On Wed, 29 May 2019 11:10:32 +0530 Aravinda Prasad <aravi...@linux.vnet.ibm.com> wrote:
> Memory error such as bit flips that cannot be corrected > by hardware are passed on to the kernel for handling. > If the memory address in error belongs to guest then > the guest kernel is responsible for taking suitable action. > Patch [1] enhances KVM to exit guest with exit reason > set to KVM_EXIT_NMI in such cases. This patch handles > KVM_EXIT_NMI exit. > > [1] https://www.spinics.net/lists/kvm-ppc/msg12637.html > (e20bbd3d and related commits) > > Signed-off-by: Aravinda Prasad <aravi...@linux.vnet.ibm.com> > --- LGTM Reviewed-by: Greg Kurz <gr...@kaod.org> > hw/ppc/spapr.c | 1 + > hw/ppc/spapr_events.c | 23 +++++++++++++++++++++++ > hw/ppc/spapr_rtas.c | 5 +++++ > include/hw/ppc/spapr.h | 6 ++++++ > target/ppc/kvm.c | 16 ++++++++++++++++ > target/ppc/kvm_ppc.h | 2 ++ > target/ppc/trace-events | 1 + > 7 files changed, 54 insertions(+) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index fae28a9..6b6c962 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -1809,6 +1809,7 @@ static void spapr_machine_reset(void) > > spapr->cas_reboot = false; > > + spapr->mc_status = -1; > spapr->guest_machine_check_addr = -1; > > /* Signal all vCPUs waiting on this condition */ > diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c > index ae0f093..a18446b 100644 > --- a/hw/ppc/spapr_events.c > +++ b/hw/ppc/spapr_events.c > @@ -620,6 +620,29 @@ void > spapr_hotplug_req_remove_by_count_indexed(SpaprDrcType drc_type, > RTAS_LOG_V6_HP_ACTION_REMOVE, drc_type, &drc_id); > } > > +void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered) > +{ > + SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine()); > + > + while (spapr->mc_status != -1) { > + /* > + * Check whether the same CPU got machine check error > + * while still handling the mc error (i.e., before > + * that CPU called "ibm,nmi-interlock") > + */ > + if (spapr->mc_status == cpu->vcpu_id) { > + qemu_system_guest_panicked(NULL); > + return; > + } > + qemu_cond_wait_iothread(&spapr->mc_delivery_cond); > + /* Meanwhile if the system is reset, then just return */ > + if (spapr->guest_machine_check_addr == -1) { > + return; > + } > + } > + spapr->mc_status = cpu->vcpu_id; > +} > + > static void check_exception(PowerPCCPU *cpu, SpaprMachineState *spapr, > uint32_t token, uint32_t nargs, > target_ulong args, > diff --git a/hw/ppc/spapr_rtas.c b/hw/ppc/spapr_rtas.c > index e7509cf..e0bdfc8 100644 > --- a/hw/ppc/spapr_rtas.c > +++ b/hw/ppc/spapr_rtas.c > @@ -379,6 +379,11 @@ static void rtas_ibm_nmi_interlock(PowerPCCPU *cpu, > /* NMI register not called */ > rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR); > } else { > + /* > + * vCPU issuing "ibm,nmi-interlock" is done with NMI handling, > + * hence unset mc_status. > + */ > + spapr->mc_status = -1; > qemu_cond_signal(&spapr->mc_delivery_cond); > rtas_st(rets, 0, RTAS_OUT_SUCCESS); > } > diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h > index 9dc5e30..fc3a776 100644 > --- a/include/hw/ppc/spapr.h > +++ b/include/hw/ppc/spapr.h > @@ -190,6 +190,11 @@ struct SpaprMachineState { > > /* State related to "ibm,nmi-register" and "ibm,nmi-interlock" calls */ > target_ulong guest_machine_check_addr; > + /* > + * mc_status is set to -1 if mc is not in progress, else is set to the > CPU > + * handling the mc. > + */ > + int mc_status; > QemuCond mc_delivery_cond; > > /*< public >*/ > @@ -793,6 +798,7 @@ void spapr_clear_pending_events(SpaprMachineState *spapr); > int spapr_max_server_number(SpaprMachineState *spapr); > void spapr_store_hpte(PowerPCCPU *cpu, hwaddr ptex, > uint64_t pte0, uint64_t pte1); > +void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered); > > /* DRC callbacks. */ > void spapr_core_release(DeviceState *dev); > diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c > index 3bf0a46..39f1a73 100644 > --- a/target/ppc/kvm.c > +++ b/target/ppc/kvm.c > @@ -1761,6 +1761,11 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run > *run) > ret = 0; > break; > > + case KVM_EXIT_NMI: > + trace_kvm_handle_nmi_exception(); > + ret = kvm_handle_nmi(cpu, run); > + break; > + > default: > fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason); > ret = -1; > @@ -2844,6 +2849,17 @@ int kvm_arch_msi_data_to_gsi(uint32_t data) > return data & 0xffff; > } > > +int kvm_handle_nmi(PowerPCCPU *cpu, struct kvm_run *run) > +{ > + bool recovered = run->flags & KVM_RUN_PPC_NMI_DISP_FULLY_RECOV; > + > + cpu_synchronize_state(CPU(cpu)); > + > + spapr_mce_req_event(cpu, recovered); > + > + return 0; > +} > + > int kvmppc_enable_hwrng(void) > { > if (!kvm_enabled() || !kvm_check_extension(kvm_state, > KVM_CAP_PPC_HWRNG)) { > diff --git a/target/ppc/kvm_ppc.h b/target/ppc/kvm_ppc.h > index 45776ca..18693f1 100644 > --- a/target/ppc/kvm_ppc.h > +++ b/target/ppc/kvm_ppc.h > @@ -81,6 +81,8 @@ bool kvmppc_hpt_needs_host_contiguous_pages(void); > void kvm_check_mmu(PowerPCCPU *cpu, Error **errp); > void kvmppc_set_reg_ppc_online(PowerPCCPU *cpu, unsigned int online); > > +int kvm_handle_nmi(PowerPCCPU *cpu, struct kvm_run *run); > + > #else > > static inline uint32_t kvmppc_get_tbfreq(void) > diff --git a/target/ppc/trace-events b/target/ppc/trace-events > index 3dc6740..6d15aa9 100644 > --- a/target/ppc/trace-events > +++ b/target/ppc/trace-events > @@ -28,3 +28,4 @@ kvm_handle_papr_hcall(void) "handle PAPR hypercall" > kvm_handle_epr(void) "handle epr" > kvm_handle_watchdog_expiry(void) "handle watchdog expiry" > kvm_handle_debug_exception(void) "handle debug exception" > +kvm_handle_nmi_exception(void) "handle NMI exception" > >