* Re: [Qemu-devel] [PULL 24/25] target-i386: Fix eflags.TF/#DB handling of syscall/sysret insns
@ 2016-12-23 19:33 Doug Evans
0 siblings, 0 replies; 2+ messages in thread
From: Doug Evans @ 2016-12-23 19:33 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel
Paolo Bonzini writes:
> From: Doug Evans <dje@google.com>
>
> The syscall and sysret instructions behave a bit differently:
> TF is checked after the instruction completes.
> This allows the o/s to disable #DB at a syscall by adding TF to FMASK.
> And then when the sysret is executed the #DB is taken "as if" the
> syscall insn just completed.
>
> Signed-off-by: Doug Evans <dje@google.com>
> Message-Id: <94eb2c0bfa1c6a9fec0543057483@google.com>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> target/i386/bpt_helper.c | 7 +++++++
> target/i386/helper.h | 1 +
> target/i386/translate.c | 29 ++++++++++++++++++++++++-----
> 3 files changed, 32 insertions(+), 5 deletions(-)
>
> ...
> diff --git a/target/i386/translate.c b/target/i386/translate.c
> index 324103c..59e11fc 100644
> --- a/target/i386/translate.c
> +++ b/target/i386/translate.c
> @@ -6423,7 +6435,10 @@ static target_ulong disas_insn(CPUX86State *env,
DisasContext *s,
> tcg_const_i32(s->pc -
s->cs_base));
> set_cc_op(s, CC_OP_EFLAGS);
> }
> - gen_eob(s);
> + /* TF handling for the syscall insn is different. The TF bit is
checked
> + after the syscall insn completes. This allows #DB to not be
> + generated after one has entered CPL0 if TF is set in FMASK.
*/
> + gen_eob_worker(s, false, true);
> break;
> case 0xe8: /* call im */
> {
> @@ -7115,7 +7130,11 @@ static target_ulong disas_insn(CPUX86State *env,
DisasContext *s,
> if (s->lma) {
> set_cc_op(s, CC_OP_EFLAGS);
> }
> - gen_eob(s);
> + /* TF handling for the sysret insn is different. The TF bit
is
> + checked after the sysret insn completes. This allows #DB
to be
> + generated "as if" the syscall insn in userspace has just
> + completed. */
> + gen_eob_worker(s, false, true);
> }
> break;
> #endif
Hi. Just a heads up that this patch got applied wrong (patch does that some
times).
The change to the "syscall" insn got applied to the "iret" instruction
instead.
Working on a fix.
^ permalink raw reply [flat|nested] 2+ messages in thread* [Qemu-devel] [PULL 00/25] First round of misc patches for QEMU 2.9
@ 2016-12-22 15:22 Paolo Bonzini
2016-12-22 15:22 ` [Qemu-devel] [PULL 24/25] target-i386: Fix eflags.TF/#DB handling of syscall/sysret insns Paolo Bonzini
0 siblings, 1 reply; 2+ messages in thread
From: Paolo Bonzini @ 2016-12-22 15:22 UTC (permalink / raw)
To: qemu-devel
The following changes since commit d1e8e8ecc3d2a1a72504912d671f1cbbac1b06e5:
Merge remote-tracking branch 'remotes/huth/tags/target-dirs-20161220' into staging (2016-12-21 21:11:48 +0000)
are available in the git repository at:
git://github.com/bonzini/qemu.git tags/for-upstream
for you to fetch changes up to 6c7c3c21f95dd9af8a0691c0dd29b07247984122:
x86: implement la57 paging mode (2016-12-22 16:01:04 +0100)
----------------------------------------------------------------
* core support for MemoryRegionCache from myself
* rules.mak speedup and cleanups from myself and Marc-Adnré
* multiboot command line fix from Vlad
* SCSI fixes from myself
* small qemu-timer speedup from myself
* x86 debugging improvements from Doug
* configurable Q35 devices from Chao
* x86 5-level paging support from Kirill
* x86 SHA_NI support for KVM from Yi Sun
* improved kvmclock migration logic from Marcelo
* bugfixes and doc fixes from others
----------------------------------------------------------------
Chao Peng (3):
pc: make smbus configurable
pc: make sata configurable
pc: make pit configurable
Doug Evans (2):
x86: Fix x86_64 'g' packet response to gdb from 32-bit mode.
target-i386: Fix eflags.TF/#DB handling of syscall/sysret insns
Kirill A. Shutemov (1):
x86: implement la57 paging mode
Li Qiang (1):
watchdog: 6300esb: add exit function
Marc-André Lureau (1):
build-sys: remove libtool left-over
Marcelo Tosatti (2):
kvm: sync linux headers
kvmclock: reduce kvmclock difference on migration
Paolo Bonzini (9):
exec: optimize remaining address_space_* cases
exec: introduce memory_ldst.inc.c
exec: introduce address_space_extend_translation
exec: introduce MemoryRegionCache
rules.mak: speedup save-vars load-vars
rules.mak: add more rules to avoid chaining
virtio-scsi: introduce virtio_scsi_acquire/release
qemu-timer: check active_timers outside lock/event
scsi-disk: fix VERIFY for scsi-block
Vlad Lungu (1):
multiboot: copy the cmdline verbatim, unescape module strings
Yaowei Bai (3):
timer: fix misleading comment in timer.h
main-loop: update comment for qemu_mutex_lock/unlock_iothread
block: drop remaining legacy aio functions in comment
Yi Sun (1):
target-i386: Add Intel SHA_NI instruction support.
Ziyue Yang (1):
hw/block/pflash_cfi*.c: fix confusing assert fail message
.gitignore | 4 -
Makefile | 9 +-
Makefile.objs | 1 -
Makefile.target | 1 +
configure | 2 -
exec.c | 687 ++++-------------------------
hw/block/pflash_cfi01.c | 13 +
hw/block/pflash_cfi02.c | 13 +
hw/i386/kvm/clock.c | 142 +++++-
hw/i386/multiboot.c | 20 +-
hw/i386/pc.c | 68 ++-
hw/i386/pc_piix.c | 2 +-
hw/i386/pc_q35.c | 39 +-
hw/scsi/scsi-disk.c | 9 +-
hw/scsi/virtio-scsi.c | 27 +-
hw/watchdog/wdt_i6300esb.c | 9 +
include/block/aio.h | 4 +-
include/exec/cpu-all.h | 23 +
include/exec/cpu-common.h | 15 -
include/exec/memory.h | 166 +++++++
include/hw/i386/pc.h | 12 +
include/qemu/main-loop.h | 4 +-
include/qemu/timer.h | 2 +-
include/qemu/typedefs.h | 1 +
include/standard-headers/linux/input.h | 1 +
include/standard-headers/linux/pci_regs.h | 15 +-
linux-headers/asm-arm/kvm.h | 7 +
linux-headers/asm-x86/unistd_32.h | 3 +
linux-headers/asm-x86/unistd_64.h | 3 +
linux-headers/asm-x86/unistd_x32.h | 3 +
linux-headers/linux/kvm.h | 7 +
memory_ldst.inc.c | 709 ++++++++++++++++++++++++++++++
qemu-timer.c | 20 +-
rules.mak | 26 +-
target/i386/arch_memory_mapping.c | 42 +-
target/i386/bpt_helper.c | 7 +
target/i386/cpu.c | 18 +-
target/i386/cpu.h | 3 +
target/i386/gdbstub.c | 52 ++-
target/i386/helper.c | 54 ++-
target/i386/helper.h | 1 +
target/i386/kvm.c | 7 +
target/i386/kvm_i386.h | 1 +
target/i386/monitor.c | 234 +++++++---
target/i386/translate.c | 29 +-
45 files changed, 1722 insertions(+), 793 deletions(-)
create mode 100644 memory_ldst.inc.c
--
2.9.3
^ permalink raw reply [flat|nested] 2+ messages in thread* [Qemu-devel] [PULL 24/25] target-i386: Fix eflags.TF/#DB handling of syscall/sysret insns 2016-12-22 15:22 [Qemu-devel] [PULL 00/25] First round of misc patches for QEMU 2.9 Paolo Bonzini @ 2016-12-22 15:22 ` Paolo Bonzini 0 siblings, 0 replies; 2+ messages in thread From: Paolo Bonzini @ 2016-12-22 15:22 UTC (permalink / raw) To: qemu-devel; +Cc: Doug Evans From: Doug Evans <dje@google.com> The syscall and sysret instructions behave a bit differently: TF is checked after the instruction completes. This allows the o/s to disable #DB at a syscall by adding TF to FMASK. And then when the sysret is executed the #DB is taken "as if" the syscall insn just completed. Signed-off-by: Doug Evans <dje@google.com> Message-Id: <94eb2c0bfa1c6a9fec0543057483@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- target/i386/bpt_helper.c | 7 +++++++ target/i386/helper.h | 1 + target/i386/translate.c | 29 ++++++++++++++++++++++++----- 3 files changed, 32 insertions(+), 5 deletions(-) diff --git a/target/i386/bpt_helper.c b/target/i386/bpt_helper.c index 6fd7fe0..b3efdc7 100644 --- a/target/i386/bpt_helper.c +++ b/target/i386/bpt_helper.c @@ -244,6 +244,13 @@ void helper_single_step(CPUX86State *env) raise_exception(env, EXCP01_DB); } +void helper_rechecking_single_step(CPUX86State *env) +{ + if ((env->eflags & TF_MASK) != 0) { + helper_single_step(env); + } +} + void helper_set_dr(CPUX86State *env, int reg, target_ulong t0) { #ifndef CONFIG_USER_ONLY diff --git a/target/i386/helper.h b/target/i386/helper.h index 4e859eb..bd9b2cf 100644 --- a/target/i386/helper.h +++ b/target/i386/helper.h @@ -79,6 +79,7 @@ DEF_HELPER_2(cmpxchg16b_unlocked, void, env, tl) DEF_HELPER_2(cmpxchg16b, void, env, tl) #endif DEF_HELPER_1(single_step, void, env) +DEF_HELPER_1(rechecking_single_step, void, env) DEF_HELPER_1(cpuid, void, env) DEF_HELPER_1(rdtsc, void, env) DEF_HELPER_1(rdtscp, void, env) diff --git a/target/i386/translate.c b/target/i386/translate.c index 324103c..59e11fc 100644 --- a/target/i386/translate.c +++ b/target/i386/translate.c @@ -2500,8 +2500,10 @@ static void gen_bnd_jmp(DisasContext *s) } /* Generate an end of block. Trace exception is also generated if needed. - If IIM, set HF_INHIBIT_IRQ_MASK if it isn't already set. */ -static void gen_eob_inhibit_irq(DisasContext *s, bool inhibit) + If INHIBIT, set HF_INHIBIT_IRQ_MASK if it isn't already set. + If RECHECK_TF, emit a rechecking helper for #DB, ignoring the state of + S->TF. This is used by the syscall/sysret insns. */ +static void gen_eob_worker(DisasContext *s, bool inhibit, bool recheck_tf) { gen_update_cc_op(s); @@ -2517,6 +2519,9 @@ static void gen_eob_inhibit_irq(DisasContext *s, bool inhibit) } if (s->singlestep_enabled) { gen_helper_debug(cpu_env); + } else if (recheck_tf) { + gen_helper_rechecking_single_step(cpu_env); + tcg_gen_exit_tb(0); } else if (s->tf) { gen_helper_single_step(cpu_env); } else { @@ -2525,10 +2530,17 @@ static void gen_eob_inhibit_irq(DisasContext *s, bool inhibit) s->is_jmp = DISAS_TB_JUMP; } +/* End of block. + If INHIBIT, set HF_INHIBIT_IRQ_MASK if it isn't already set. */ +static void gen_eob_inhibit_irq(DisasContext *s, bool inhibit) +{ + gen_eob_worker(s, inhibit, false); +} + /* End of block, resetting the inhibit irq flag. */ static void gen_eob(DisasContext *s) { - gen_eob_inhibit_irq(s, false); + gen_eob_worker(s, false, false); } /* generate a jump to eip. No segment change must happen before as a @@ -6423,7 +6435,10 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s, tcg_const_i32(s->pc - s->cs_base)); set_cc_op(s, CC_OP_EFLAGS); } - gen_eob(s); + /* TF handling for the syscall insn is different. The TF bit is checked + after the syscall insn completes. This allows #DB to not be + generated after one has entered CPL0 if TF is set in FMASK. */ + gen_eob_worker(s, false, true); break; case 0xe8: /* call im */ { @@ -7115,7 +7130,11 @@ static target_ulong disas_insn(CPUX86State *env, DisasContext *s, if (s->lma) { set_cc_op(s, CC_OP_EFLAGS); } - gen_eob(s); + /* TF handling for the sysret insn is different. The TF bit is + checked after the sysret insn completes. This allows #DB to be + generated "as if" the syscall insn in userspace has just + completed. */ + gen_eob_worker(s, false, true); } break; #endif -- 2.9.3 ^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2016-12-23 19:33 UTC | newest] Thread overview: 2+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2016-12-23 19:33 [Qemu-devel] [PULL 24/25] target-i386: Fix eflags.TF/#DB handling of syscall/sysret insns Doug Evans -- strict thread matches above, loose matches on Subject: below -- 2016-12-22 15:22 [Qemu-devel] [PULL 00/25] First round of misc patches for QEMU 2.9 Paolo Bonzini 2016-12-22 15:22 ` [Qemu-devel] [PULL 24/25] target-i386: Fix eflags.TF/#DB handling of syscall/sysret insns Paolo Bonzini
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