On Mon, May 13, 2019 at 11:10:28AM +0530, Aravinda Prasad wrote: > > > On Friday 10 May 2019 09:55 PM, Greg Kurz wrote: > > On Mon, 22 Apr 2019 12:33:16 +0530 > > Aravinda Prasad 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 > >> --- > >> hw/ppc/spapr.c | 3 +++ > >> hw/ppc/spapr_events.c | 22 ++++++++++++++++++++++ > >> 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 | 2 ++ > >> 7 files changed, 56 insertions(+) > >> > >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > >> index 6642cb5..2779efe 100644 > >> --- a/hw/ppc/spapr.c > >> +++ b/hw/ppc/spapr.c > >> @@ -1806,6 +1806,7 @@ 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 */ > >> @@ -2106,6 +2107,7 @@ static const VMStateDescription vmstate_spapr_machine_check = { > >> .minimum_version_id = 1, > >> .fields = (VMStateField[]) { > >> VMSTATE_UINT64(guest_machine_check_addr, SpaprMachineState), > >> + VMSTATE_INT32(mc_status, SpaprMachineState), > >> VMSTATE_END_OF_LIST() > >> }, > >> }; > >> @@ -3085,6 +3087,7 @@ static void spapr_machine_init(MachineState *machine) > >> kvmppc_spapr_enable_inkernel_multitce(); > >> } > >> > >> + spapr->mc_status = -1; > > > > Since this is done at reset, do we need it here ? > > Yes, because we need to initialize this on a fresh boot. I need to > check, but if spapr_machine_reset() is called every time a system boots It is. > then we don't need qemu_cond_init() here as well. > > > > >> qemu_cond_init(&spapr->mc_delivery_cond); > >> } > >> > >> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c > >> index ae0f093..9922a23 100644 > >> --- a/hw/ppc/spapr_events.c > >> +++ b/hw/ppc/spapr_events.c > >> @@ -620,6 +620,28 @@ 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" > > > > Missing ) > > ok. > > > > >> + */ > >> + if (spapr->mc_status == cpu->vcpu_id) { > >> + qemu_system_guest_panicked(NULL); > > > > If we don't also return, is there a chance we end up stuck in > > qemu_cond_wait_iothread() below ? > > I think I need to return here > > > > > >> + } > >> + 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 c2f3991..d3499f9 100644 > >> --- a/hw/ppc/spapr_rtas.c > >> +++ b/hw/ppc/spapr_rtas.c > >> @@ -375,6 +375,11 @@ 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 ec6f33e..f7204d0 100644 > >> --- a/include/hw/ppc/spapr.h > >> +++ b/include/hw/ppc/spapr.h > >> @@ -189,6 +189,11 @@ 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 >*/ > >> @@ -792,6 +797,7 @@ 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 9e86db0..5eedce8 100644 > >> --- a/target/ppc/kvm.c > >> +++ b/target/ppc/kvm.c > >> @@ -1759,6 +1759,11 @@ 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; > >> @@ -2837,6 +2842,17 @@ 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 2238513..6edc42f 100644 > >> --- a/target/ppc/kvm_ppc.h > >> +++ b/target/ppc/kvm_ppc.h > >> @@ -80,6 +80,8 @@ 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 7b3cfe1..d5691d2 100644 > >> --- a/target/ppc/trace-events > >> +++ b/target/ppc/trace-events > >> @@ -28,3 +28,5 @@ 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" > >> + > > > > new blank line at EOF. > > ok > > > > >> > >> > > > > > -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson