Commit c953f750 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

KVM: PPC: Book3S HV P9: Fix irq disabling in tick accounting 



kvmhv_run_single_vcpu() disables PMIs as well as Linux irqs,
however the tick time accounting code enables and disables irqs and
not PMIs within this region. By chance this might not actually cause
a bug, but it is clearly an incorrect use of the APIs.

Fixes: 2251fbe7 ("KVM: PPC: Book3S HV P9: Improve mtmsrd scheduling by delaying MSR[EE] disable")
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220908132545.4085849-2-npiggin@gmail.com
parent bc91c04b

arch/powerpc/kvm/book3s_hv.c

+2 −2
Original line number Diff line number Diff line
@@ -4634,7 +4634,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, 


	context_tracking_guest_exit();

	if (!vtime_accounting_enabled_this_cpu()) {

		local_irq_enable();

		powerpc_local_irq_pmu_restore(flags);

		/*

		 * Service IRQs here before vtime_account_guest_exit() so any

		 * ticks that occurred while running the guest are accounted to
@@ -4643,7 +4643,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, 
		 * interrupts here, which has the problem that it accounts

		 * interrupt processing overhead to the host.

		 */

		local_irq_disable();

		powerpc_local_irq_pmu_save(flags);

	}

	vtime_account_guest_exit();