From d0fc41071a6884d0a10077bb6dc87f9267f32dd6 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 22 Jun 2015 17:26:40 +0200 Subject: [PATCH] s390/kvm: integrate HANDLE_SIE_INTERCEPT into cleanup_critical Currently there are two mechanisms to deal with cleanup work due to interrupts. The HANDLE_SIE_INTERCEPT macro is used to undo the changes required to enter SIE in sie64a. If the SIE instruction causes a program check, or an asynchronous interrupt is received the HANDLE_SIE_INTERCEPT code forwards the program execution to sie_exit. All the other critical sections in entry.S are handled by the code in cleanup_critical that is called by the SWITCH_ASYNC macro. Move the sie64a function to the beginning of the critical section and add the code from HANDLE_SIE_INTERCEPT to cleanup_critical. Add a special case for the sie64a cleanup to the program check handler. Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry.S | 241 ++++++++++++++++++++------------------- 1 file changed, 123 insertions(+), 118 deletions(-) diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 391db6412b85..9406e7a62d2f 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -75,31 +75,6 @@ _PIF_WORK = (_PIF_PER_TRAP) #endif .endm - .macro LPP newpp -#if IS_ENABLED(CONFIG_KVM) - tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_LPP - jz .+8 - .insn s,0xb2800000,\newpp -#endif - .endm - - .macro HANDLE_SIE_INTERCEPT scratch,reason -#if IS_ENABLED(CONFIG_KVM) - tmhh %r8,0x0001 # interrupting from user ? - jnz .+62 - lgr \scratch,%r9 - slg \scratch,BASED(.Lsie_critical) - clg \scratch,BASED(.Lsie_critical_length) - jhe .+42 - lg %r14,__SF_EMPTY(%r15) # get control block pointer - LPP __SF_EMPTY+16(%r15) # set host id - ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE - lctlg %c1,%c1,__LC_USER_ASCE # load primary asce - larl %r9,sie_exit # skip forward to sie_exit - mvi __SF_EMPTY+31(%r15),\reason # set exit reason -#endif - .endm - .macro CHECK_STACK stacksize,savearea #ifdef CONFIG_CHECK_STACK tml %r15,\stacksize - CONFIG_STACK_GUARD @@ -192,6 +167,70 @@ ENTRY(__switch_to) br %r14 .L__critical_start: + +#if IS_ENABLED(CONFIG_KVM) +/* + * sie64a calling convention: + * %r2 pointer to sie control block + * %r3 guest register save area + */ +ENTRY(sie64a) + stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers + stg %r2,__SF_EMPTY(%r15) # save control block pointer + stg %r3,__SF_EMPTY+8(%r15) # save guest register save area + xc __SF_EMPTY+16(16,%r15),__SF_EMPTY+16(%r15) # host id & reason + tm __LC_CPU_FLAGS+7,_CIF_FPU # load guest fp/vx registers ? + jno .Lsie_load_guest_gprs + lg %r12,__LC_THREAD_INFO # load fp/vx regs save area + brasl %r14,load_fpu_regs # load guest fp/vx regs +.Lsie_load_guest_gprs: + lmg %r0,%r13,0(%r3) # load guest gprs 0-13 + lg %r14,__LC_GMAP # get gmap pointer + ltgr %r14,%r14 + jz .Lsie_gmap + lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce +.Lsie_gmap: + lg %r14,__SF_EMPTY(%r15) # get control block pointer + oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now + tm __SIE_PROG20+3(%r14),3 # last exit... + jnz .Lsie_skip + tm __LC_CPU_FLAGS+7,_CIF_FPU + jo .Lsie_skip # exit if fp/vx regs changed + tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_LPP + jz .Lsie_enter + .insn s,0xb2800000,__SF_EMPTY(%r15) # set guest id +.Lsie_enter: + sie 0(%r14) + tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_LPP + jz .Lsie_skip + .insn s,0xb2800000,__SF_EMPTY+16(%r15)# set host id +.Lsie_skip: + ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE + lctlg %c1,%c1,__LC_USER_ASCE # load primary asce +.Lsie_done: +# some program checks are suppressing. C code (e.g. do_protection_exception) +# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other +# instructions between sie64a and .Lsie_done should not cause program +# interrupts. So lets use a nop (47 00 00 00) as a landing pad. +# See also .Lcleanup_sie +.Lrewind_pad: + nop 0 + .globl sie_exit +sie_exit: + lg %r14,__SF_EMPTY+8(%r15) # load guest register save area + stmg %r0,%r13,0(%r14) # save guest gprs 0-13 + lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers + lg %r2,__SF_EMPTY+24(%r15) # return exit reason code + br %r14 +.Lsie_fault: + lghi %r14,-EFAULT + stg %r14,__SF_EMPTY+24(%r15) # set exit reason code + j sie_exit + + EX_TABLE(.Lrewind_pad,.Lsie_fault) + EX_TABLE(sie_exit,.Lsie_fault) +#endif + /* * SVC interrupt handler routine. System calls are synchronous events and * are executed with interrupts enabled. @@ -411,26 +450,33 @@ ENTRY(pgm_check_handler) lg %r12,__LC_THREAD_INFO larl %r13,cleanup_critical lmg %r8,%r9,__LC_PGM_OLD_PSW - HANDLE_SIE_INTERCEPT %r14,1 tmhh %r8,0x0001 # test problem state bit - jnz 1f # -> fault in user space - tmhh %r8,0x4000 # PER bit set in old PSW ? - jnz 0f # -> enabled, can't be a double fault + jnz 2f # -> fault in user space +#if IS_ENABLED(CONFIG_KVM) + # cleanup critical section for sie64a + lgr %r14,%r9 + slg %r14,BASED(.Lsie_critical_start) + clg %r14,BASED(.Lsie_critical_length) + jhe 0f + brasl %r14,.Lcleanup_sie +#endif +0: tmhh %r8,0x4000 # PER bit set in old PSW ? + jnz 1f # -> enabled, can't be a double fault tm __LC_PGM_ILC+3,0x80 # check for per exception jnz .Lpgm_svcper # -> single stepped svc -0: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC +1: CHECK_STACK STACK_SIZE,__LC_SAVE_AREA_SYNC aghi %r15,-(STACK_FRAME_OVERHEAD + __PT_SIZE) - j 2f -1: UPDATE_VTIME %r14,__LC_SYNC_ENTER_TIMER + j 3f +2: UPDATE_VTIME %r14,__LC_SYNC_ENTER_TIMER LAST_BREAK %r14 lg %r15,__LC_KERNEL_STACK lg %r14,__TI_task(%r12) aghi %r14,__TASK_thread # pointer to thread_struct lghi %r13,__LC_PGM_TDB tm __LC_PGM_ILC+2,0x02 # check for transaction abort - jz 2f + jz 3f mvc __THREAD_trap_tdb(256,%r14),0(%r13) -2: la %r11,STACK_FRAME_OVERHEAD(%r15) +3: la %r11,STACK_FRAME_OVERHEAD(%r15) stmg %r0,%r7,__PT_R0(%r11) mvc __PT_R8(64,%r11),__LC_SAVE_AREA_SYNC stmg %r8,%r9,__PT_PSW(%r11) @@ -439,14 +485,14 @@ ENTRY(pgm_check_handler) xc __PT_FLAGS(8,%r11),__PT_FLAGS(%r11) stg %r10,__PT_ARGS(%r11) tm __LC_PGM_ILC+3,0x80 # check for per exception - jz 0f + jz 4f tmhh %r8,0x0001 # kernel per event ? jz .Lpgm_kprobe oi __PT_FLAGS+7(%r11),_PIF_PER_TRAP mvc __THREAD_per_address(8,%r14),__LC_PER_ADDRESS mvc __THREAD_per_cause(2,%r14),__LC_PER_CODE mvc __THREAD_per_paid(1,%r14),__LC_PER_ACCESS_ID -0: REENABLE_IRQS +4: REENABLE_IRQS xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) larl %r1,pgm_check_table llgh %r10,__PT_INT_CODE+2(%r11) @@ -489,7 +535,6 @@ ENTRY(io_int_handler) lg %r12,__LC_THREAD_INFO larl %r13,cleanup_critical lmg %r8,%r9,__LC_IO_OLD_PSW - HANDLE_SIE_INTERCEPT %r14,2 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT tmhh %r8,0x0001 # interrupting from user? jz .Lio_skip @@ -667,7 +712,6 @@ ENTRY(ext_int_handler) lg %r12,__LC_THREAD_INFO larl %r13,cleanup_critical lmg %r8,%r9,__LC_EXT_OLD_PSW - HANDLE_SIE_INTERCEPT %r14,3 SWITCH_ASYNC __LC_SAVE_AREA_ASYNC,__LC_ASYNC_STACK,STACK_SHIFT tmhh %r8,0x0001 # interrupting from user ? jz .Lext_skip @@ -832,7 +876,6 @@ ENTRY(mcck_int_handler) lg %r12,__LC_THREAD_INFO larl %r13,cleanup_critical lmg %r8,%r9,__LC_MCK_OLD_PSW - HANDLE_SIE_INTERCEPT %r14,4 tm __LC_MCCK_CODE,0x80 # system damage? jo .Lmcck_panic # yes -> rest of mcck code invalid lghi %r14,__LC_CPU_TIMER_SAVE_AREA @@ -947,26 +990,13 @@ stack_overflow: jg kernel_stack_overflow #endif - .align 8 -.Lcleanup_table: - .quad system_call - .quad .Lsysc_do_svc - .quad .Lsysc_tif - .quad .Lsysc_restore - .quad .Lsysc_done - .quad .Lio_tif - .quad .Lio_restore - .quad .Lio_done - .quad psw_idle - .quad .Lpsw_idle_end - .quad save_fpu_regs - .quad .Lsave_fpu_regs_end - .quad load_fpu_regs - .quad .Lload_fpu_regs_end - .quad __ctl_set_vx - .quad .L__ctl_set_vx_end - cleanup_critical: +#if IS_ENABLED(CONFIG_KVM) + clg %r9,BASED(.Lcleanup_table_sie) # .Lsie_gmap + jl 0f + clg %r9,BASED(.Lcleanup_table_sie+8)# .Lsie_done + jl .Lcleanup_sie +#endif clg %r9,BASED(.Lcleanup_table) # system_call jl 0f clg %r9,BASED(.Lcleanup_table+8) # .Lsysc_do_svc @@ -1001,6 +1031,40 @@ cleanup_critical: jl .Lcleanup___ctl_set_vx 0: br %r14 + .align 8 +.Lcleanup_table: + .quad system_call + .quad .Lsysc_do_svc + .quad .Lsysc_tif + .quad .Lsysc_restore + .quad .Lsysc_done + .quad .Lio_tif + .quad .Lio_restore + .quad .Lio_done + .quad psw_idle + .quad .Lpsw_idle_end + .quad save_fpu_regs + .quad .Lsave_fpu_regs_end + .quad load_fpu_regs + .quad .Lload_fpu_regs_end + .quad __ctl_set_vx + .quad .L__ctl_set_vx_end + +#if IS_ENABLED(CONFIG_KVM) +.Lcleanup_table_sie: + .quad .Lsie_gmap + .quad .Lsie_done + +.Lcleanup_sie: + lg %r9,__SF_EMPTY(%r15) # get control block pointer + tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_LPP + jz 0f + .insn s,0xb2800000,__SF_EMPTY+16(%r15)# set host id +0: ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE + lctlg %c1,%c1,__LC_USER_ASCE # load primary asce + larl %r9,sie_exit # skip forward to sie_exit + br %r14 +#endif .Lcleanup_system_call: # check if stpt has been executed @@ -1274,70 +1338,11 @@ cleanup_critical: .quad .L__critical_start .Lcritical_length: .quad .L__critical_end - .L__critical_start - - #if IS_ENABLED(CONFIG_KVM) -/* - * sie64a calling convention: - * %r2 pointer to sie control block - * %r3 guest register save area - */ -ENTRY(sie64a) - stmg %r6,%r14,__SF_GPRS(%r15) # save kernel registers - stg %r2,__SF_EMPTY(%r15) # save control block pointer - stg %r3,__SF_EMPTY+8(%r15) # save guest register save area - xc __SF_EMPTY+16(16,%r15),__SF_EMPTY+16(%r15) # host id & reason - tm __LC_CPU_FLAGS+7,_CIF_FPU # load guest fp/vx registers ? - jno .Lsie_load_guest_gprs - lg %r12,__LC_THREAD_INFO # load fp/vx regs save area - brasl %r14,load_fpu_regs # load guest fp/vx regs -.Lsie_load_guest_gprs: - lmg %r0,%r13,0(%r3) # load guest gprs 0-13 - lg %r14,__LC_GMAP # get gmap pointer - ltgr %r14,%r14 - jz .Lsie_gmap - lctlg %c1,%c1,__GMAP_ASCE(%r14) # load primary asce -.Lsie_gmap: - lg %r14,__SF_EMPTY(%r15) # get control block pointer - oi __SIE_PROG0C+3(%r14),1 # we are going into SIE now - tm __SIE_PROG20+3(%r14),3 # last exit... - jnz .Lsie_skip - tm __LC_CPU_FLAGS+7,_CIF_FPU - jo .Lsie_skip # exit if fp/vx regs changed - LPP __SF_EMPTY(%r15) # set guest id - sie 0(%r14) - LPP __SF_EMPTY+16(%r15) # set host id -.Lsie_skip: - ni __SIE_PROG0C+3(%r14),0xfe # no longer in SIE - lctlg %c1,%c1,__LC_USER_ASCE # load primary asce -.Lsie_done: -# some program checks are suppressing. C code (e.g. do_protection_exception) -# will rewind the PSW by the ILC, which is 4 bytes in case of SIE. Other -# instructions between sie64a and .Lsie_done should not cause program -# interrupts. So lets use a nop (47 00 00 00) as a landing pad. -# See also HANDLE_SIE_INTERCEPT -.Lrewind_pad: - nop 0 - .globl sie_exit -sie_exit: - lg %r14,__SF_EMPTY+8(%r15) # load guest register save area - stmg %r0,%r13,0(%r14) # save guest gprs 0-13 - lmg %r6,%r14,__SF_GPRS(%r15) # restore kernel registers - lg %r2,__SF_EMPTY+24(%r15) # return exit reason code - br %r14 -.Lsie_fault: - lghi %r14,-EFAULT - stg %r14,__SF_EMPTY+24(%r15) # set exit reason code - j sie_exit - - .align 8 -.Lsie_critical: +.Lsie_critical_start: .quad .Lsie_gmap .Lsie_critical_length: .quad .Lsie_done - .Lsie_gmap - - EX_TABLE(.Lrewind_pad,.Lsie_fault) - EX_TABLE(sie_exit,.Lsie_fault) #endif .section .rodata, "a"