In the current emulation of the load-and-reserve (lwarx) and
store-conditional (stwcx.) instructions, the internal reservation
mechanism is taken into account, however each CPU has its own
reservation information and this information is not synchronized between
CPUs to perform proper synchronization.
The following test case with 2 CPUs shows that the semantics of the
"lwarx" and "stwcx." instructions are not preserved by the emulation.
The test case does the following :
- CPU0: reserve a memory location
- CPU1: reserve the same memory location
- CPU0: perform stwcx. on the location
The last store-conditional operation succeeds while it is supposed to
fail since the reservation was supposed to be lost at the second reserve
operation.
This (one line) patch fixes this problem in a very simple manner by
removing the reservation of a CPU every time it is scheduled (in
cpu_exec()). While this is a harsh workaround, it does not affect the
guest code much because reservations are usually held for a very short
time, that is an lwarx is almost always followed by an stwcx. a few
instructions below. Therefore, in most cases, the reservation will be
taken and consumed before a CPU switch occurs. However in the rare case
where a CPU switch does occur between the lwarx and its corresponding
stwcx. this patch solves a potential erroneous behavior of the
synchronization instructions.
Signed-off-by: Elie Richa <richa@adacore.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
- mark privileged opcodes with ring check;
- make debug exception on exception handler entry.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Avoid this warning from clang analyzer:
/src/qemu/cpu-exec.c:97:5: warning: Value stored to 'phys_page2' is never read
phys_page2 = -1;
Adjust the scope of the variable while at it.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Recent compilers look deep into cpu_exec, find longjmp as a noreturn
function and decide to smash some stack variables as they won't be used
again. This may lead to env becoming invalid after return from setjmp,
causing crashes. Fix it by reloading env from cpu_single_env in that
case.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Make functions take a parameter for CPUState instead of relying
on global env. Pass CPUState pointer to TCG prologue, which moves
it to AREG0.
Thanks to Peter Maydell and Laurent Desnogues for the ARM prologue
change.
Revert the hacks to avoid AREG0 use on Sparc hosts.
Move cpu_has_work() and cpu_pc_from_tb() from exec.h to cpu.h.
Compile the file without HELPER_CFLAGS.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Before the next patch, fix coding style of the areas affected.
Change the type of the return value from cpu_has_work() and
qemu_cpu_has_work() to bool.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Now that all targets use common function signature for do_interrupt(), there is no
need for the #ifdeffery anymore.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Pass CPUState to do_interrupt(). This is needed by later patches.
It would be cleaner to move the function to helper.c, but there are
a few dependencies between do_interrupt() and other functions.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Several x86 specific functions are called from cpu-exec.c with the
assumption that global env register is valid. This will be changed
later, so make the functions use caller supplied CPUState parameter.
It would be cleaner to move the functions to helper.c, but there are
quite a lot of dependencies between do_interrupt() and other functions.
Add helpers for svm_check_intercept() and cpu_cc_compute_all() instead
of calling the helper (which uses global env, AREG0) directly.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
There is little in common with user and softmmu versions of cpu_resume_signal(),
split them.
Fix coding style for the user emulator part.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
tb_invalidate_page_range() was intended to be used to invalidate an
area of a TB which the guest explicitly flushes from i-cache. However,
QEMU detects writes to code areas where TBs have been generated, so
his has never been useful.
Delete the function, adjust callers.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This bit is never set, therefore we should not read it either.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This mask contains all of the bits that should be ignored while single
stepping in the debugger. The mask contains 2 bits that are not currently
cleared, but are also never set. The bits are included in the mask for
consistency in handling of the CPU_INTERRUPT_TGT_EXT_N bits.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The code changed here is an unused data type name (evt_flush_occurred).
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
The previous patch removed the need for parameter puc.
Is is now unused, so remove it.
Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
This patch adds some code paths for running s390x guest OSs without the
need for KVM.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Commit 83f338f73e broke x86 hardware breakpoint emulation by moving the
debug exception handling out of cpu_exec. Fix this by moving all TCG
related bits back, only leaving the generic guest debugging parts in
cpus.c.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
CC: TeLeMan <geleman@gmail.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
All implementations are now the same, and there is only one caller,
so inline the function there.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This patch adds support for the LatticeMico32 softcore processor by Lattice
Semiconductor.
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Mixing up TCG bits with KVM already led to problems around eflags
emulation on x86. Moreover, quite some code that TCG requires on cpu
enty/exit is useless for KVM. So dispatch between tcg_cpu_exec and
kvm_cpu_exec as early as possible.
The core logic of cpu_halted from cpu_exec is added to
kvm_arch_process_irqchip_events. Moving away from cpu_exec makes
exception_index meaningless for KVM, we can simply pass the exit reason
directly (only "EXCP_DEBUG vs. rest" is relevant).
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
To prepare splitting up KVM and TCG CPU entry/exit, move the debug
exception into cpus.c and invoke cpu_handle_debug_exception on return
from qemu_cpu_exec.
This also allows to clean up the debug request signaling: We can assign
the job of informing main-loop to qemu_system_debug_request and stop the
calling cpu directly in cpu_handle_debug_exception. That means a debug
stop will now only be signaled via debug_requested and not additionally
via vmstop_requested.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
When the CPU is in wait state, do not wake-up if an interrupt can't be
taken. This avoid host CPU running at 100% if a device (e.g. timer) has
an interrupt line left enabled.
Also factorize code to check if interrupts are enabled in
cpu_mips_hw_interrupts_pending().
Based on a patch from Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Move the last found TB to the head of the list so it will be found more quickly next time it will be looked for.
Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru>
Signed-off-by: Pavel Yushchenko <pau@ispras.ru>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
If a cpu_exit request is pending, ensure that we leave the CPU loop
quickly. For this purpose, keep the global exit_request pending until
we are about to leave tcg_cpu_exec. Also, immediately break out of the
SMP loop if the request is set, do not run till the end of the chain.
This preserves the VCPU scheduling order in SMP mode.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
If a signal hit after the env->exit_request check but before cpu_exec
updated env->current_tb, cpu_unlink_tb called from the signal hander
will not unlink the current TB. This may leave us stuck in a guest loop
if no further unlink is invoked.
Fix this by reordering current_tb update and exit_request check,
additionally enforcing the correct order via a compiler barrier.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Store tcg loop exit request on a global variable, and transfer it to
per-CPUState exit_request after assignment of cpu_single_env.
This makes exit request signal from robust. Drop the timedlock hack.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When -d cpu logging was handled by target-foo/translate.c,
it was controled by DEBUG_DISAS, which is enabled by default.
Use the same condition in cpu_exec.
At the same time, reduce the if-deffery by assuming no flags
update is required for the target.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
ia64 has some strangenesses that need to be workaround:
- it has a __clone2() syscall instead of the using clone() one, with
different arguments, and which is not declared in the usual headers.
- ucontext.uc_sigmask is declared with type long int, while it is
actually of type sigset_t.
- uc_mcontext, uc_sigmask, uc_stack, uc_link are declared using #define,
which clashes with the target_ucontext fields. Change their names to
tuc_*, as already done for some target architectures.
The page tracking code in exec.c is used by both userspace and system
emulation. Userspace emulation uses it to track virtual pages, and
system emulation to track ram pages. Introduce a new type to hold this
kind of address.
Signed-off-by: Paul Brook <paul@codesourcery.com>
This ensures that the compiler does not move it away from
the "env = env1;" assignment. Fixes a miscompilation
on gcc 4.4, reported by Jay Foad.
Cc: <jay.foad@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This should explain a lot of the weird breakages of upstream KVM we've
seen recently (actually we should have seen it much earlier):
Stop translating eflags into TCG format when in kvm mode as we never
translate it back and rather sync this broken state into the kernel.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Since b567b38 (target-arm: remove T0 and T1, 2009-10-16) the only global
register that is used is AREG0, so the complexity of hostregs_helper.h
is unused. Use regular assignments and a compiler optimization barrier.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The while loop will be executed exactly 0 or 1 times, depending on
env->exit_request.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
