On Mon, Apr 22, 2019 at 12:33:26PM +0530, Aravinda Prasad wrote:
> Upon a machine check exception (MCE) in a guest address space,
> KVM causes a guest exit to enable QEMU to build and pass the
> error to the guest in the PAPR defined rtas error log format.
>
> This patch builds the rtas error log, copies it to the rtas_addr
> and then invokes the guest registered machine check handler. The
> handler in the guest takes suitable action(s) depending on the type
> and criticality of the error. For example, if an error is
> unrecoverable memory corruption in an application inside the
> guest, then the guest kernel sends a SIGBUS to the application.
> For recoverable errors, the guest performs recovery actions and
> logs the error.
>
> Signed-off-by: Aravinda Prasad <aravi...@linux.vnet.ibm.com>
> ---
> hw/ppc/spapr.c | 4 +
> hw/ppc/spapr_events.c | 245
> ++++++++++++++++++++++++++++++++++++++++++++++++
> include/hw/ppc/spapr.h | 4 +
> 3 files changed, 253 insertions(+)
>
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 2779efe..ffd1715 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -2918,6 +2918,10 @@ static void spapr_machine_init(MachineState *machine)
> error_report("Could not get size of LPAR rtas '%s'", filename);
> exit(1);
> }
> +
> + /* Resize blob to accommodate error log. */
> + spapr->rtas_size = spapr_get_rtas_size(spapr->rtas_size);
> +
> spapr->rtas_blob = g_malloc(spapr->rtas_size);
> if (load_image_size(filename, spapr->rtas_blob, spapr->rtas_size) < 0) {
> error_report("Could not load LPAR rtas '%s'", filename);
> diff --git a/hw/ppc/spapr_events.c b/hw/ppc/spapr_events.c
> index 9922a23..4032db0 100644
> --- a/hw/ppc/spapr_events.c
> +++ b/hw/ppc/spapr_events.c
> @@ -212,6 +212,106 @@ struct hp_extended_log {
> struct rtas_event_log_v6_hp hp;
> } QEMU_PACKED;
>
> +struct rtas_event_log_v6_mc {
> +#define RTAS_LOG_V6_SECTION_ID_MC 0x4D43 /* MC */
> + struct rtas_event_log_v6_section_header hdr;
> + uint32_t fru_id;
> + uint32_t proc_id;
> + uint8_t error_type;
> +#define RTAS_LOG_V6_MC_TYPE_UE 0
> +#define RTAS_LOG_V6_MC_TYPE_SLB 1
> +#define RTAS_LOG_V6_MC_TYPE_ERAT 2
> +#define RTAS_LOG_V6_MC_TYPE_TLB 4
> +#define RTAS_LOG_V6_MC_TYPE_D_CACHE 5
> +#define RTAS_LOG_V6_MC_TYPE_I_CACHE 7
> + uint8_t sub_err_type;
> +#define RTAS_LOG_V6_MC_UE_INDETERMINATE 0
> +#define RTAS_LOG_V6_MC_UE_IFETCH 1
> +#define RTAS_LOG_V6_MC_UE_PAGE_TABLE_WALK_IFETCH 2
> +#define RTAS_LOG_V6_MC_UE_LOAD_STORE 3
> +#define RTAS_LOG_V6_MC_UE_PAGE_TABLE_WALK_LOAD_STORE 4
> +#define RTAS_LOG_V6_MC_SLB_PARITY 0
> +#define RTAS_LOG_V6_MC_SLB_MULTIHIT 1
> +#define RTAS_LOG_V6_MC_SLB_INDETERMINATE 2
> +#define RTAS_LOG_V6_MC_ERAT_PARITY 1
> +#define RTAS_LOG_V6_MC_ERAT_MULTIHIT 2
> +#define RTAS_LOG_V6_MC_ERAT_INDETERMINATE 3
> +#define RTAS_LOG_V6_MC_TLB_PARITY 1
> +#define RTAS_LOG_V6_MC_TLB_MULTIHIT 2
> +#define RTAS_LOG_V6_MC_TLB_INDETERMINATE 3
> + uint8_t reserved_1[6];
> + uint64_t effective_address;
> + uint64_t logical_address;
> +} QEMU_PACKED;
> +
> +struct mc_extended_log {
> + struct rtas_event_log_v6 v6hdr;
> + struct rtas_event_log_v6_mc mc;
> +} QEMU_PACKED;
> +
> +struct MC_ierror_table {
> + unsigned long srr1_mask;
> + unsigned long srr1_value;
> + bool nip_valid; /* nip is a valid indicator of faulting address */
> + uint8_t error_type;
> + uint8_t error_subtype;
> + unsigned int initiator;
> + unsigned int severity;
> +};
> +
> +static const struct MC_ierror_table mc_ierror_table[] = {
> +{ 0x00000000081c0000, 0x0000000000040000, true,
> + RTAS_LOG_V6_MC_TYPE_UE, RTAS_LOG_V6_MC_UE_IFETCH,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000000081c0000, 0x0000000000080000, true,
> + RTAS_LOG_V6_MC_TYPE_SLB, RTAS_LOG_V6_MC_SLB_PARITY,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000000081c0000, 0x00000000000c0000, true,
> + RTAS_LOG_V6_MC_TYPE_SLB, RTAS_LOG_V6_MC_SLB_MULTIHIT,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000000081c0000, 0x0000000000100000, true,
> + RTAS_LOG_V6_MC_TYPE_ERAT, RTAS_LOG_V6_MC_ERAT_MULTIHIT,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000000081c0000, 0x0000000000140000, true,
> + RTAS_LOG_V6_MC_TYPE_TLB, RTAS_LOG_V6_MC_TLB_MULTIHIT,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000000081c0000, 0x0000000000180000, true,
> + RTAS_LOG_V6_MC_TYPE_UE, RTAS_LOG_V6_MC_UE_PAGE_TABLE_WALK_IFETCH,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0, 0, 0, 0, 0, 0 } };
> +
> +struct MC_derror_table {
> + unsigned long dsisr_value;
> + bool dar_valid; /* dar is a valid indicator of faulting address */
> + uint8_t error_type;
> + uint8_t error_subtype;
> + unsigned int initiator;
> + unsigned int severity;
> +};
> +
> +static const struct MC_derror_table mc_derror_table[] = {
> +{ 0x00008000, false,
> + RTAS_LOG_V6_MC_TYPE_UE, RTAS_LOG_V6_MC_UE_LOAD_STORE,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00004000, true,
> + RTAS_LOG_V6_MC_TYPE_UE, RTAS_LOG_V6_MC_UE_PAGE_TABLE_WALK_LOAD_STORE,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000800, true,
> + RTAS_LOG_V6_MC_TYPE_ERAT, RTAS_LOG_V6_MC_ERAT_MULTIHIT,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000400, true,
> + RTAS_LOG_V6_MC_TYPE_TLB, RTAS_LOG_V6_MC_TLB_MULTIHIT,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000080, true,
> + RTAS_LOG_V6_MC_TYPE_SLB, RTAS_LOG_V6_MC_SLB_MULTIHIT, /* Before PARITY */
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0x00000100, true,
> + RTAS_LOG_V6_MC_TYPE_SLB, RTAS_LOG_V6_MC_SLB_PARITY,
> + RTAS_LOG_INITIATOR_CPU, RTAS_LOG_SEVERITY_ERROR_SYNC, },
> +{ 0, false, 0, 0, 0, 0 } };
> +
> +#define SRR1_MC_LOADSTORE(srr1) ((srr1) & PPC_BIT(42))
> +
> typedef enum EventClass {
> EVENT_CLASS_INTERNAL_ERRORS = 0,
> EVENT_CLASS_EPOW = 1,
> @@ -620,6 +720,147 @@ void
> spapr_hotplug_req_remove_by_count_indexed(SpaprDrcType drc_type,
> RTAS_LOG_V6_HP_ACTION_REMOVE, drc_type, &drc_id);
> }
>
> +ssize_t spapr_get_rtas_size(ssize_t old_rtas_size)
> +{
> + g_assert(old_rtas_size < RTAS_ERRLOG_OFFSET);
> + return RTAS_ERROR_LOG_MAX;
> +}
> +
> +static uint32_t spapr_mce_get_elog_type(PowerPCCPU *cpu, bool recovered,
> + struct mc_extended_log *ext_elog)
> +{
> + int i;
> + CPUPPCState *env = &cpu->env;
> + uint32_t summary;
> + uint64_t dsisr = env->spr[SPR_DSISR];
> +
> + summary = RTAS_LOG_VERSION_6 | RTAS_LOG_OPTIONAL_PART_PRESENT;
> + if (recovered) {
> + summary |= RTAS_LOG_DISPOSITION_FULLY_RECOVERED;
> + } else {
> + summary |= RTAS_LOG_DISPOSITION_NOT_RECOVERED;
> + }
> +
> + if (SRR1_MC_LOADSTORE(env->spr[SPR_SRR1])) {
> + for (i = 0; mc_derror_table[i].dsisr_value; i++) {
> + if (!(dsisr & mc_derror_table[i].dsisr_value)) {
> + continue;
> + }
> +
> + ext_elog->mc.error_type = mc_derror_table[i].error_type;
> + ext_elog->mc.sub_err_type = mc_derror_table[i].error_subtype;
> + if (mc_derror_table[i].dar_valid) {
> + ext_elog->mc.effective_address =
> cpu_to_be64(env->spr[SPR_DAR]);
> + }
> +
> + summary |= mc_derror_table[i].initiator
> + | mc_derror_table[i].severity;
> +
> + return summary;
> + }
> + } else {
> + for (i = 0; mc_ierror_table[i].srr1_mask; i++) {
> + if ((env->spr[SPR_SRR1] & mc_ierror_table[i].srr1_mask) !=
> + mc_ierror_table[i].srr1_value) {
> + continue;
> + }
> +
> + ext_elog->mc.error_type = mc_ierror_table[i].error_type;
> + ext_elog->mc.sub_err_type = mc_ierror_table[i].error_subtype;
> + if (mc_ierror_table[i].nip_valid) {
> + ext_elog->mc.effective_address = cpu_to_be64(env->nip);
> + }
> +
> + summary |= mc_ierror_table[i].initiator
> + | mc_ierror_table[i].severity;
> +
> + return summary;
> + }
> + }
> +
> + summary |= RTAS_LOG_INITIATOR_CPU;
> + return summary;
> +}
> +
> +static void spapr_mce_dispatch_elog(PowerPCCPU *cpu, bool recovered)
> +{
> + SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> + CPUState *cs = CPU(cpu);
> + uint64_t rtas_addr;
> + CPUPPCState *env = &cpu->env;
> + PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
> + target_ulong r3, msr = 0;
> + struct rtas_error_log log;
> + struct mc_extended_log *ext_elog;
> + uint32_t summary;
> +
> + /*
> + * Properly set bits in MSR before we invoke the handler.
> + * SRR0/1, DAR and DSISR are properly set by KVM
> + */
> + if (!(*pcc->interrupts_big_endian)(cpu)) {
> + msr |= (1ULL << MSR_LE);
> + }
> +
> + if (env->msr && (1ULL << MSR_SF)) {
> + msr |= (1ULL << MSR_SF);
> + }
> +
> + msr |= (1ULL << MSR_ME);
> +
> + if (spapr->guest_machine_check_addr == -1) {
> + /*
> + * This implies that we have hit a machine check between system
> + * reset and "ibm,nmi-register". Fall back to the old machine
> + * check behavior in such cases.
> + */
> + env->spr[SPR_SRR0] = env->nip;
> + env->spr[SPR_SRR1] = env->msr;
> + env->msr = msr;
> + env->nip = 0x200;
> + return;
> + }
> +
> + ext_elog = g_malloc0(sizeof(struct mc_extended_log));
> + summary = spapr_mce_get_elog_type(cpu, recovered, ext_elog);
> +
> + log.summary = cpu_to_be32(summary);
> + log.extended_length = cpu_to_be32(sizeof(struct mc_extended_log));
> +
> + /* r3 should be in BE always */
> + r3 = cpu_to_be64(env->gpr[3]);
> + env->msr = msr;
> +
> + spapr_init_v6hdr(&ext_elog->v6hdr);
> + ext_elog->mc.hdr.section_id = cpu_to_be16(RTAS_LOG_V6_SECTION_ID_MC);
> + ext_elog->mc.hdr.section_length =
> + cpu_to_be16(sizeof(struct rtas_event_log_v6_mc));
> + ext_elog->mc.hdr.section_version = 1;
> +
> + /* get rtas addr from fdt */
> + rtas_addr = spapr_get_rtas_addr();
> + if (!rtas_addr) {
> + /* Unable to fetch rtas_addr. Hence reset the guest */
> + ppc_cpu_do_system_reset(cs);
> + }
> +
> + cpu_physical_memory_write(rtas_addr + RTAS_ERRLOG_OFFSET, &r3,
> sizeof(r3));
> + cpu_physical_memory_write(rtas_addr + RTAS_ERRLOG_OFFSET + sizeof(r3),
> + &log, sizeof(log));
> + cpu_physical_memory_write(rtas_addr + RTAS_ERRLOG_OFFSET + sizeof(r3) +
> + sizeof(log), ext_elog,
> + sizeof(struct mc_extended_log));
> +
> + /* Save gpr[3] in the guest endian mode */
> + if ((*pcc->interrupts_big_endian)(cpu)) {
> + env->gpr[3] = cpu_to_be64(rtas_addr + RTAS_ERRLOG_OFFSET);
I don't think this is right. AIUI env->gpr[] are all stored in *host*
endianness (for ease of doing arithmetic).
> + } else {
> + env->gpr[3] = cpu_to_le64(rtas_addr + RTAS_ERRLOG_OFFSET);
> + }
> +
> + env->nip = spapr->guest_machine_check_addr;
> +}
> +
> void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
> {
> SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> @@ -640,6 +881,10 @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
> }
> }
> spapr->mc_status = cpu->vcpu_id;
> +
> + spapr_mce_dispatch_elog(cpu, recovered);
> +
> + return;
> }
>
> static void check_exception(PowerPCCPU *cpu, SpaprMachineState *spapr,
> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> index f7204d0..03f34bf 100644
> --- a/include/hw/ppc/spapr.h
> +++ b/include/hw/ppc/spapr.h
> @@ -661,6 +661,9 @@ target_ulong spapr_hypercall(PowerPCCPU *cpu,
> target_ulong opcode,
> #define DIAGNOSTICS_RUN_MODE_IMMEDIATE 2
> #define DIAGNOSTICS_RUN_MODE_PERIODIC 3
>
> +/* Offset from rtas-base where error log is placed */
> +#define RTAS_ERRLOG_OFFSET 0x25
Is this offset PAPR defined, or chosen here? Using an entirely
unaliged (odd) address seems a very strange choice.
> +
> static inline uint64_t ppc64_phys_to_real(uint64_t addr)
> {
> return addr & ~0xF000000000000000ULL;
> @@ -798,6 +801,7 @@ 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);
> +ssize_t spapr_get_rtas_size(ssize_t old_rtas_sizea);
>
> /* DRC callbacks. */
> void spapr_core_release(DeviceState *dev);
>
--
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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