diff options
| -rw-r--r-- | arch/s390/include/asm/processor.h | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/entry.S | 17 |
2 files changed, 16 insertions, 3 deletions
diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h index 7cf00cf8fb0b..db9982f0e8cd 100644 --- a/arch/s390/include/asm/processor.h +++ b/arch/s390/include/asm/processor.h @@ -14,11 +14,13 @@ #include <linux/bits.h> +#define CIF_SIE 0 /* CPU needs SIE exit cleanup */ #define CIF_NOHZ_DELAY 2 /* delay HZ disable for a tick */ #define CIF_ENABLED_WAIT 5 /* in enabled wait state */ #define CIF_MCCK_GUEST 6 /* machine check happening in guest */ #define CIF_DEDICATED_CPU 7 /* this CPU is dedicated */ +#define _CIF_SIE BIT(CIF_SIE) #define _CIF_NOHZ_DELAY BIT(CIF_NOHZ_DELAY) #define _CIF_ENABLED_WAIT BIT(CIF_ENABLED_WAIT) #define _CIF_MCCK_GUEST BIT(CIF_MCCK_GUEST) diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index fc5277eab554..4e0ff79ffee3 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -146,6 +146,7 @@ _LPP_OFFSET = __LC_LPP lg %r9,__SF_SIE_CONTROL(%r15) # get control block pointer ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE lctlg %c1,%c1,__LC_KERNEL_ASCE # load primary asce + ni __LC_CPU_FLAGS+7,255-_CIF_SIE larl %r9,sie_exit # skip forward to sie_exit .endm #endif @@ -214,6 +215,7 @@ SYM_FUNC_START(__sie64a) lg %r14,__LC_GMAP # get gmap pointer ltgr %r14,%r14 jz .Lsie_gmap + oi __LC_CPU_FLAGS+7,_CIF_SIE lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce .Lsie_gmap: lg %r14,__SF_SIE_CONTROL(%r15) # get control block pointer @@ -235,6 +237,7 @@ SYM_FUNC_START(__sie64a) ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE lctlg %c1,%c1,__LC_KERNEL_ASCE # load primary asce .Lsie_done: + ni __LC_CPU_FLAGS+7,255-_CIF_SIE # some program checks are suppressing. C code (e.g. do_protection_exception) # will rewind the PSW by the ILC, which is often 4 bytes in case of SIE. There # are some corner cases (e.g. runtime instrumentation) where ILC is unpredictable. @@ -346,7 +349,8 @@ SYM_CODE_START(pgm_check_handler) .Lpgm_skip_asce: #if IS_ENABLED(CONFIG_KVM) # cleanup critical section for program checks in __sie64a - OUTSIDE %r9,.Lsie_gmap,.Lsie_done,1f + TSTMSK __LC_CPU_FLAGS,_CIF_SIE + jz 1f BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST SIEEXIT lghi %r10,_PIF_GUEST_FAULT @@ -416,7 +420,8 @@ SYM_CODE_START(\name) tmhh %r8,0x0001 # interrupting from user ? jnz 1f #if IS_ENABLED(CONFIG_KVM) - OUTSIDE %r9,.Lsie_gmap,.Lsie_done,0f + TSTMSK __LC_CPU_FLAGS,_CIF_SIE + jz 0f BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST SIEEXIT #endif @@ -513,7 +518,13 @@ SYM_CODE_START(mcck_int_handler) TSTMSK __LC_MCCK_CODE,MCCK_CODE_PSW_IA_VALID jno .Lmcck_panic #if IS_ENABLED(CONFIG_KVM) - OUTSIDE %r9,.Lsie_gmap,.Lsie_done,.Lmcck_user + TSTMSK __LC_CPU_FLAGS,_CIF_SIE + jz .Lmcck_user + # Need to compare the address instead of a CIF_SIE* flag. + # Otherwise there would be a race between setting the flag + # and entering SIE (or leaving and clearing the flag). This + # would cause machine checks targeted at the guest to be + # handled by the host. OUTSIDE %r9,.Lsie_entry,.Lsie_leave,4f oi __LC_CPU_FLAGS+7, _CIF_MCCK_GUEST 4: BPENTER __SF_SIE_FLAGS(%r15),_TIF_ISOLATE_BP_GUEST |