On 18.05.2017 15:20, Aurelien Jarno wrote: > On 2017-05-18 13:39, Thomas Huth wrote: >> TEST BLOCK was likely once used to execute basic memory >> tests, but nowadays it's just a (slow) way to clear a page. >> >> Signed-off-by: Thomas Huth <th...@redhat.com> >> --- >> v2: >> - Use DEF_HELPER_FLAGS_2 instead for DEF_HELPER_2 for returning CC value >> - Convert real to absolute address >> - Added a check for valid RAM page >> - Added low-address protection check >> >> target/s390x/cpu.h | 1 + >> target/s390x/helper.h | 1 + >> target/s390x/insn-data.def | 2 ++ >> target/s390x/mem_helper.c | 28 ++++++++++++++++++++++++++++ >> target/s390x/mmu_helper.c | 2 +- >> target/s390x/translate.c | 10 ++++++++++ >> 6 files changed, 43 insertions(+), 1 deletion(-) >> >> diff --git a/target/s390x/cpu.h b/target/s390x/cpu.h >> index 240b8a5..4f38ba0 100644 >> --- a/target/s390x/cpu.h >> +++ b/target/s390x/cpu.h >> @@ -1082,6 +1082,7 @@ struct sysib_322 { >> #define SIGP_ORDER_MASK 0x000000ff >> >> void load_psw(CPUS390XState *env, uint64_t mask, uint64_t addr); >> +target_ulong mmu_real2abs(CPUS390XState *env, target_ulong raddr); >> int mmu_translate(CPUS390XState *env, target_ulong vaddr, int rw, uint64_t >> asc, >> target_ulong *raddr, int *flags, bool exc); >> int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code); >> diff --git a/target/s390x/helper.h b/target/s390x/helper.h >> index 0b70770..1fae191 100644 >> --- a/target/s390x/helper.h >> +++ b/target/s390x/helper.h >> @@ -102,6 +102,7 @@ DEF_HELPER_FLAGS_4(lctl, TCG_CALL_NO_WG, void, env, i32, >> i64, i32) >> DEF_HELPER_FLAGS_4(lctlg, TCG_CALL_NO_WG, void, env, i32, i64, i32) >> DEF_HELPER_FLAGS_4(stctl, TCG_CALL_NO_WG, void, env, i32, i64, i32) >> DEF_HELPER_FLAGS_4(stctg, TCG_CALL_NO_WG, void, env, i32, i64, i32) >> +DEF_HELPER_FLAGS_2(testblock, TCG_CALL_NO_WG, i32, env, i64) > > As the helper does not read any values from the global, you can even use > TCG_CALL_NO_RWG.
Ok. >> DEF_HELPER_FLAGS_2(tprot, TCG_CALL_NO_RWG, i32, i64, i64) >> DEF_HELPER_FLAGS_2(iske, TCG_CALL_NO_RWG_SE, i64, env, i64) >> DEF_HELPER_FLAGS_3(sske, TCG_CALL_NO_RWG, void, env, i64, i64) >> diff --git a/target/s390x/insn-data.def b/target/s390x/insn-data.def >> index 55a7c52..cac0f51 100644 >> --- a/target/s390x/insn-data.def >> +++ b/target/s390x/insn-data.def >> @@ -918,6 +918,8 @@ >> /* STORE USING REAL ADDRESS */ >> C(0xb246, STURA, RRE, Z, r1_o, r2_o, 0, 0, stura, 0) >> C(0xb925, STURG, RRE, Z, r1_o, r2_o, 0, 0, sturg, 0) >> +/* TEST BLOCK */ >> + C(0xb22c, TB, RRE, Z, 0, r2_o, 0, 0, testblock, 0) >> /* TEST PROTECTION */ >> C(0xe501, TPROT, SSE, Z, la1, a2, 0, 0, tprot, 0) >> >> diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c >> index f6e5bce..de0ecd4 100644 >> --- a/target/s390x/mem_helper.c >> +++ b/target/s390x/mem_helper.c >> @@ -20,6 +20,7 @@ >> >> #include "qemu/osdep.h" >> #include "cpu.h" >> +#include "exec/address-spaces.h" >> #include "exec/helper-proto.h" >> #include "exec/exec-all.h" >> #include "exec/cpu_ldst.h" >> @@ -973,6 +974,33 @@ void HELPER(stctl)(CPUS390XState *env, uint32_t r1, >> uint64_t a2, uint32_t r3) >> } >> } >> >> +uint32_t HELPER(testblock)(CPUS390XState *env, uint64_t real_addr) >> +{ >> + CPUState *cs = CPU(s390_env_get_cpu(env)); >> + uint64_t abs_addr; >> + int i; >> + >> + real_addr = fix_address(env, real_addr); >> + abs_addr = mmu_real2abs(env, real_addr) & TARGET_PAGE_MASK; >> + if (!address_space_access_valid(&address_space_memory, abs_addr, >> + TARGET_PAGE_SIZE, true)) { >> + program_interrupt(env, PGM_ADDRESSING, 4); >> + return 1; >> + } >> + >> + /* Check low-address protection */ >> + if ((env->cregs[0] & CR0_LOWPROT) != 0 && real_addr < 0x2000) { >> + program_interrupt(env, PGM_PROTECTION, 4); >> + return 1; >> + } >> + >> + for (i = 0; i < TARGET_PAGE_SIZE; i += 8) { >> + stq_phys(cs->as, abs_addr + i, 0); >> + } >> + >> + return 0; >> +} >> + >> uint32_t HELPER(tprot)(uint64_t a1, uint64_t a2) >> { >> /* XXX implement */ >> diff --git a/target/s390x/mmu_helper.c b/target/s390x/mmu_helper.c >> index b11a027..31eb9ef 100644 >> --- a/target/s390x/mmu_helper.c >> +++ b/target/s390x/mmu_helper.c >> @@ -108,7 +108,7 @@ static void trigger_page_fault(CPUS390XState *env, >> target_ulong vaddr, >> * Translate real address to absolute (= physical) >> * address by taking care of the prefix mapping. >> */ >> -static target_ulong mmu_real2abs(CPUS390XState *env, target_ulong raddr) >> +target_ulong mmu_real2abs(CPUS390XState *env, target_ulong raddr) >> { >> if (raddr < 0x2000) { >> return raddr + env->psa; /* Map the lowcore. */ >> diff --git a/target/s390x/translate.c b/target/s390x/translate.c >> index 4c48c59..61aa2c9 100644 >> --- a/target/s390x/translate.c >> +++ b/target/s390x/translate.c >> @@ -4057,6 +4057,15 @@ static ExitStatus op_tcxb(DisasContext *s, DisasOps >> *o) >> } >> >> #ifndef CONFIG_USER_ONLY >> + >> +static ExitStatus op_testblock(DisasContext *s, DisasOps *o) >> +{ >> + check_privileged(s); > > You should also call potential_page_fault as the helper can trigger an > exception. Right, that makes sense now, too. I'll send a v3 ... Thanks! Thomas