From b31bc24a49037aad7aa00d2b0354e9704d8134dc Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Thu, 8 Sep 2022 23:25:43 +1000 Subject: KVM: PPC: Book3S HV: Update guest state entry/exit accounting to new API Update the guest state and timing entry/exit accounting to use the new API, which was introduced following issues found[1]. KVM HV does possibly call instrumented code inside the guest context, and it does call srcu inside the guest context which is fragile at best. Switch to the new API, moving the guest context inside the srcu_read_lock/unlock region. [1] https://lore.kernel.org/lkml/20220201132926.3301912-1-mark.rutland@arm.com/ Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220908132545.4085849-3-npiggin@gmail.com --- arch/powerpc/kvm/book3s_hv.c | 31 ++++++++++--------------------- 1 file changed, 10 insertions(+), 21 deletions(-) (limited to 'arch/powerpc/kvm/book3s_hv.c') diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 0f8dee657336..23bcda3585fe 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -3854,23 +3854,17 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) for (sub = 0; sub < core_info.n_subcores; ++sub) spin_unlock(&core_info.vc[sub]->lock); - guest_enter_irqoff(); + guest_timing_enter_irqoff(); srcu_idx = srcu_read_lock(&vc->kvm->srcu); + guest_state_enter_irqoff(); this_cpu_disable_ftrace(); - /* - * Interrupts will be enabled once we get into the guest, - * so tell lockdep that we're about to enable interrupts. - */ - trace_hardirqs_on(); - trap = __kvmppc_vcore_entry(); - trace_hardirqs_off(); - this_cpu_enable_ftrace(); + guest_state_exit_irqoff(); srcu_read_unlock(&vc->kvm->srcu, srcu_idx); @@ -3905,11 +3899,10 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) kvmppc_set_host_core(pcpu); - context_tracking_guest_exit(); if (!vtime_accounting_enabled_this_cpu()) { local_irq_enable(); /* - * Service IRQs here before vtime_account_guest_exit() so any + * Service IRQs here before guest_timing_exit_irqoff() so any * ticks that occurred while running the guest are accounted to * the guest. If vtime accounting is enabled, accounting uses * TB rather than ticks, so it can be done without enabling @@ -3918,7 +3911,7 @@ static noinline void kvmppc_run_core(struct kvmppc_vcore *vc) */ local_irq_disable(); } - vtime_account_guest_exit(); + guest_timing_exit_irqoff(); local_irq_enable(); @@ -4609,21 +4602,18 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, trace_kvm_guest_enter(vcpu); - guest_enter_irqoff(); + guest_timing_enter_irqoff(); srcu_idx = srcu_read_lock(&kvm->srcu); + guest_state_enter_irqoff(); this_cpu_disable_ftrace(); - /* Tell lockdep that we're about to enable interrupts */ - trace_hardirqs_on(); - trap = kvmhv_p9_guest_entry(vcpu, time_limit, lpcr, &tb); vcpu->arch.trap = trap; - trace_hardirqs_off(); - this_cpu_enable_ftrace(); + guest_state_exit_irqoff(); srcu_read_unlock(&kvm->srcu, srcu_idx); @@ -4632,11 +4622,10 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, vcpu->cpu = -1; vcpu->arch.thread_cpu = -1; - context_tracking_guest_exit(); if (!vtime_accounting_enabled_this_cpu()) { powerpc_local_irq_pmu_restore(flags); /* - * Service IRQs here before vtime_account_guest_exit() so any + * Service IRQs here before guest_timing_exit_irqoff() so any * ticks that occurred while running the guest are accounted to * the guest. If vtime accounting is enabled, accounting uses * TB rather than ticks, so it can be done without enabling @@ -4645,7 +4634,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, */ powerpc_local_irq_pmu_save(flags); } - vtime_account_guest_exit(); + guest_timing_exit_irqoff(); powerpc_local_irq_pmu_restore(flags); -- cgit