Except for timer events, we currently do not leave the loop over all
VCPUs if an IO event was filed. That may cause unexpected IO latencies
under !CONFIG_IOTHREAD in SMP scenarios. Fix it by setting the global
exit_request which breaks the loop.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If some I/O operation ends up calling qemu_system_reset_request in VCPU
context, we record this and inform the io-thread, but we do not
terminate the VCPU loop. This can lead to fairly unexpected behavior if
the triggering reset operation is supposed to work synchronously.
Fix this for TCG (when run in deterministic I/O mode) by setting the
VCPU on stop and issuing a cpu_exit. KVM requires some more work on its
VCPU loop.
[ ported from qemu-kvm ]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
If we call qemu_cpu_kick more than once before the target was able to
process the signal, pthread_kill will fail, and qemu will abort. Prevent
this by avoiding the redundant signal.
This logic can be found in qemu-kvm as well.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
The imbalance in the hold time of qemu_global_mutex only exists in TCG
mode. In contrast to TCG VCPUs, KVM drops the global lock during guest
execution. We already avoid touching the fairness lock from the
IO-thread in KVM mode, so also stop using it from the VCPU threads.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Flush all requests once we have stopped all
cpus and devices.
Make sure disk is in consistent state.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Jason Wang <jasowang@redhat.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>
fprintf_function uses format checking with GCC_FMT_ATTR.
Format errors were fixed in
* target-i386/helper.c
* target-mips/translate.c
* target-ppc/translate.c
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Port qemu-kvm's
commit 4b62fff1101a7ad77553147717a8bd3bf79df7ef
Author: Huang Ying <ying.huang@intel.com>
Date: Mon Sep 21 10:43:25 2009 +0800
MCE: Relay UCR MCE to guest
UCR (uncorrected recovery) MCE is supported in recent Intel CPUs,
where some hardware error such as some memory error can be reported
without PCC (processor context corrupted). To recover from such MCE,
the corresponding memory will be unmapped, and all processes accessing
the memory will be killed via SIGBUS.
For KVM, if QEMU/KVM is killed, all guest processes will be killed
too. So we relay SIGBUS from host OS to guest system via a UCR MCE
injection. Then guest OS can isolate corresponding memory and kill
necessary guest processes only. SIGBUS sent to main thread (not VCPU
threads) will be broadcast to all VCPU threads as UCR MCE.
aliguori: fix build
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Guest debugging is currently broken under CONFIG_IOTHREAD. The reason is
inconsistent or even lacking signaling the debug events from the source
VCPU to the main loop and the gdbstub.
This patch addresses the issue by pushing this signaling into a
CPUDebugExcpHandler: cpu_debug_handler is registered as first handler,
thus will be executed last after potential breakpoint emulation
handlers. It sets informs the gdbstub about the debug event source,
requests a debug exit of the main loop and stops the current VCPU. This
mechanism works both for TCG and KVM, with and without IO-thread.
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>
These functions are also used for kvm under !CONFIG_IOTHREAD, having
'tcg' in their name is just misleading.
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>
When checking for I/O events in the tcg CPU loop, make sure that we
call qemu_wait_io_event_common for all CPUs, not only the current one.
Otherwise pause_all_vcpus may lock up or run_on_cpu requests may starve.
Rename qemu_wait_io_event to qemu_tcg_wait_io_event at this chance and
purge its argument list as it has no use for it.
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 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>
All signals will thus be routed through the IO thread.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
run_on_cpu allows to execute work on a given CPUState context.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
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>
> Hello,
>
> d6f4ade (disentangle tcg and deadline calculation, 2010-03-10)
> introduces following regression(s):
>
> 100% cpu utilization when QEMU is invoked like:
> qemu -S -s ...
>
> ditto when gdb takes control over the session via gdb-stub
> (i.e. the breakpoint is hit or C-c is pressed inside gdb to
> interrupt the attached qemu instance)
The bug is that env->stopped is not really as comprehensive as it seems to
be (and cpu_has_work thinks); it is only valid with iothread basically,
and even then it is cleared by reset and it is not set when starting
qemu with -S.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: malc <av1474@comtv.ru>
Signed-off-by: malc <av1474@comtv.ru>
Arrange various declarations so that also non-CPU code can access
them, adjust users.
Move CPU specific code to cpus.c.
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
