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Re: [Qemu-ppc] [PATCH v9 4/6] target/ppc: Build rtas error log upon an M
From: |
David Gibson |
Subject: |
Re: [Qemu-ppc] [PATCH v9 4/6] target/ppc: Build rtas error log upon an MCE |
Date: |
Thu, 6 Jun 2019 12:58:27 +1000 |
User-agent: |
Mutt/1.11.4 (2019-03-13) |
On Tue, Jun 04, 2019 at 11:01:19AM +0200, Greg Kurz wrote:
> On Tue, 4 Jun 2019 11:59:13 +0530
> Aravinda Prasad <address@hidden> wrote:
>
> > On Monday 03 June 2019 07:30 PM, Greg Kurz wrote:
> > > On Wed, 29 May 2019 11:10:40 +0530
> > > Aravinda Prasad <address@hidden> 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 <address@hidden>
> > >> ---
> > >> hw/ppc/spapr.c | 5 +
> > >> hw/ppc/spapr_events.c | 236
> > >> ++++++++++++++++++++++++++++++++++++++++++++++++
> > >> include/hw/ppc/spapr.h | 4 +
> > >> 3 files changed, 245 insertions(+)
> > >>
> > >> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> > >> index 6b6c962..c97f6a6 100644
> > >> --- a/hw/ppc/spapr.c
> > >> +++ b/hw/ppc/spapr.c
> > >> @@ -2910,6 +2910,11 @@ 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. */
> > >> + g_assert(spapr->rtas_size < RTAS_ERROR_LOG_OFFSET);
> > >
> > > I don't see the point of this assertion... especially with the assignment
> > > below.
> >
> > It is required because we want to ensure that the rtas image size is
> > less than RTAS_ERROR_LOG_OFFSET, or else we will overwrite the rtas
> > image with rtas error when we hit machine check exception. But I think a
> > comment in the code will help. Will add it.
>
> I'd rather exit QEMU properly instead of aborting then. Also this is only
> needed if the guest has a chance to use FWNMI, ie. the spapr cap is
> set.
I think assert() is appropriate in this case. If it fails it means
something is wrong in the code, not with configuration.
>
> >
> > >
> > >> + spapr->rtas_size = RTAS_ERROR_LOG_MAX;
> > >
> > > As requested by David, this should only be done when the spapr cap is set,
> > > so that 4.0 machine types and older continue to use the current size.
> >
> > Due to other issue of re-allocating the blob and as this is not that
> > much space, we agreed to keep the size to RTAS_ERROR_LOG_MAX always.
> >
> > Link to the discussion on this:
> > http://lists.nongnu.org/archive/html/qemu-ppc/2019-05/msg00275.html
> >
>
> Indeed, and in the next mail in that thread, David writes:
>
> > No, that's not right. It's impractical to change the allocation
> > depending on whether fwnmi is currently active. But you *can* (and
> > should) base the allocation on whether fwnmi is *possible* - that is,
> > the value of the spapr cap.
>
> ie, allocate RTAS_ERROR_LOG_MAX when the spapr cap is set, allocate
> the file size otherwise.
>
> > >
> > >> +
> > >> 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 a18446b..573c0b7 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 +720,138 @@ void
> > >> spapr_hotplug_req_remove_by_count_indexed(SpaprDrcType drc_type,
> > >> RTAS_LOG_V6_HP_ACTION_REMOVE, drc_type,
> > >> &drc_id);
> > >> }
> > >>
> > >> +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(*ext_elog));
> > >> + summary = spapr_mce_get_elog_type(cpu, recovered, ext_elog);
> > >> +
> > >> + log.summary = cpu_to_be32(summary);
> > >> + log.extended_length = cpu_to_be32(sizeof(*ext_elog));
> > >> +
> > >> + /* 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_ERROR_LOG_OFFSET, &r3,
> > >> + sizeof(r3));
> > >> + cpu_physical_memory_write(rtas_addr + RTAS_ERROR_LOG_OFFSET +
> > >> sizeof(r3),
> > >> + &log, sizeof(log));
> > >> + cpu_physical_memory_write(rtas_addr + RTAS_ERROR_LOG_OFFSET +
> > >> sizeof(r3) +
> > >> + sizeof(log), ext_elog,
> > >> + sizeof(*ext_elog));
> > >> +
> > >> + env->gpr[3] = rtas_addr + RTAS_ERROR_LOG_OFFSET;
> > >> + env->nip = spapr->guest_machine_check_addr;
> > >> +
> > >> + g_free(ext_elog);
> > >> +}
> > >> +
> > >> void spapr_mce_req_event(PowerPCCPU *cpu, bool recovered)
> > >> {
> > >> SpaprMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
> > >> @@ -641,6 +873,10 @@ void spapr_mce_req_event(PowerPCCPU *cpu, bool
> > >> recovered)
> > >> }
> > >> }
> > >> spapr->mc_status = cpu->vcpu_id;
> > >> +
> > >> + spapr_mce_dispatch_elog(cpu, recovered);
> > >> +
> > >> + return;
> > >
> > > Drop the last two lines.
> >
> > ok.
> >
> > >
> > >> }
> > >>
> > >> static void check_exception(PowerPCCPU *cpu, SpaprMachineState *spapr,
> > >> diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
> > >> index fc3a776..c717ab2 100644
> > >> --- a/include/hw/ppc/spapr.h
> > >> +++ b/include/hw/ppc/spapr.h
> > >> @@ -710,6 +710,9 @@ void spapr_load_rtas(SpaprMachineState *spapr, void
> > >> *fdt, hwaddr addr);
> > >>
> > >> #define RTAS_ERROR_LOG_MAX 2048
> > >>
> > >> +/* Offset from rtas-base where error log is placed */
> > >> +#define RTAS_ERROR_LOG_OFFSET 0x30
> > >> +
> > >> #define RTAS_EVENT_SCAN_RATE 1
> > >>
> > >> /* This helper should be used to encode interrupt specifiers when the
> > >> related
> > >> @@ -799,6 +802,7 @@ 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);
> > >>
> > >
> > > Looks like a leftover.
> >
> > ah.. yes.
> >
> > >
> > >> /* 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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