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: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Block SIGALRM, SIGIO and consume them via signalfd.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.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: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAurelien 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: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAurelien 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: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAurelien 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: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

Signed-off-by: NJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

All signals will thus be routed through the IO thread.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

run_on_cpu allows to execute work on a given CPUState context.
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi 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: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Fix breakage by 04c9a0cb.
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

Since it accesses data protected by the lock.
Signed-off-by: NAvi Kivity <avi@redhat.com>

Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

> Hello,
>
> d6f4ade2 (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: NPaolo Bonzini <pbonzini@redhat.com>
Cc: malc <av1474@comtv.ru>
Signed-off-by: Nmalc <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: NBlue Swirl <blauwirbel@gmail.com>

Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>