KVM: x86: WARN if hrtimer callback for periodic APIC timer fires with period=0

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commit 0ea9494be9 upstream.

WARN and don't restart the hrtimer if KVM's callback runs with the guest's
APIC timer in periodic mode but with a period of '0', as not advancing the
hrtimer's deadline would put the CPU into an infinite loop of hrtimer
events.  Observing a period of '0' should be impossible, even when the
hrtimer is running on a different CPU than the vCPU, as KVM is supposed to
cancel the hrtimer before changing (or zeroing) the period, e.g. when
switching from periodic to one-shot.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251113205114.1647493-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Sean Christopherson 2025-11-13 12:51:11 -08:00 • committed by Greg Kroah-Hartman

parent 3591884201

commit 90d3e9c62a

1 changed files with 1 additions and 1 deletions

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arch/x86/kvm/lapic.c

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