On Wed, Nov 11, 2015 at 10:46:02PM +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 > 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. If the guest OS > has registered the machine check handling routine by > calling "ibm,nmi-register", then the handler builds > the error log and invokes the registered handler else > invokes the handler at 0x200. > > [1] http://marc.info/?l=kvm-ppc&m=144726114408289 > > Signed-off-by: Aravinda Prasad <[email protected]> > --- > target-ppc/kvm.c | 69 +++++++++++++++++++++++++++++++++++++++++++ > target-ppc/kvm_ppc.h | 81 > ++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 150 insertions(+) > > diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c > index 110436d..e2e5170 100644 > --- a/target-ppc/kvm.c > +++ b/target-ppc/kvm.c > @@ -1665,6 +1665,11 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run > *run) > ret = 0; > break; > > + case KVM_EXIT_NMI: > + DPRINTF("handle NMI exception\n"); > + ret = kvm_handle_nmi(cpu); > + break; > + > default: > fprintf(stderr, "KVM: unknown exit reason %d\n", run->exit_reason); > ret = -1; > @@ -2484,3 +2489,67 @@ int kvm_arch_msi_data_to_gsi(uint32_t data) > { > return data & 0xffff; > } > + > +int kvm_handle_nmi(PowerPCCPU *cpu) > +{ > + struct rtas_mc_log mc_log; > + CPUPPCState *env = &cpu->env; > + sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine()); > + PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu); > + > + cpu_synchronize_state(CPU(ppc_env_get_cpu(env))); > + > + /* Properly set bits in MSR before we invoke the handler */ > + env->msr = 0; > + > + if (!(*pcc->interrupts_big_endian)(cpu)) { > + env->msr |= (1ULL << MSR_LE); > + } > + > +#ifdef TARGET_PPC64 > + env->msr |= (1ULL << MSR_SF); > +#endif
Surely this should depend on what the MSR actually was before, or at
the very least the cpu model, rather than just whether qemu has PPC64
support compiled in.
> +
> + if (!spapr->guest_machine_check_addr) {
> + /*
> + * If OS has not registered with "ibm,nmi-register"
> + * jump to 0x200
> + */
> + env->nip = 0x200;
> + return 0;
> + }
> +
> + qemu_mutex_lock(&spapr->mc_in_progress);
> +
> + /* Set error log fields */
> + mc_log.r3 = env->gpr[3];
> + mc_log.err_log.byte0 = 0;
> + mc_log.err_log.byte1 =
> + (RTAS_SEVERITY_ERROR_SYNC << RTAS_ELOG_SEVERITY_SHIFT);
> + mc_log.err_log.byte1 |=
> + (RTAS_DISP_NOT_RECOVERED << RTAS_ELOG_DISPOSITION_SHIFT);
> + mc_log.err_log.byte2 =
> + (RTAS_INITIATOR_MEMORY << RTAS_ELOG_INITIATOR_SHIFT);
> + mc_log.err_log.byte2 |= RTAS_TARGET_MEMORY;
> +
> + if (env->spr[SPR_DSISR] & P7_DSISR_MC_UE) {
> + mc_log.err_log.byte3 = RTAS_TYPE_ECC_UNCORR;
> + } else {
> + mc_log.err_log.byte3 = 0;
> + }
> +
> + /* Handle all Host/Guest LE/BE combinations */
> + if (env->msr & (1ULL << MSR_LE)) {
> + mc_log.r3 = cpu_to_le64(mc_log.r3);
> + } else {
> + mc_log.r3 = cpu_to_be64(mc_log.r3);
> + }
> +
> + cpu_physical_memory_write(spapr->rtas_addr + RTAS_ERRLOG_OFFSET,
> + &mc_log, sizeof(mc_log));
> +
> + env->nip = spapr->guest_machine_check_addr;
> + env->gpr[3] = spapr->rtas_addr + RTAS_ERRLOG_OFFSET;
> +
> + return 0;
> +}
> diff --git a/target-ppc/kvm_ppc.h b/target-ppc/kvm_ppc.h
> index 5c1d334..1172735 100644
> --- a/target-ppc/kvm_ppc.h
> +++ b/target-ppc/kvm_ppc.h
> @@ -53,6 +53,87 @@ void kvmppc_hash64_free_pteg(uint64_t token);
> void kvmppc_hash64_write_pte(CPUPPCState *env, target_ulong pte_index,
> target_ulong pte0, target_ulong pte1);
> bool kvmppc_has_cap_fixup_hcalls(void);
> +int kvm_handle_nmi(PowerPCCPU *cpu);
> +
> +/* Offset from rtas-base where error log is placed */
> +#define RTAS_ERRLOG_OFFSET (0x200)
> +
> +#define RTAS_ELOG_SEVERITY_SHIFT 0x5
> +#define RTAS_ELOG_DISPOSITION_SHIFT 0x3
> +#define RTAS_ELOG_INITIATOR_SHIFT 0x4
> +
> +/*
> + * Only required RTAS event severity, disposition, initiator
> + * target and type are copied from arch/powerpc/include/asm/rtas.h
> + */
> +
> +/* RTAS event severity */
> +#define RTAS_SEVERITY_ERROR_SYNC 0x3
> +
> +/* RTAS event disposition */
> +#define RTAS_DISP_NOT_RECOVERED 0x2
> +
> +/* RTAS event initiator */
> +#define RTAS_INITIATOR_MEMORY 0x4
> +
> +/* RTAS event target */
> +#define RTAS_TARGET_MEMORY 0x4
> +
> +/* RTAS event type */
> +#define RTAS_TYPE_ECC_UNCORR 0x09
> +
> +/*
> + * Currently KVM only passes on the uncorrected machine
> + * check memory error to guest. Other machine check errors
> + * such as SLB multi-hit and TLB multi-hit are recovered
> + * in KVM and are not passed on to guest.
> + *
> + * DSISR Bit for uncorrected machine check error. Based
> + * on arch/powerpc/include/asm/mce.h
> + */
> +#define PPC_BIT(bit) (0x8000000000000000ULL >> bit)
> +#define P7_DSISR_MC_UE (PPC_BIT(48)) /* P8 too */
> +
> +/* Adopted from kernel source arch/powerpc/include/asm/rtas.h */
> +struct rtas_error_log {
> + /* Byte 0 */
> + uint8_t byte0; /* Architectural version */
> +
> + /* Byte 1 */
> + uint8_t byte1;
> + /* XXXXXXXX
> + * XXX 3: Severity level of error
> + * XX 2: Degree of recovery
> + * X 1: Extended log present?
> + * XX 2: Reserved
> + */
> +
> + /* Byte 2 */
> + uint8_t byte2;
> + /* XXXXXXXX
> + * XXXX 4: Initiator of event
> + * XXXX 4: Target of failed operation
> + */
> + uint8_t byte3; /* General event or error*/
> + __be32 extended_log_length; /* length in bytes */
> + unsigned char buffer[1]; /* Start of extended log */
> + /* Variable length. */
> +};
> +
> +/*
> + * Data format in RTAS-Blob
> + *
> + * This structure contains error information related to Machine
> + * Check exception. This is filled up and copied to rtas-blob
> + * upon machine check exception. The address of rtas-blob is
> + * passed on to OS registered machine check notification
> + * routines upon machine check exception
> + */
> +struct rtas_mc_log {
> + target_ulong r3;
> + struct rtas_error_log err_log;
> +};
> +
>
> #else
>
>
--
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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