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Tue, 23 Nov 2021 01:54:28 -0800 (PST) Received: from bobo.ibm.com ([124.170.11.53]) by smtp.gmail.com with ESMTPSA id j8sm12662176pfc.8.2021.11.23.01.54.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Nov 2021 01:54:27 -0800 (PST) From: Nicholas Piggin To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v4 50/53] KVM: PPC: Book3S HV P9: Remove most of the vcore logic Date: Tue, 23 Nov 2021 19:52:28 +1000 Message-Id: <20211123095231.1036501-51-npiggin@gmail.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20211123095231.1036501-1-npiggin@gmail.com> References: <20211123095231.1036501-1-npiggin@gmail.com> MIME-Version: 1.0 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Nicholas Piggin Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" The P9 path always uses one vcpu per vcore, so none of the vcore, locks, stolen time, blocking logic, shared waitq, etc., is required. Remove most of it. Signed-off-by: Nicholas Piggin --- arch/powerpc/kvm/book3s_hv.c | 147 ++++++++++++++++++++--------------- 1 file changed, 85 insertions(+), 62 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 00c1e102c103..e56804b84804 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -276,6 +276,8 @@ static void kvmppc_core_start_stolen(struct kvmppc_vcore *vc, u64 tb) { unsigned long flags; + WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300)); + spin_lock_irqsave(&vc->stoltb_lock, flags); vc->preempt_tb = tb; spin_unlock_irqrestore(&vc->stoltb_lock, flags); @@ -285,6 +287,8 @@ static void kvmppc_core_end_stolen(struct kvmppc_vcore *vc, u64 tb) { unsigned long flags; + WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300)); + spin_lock_irqsave(&vc->stoltb_lock, flags); if (vc->preempt_tb != TB_NIL) { vc->stolen_tb += tb - vc->preempt_tb; @@ -297,7 +301,12 @@ static void kvmppc_core_vcpu_load_hv(struct kvm_vcpu *vcpu, int cpu) { struct kvmppc_vcore *vc = vcpu->arch.vcore; unsigned long flags; - u64 now = mftb(); + u64 now; + + if (cpu_has_feature(CPU_FTR_ARCH_300)) + return; + + now = mftb(); /* * We can test vc->runner without taking the vcore lock, @@ -321,7 +330,12 @@ static void kvmppc_core_vcpu_put_hv(struct kvm_vcpu *vcpu) { struct kvmppc_vcore *vc = vcpu->arch.vcore; unsigned long flags; - u64 now = mftb(); + u64 now; + + if (cpu_has_feature(CPU_FTR_ARCH_300)) + return; + + now = mftb(); if (vc->runner == vcpu && vc->vcore_state >= VCORE_SLEEPING) kvmppc_core_start_stolen(vc, now); @@ -673,6 +687,8 @@ static u64 vcore_stolen_time(struct kvmppc_vcore *vc, u64 now) u64 p; unsigned long flags; + WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300)); + spin_lock_irqsave(&vc->stoltb_lock, flags); p = vc->stolen_tb; if (vc->vcore_state != VCORE_INACTIVE && @@ -695,13 +711,19 @@ static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu, dt = vcpu->arch.dtl_ptr; vpa = vcpu->arch.vpa.pinned_addr; now = tb; - core_stolen = vcore_stolen_time(vc, now); - stolen = core_stolen - vcpu->arch.stolen_logged; - vcpu->arch.stolen_logged = core_stolen; - spin_lock_irqsave(&vcpu->arch.tbacct_lock, flags); - stolen += vcpu->arch.busy_stolen; - vcpu->arch.busy_stolen = 0; - spin_unlock_irqrestore(&vcpu->arch.tbacct_lock, flags); + + if (cpu_has_feature(CPU_FTR_ARCH_300)) { + stolen = 0; + } else { + core_stolen = vcore_stolen_time(vc, now); + stolen = core_stolen - vcpu->arch.stolen_logged; + vcpu->arch.stolen_logged = core_stolen; + spin_lock_irqsave(&vcpu->arch.tbacct_lock, flags); + stolen += vcpu->arch.busy_stolen; + vcpu->arch.busy_stolen = 0; + spin_unlock_irqrestore(&vcpu->arch.tbacct_lock, flags); + } + if (!dt || !vpa) return; memset(dt, 0, sizeof(struct dtl_entry)); @@ -898,13 +920,14 @@ static int kvm_arch_vcpu_yield_to(struct kvm_vcpu *target) * mode handler is not called but no other threads are in the * source vcore. */ - - spin_lock(&vcore->lock); - if (target->arch.state == KVMPPC_VCPU_RUNNABLE && - vcore->vcore_state != VCORE_INACTIVE && - vcore->runner) - target = vcore->runner; - spin_unlock(&vcore->lock); + if (!cpu_has_feature(CPU_FTR_ARCH_300)) { + spin_lock(&vcore->lock); + if (target->arch.state == KVMPPC_VCPU_RUNNABLE && + vcore->vcore_state != VCORE_INACTIVE && + vcore->runner) + target = vcore->runner; + spin_unlock(&vcore->lock); + } return kvm_vcpu_yield_to(target); } @@ -3131,13 +3154,6 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu, struct kvmppc_vcore *vc) kvmppc_ipi_thread(cpu); } -/* Old path does this in asm */ -static void kvmppc_stop_thread(struct kvm_vcpu *vcpu) -{ - vcpu->cpu = -1; - vcpu->arch.thread_cpu = -1; -} - static void kvmppc_wait_for_nap(int n_threads) { int cpu = smp_processor_id(); @@ -3226,6 +3242,8 @@ static void kvmppc_vcore_preempt(struct kvmppc_vcore *vc) { struct preempted_vcore_list *lp = this_cpu_ptr(&preempted_vcores); + WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300)); + vc->vcore_state = VCORE_PREEMPT; vc->pcpu = smp_processor_id(); if (vc->num_threads < threads_per_vcore(vc->kvm)) { @@ -3242,6 +3260,8 @@ static void kvmppc_vcore_end_preempt(struct kvmppc_vcore *vc) { struct preempted_vcore_list *lp; + WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300)); + kvmppc_core_end_stolen(vc, mftb()); if (!list_empty(&vc->preempt_list)) { lp = &per_cpu(preempted_vcores, vc->pcpu); @@ -3983,7 +4003,6 @@ static int kvmhv_vcpu_entry_p9_nested(struct kvm_vcpu *vcpu, u64 time_limit, uns static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, unsigned long lpcr, u64 *tb) { - struct kvmppc_vcore *vc = vcpu->arch.vcore; u64 next_timer; int trap; @@ -3999,9 +4018,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, kvmppc_subcore_enter_guest(); - vc->entry_exit_map = 1; - vc->in_guest = 1; - vcpu_vpa_increment_dispatch(vcpu); if (kvmhv_on_pseries()) { @@ -4054,9 +4070,6 @@ static int kvmhv_p9_guest_entry(struct kvm_vcpu *vcpu, u64 time_limit, vcpu_vpa_increment_dispatch(vcpu); - vc->entry_exit_map = 0x101; - vc->in_guest = 0; - kvmppc_subcore_exit_guest(); return trap; @@ -4122,6 +4135,13 @@ static bool kvmppc_vcpu_woken(struct kvm_vcpu *vcpu) return false; } +static bool kvmppc_vcpu_check_block(struct kvm_vcpu *vcpu) +{ + if (!vcpu->arch.ceded || kvmppc_vcpu_woken(vcpu)) + return true; + return false; +} + /* * Check to see if any of the runnable vcpus on the vcore have pending * exceptions or are no longer ceded @@ -4132,7 +4152,7 @@ static int kvmppc_vcore_check_block(struct kvmppc_vcore *vc) int i; for_each_runnable_thread(i, vcpu, vc) { - if (!vcpu->arch.ceded || kvmppc_vcpu_woken(vcpu)) + if (kvmppc_vcpu_check_block(vcpu)) return 1; } @@ -4149,6 +4169,8 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc) int do_sleep = 1; u64 block_ns; + WARN_ON_ONCE(cpu_has_feature(CPU_FTR_ARCH_300)); + /* Poll for pending exceptions and ceded state */ cur = start_poll = ktime_get(); if (vc->halt_poll_ns) { @@ -4426,11 +4448,7 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, vcpu->arch.ceded = 0; vcpu->arch.run_task = current; vcpu->arch.state = KVMPPC_VCPU_RUNNABLE; - vcpu->arch.busy_preempt = TB_NIL; vcpu->arch.last_inst = KVM_INST_FETCH_FAILED; - vc->runnable_threads[0] = vcpu; - vc->n_runnable = 1; - vc->runner = vcpu; /* See if the MMU is ready to go */ if (unlikely(!kvm->arch.mmu_ready)) { @@ -4448,11 +4466,8 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, kvmppc_update_vpas(vcpu); - init_vcore_to_run(vc); - preempt_disable(); pcpu = smp_processor_id(); - vc->pcpu = pcpu; if (kvm_is_radix(kvm)) kvmppc_prepare_radix_vcpu(vcpu, pcpu); @@ -4481,21 +4496,23 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, goto out; } - tb = mftb(); + if (vcpu->arch.timer_running) { + hrtimer_try_to_cancel(&vcpu->arch.dec_timer); + vcpu->arch.timer_running = 0; + } - vcpu->arch.stolen_logged = vcore_stolen_time(vc, tb); - vc->preempt_tb = TB_NIL; + tb = mftb(); - kvmppc_clear_host_core(pcpu); + vcpu->cpu = pcpu; + vcpu->arch.thread_cpu = pcpu; + vc->pcpu = pcpu; + local_paca->kvm_hstate.kvm_vcpu = vcpu; + local_paca->kvm_hstate.ptid = 0; + local_paca->kvm_hstate.fake_suspend = 0; - local_paca->kvm_hstate.napping = 0; - local_paca->kvm_hstate.kvm_split_mode = NULL; - kvmppc_start_thread(vcpu, vc); kvmppc_create_dtl_entry(vcpu, vc, tb); - trace_kvm_guest_enter(vcpu); - vc->vcore_state = VCORE_RUNNING; - trace_kvmppc_run_core(vc, 0); + trace_kvm_guest_enter(vcpu); guest_enter_irqoff(); @@ -4517,8 +4534,6 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, set_irq_happened(trap); - kvmppc_set_host_core(pcpu); - context_tracking_guest_exit(); if (!vtime_accounting_enabled_this_cpu()) { local_irq_enable(); @@ -4534,7 +4549,8 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, } vtime_account_guest_exit(); - kvmppc_stop_thread(vcpu); + vcpu->cpu = -1; + vcpu->arch.thread_cpu = -1; powerpc_local_irq_pmu_restore(flags); @@ -4561,28 +4577,31 @@ int kvmhv_run_single_vcpu(struct kvm_vcpu *vcpu, u64 time_limit, } vcpu->arch.ret = r; - if (is_kvmppc_resume_guest(r) && vcpu->arch.ceded && - !kvmppc_vcpu_woken(vcpu)) { + if (is_kvmppc_resume_guest(r) && !kvmppc_vcpu_check_block(vcpu)) { kvmppc_set_timer(vcpu); - while (vcpu->arch.ceded && !kvmppc_vcpu_woken(vcpu)) { + + prepare_to_rcuwait(&vcpu->wait); + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); if (signal_pending(current)) { vcpu->stat.signal_exits++; run->exit_reason = KVM_EXIT_INTR; vcpu->arch.ret = -EINTR; break; } - spin_lock(&vc->lock); - kvmppc_vcore_blocked(vc); - spin_unlock(&vc->lock); + + if (kvmppc_vcpu_check_block(vcpu)) + break; + + trace_kvmppc_vcore_blocked(vc, 0); + schedule(); + trace_kvmppc_vcore_blocked(vc, 1); } + finish_rcuwait(&vcpu->wait); } vcpu->arch.ceded = 0; - vc->vcore_state = VCORE_INACTIVE; - trace_kvmppc_run_core(vc, 1); - done: - kvmppc_remove_runnable(vc, vcpu, tb); trace_kvmppc_run_vcpu_exit(vcpu); return vcpu->arch.ret; @@ -4664,7 +4683,8 @@ static int kvmppc_vcpu_run_hv(struct kvm_vcpu *vcpu) kvmppc_save_current_sprs(); - vcpu->arch.waitp = &vcpu->arch.vcore->wait; + if (!cpu_has_feature(CPU_FTR_ARCH_300)) + vcpu->arch.waitp = &vcpu->arch.vcore->wait; vcpu->arch.pgdir = kvm->mm->pgd; vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST; @@ -5126,6 +5146,9 @@ void kvmppc_alloc_host_rm_ops(void) int cpu, core; int size; + if (cpu_has_feature(CPU_FTR_ARCH_300)) + return; + /* Not the first time here ? */ if (kvmppc_host_rm_ops_hv != NULL) return;