From 603d1a50acf252621a3598618b018b8123aaba64 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Sun, 24 Jul 2011 10:48:18 +0200 Subject: [PATCH] [S390] move sie code to entry.S The entry to / exit from sie has subtle dependencies to the first level interrupt handler. Move the sie assembler code to entry64.S and replace the SIE_HOOK callback with a test and the new _TIF_SIE bit. In addition this patch fixes several problems in regard to the check for the_TIF_EXIT_SIE bits. The old code checked the TIF bits before executing the interrupt handler and it only modified the instruction address if it pointed directly to the sie instruction. In both cases it could miss a TIF bit that normally would cause an exit from the guest and would reenter the guest context. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/thread_info.h | 2 + arch/s390/kernel/entry64.S | 80 +++++++++++++++++++++++++++--- arch/s390/kernel/s390_ksyms.c | 4 ++ arch/s390/kvm/Makefile | 2 +- arch/s390/kvm/sie64a.S | 98 ------------------------------------- 5 files changed, 79 insertions(+), 107 deletions(-) delete mode 100644 arch/s390/kvm/sie64a.S diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h index ad1382f..1a5dbb6 100644 --- a/arch/s390/include/asm/thread_info.h +++ b/arch/s390/include/asm/thread_info.h @@ -94,6 +94,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_SYSCALL_AUDIT 9 /* syscall auditing active */ #define TIF_SECCOMP 10 /* secure computing */ #define TIF_SYSCALL_TRACEPOINT 11 /* syscall tracepoint instrumentation */ +#define TIF_SIE 12 /* guest execution active */ #define TIF_POLLING_NRFLAG 16 /* true if poll_idle() is polling TIF_NEED_RESCHED */ #define TIF_31BIT 17 /* 32bit process */ @@ -113,6 +114,7 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_SYSCALL_AUDIT (1<>8 | _TIF_SYSCALL_AUDIT>>8 | \ _TIF_SECCOMP>>8 | _TIF_SYSCALL_TRACEPOINT>>8) +_TIF_EXIT_SIE = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING) #define BASED(name) name-system_call(%r13) + .macro SPP newpp +#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) + tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_SPP + jz .+8 + .insn s,0xb2800000,\newpp +#endif + .endm + .macro HANDLE_SIE_INTERCEPT #if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) - lg %r3,__LC_SIE_HOOK - ltgr %r3,%r3 + tm __TI_flags+6(%r12),_TIF_SIE>>8 jz 0f - basr %r14,%r3 + SPP __LC_CMF_HPP # set host id + clc SP_PSW+8(8,%r15),BASED(.Lsie_loop) + jl 0f + clc SP_PSW+8(8,%r15),BASED(.Lsie_done) + jhe 0f + mvc SP_PSW+8(8,%r15),BASED(.Lsie_loop) 0: #endif .endm @@ -465,6 +478,7 @@ pgm_check_handler: xc SP_ILC(4,%r15),SP_ILC(%r15) mvc SP_PSW(16,%r15),__LC_PGM_OLD_PSW lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct + HANDLE_SIE_INTERCEPT tm SP_PSW+1(%r15),0x01 # interrupting from user ? jz pgm_no_vtime UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER @@ -472,7 +486,6 @@ pgm_check_handler: mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER LAST_BREAK pgm_no_vtime: - HANDLE_SIE_INTERCEPT stg %r11,SP_ARGS(%r15) lgf %r3,__LC_PGM_ILC # load program interruption code lg %r4,__LC_TRANS_EXC_CODE @@ -507,6 +520,7 @@ pgm_per_std: CREATE_STACK_FRAME __LC_SAVE_AREA mvc SP_PSW(16,%r15),__LC_PGM_OLD_PSW lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct + HANDLE_SIE_INTERCEPT tm SP_PSW+1(%r15),0x01 # interrupting from user ? jz pgm_no_vtime2 UPDATE_VTIME __LC_EXIT_TIMER,__LC_SYNC_ENTER_TIMER,__LC_USER_TIMER @@ -514,7 +528,6 @@ pgm_per_std: mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER LAST_BREAK pgm_no_vtime2: - HANDLE_SIE_INTERCEPT lg %r1,__TI_task(%r12) tm SP_PSW+1(%r15),0x01 # kernel per event ? jz kernel_per @@ -579,6 +592,7 @@ io_int_handler: CREATE_STACK_FRAME __LC_SAVE_AREA+40 mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct + HANDLE_SIE_INTERCEPT tm SP_PSW+1(%r15),0x01 # interrupting from user ? jz io_no_vtime UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER @@ -586,7 +600,6 @@ io_int_handler: mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER LAST_BREAK io_no_vtime: - HANDLE_SIE_INTERCEPT TRACE_IRQS_OFF la %r2,SP_PTREGS(%r15) # address of register-save area brasl %r14,do_IRQ # call standard irq handler @@ -714,6 +727,7 @@ ext_int_handler: CREATE_STACK_FRAME __LC_SAVE_AREA+40 mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct + HANDLE_SIE_INTERCEPT tm SP_PSW+1(%r15),0x01 # interrupting from user ? jz ext_no_vtime UPDATE_VTIME __LC_EXIT_TIMER,__LC_ASYNC_ENTER_TIMER,__LC_USER_TIMER @@ -721,7 +735,6 @@ ext_int_handler: mvc __LC_LAST_UPDATE_TIMER(8),__LC_ASYNC_ENTER_TIMER LAST_BREAK ext_no_vtime: - HANDLE_SIE_INTERCEPT TRACE_IRQS_OFF lghi %r1,4096 la %r2,SP_PTREGS(%r15) # address of register-save area @@ -785,6 +798,7 @@ mcck_int_main: lg %r12,__LC_THREAD_INFO # load pointer to thread_info struct tm __LC_MCCK_CODE+2,0x08 # mwp of old psw valid? jno mcck_no_vtime # no -> no timer update + HANDLE_SIE_INTERCEPT tm SP_PSW+1(%r15),0x01 # interrupting from user ? jz mcck_no_vtime UPDATE_VTIME __LC_EXIT_TIMER,__LC_MCCK_ENTER_TIMER,__LC_USER_TIMER @@ -804,7 +818,6 @@ mcck_no_vtime: stosm __SF_EMPTY(%r15),0x04 # turn dat on tm __TI_flags+7(%r12),_TIF_MCCK_PENDING jno mcck_return - HANDLE_SIE_INTERCEPT TRACE_IRQS_OFF brasl %r14,s390_handle_mcck TRACE_IRQS_ON @@ -1036,6 +1049,57 @@ cleanup_io_restore_insn: .Lcritical_end: .quad __critical_end +#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) +/* + * sie64a calling convention: + * %r2 pointer to sie control block + * %r3 guest register save area + */ + .globl sie64a +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 + lmg %r0,%r13,0(%r3) # load guest gprs 0-13 + lg %r14,__LC_THREAD_INFO # pointer thread_info struct + oi __TI_flags+6(%r14),_TIF_SIE>>8 +sie_loop: + lg %r14,__LC_THREAD_INFO # pointer thread_info struct + tm __TI_flags+7(%r14),_TIF_EXIT_SIE + jnz sie_exit + lg %r14,__SF_EMPTY(%r15) # get control block pointer + SPP __SF_EMPTY(%r15) # set guest id + sie 0(%r14) +sie_done: + SPP __LC_CMF_HPP # set host id + lg %r14,__LC_THREAD_INFO # pointer thread_info struct +sie_exit: + ni __TI_flags+6(%r14),255-(_TIF_SIE>>8) + 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 + lghi %r2,0 + br %r14 +sie_fault: + lg %r14,__LC_THREAD_INFO # pointer thread_info struct + ni __TI_flags+6(%r14),255-(_TIF_SIE>>8) + 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 + lghi %r2,-EFAULT + br %r14 + + .align 8 +.Lsie_loop: + .quad sie_loop +.Lsie_done: + .quad sie_done + + .section __ex_table,"a" + .quad sie_loop,sie_fault + .previous +#endif + .section .rodata, "a" #define SYSCALL(esa,esame,emu) .long esame .globl sys_call_table diff --git a/arch/s390/kernel/s390_ksyms.c b/arch/s390/kernel/s390_ksyms.c index 656fcbb..57b5366 100644 --- a/arch/s390/kernel/s390_ksyms.c +++ b/arch/s390/kernel/s390_ksyms.c @@ -1,6 +1,10 @@ #include +#include #include #ifdef CONFIG_FUNCTION_TRACER EXPORT_SYMBOL(_mcount); #endif +#if defined(CONFIG_KVM) || defined(CONFIG_KVM_MODULE) +EXPORT_SYMBOL(sie64a); +#endif diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile index 860d265..3975722 100644 --- a/arch/s390/kvm/Makefile +++ b/arch/s390/kvm/Makefile @@ -10,5 +10,5 @@ common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o) ccflags-y := -Ivirt/kvm -Iarch/s390/kvm -kvm-objs := $(common-objs) kvm-s390.o sie64a.o intercept.o interrupt.o priv.o sigp.o diag.o +kvm-objs := $(common-objs) kvm-s390.o intercept.o interrupt.o priv.o sigp.o diag.o obj-$(CONFIG_KVM) += kvm.o diff --git a/arch/s390/kvm/sie64a.S b/arch/s390/kvm/sie64a.S deleted file mode 100644 index 5faa1b1..0000000 --- a/arch/s390/kvm/sie64a.S +++ /dev/null @@ -1,98 +0,0 @@ -/* - * sie64a.S - low level sie call - * - * Copyright IBM Corp. 2008,2010 - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License (version 2 only) - * as published by the Free Software Foundation. - * - * Author(s): Heiko Carstens - * Christian Ehrhardt - */ - -#include -#include -#include -#include -#include -#include - -_TIF_EXIT_SIE = (_TIF_SIGPENDING | _TIF_NEED_RESCHED | _TIF_MCCK_PENDING) - -/* - * offsets into stackframe - * SP_ = offsets into stack sie64 is called with - * SPI_ = offsets into irq stack - */ -SP_GREGS = __SF_EMPTY -SP_HOOK = __SF_EMPTY+8 -SP_GPP = __SF_EMPTY+16 -SPI_PSW = STACK_FRAME_OVERHEAD + __PT_PSW - - - .macro SPP newpp - tm __LC_MACHINE_FLAGS+6,0x20 # MACHINE_FLAG_SPP - jz 0f - .insn s,0xb2800000,\newpp -0: - .endm - -sie_irq_handler: - SPP __LC_CMF_HPP # set host id - larl %r2,sie_inst - clg %r2,SPI_PSW+8(0,%r15) # intercepted sie - jne 1f - xc __LC_SIE_HOOK(8),__LC_SIE_HOOK - lg %r2,__LC_THREAD_INFO # pointer thread_info struct - tm __TI_flags+7(%r2),_TIF_EXIT_SIE - jz 0f - larl %r2,sie_exit # work pending, leave sie - stg %r2,SPI_PSW+8(0,%r15) - br %r14 -0: larl %r2,sie_reenter # re-enter with guest id - stg %r2,SPI_PSW+8(0,%r15) -1: br %r14 - -/* - * sie64a calling convention: - * %r2 pointer to sie control block - * %r3 guest register save area - */ - .globl sie64a -sie64a: - stg %r3,SP_GREGS(%r15) # save guest register save area - stmg %r6,%r14,__SF_GPRS(%r15) # save registers on entry - lgr %r14,%r2 # pointer to sie control block - larl %r5,sie_irq_handler - stg %r2,SP_GPP(%r15) - stg %r5,SP_HOOK(%r15) # save hook target - lmg %r0,%r13,0(%r3) # load guest gprs 0-13 -sie_reenter: - mvc __LC_SIE_HOOK(8),SP_HOOK(%r15) - SPP SP_GPP(%r15) # set guest id -sie_inst: - sie 0(%r14) - xc __LC_SIE_HOOK(8),__LC_SIE_HOOK - SPP __LC_CMF_HPP # set host id -sie_exit: - lg %r14,SP_GREGS(%r15) - stmg %r0,%r13,0(%r14) # save guest gprs 0-13 - lghi %r2,0 - lmg %r6,%r14,__SF_GPRS(%r15) - br %r14 - -sie_err: - xc __LC_SIE_HOOK(8),__LC_SIE_HOOK - SPP __LC_CMF_HPP # set host id - lg %r14,SP_GREGS(%r15) - stmg %r0,%r13,0(%r14) # save guest gprs 0-13 - lghi %r2,-EFAULT - lmg %r6,%r14,__SF_GPRS(%r15) - br %r14 - - .section __ex_table,"a" - .quad sie_inst,sie_err - .quad sie_exit,sie_err - .quad sie_reenter,sie_err - .previous -- 2.7.4