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Peter Anvin" , David Woodhouse , Paul Durrant , Gleb Natapov , Raghavendra K T , Suzuki Poulose , Srivatsa Vaddagiri , Jan Kiszka , kvm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" On Mon, Jan 13, 2025, Jim Mattson wrote: > @@ -11288,7 +11287,7 @@ static int __kvm_emulate_halt(struct kvm_vcpu *vcpu, int state, int reason) > if (kvm_vcpu_has_events(vcpu)) > vcpu->arch.pv.pv_unhalted = false; > else > - vcpu->arch.mp_state = state; > + kvm_set_mp_state(vcpu, state); It wouldn't be appropriate in this patch, but I think it makes sense to invoke kvm_set_mp_state() instead of open coding the pv.pv_unhalted change. E.g. if the vCPU is somehow not already RUNNABLE (which is a bug?), then depending on when pv_unhalted is set, KVM could either leave the vCPU in the non-RUNNABLE state (set before __kvm_emulate_halt()), or transition the vCPU to HALTED and then RUNNABLE (pv_unhalted set after the kvm_vcpu_has_events() check). Untested, but this? I'll test and post a patch (assuming it works). diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0aca2a5dac7e..c51499c66cfa 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11292,9 +11292,8 @@ static int __kvm_emulate_halt(struct kvm_vcpu *vcpu, int state, int reason) ++vcpu->stat.halt_exits; if (lapic_in_kernel(vcpu)) { if (kvm_vcpu_has_events(vcpu)) - vcpu->arch.pv.pv_unhalted = false; - else - kvm_set_mp_state(vcpu, state); + state = KVM_MP_STATE_RUNNABLE; + kvm_set_mp_state(vcpu, state); return 1; } else { vcpu->run->exit_reason = reason;