On Fri, Mar 22, 2019 at 12:03:58PM +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 <aravi...@linux.vnet.ibm.com> > --- > hw/ppc/spapr_events.c | 22 ++++++++++++++++++++++ > include/hw/ppc/spapr.h | 1 + > target/ppc/kvm.c | 16 ++++++++++++++++ > target/ppc/kvm_ppc.h | 2 ++ > 4 files changed, 41 insertions(+) > > diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c > index ae0f093..e7a24ad 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" > + */ > + if (spapr->mc_status == cpu->vcpu_id) { > + qemu_system_guest_panicked(NULL); > + } > + qemu_cond_wait_iothread(&spapr->mc_delivery_cond); > + /* If the system is reset meanwhile, then just return */ > + if (spapr->mc_reset) {
I don't really see what this accomplishes. IIUC mc_reset is true from
reset time until nmi-register is called. Which means you could just
check for guest_mnachine_check_addre being unset - in which case don't
you need to fallback to the old machine check behaviour anyway?
> + 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/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index ee5589d..b0d8c18 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -792,6 +792,7 @@ void spapr_reallocate_hpt(SpaprMachineState *spapr, int
> shift,
> Error **errp);
> void spapr_clear_pending_events(SpaprMachineState *spapr);
> int spapr_max_server_number(SpaprMachineState *spapr);
> +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 2427c8e..a593448 100644
> --- a/target/ppc/kvm.c
> +++ b/target/ppc/kvm.c
> @@ -1738,6 +1738,11 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run
> *run)
> ret = 0;
> break;
>
> + case KVM_EXIT_NMI:
> + DPRINTF("handle NMI exception\n");
tracepoints are generally preferred to new DPRINTFs.
> + ret = kvm_handle_nmi(cpu, run);
> + break;
> +
> default:
> fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason);
> ret = -1;
> @@ -2803,6 +2808,17 @@ 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 2c2ea30..df5e85f 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)
>
--
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
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