diff options
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 11 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rm_xics.c | 92 | ||||
| -rw-r--r-- | arch/powerpc/kvm/powerpc.c | 10 |
3 files changed, 110 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index e222efcf6aef..cb8be5dc118a 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -257,6 +257,17 @@ irqreturn_t smp_ipi_demux(void) do { all = xchg(&info->messages, 0); +#if defined(CONFIG_KVM_XICS) && defined(CONFIG_KVM_BOOK3S_HV_POSSIBLE) + /* + * Must check for PPC_MSG_RM_HOST_ACTION messages + * before PPC_MSG_CALL_FUNCTION messages because when + * a VM is destroyed, we call kick_all_cpus_sync() + * to ensure that any pending PPC_MSG_RM_HOST_ACTION + * messages have completed before we free any VCPUs. + */ + if (all & IPI_MESSAGE(PPC_MSG_RM_HOST_ACTION)) + kvmppc_xics_ipi_action(); +#endif if (all & IPI_MESSAGE(PPC_MSG_CALL_FUNCTION)) generic_smp_call_function_interrupt(); if (all & IPI_MESSAGE(PPC_MSG_RESCHEDULE)) diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c b/arch/powerpc/kvm/book3s_hv_rm_xics.c index 43ffbfe2a18a..e673fb9fee98 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_xics.c +++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c @@ -51,11 +51,84 @@ static void ics_rm_check_resend(struct kvmppc_xics *xics, /* -- ICP routines -- */ +#ifdef CONFIG_SMP +static inline void icp_send_hcore_msg(int hcore, struct kvm_vcpu *vcpu) +{ + int hcpu; + + hcpu = hcore << threads_shift; + kvmppc_host_rm_ops_hv->rm_core[hcore].rm_data = vcpu; + smp_muxed_ipi_set_message(hcpu, PPC_MSG_RM_HOST_ACTION); + icp_native_cause_ipi_rm(hcpu); +} +#else +static inline void icp_send_hcore_msg(int hcore, struct kvm_vcpu *vcpu) { } +#endif + +/* + * We start the search from our current CPU Id in the core map + * and go in a circle until we get back to our ID looking for a + * core that is running in host context and that hasn't already + * been targeted for another rm_host_ops. + * + * In the future, could consider using a fairer algorithm (one + * that distributes the IPIs better) + * + * Returns -1, if no CPU could be found in the host + * Else, returns a CPU Id which has been reserved for use + */ +static inline int grab_next_hostcore(int start, + struct kvmppc_host_rm_core *rm_core, int max, int action) +{ + bool success; + int core; + union kvmppc_rm_state old, new; + + for (core = start + 1; core < max; core++) { + old = new = READ_ONCE(rm_core[core].rm_state); + + if (!old.in_host || old.rm_action) + continue; + + /* Try to grab this host core if not taken already. */ + new.rm_action = action; + + success = cmpxchg64(&rm_core[core].rm_state.raw, + old.raw, new.raw) == old.raw; + if (success) { + /* + * Make sure that the store to the rm_action is made + * visible before we return to caller (and the + * subsequent store to rm_data) to synchronize with + * the IPI handler. + */ + smp_wmb(); + return core; + } + } + + return -1; +} + +static inline int find_available_hostcore(int action) +{ + int core; + int my_core = smp_processor_id() >> threads_shift; + struct kvmppc_host_rm_core *rm_core = kvmppc_host_rm_ops_hv->rm_core; + + core = grab_next_hostcore(my_core, rm_core, cpu_nr_cores(), action); + if (core == -1) + core = grab_next_hostcore(core, rm_core, my_core, action); + + return core; +} + static void icp_rm_set_vcpu_irq(struct kvm_vcpu *vcpu, struct kvm_vcpu *this_vcpu) { struct kvmppc_icp *this_icp = this_vcpu->arch.icp; int cpu; + int hcore; /* Mark the target VCPU as having an interrupt pending */ vcpu->stat.queue_intr++; @@ -67,11 +140,22 @@ static void icp_rm_set_vcpu_irq(struct kvm_vcpu *vcpu, return; } - /* Check if the core is loaded, if not, too hard */ + /* + * Check if the core is loaded, + * if not, find an available host core to post to wake the VCPU, + * if we can't find one, set up state to eventually return too hard. + */ cpu = vcpu->arch.thread_cpu; if (cpu < 0 || cpu >= nr_cpu_ids) { - this_icp->rm_action |= XICS_RM_KICK_VCPU; - this_icp->rm_kick_target = vcpu; + hcore = -1; + if (kvmppc_host_rm_ops_hv) + hcore = find_available_hostcore(XICS_RM_KICK_VCPU); + if (hcore != -1) { + icp_send_hcore_msg(hcore, vcpu); + } else { + this_icp->rm_action |= XICS_RM_KICK_VCPU; + this_icp->rm_kick_target = vcpu; + } return; } @@ -655,7 +739,9 @@ void kvmppc_xics_ipi_action(void) if (rm_corep->rm_data) { rm_host_ipi_action(rm_corep->rm_state.rm_action, rm_corep->rm_data); + /* Order these stores against the real mode KVM */ rm_corep->rm_data = NULL; + smp_wmb(); rm_corep->rm_state.rm_action = 0; } } diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 69f897da782d..9258675e2ff7 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -437,6 +437,16 @@ void kvm_arch_destroy_vm(struct kvm *kvm) unsigned int i; struct kvm_vcpu *vcpu; +#ifdef CONFIG_KVM_XICS + /* + * We call kick_all_cpus_sync() to ensure that all + * CPUs have executed any pending IPIs before we + * continue and free VCPUs structures below. + */ + if (is_kvmppc_hv_enabled(kvm)) + kick_all_cpus_sync(); +#endif + kvm_for_each_vcpu(i, vcpu, kvm) kvm_arch_vcpu_free(vcpu); |