From 742aed05af97dc5ba6c53a4b6cb6a7b31e32f9e9 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 29 Nov 2022 17:22:14 +0100 Subject: [PATCH] s390/nmi: move storage error checking back to C, enter with DAT on Checking for storage errors in machine check entry code was done in order to handle also storage errors on kernel page tables. However this is extremely unlikely and some basic assumptions what works on machine check entry are necessary anyway. In order to simplify machine check handling delay checking for storage errors to C code. With this also change the machine check new PSW to have DAT on, which simplifies the entry code even further. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev --- arch/s390/kernel/entry.S | 34 ++++------------------------------ arch/s390/kernel/nmi.c | 16 +++++++++++++++- arch/s390/kernel/setup.c | 3 ++- 3 files changed, 21 insertions(+), 32 deletions(-) diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index d2a1f2f..e0d11f3 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -122,24 +122,6 @@ _LPP_OFFSET = __LC_LPP "jnz .+8; .insn rrf,0xb2e80000,0,0,13,0", 82 .endm - /* - * The CHKSTG macro jumps to the provided label in case the - * machine check interruption code reports one of unrecoverable - * storage errors: - * - Storage error uncorrected - * - Storage key error uncorrected - * - Storage degradation with Failing-storage-address validity - */ - .macro CHKSTG errlabel - TSTMSK __LC_MCCK_CODE,(MCCK_CODE_STG_ERROR|MCCK_CODE_STG_KEY_ERROR) - jnz \errlabel - TSTMSK __LC_MCCK_CODE,MCCK_CODE_STG_DEGRAD - jz .Loklabel\@ - TSTMSK __LC_MCCK_CODE,MCCK_CODE_STG_FAIL_ADDR - jnz \errlabel -.Loklabel\@: - .endm - #if IS_ENABLED(CONFIG_KVM) /* * The OUTSIDE macro jumps to the provided label in case the value @@ -546,26 +528,18 @@ ENTRY(mcck_int_handler) 3: TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_MWP_VALID jno .Lmcck_panic tmhh %r8,0x0001 # interrupting from user ? - jnz 6f + jnz .Lmcck_user TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID jno .Lmcck_panic #if IS_ENABLED(CONFIG_KVM) - OUTSIDE %r9,.Lsie_gmap,.Lsie_done,6f + OUTSIDE %r9,.Lsie_gmap,.Lsie_done,.Lmcck_stack OUTSIDE %r9,.Lsie_entry,.Lsie_leave,4f oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST - j 5f -4: CHKSTG .Lmcck_panic -5: larl %r14,.Lstosm_tmp - stosm 0(%r14),0x04 # turn dat on, keep irqs off - BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST) +4: BPENTER __SF_SIE_FLAGS(%r15),(_TIF_ISOLATE_BP|_TIF_ISOLATE_BP_GUEST) SIEEXIT j .Lmcck_stack #endif -6: CHKSTG .Lmcck_panic - larl %r14,.Lstosm_tmp - stosm 0(%r14),0x04 # turn dat on, keep irqs off - tmhh %r8,0x0001 # interrupting from user ? - jz .Lmcck_stack +.Lmcck_user: BPENTER __TI_flags(%r12),_TIF_ISOLATE_BP .Lmcck_stack: lg %r15,__LC_MCCK_STACK diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c index b1579c8..b54d4aa 100644 --- a/arch/s390/kernel/nmi.c +++ b/arch/s390/kernel/nmi.c @@ -487,7 +487,21 @@ int notrace s390_do_machine_check(struct pt_regs *regs) mcck->stp_queue |= stp_island_check(); mcck_pending = 1; } - + /* + * Reinject storage related machine checks into the guest if they + * happen when the guest is running. + */ + if (!test_cpu_flag(CIF_MCCK_GUEST)) { + /* Storage error uncorrected */ + if (mci.se) + s390_handle_damage(); + /* Storage key-error uncorrected */ + if (mci.ke) + s390_handle_damage(); + /* Storage degradation */ + if (mci.ds && mci.fa) + s390_handle_damage(); + } if (mci.cp) { /* Channel report word pending */ mcck->channel_report = 1; diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index ab19ddb..2094f57 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -437,7 +437,7 @@ static void __init setup_lowcore_dat_off(void) lc->svc_new_psw.addr = (unsigned long) system_call; lc->program_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK; lc->program_new_psw.addr = (unsigned long) pgm_check_handler; - lc->mcck_new_psw.mask = PSW_KERNEL_BITS; + lc->mcck_new_psw.mask = int_psw_mask; lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler; lc->io_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK; lc->io_new_psw.addr = (unsigned long) io_int_handler; @@ -512,6 +512,7 @@ static void __init setup_lowcore_dat_on(void) S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT; S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT; S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT; + S390_lowcore.mcck_new_psw.mask |= PSW_MASK_DAT; S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT; __ctl_set_bit(0, 28); __ctl_store(S390_lowcore.cregs_save_area, 0, 15); -- 2.7.4