linux/arch/x86, branch master

Merge tag 'x86-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-05-17T18:40:18Z

Pull x86 fix from Ingo Molnar: - Fix x86 boot crash for non-kjump kexecs (David Woodhouse) * tag 'x86-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kexec: Push kjump return address even for non-kjump kexec

Merge tag 'ras-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2026-05-17T17:50:13Z

Pull MCE fix from Ingo Molnar: - Fix an MCE polling interval adjustment regression (Borislav Petkov) * tag 'ras-urgent-2026-05-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Restore MCA polling interval halving

Merge tag 'for-linus-7.1b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2026-05-15T18:24:51Z

Pull xen fixes from Juergen Gross: - one simple cleanup - a fix for a corner case when running as Xen PV dom0 - a fix of a regression for Xen PV guests, introduced in 7.0 * tag 'for-linus-7.1b-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: x86/xen: Tolerate nested XEN_LAZY_MMU entering/leaving x86/xen: Fix xen_e820_swap_entry_with_ram() xen/arm: Replace __ASSEMBLY__ with __ASSEMBLER__ in interface.h

Merge tag 'acpi-7.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

2026-05-14T21:06:31Z

Pull ACPI support fixes from Rafael Wysocki: "These fix several platform drivers that use the ACPI companion of the given platform device without checking its presence, which may lead to a NULL pointer dereference or other kind of malfunction if the driver is forced to match a device without an ACPI companion via driver override, and restore debug log level for some messages in the ACPI CPPC library: - Check ACPI_COMPANION() against NULL during probe in several core ACPI device drivers (Rafael Wysocki) - Restore log level of messages in amd_set_max_freq_ratio() (Mario Limonciello)" * tag 'acpi-7.1-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI: PAD: xen: Check ACPI_COMPANION() against NULL ACPI: driver: Check ACPI_COMPANION() against NULL during probe Revert "ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn"

Merge branch 'acpi-cppc'

2026-05-14T20:46:33Z

Merge a revert of an ACPI CPPC commit that increased the log level of some debug messages which turned out to be a bad idea: - Restore log level of messages in amd_set_max_freq_ratio() (Mario Limonciello) * acpi-cppc: Revert "ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn"

x86/xen: Tolerate nested XEN_LAZY_MMU entering/leaving

2026-05-14T16:33:05Z

With the support of nested lazy mmu sections it can happen that arch_enter_lazy_mmu_mode() is being called twice without a call of arch_leave_lazy_mmu_mode() in between, as the lazy_mmu_*() helpers are not disabling preemption when checking for nested lazy mmu sections. This is a problem when running as a Xen PV guest, as xen_enter_lazy_mmu() and xen_leave_lazy_mmu() don't tolerate this case. Fix that in xen_enter_lazy_mmu() and xen_leave_lazy_mmu() in order not to hurt all other lazy mmu mode users. Fixes: 291b3abed657 ("x86/xen: use lazy_mmu_state when context-switching") Tested-by: Marek Marczykowski-Górecki Signed-off-by: Juergen Gross Message-ID: <20260508143933.493013-1-jgross@suse.com>

x86/xen: Fix xen_e820_swap_entry_with_ram()

2026-05-14T16:33:05Z

When swapping a not page-aligned E820 map entry with RAM, the start address of the modified entry is calculated wrong (the offset into the page is subtracted instead of being added to the page address). Fixes: be35d91c8880 ("xen: tolerate ACPI NVS memory overlapping with Xen allocated memory") Reported-by: Jan Beulich Reviewed-by: Jan Beulich Signed-off-by: Juergen Gross Message-ID: <20260505102417.208138-1-jgross@suse.com>

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2026-05-13T18:53:51Z

Pull kvm fixes from Paolo Bonzini: "arm64: - Add the pKVM side of the workaround for ARM's erratum 4193714, provided that the EL3 firmware does its part of the job. KVM will refuse to initialise otherwise - Correctly handle 52bit VAs for guest EL2 stage-1 translations when running under NV with E2H==0 - Correctly deal with permission faults in guest_memfd memslots - Fix the steal-time selftest after the infrastructure was reworked - Make sure the host cannot pass a non-sensical clock update to the EL2 tracing infrastructure - Appoint Steffen Eiden as a reviewer in anticipation of the KVM/s390 ability to run arm64 guests, which will inevitably lead to arm64 code being directly used on s390 - Make sure that EL2 is configured with both exception entry and exit being Context Synchronization Events - Handle the current vcpu being NULL on EL2 panic - Fix the selftest_vcpu memcache being empty at the point of donation or sharing - Check that the memcache has enough capacity before engaging on the share/donate path - Fix __deactivate_fgt() to use its parameter rather than a variable in the macro context s390: - Fix array overrun with large amounts of PCI devices x86: - Never use L0's PAUSE loop exiting while L2 is running, since it's unlikely that a nested guest will help solving the hypervisor's spinlock contention - Fix emulation of MOVNTDQA - Fix typo in Xen hypercall tracepoint - Add back an optimization that was left behind when recently fixing a bug - Add module parameter to disable CET, whose implementation seems to have issues. For now it remains enabled by default Generic: - Reject offset causing an unsigned overflow in kvm_reset_dirty_gfn() Documentation: - Update stale links Selftests: - Fix guest_memfd_test with host page size > guest page size" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits) KVM: VMX: introduce module parameter to disable CET KVM: x86: Swap the dst and src operand for MOVNTDQA KVM: x86: use again the flush argument of __link_shadow_page() KVM: selftests: Ensure gmem file sizes are multiple of host page size Documentation: kvm: update links in the references section of AMD Memory Encryption KVM: nSVM: Never use L0's PAUSE loop exiting while L2 is running KVM: x86: Fix Xen hypercall tracepoint argument assignment KVM: Reject wrapped offset in kvm_reset_dirty_gfn() KVM: arm64: Pre-check vcpu memcache for host->guest donate KVM: arm64: Pre-check vcpu memcache for host->guest share KVM: arm64: Seed pkvm_ownership_selftest vcpu memcache KVM: arm64: Fix __deactivate_fgt macro parameter typo KVM: arm64: Guard against NULL vcpu on VHE hyp panic path KVM: arm64: Make EL2 exception entry and exit context-synchronization events MAINTAINERS: Add Steffen as reviewer for KVM/arm64 KVM: arm64: Remove potential UB on nvhe tracing clock update KVM: selftests: arm64: Fix steal_time test after UAPI refactoring KVM: arm64: Handle permission faults with guest_memfd KVM: arm64: nv: Consider the DS bit when translating TCR_EL2 KVM: arm64: Work around C1-Pro erratum 4193714 for protected guests ...

x86/mce: Restore MCA polling interval halving

2026-05-13T15:38:35Z

RongQing reported that the MCA polling interval doesn't halve when an error gets logged. It was traced down to the commit in Fixes:, because: mce_timer_fn() |-> mce_poll_banks() |-> machine_check_poll() |-> mce_log() which will queue the work and return. Now, back in mce_timer_fn(): /* * Alert userspace if needed. If we logged an MCE, reduce the polling * interval, otherwise increase the polling interval. */ if (mce_notify_irq()) <--- here we haven't ran the notifier chain yet so mce_need_notify is not set yet so this won't hit and we won't halve the interval iv. Now the notifier chain runs. mce_early_notifier() sets the bit, does mce_notify_irq(), that clears the bit and then the notifier chain a little later logs the error. So this is a silly timing issue. But, that's all unnecessary. All it needs to happen here is, the "should we notify of a logged MCE" mce_notify_irq() asks, should be simply a question to the mce gen pool: "Are you empty?" And that then turns into a simple yes or no answer and it all JustWorks(tm). So do that and also distribute the functionality where it belongs: - Print that MCE events have been logged in mce_log() - Trigger the mcelog tool specific work in the first notifier As a result, mce_notify_irq() can go now. Fixes: 011d82611172 ("RAS: Add a Corrected Errors Collector") Reported-by: Li RongQing Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Qiuxu Zhuo Tested-by: Qiuxu Zhuo Link: https://lore.kernel.org/r/20260112082747.2842-1-lirongqing@baidu.com

KVM: VMX: introduce module parameter to disable CET

2026-05-13T13:38:22Z

There have been reports of host hangs caused by CET virtualization. Until these are analyzed further, introduce a module parameter that makes it possible to easily disable it. Link: https://lore.kernel.org/all/85548beb-1486-40f9-beb4-632c78e3360b@proxmox.com/ Cc: David Riley Signed-off-by: Paolo Bonzini