From 36df96f8acaf51992177645eb2d781f766ce97dc Mon Sep 17 00:00:00 2001 From: Mahesh Salgaonkar Date: Wed, 30 Oct 2013 20:05:40 +0530 Subject: powerpc/book3s: Decode and save machine check event. Now that we handle machine check in linux, the MCE decoding should also take place in linux host. This info is crucial to log before we go down in case we can not handle the machine check errors. This patch decodes and populates a machine check event which contain high level meaning full MCE information. We do this in real mode C code with ME bit on. The MCE information is still available on emergency stack (in pt_regs structure format). Even if we take another exception at this point the MCE early handler will allocate a new stack frame on top of current one. So when we return back here we still have our MCE information safe on current stack. We use per cpu buffer to save high level MCE information. Each per cpu buffer is an array of machine check event structure indexed by per cpu counter mce_nest_count. The mce_nest_count is incremented every time we enter machine check early handler in real mode to get the current free slot (index = mce_nest_count - 1). The mce_nest_count is decremented once the MCE info is consumed by virtual mode machine exception handler. This patch provides save_mce_event(), get_mce_event() and release_mce_event() generic routines that can be used by machine check handlers to populate and retrieve the event. The routine release_mce_event() will free the event slot so that it can be reused. Caller can invoke get_mce_event() with a release flag either to release the event slot immediately OR keep it so that it can be fetched again. The event slot can be also released anytime by invoking release_mce_event(). This patch also updates kvm code to invoke get_mce_event to retrieve generic mce event rather than paca->opal_mce_evt. The KVM code always calls get_mce_event() with release flags set to false so that event is available for linus host machine If machine check occurs while we are in guest, KVM tries to handle the error. If KVM is able to handle MC error successfully, it enters the guest and delivers the machine check to guest. If KVM is not able to handle MC error, it exists the guest and passes the control to linux host machine check handler which then logs MC event and decides how to handle it in linux host. In failure case, KVM needs to make sure that the MC event is available for linux host to consume. Hence KVM always calls get_mce_event() with release flags set to false and later it invokes release_mce_event() only if it succeeds to handle error. Signed-off-by: Mahesh Salgaonkar Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/mce.h | 124 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 124 insertions(+) (limited to 'arch/powerpc/include/asm/mce.h') diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h index e3ffa825b970..87cad2a808c2 100644 --- a/arch/powerpc/include/asm/mce.h +++ b/arch/powerpc/include/asm/mce.h @@ -66,5 +66,129 @@ #define P8_DSISR_MC_SLB_ERRORS (P7_DSISR_MC_SLB_ERRORS | \ P8_DSISR_MC_ERAT_MULTIHIT_SEC) +enum MCE_Version { + MCE_V1 = 1, +}; + +enum MCE_Severity { + MCE_SEV_NO_ERROR = 0, + MCE_SEV_WARNING = 1, + MCE_SEV_ERROR_SYNC = 2, + MCE_SEV_FATAL = 3, +}; + +enum MCE_Disposition { + MCE_DISPOSITION_RECOVERED = 0, + MCE_DISPOSITION_NOT_RECOVERED = 1, +}; + +enum MCE_Initiator { + MCE_INITIATOR_UNKNOWN = 0, + MCE_INITIATOR_CPU = 1, +}; + +enum MCE_ErrorType { + MCE_ERROR_TYPE_UNKNOWN = 0, + MCE_ERROR_TYPE_UE = 1, + MCE_ERROR_TYPE_SLB = 2, + MCE_ERROR_TYPE_ERAT = 3, + MCE_ERROR_TYPE_TLB = 4, +}; + +enum MCE_UeErrorType { + MCE_UE_ERROR_INDETERMINATE = 0, + MCE_UE_ERROR_IFETCH = 1, + MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH = 2, + MCE_UE_ERROR_LOAD_STORE = 3, + MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE = 4, +}; + +enum MCE_SlbErrorType { + MCE_SLB_ERROR_INDETERMINATE = 0, + MCE_SLB_ERROR_PARITY = 1, + MCE_SLB_ERROR_MULTIHIT = 2, +}; + +enum MCE_EratErrorType { + MCE_ERAT_ERROR_INDETERMINATE = 0, + MCE_ERAT_ERROR_PARITY = 1, + MCE_ERAT_ERROR_MULTIHIT = 2, +}; + +enum MCE_TlbErrorType { + MCE_TLB_ERROR_INDETERMINATE = 0, + MCE_TLB_ERROR_PARITY = 1, + MCE_TLB_ERROR_MULTIHIT = 2, +}; + +struct machine_check_event { + enum MCE_Version version:8; /* 0x00 */ + uint8_t in_use; /* 0x01 */ + enum MCE_Severity severity:8; /* 0x02 */ + enum MCE_Initiator initiator:8; /* 0x03 */ + enum MCE_ErrorType error_type:8; /* 0x04 */ + enum MCE_Disposition disposition:8; /* 0x05 */ + uint8_t reserved_1[2]; /* 0x06 */ + uint64_t gpr3; /* 0x08 */ + uint64_t srr0; /* 0x10 */ + uint64_t srr1; /* 0x18 */ + union { /* 0x20 */ + struct { + enum MCE_UeErrorType ue_error_type:8; + uint8_t effective_address_provided; + uint8_t physical_address_provided; + uint8_t reserved_1[5]; + uint64_t effective_address; + uint64_t physical_address; + uint8_t reserved_2[8]; + } ue_error; + + struct { + enum MCE_SlbErrorType slb_error_type:8; + uint8_t effective_address_provided; + uint8_t reserved_1[6]; + uint64_t effective_address; + uint8_t reserved_2[16]; + } slb_error; + + struct { + enum MCE_EratErrorType erat_error_type:8; + uint8_t effective_address_provided; + uint8_t reserved_1[6]; + uint64_t effective_address; + uint8_t reserved_2[16]; + } erat_error; + + struct { + enum MCE_TlbErrorType tlb_error_type:8; + uint8_t effective_address_provided; + uint8_t reserved_1[6]; + uint64_t effective_address; + uint8_t reserved_2[16]; + } tlb_error; + } u; +}; + +struct mce_error_info { + enum MCE_ErrorType error_type:8; + union { + enum MCE_UeErrorType ue_error_type:8; + enum MCE_SlbErrorType slb_error_type:8; + enum MCE_EratErrorType erat_error_type:8; + enum MCE_TlbErrorType tlb_error_type:8; + } u; + uint8_t reserved[2]; +}; + +#define MAX_MC_EVT 100 + +/* Release flags for get_mce_event() */ +#define MCE_EVENT_RELEASE true +#define MCE_EVENT_DONTRELEASE false + +extern void save_mce_event(struct pt_regs *regs, long handled, + struct mce_error_info *mce_err, uint64_t addr); +extern int get_mce_event(struct machine_check_event *mce, bool release); +extern void release_mce_event(void); #endif /* __ASM_PPC64_MCE_H__ */ -- cgit v1.2.3