linux/arch/powerpc/kernel/mce_power.c

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/*
* Machine check exception handling CPU-side for power7 and power8
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright 2013 IBM Corporation
* Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
*/
#undef DEBUG
#define pr_fmt(fmt) "mce_power: " fmt
#include <linux/types.h>
#include <linux/ptrace.h>
#include <asm/mmu.h>
#include <asm/mce.h>
#include <asm/machdep.h>
/* flush SLBs and reload */
static void flush_and_reload_slb(void)
{
struct slb_shadow *slb;
unsigned long i, n;
/* Invalidate all SLBs */
asm volatile("slbmte %0,%0; slbia" : : "r" (0));
#ifdef CONFIG_KVM_BOOK3S_HANDLER
/*
* If machine check is hit when in guest or in transition, we will
* only flush the SLBs and continue.
*/
if (get_paca()->kvm_hstate.in_guest)
return;
#endif
/* For host kernel, reload the SLBs from shadow SLB buffer. */
slb = get_slb_shadow();
if (!slb)
return;
n = min_t(u32, be32_to_cpu(slb->persistent), SLB_MIN_SIZE);
/* Load up the SLB entries from shadow SLB */
for (i = 0; i < n; i++) {
unsigned long rb = be64_to_cpu(slb->save_area[i].esid);
unsigned long rs = be64_to_cpu(slb->save_area[i].vsid);
rb = (rb & ~0xFFFul) | i;
asm volatile("slbmte %0,%1" : : "r" (rs), "r" (rb));
}
}
static long mce_handle_derror(uint64_t dsisr, uint64_t slb_error_bits)
{
long handled = 1;
/*
* flush and reload SLBs for SLB errors and flush TLBs for TLB errors.
* reset the error bits whenever we handle them so that at the end
* we can check whether we handled all of them or not.
* */
if (dsisr & slb_error_bits) {
flush_and_reload_slb();
/* reset error bits */
dsisr &= ~(slb_error_bits);
}
if (dsisr & P7_DSISR_MC_TLB_MULTIHIT_MFTLB) {
if (cur_cpu_spec && cur_cpu_spec->flush_tlb)
cur_cpu_spec->flush_tlb(TLBIEL_INVAL_PAGE);
/* reset error bits */
dsisr &= ~P7_DSISR_MC_TLB_MULTIHIT_MFTLB;
}
/* Any other errors we don't understand? */
if (dsisr & 0xffffffffUL)
handled = 0;
return handled;
}
static long mce_handle_derror_p7(uint64_t dsisr)
{
return mce_handle_derror(dsisr, P7_DSISR_MC_SLB_ERRORS);
}
static long mce_handle_common_ierror(uint64_t srr1)
{
long handled = 0;
switch (P7_SRR1_MC_IFETCH(srr1)) {
case 0:
break;
case P7_SRR1_MC_IFETCH_SLB_PARITY:
case P7_SRR1_MC_IFETCH_SLB_MULTIHIT:
/* flush and reload SLBs for SLB errors. */
flush_and_reload_slb();
handled = 1;
break;
case P7_SRR1_MC_IFETCH_TLB_MULTIHIT:
if (cur_cpu_spec && cur_cpu_spec->flush_tlb) {
cur_cpu_spec->flush_tlb(TLBIEL_INVAL_PAGE);
handled = 1;
}
break;
default:
break;
}
return handled;
}
static long mce_handle_ierror_p7(uint64_t srr1)
{
long handled = 0;
handled = mce_handle_common_ierror(srr1);
if (P7_SRR1_MC_IFETCH(srr1) == P7_SRR1_MC_IFETCH_SLB_BOTH) {
flush_and_reload_slb();
handled = 1;
}
return handled;
}
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
static void mce_get_common_ierror(struct mce_error_info *mce_err, uint64_t srr1)
{
switch (P7_SRR1_MC_IFETCH(srr1)) {
case P7_SRR1_MC_IFETCH_SLB_PARITY:
mce_err->error_type = MCE_ERROR_TYPE_SLB;
mce_err->u.slb_error_type = MCE_SLB_ERROR_PARITY;
break;
case P7_SRR1_MC_IFETCH_SLB_MULTIHIT:
mce_err->error_type = MCE_ERROR_TYPE_SLB;
mce_err->u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
break;
case P7_SRR1_MC_IFETCH_TLB_MULTIHIT:
mce_err->error_type = MCE_ERROR_TYPE_TLB;
mce_err->u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
break;
case P7_SRR1_MC_IFETCH_UE:
case P7_SRR1_MC_IFETCH_UE_IFU_INTERNAL:
mce_err->error_type = MCE_ERROR_TYPE_UE;
mce_err->u.ue_error_type = MCE_UE_ERROR_IFETCH;
break;
case P7_SRR1_MC_IFETCH_UE_TLB_RELOAD:
mce_err->error_type = MCE_ERROR_TYPE_UE;
mce_err->u.ue_error_type =
MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH;
break;
}
}
static void mce_get_ierror_p7(struct mce_error_info *mce_err, uint64_t srr1)
{
mce_get_common_ierror(mce_err, srr1);
if (P7_SRR1_MC_IFETCH(srr1) == P7_SRR1_MC_IFETCH_SLB_BOTH) {
mce_err->error_type = MCE_ERROR_TYPE_SLB;
mce_err->u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
}
}
static void mce_get_derror_p7(struct mce_error_info *mce_err, uint64_t dsisr)
{
if (dsisr & P7_DSISR_MC_UE) {
mce_err->error_type = MCE_ERROR_TYPE_UE;
mce_err->u.ue_error_type = MCE_UE_ERROR_LOAD_STORE;
} else if (dsisr & P7_DSISR_MC_UE_TABLEWALK) {
mce_err->error_type = MCE_ERROR_TYPE_UE;
mce_err->u.ue_error_type =
MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE;
} else if (dsisr & P7_DSISR_MC_ERAT_MULTIHIT) {
mce_err->error_type = MCE_ERROR_TYPE_ERAT;
mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
} else if (dsisr & P7_DSISR_MC_SLB_MULTIHIT) {
mce_err->error_type = MCE_ERROR_TYPE_SLB;
mce_err->u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
} else if (dsisr & P7_DSISR_MC_SLB_PARITY_MFSLB) {
mce_err->error_type = MCE_ERROR_TYPE_SLB;
mce_err->u.slb_error_type = MCE_SLB_ERROR_PARITY;
} else if (dsisr & P7_DSISR_MC_TLB_MULTIHIT_MFTLB) {
mce_err->error_type = MCE_ERROR_TYPE_TLB;
mce_err->u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
} else if (dsisr & P7_DSISR_MC_SLB_MULTIHIT_PARITY) {
mce_err->error_type = MCE_ERROR_TYPE_SLB;
mce_err->u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
}
}
static long mce_handle_ue_error(struct pt_regs *regs)
{
long handled = 0;
/*
* On specific SCOM read via MMIO we may get a machine check
* exception with SRR0 pointing inside opal. If that is the
* case OPAL may have recovery address to re-read SCOM data in
* different way and hence we can recover from this MC.
*/
if (ppc_md.mce_check_early_recovery) {
if (ppc_md.mce_check_early_recovery(regs))
handled = 1;
}
return handled;
}
long __machine_check_early_realmode_p7(struct pt_regs *regs)
{
uint64_t srr1, nip, addr;
long handled = 1;
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
struct mce_error_info mce_error_info = { 0 };
srr1 = regs->msr;
nip = regs->nip;
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
/*
* Handle memory errors depending whether this was a load/store or
* ifetch exception. Also, populate the mce error_type and
* type-specific error_type from either SRR1 or DSISR, depending
* whether this was a load/store or ifetch exception
*/
if (P7_SRR1_MC_LOADSTORE(srr1)) {
handled = mce_handle_derror_p7(regs->dsisr);
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
mce_get_derror_p7(&mce_error_info, regs->dsisr);
addr = regs->dar;
} else {
handled = mce_handle_ierror_p7(srr1);
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
mce_get_ierror_p7(&mce_error_info, srr1);
addr = regs->nip;
}
/* Handle UE error. */
if (mce_error_info.error_type == MCE_ERROR_TYPE_UE)
handled = mce_handle_ue_error(regs);
save_mce_event(regs, handled, &mce_error_info, nip, addr);
return handled;
}
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
static void mce_get_ierror_p8(struct mce_error_info *mce_err, uint64_t srr1)
{
mce_get_common_ierror(mce_err, srr1);
if (P7_SRR1_MC_IFETCH(srr1) == P8_SRR1_MC_IFETCH_ERAT_MULTIHIT) {
mce_err->error_type = MCE_ERROR_TYPE_ERAT;
mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
}
}
static void mce_get_derror_p8(struct mce_error_info *mce_err, uint64_t dsisr)
{
mce_get_derror_p7(mce_err, dsisr);
if (dsisr & P8_DSISR_MC_ERAT_MULTIHIT_SEC) {
mce_err->error_type = MCE_ERROR_TYPE_ERAT;
mce_err->u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
}
}
static long mce_handle_ierror_p8(uint64_t srr1)
{
long handled = 0;
handled = mce_handle_common_ierror(srr1);
if (P7_SRR1_MC_IFETCH(srr1) == P8_SRR1_MC_IFETCH_ERAT_MULTIHIT) {
flush_and_reload_slb();
handled = 1;
}
return handled;
}
static long mce_handle_derror_p8(uint64_t dsisr)
{
return mce_handle_derror(dsisr, P8_DSISR_MC_SLB_ERRORS);
}
long __machine_check_early_realmode_p8(struct pt_regs *regs)
{
uint64_t srr1, nip, addr;
long handled = 1;
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
struct mce_error_info mce_error_info = { 0 };
srr1 = regs->msr;
nip = regs->nip;
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
if (P7_SRR1_MC_LOADSTORE(srr1)) {
handled = mce_handle_derror_p8(regs->dsisr);
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
mce_get_derror_p8(&mce_error_info, regs->dsisr);
addr = regs->dar;
} else {
handled = mce_handle_ierror_p8(srr1);
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 <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-10-30 14:35:40 +00:00
mce_get_ierror_p8(&mce_error_info, srr1);
addr = regs->nip;
}
/* Handle UE error. */
if (mce_error_info.error_type == MCE_ERROR_TYPE_UE)
handled = mce_handle_ue_error(regs);
save_mce_event(regs, handled, &mce_error_info, nip, addr);
return handled;
}