - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets us closer to being able to remove page->mapping - "relayfs: misc changes" (Jason Xing) does some maintenance and minor feature addition work in relayfs - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches us from static preallocation of the kdump crashkernel's working memory over to dynamic allocation. So the difficulty of a-priori estimation of the second kernel's needs is removed and the first kernel obtains extra memory - "generalize panic_print's dump function to be used by other kernel parts" (Feng Tang) implements some consolidation and rationalization of the various ways in which a failing kernel splats information at the operator * tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits) tools/getdelays: add backward compatibility for taskstats version kho: add test for kexec handover delaytop: enhance error logging and add PSI feature description samples: Kconfig: fix spelling mistake "instancess" -> "instances" fat: fix too many log in fat_chain_add() scripts/spelling.txt: add notifer||notifier to spelling.txt xen/xenbus: fix typo "notifer" net: mvneta: fix typo "notifer" drm/xe: fix typo "notifer" cxl: mce: fix typo "notifer" KVM: x86: fix typo "notifer" MAINTAINERS: add maintainers for delaytop ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below() ucount: fix atomic_long_inc_below() argument type kexec: enable CMA based contiguous allocation stackdepot: make max number of pools boot-time configurable lib/xxhash: remove unused functions init/Kconfig: restore CONFIG_BROKEN help text lib/raid6: update recov_rvv.c zero page usage docs: update docs after introducing delaytop ...

KVM: x86: fix typo "notifer"

2025-08-02T19:01:39Z

Patch series "treewide: Fix typo "notifer"", v3. There are some spelling mistakes of 'notifer' in comments which should be 'notifier'. Fix them and add it to scripts/spelling.txt. This patch (of 8): There are some spelling mistakes of 'notifer' which should be 'notifier'. Link: https://lkml.kernel.org/r/576F0D85F6853074+20250722072734.19367-1-wangyuli@uniontech.com Link: https://lkml.kernel.org/r/7F05778C3A1A9F8B+20250722073431.21983-1-wangyuli@uniontech.com Signed-off-by: WangYuli Signed-off-by: Andrew Morton

KVM: x86: Don't clear PIT's IRQ line status when destroying PIT

2025-06-20T20:52:48Z

Don't bother clearing the PIT's IRQ line status when destroying the PIT, as userspace can't possibly rely on KVM to lower the IRQ line in any sane use case, and it's not at all obvious that clearing the PIT's IRQ line is correct/desirable in kvm_create_pit()'s error path. When called from kvm_arch_pre_destroy_vm(), the entire VM is being torn down and thus {kvm_pic,kvm_ioapic}.irq_states are unreachable. As for the error path in kvm_create_pit(), the only way the PIT's bit in irq_states can be set is if userspace raises the associated IRQ before KVM_CREATE_PIT{2} completes. Forcefully clearing the bit would clobber userspace's input, nonsensical though that input may be. Not to mention that no known VMM will continue on if PIT creation fails. Acked-by: Kai Huang Link: https://lore.kernel.org/r/20250611213557.294358-12-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: x86: Hardcode the PIT IRQ source ID to '2'

2025-06-20T20:52:47Z

Hardcode the PIT's source IRQ ID to '2' instead of "finding" that bit 2 is always the first available bit in irq_sources_bitmap. Bits 0 and 1 are set/reserved by kvm_arch_init_vm(), i.e. long before kvm_create_pit() can be invoked, and KVM allows at most one in-kernel PIT instance, i.e. it's impossible for the PIT to find a different free bit (there are no other users of kvm_request_irq_source_id(). Delete the now-defunct irq_sources_bitmap and all its associated code. Acked-by: Kai Huang Link: https://lore.kernel.org/r/20250611213557.294358-11-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: x86: Move kvm_{request,free}_irq_source_id() to i8254.c (PIT)

2025-06-20T20:52:47Z

Move kvm_{request,free}_irq_source_id() to i8254.c, i.e. the dedicated PIT emulation file, in anticipation of removing them entirely in favor of hardcoding the PIT's "requested" source ID (the source ID can only ever be '2', and the request can never fail). No functional change intended. Acked-by: Kai Huang Link: https://lore.kernel.org/r/20250611213557.294358-10-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: x86: Move PIT ioctl helpers to i8254.c

2025-06-20T20:52:44Z

Move the PIT ioctl helpers to i8254.c, i.e. to the file that implements PIT emulation. Eliminating PIT code in x86.c will allow adding a Kconfig to control support for in-kernel I/O APIC, PIC, and PIT emulation with minimal #ifdefs. Opportunistically make kvm_pit_set_reinject() and kvm_pit_load_count() local to i8254.c as they were only publicly visible to make them available to the ioctl helpers. No functional change intended. Acked-by: Kai Huang Link: https://lore.kernel.org/r/20250611213557.294358-6-seanjc@google.com Signed-off-by: Sean Christopherson

KVM: x86: Switch to use hrtimer_setup()

2025-02-18T09:32:31Z

hrtimer_setup() takes the callback function pointer as argument and initializes the timer completely. Replace hrtimer_init() and the open coded initialization of hrtimer::function with the new setup mechanism. Patch was created by using Coccinelle. Signed-off-by: Nam Cao Signed-off-by: Thomas Gleixner Acked-by: Sean Christopherson Link: https://lore.kernel.org/all/5051cfe7ed48ef9913bf2583eeca6795cb53d6ae.1738746821.git.namcao@linutronix.de

treewide: Introduce kthread_run_worker[_on_cpu]()

2025-01-08T17:15:03Z

kthread_create() creates a kthread without running it yet. kthread_run() creates a kthread and runs it. On the other hand, kthread_create_worker() creates a kthread worker and runs it. This difference in behaviours is confusing. Also there is no way to create a kthread worker and affine it using kthread_bind_mask() or kthread_affine_preferred() before starting it. Consolidate the behaviours and introduce kthread_run_worker[_on_cpu]() that behaves just like kthread_run(). kthread_create_worker[_on_cpu]() will now only create a kthread worker without starting it. Signed-off-by: Frederic Weisbecker Signed-off-by: Dan Carpenter

KVM: x86: Unify pr_fmt to use module name for all KVM modules

2022-12-29T20:47:35Z

Define pr_fmt using KBUILD_MODNAME for all KVM x86 code so that printks use consistent formatting across common x86, Intel, and AMD code. In addition to providing consistent print formatting, using KBUILD_MODNAME, e.g. kvm_amd and kvm_intel, allows referencing SVM and VMX (and SEV and SGX and ...) as technologies without generating weird messages, and without causing naming conflicts with other kernel code, e.g. "SEV: ", "tdx: ", "sgx: " etc.. are all used by the kernel for non-KVM subsystems. Opportunistically move away from printk() for prints that need to be modified anyways, e.g. to drop a manual "kvm: " prefix. Opportunistically convert a few SGX WARNs that are similarly modified to WARN_ONCE; in the very unlikely event that the WARNs fire, odds are good that they would fire repeatedly and spam the kernel log without providing unique information in each print. Note, defining pr_fmt yields undesirable results for code that uses KVM's printk wrappers, e.g. vcpu_unimpl(). But, that's a pre-existing problem as SVM/kvm_amd already defines a pr_fmt, and thankfully use of KVM's wrappers is relatively limited in KVM x86 code. Signed-off-by: Sean Christopherson Reviewed-by: Paul Durrant Message-Id: <20221130230934.1014142-35-seanjc@google.com> Signed-off-by: Paolo Bonzini

KVM: x86: PIT: Preserve state of speaker port data bit

2022-06-08T17:06:20Z

Currently the state of the speaker port (0x61) data bit (bit 1) is not saved in the exported state (kvm_pit_state2) and hence is lost when re-constructing guest state. This patch removes the 'speaker_data_port' field from kvm_kpit_state and instead tracks the state using a new KVM_PIT_FLAGS_SPEAKER_DATA_ON flag defined in the API. Signed-off-by: Paul Durrant Message-Id: <20220531124421.1427-1-pdurrant@amazon.com> Signed-off-by: Paolo Bonzini