In order to perform critical manipulations on the VM state in the
context of a VCPU, specifically code patching, stopping and resuming of
all VCPUs may be necessary. resume_all_vcpus is already compatible, now
enable pause_all_vcpus for this use case by stopping the calling context
before starting to wait for the whole gang.
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
When the TCG thread is started but not yet the machine, we wait in
qemu_tcg_cpu_thread_fn on tcg_halt_cond. To allow run_on_cpu already at
this time, we need to process pending request in that loop.
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
As we have thread-local cpu_single_env now and KVM uses exactly one
thread per VCPU, we can drop the cpu_single_env updates from the loop
and initialize this variable only once during setup.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
On real hardware, NMI button events are injected via the LINT1 line of
the APICs. E.g. kdump expect this wiring and gets upset if the per-APIC
LINT1 mask is not respected, i.e. if NMIs are injected to VCPUs that
should not receive them. Change the APIC emulation code to reflect this.
Based on qemu-kvm patch by Lai Jiangshan.
CC: Lai Jiangshan <laijs@cn.fujitsu.com>
Reported-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
These two blocks of code are exactly the same, remove one.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
On Windows, cpus.c needs access to the hThread. Add a Windows-specific
function to grab it. This requires changing the CPU threads to
joinable. There is no substantial change because the threads run
in an infinite loop.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Split from Jan's original qemu-thread-posix.c patch. No semantic change,
just introduce the new API that POSIX and Win32 implementations will
conform to.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Please, note that the QMP command has a new 'cpu-index' parameter.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Double semicolons should be single.
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Many places in QEMU call qemu_aio_flush() to complete all pending
asynchronous I/O. Most of these places actually want to drain all block
requests but there is no block layer API to do so.
This patch introduces the bdrv_drain_all() API to wait for requests
across all BlockDriverStates to complete. As a bonus we perform checks
after qemu_aio_wait() to ensure that requests really have finished.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We disable vm_clock when pausing all vcpus, but we forget to
reenable it when resuming all vcpus. It will cause that the
guest can not be rebooted.
Tested-by: Zhi Yong Wu <zwu.kernel@gmai.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
After the removal of the non-threaded mode cpu_exec_all is now only used
by TCG. Refactor it accordingly, also dropping its unused return value.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
It should be a matter of allowing the transition POSTMIGRATE ->
FINISH_MIGRATE, but it turns out that the VM won't do the
transition the second time because it's already stopped.
So this commit also adds vm_stop_force_state() which performs
the transition even if the VM is already stopped.
While there also allow other states to migrate.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Now that iothread is always compiled sending a signal seems only an
additional step. This patch also avoid writing to two pipe (one from signal
and one in qemu_service_io).
Work with kvm enabled or disabled. strace output is more readable (less syscalls).
[ kwolf: Merged build fix by Paolo Bonzini ]
Signed-off-by: Frediano Ziglio <freddy77@gmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Currently, only vm_start() and vm_stop() change the VM state.
That's, the state is only changed when starting or stopping the VM.
This commit adds the runstate_set() function, which makes it possible
to also do state transitions when the VM is stopped or running.
Additional states are also added and the current state is stored.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Today, when notifying a VM state change with vm_state_notify(),
we pass a VMSTOP macro as the 'reason' argument. This is not ideal
because the VMSTOP macros tell why qemu stopped and not exactly
what the current VM state is.
One example to demonstrate this problem is that vm_start() calls
vm_state_notify() with reason=0, which turns out to be VMSTOP_USER.
This commit fixes that by replacing the VMSTOP macros with a proper
state type called RunState.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Enabling the I/O thread by default seems like an important part of declaring
1.0. Besides allowing true SMP support with KVM, the I/O thread means that the
TCG VCPU doesn't have to multiplex itself with the I/O dispatch routines which
currently requires a (racey) signal based alarm system.
I know there have been concerns about performance. I think so far the ones that
have come up (virtio-net) are most likely due to secondary reasons like
decreased batching.
I think we ought to force enabling I/O thread early in 1.0 development and
commit to resolving any lingering issues.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We can express the VCPU thread wakeup with the stop mechanism, saving
both qemu_system_ready and the qemu_system_cond. For KVM threads, we can
just enter the main loop as long as the thread is stopped. The central
TCG thread is better held back before the loop as there can be side
effects of the services called even when all CPUs are stopped.
Creating VCPUs in stopped state will also be required for proper CPU
hotplugging support.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
In TCG mode, iothread and vcpus run in lock-step. So it's pointless to
send a signal from qemu_cpu_kick to the vcpu thread - if we got here,
the receiver already left the vcpu loop.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This conveys the intention better, and scales to more than >1
threads contending the mutex with the iothread (as long as all
of them have a "quiescent point" like the TCG thread has).
Also, on Mac OS X the fair_mutex somehow didn't work as intended
and deadlocked.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Both the signal thread (via sigwait()) and the cpu thread (via
a normal signal handler) were attempting to catch SIG_IPI.
This resulted in random freezes under Darwin.
This patch separates SIG_IPI from the rest of the signals handled
by the signal thread, because it is independently caught by the cpu
thread.
Signed-off-by: Alexandre Raymond <cerbere@gmail.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Changes since v1:
- take pthread_sigmask() out of the ifdef as it is now common
to both parts.
This fix effectively blocks, in the main thread, the signals handled
by signalfd or the compatibility signal thread.
This way, such signals are received synchronously in the main thread
through sigfd_handler() instead of triggering the signal handler
directly, asynchronously.
Signed-off-by: Alexandre Raymond <cerbere@gmail.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
sigset_t, used by that header, is not available in mingw32 environments.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Add command line support for logging to a location other than /tmp/qemu.log.
With logging enabled (command line option -d), the log is written to
the hard-coded path /tmp/qemu.log. This patch adds support for writing
the log to a different location by passing the -D option.
Signed-off-by: Matthew Fernandez <matthew.fernandez@gmail.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
It is purely for icount-based virtual timers. And now that we got the
code right, rename the function to clarify the intended scope.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
The previous patch however is not enough, because if the virtual CPU
goes to sleep waiting for a future timer interrupt to wake it up, qemu
deadlocks. The timer interrupt never comes because time is driven by
icount, but the vCPU doesn't run any insns.
You could say that VCPUs should never go to sleep in icount
mode if there is a pending vm_clock timer; rather time should
just warp to the next vm_clock event with no sleep ever taking place.
Even better, you can sleep for some time related to the
time left until the next event, to avoid that the warps are too visible
externally; for example, you could be sending network packets continously
instead of every 100ms.
This is what this patch implements. qemu_clock_warp is called: 1)
whenever a vm_clock timer is adjusted, to ensure the warp_timer is
synchronized; 2) at strategic points in the CPU thread, to make sure
the insn counter is synchronized before the CPU starts running.
In any case, the warp_timer is disabled while the CPU is running,
because the insn counter will then be making progress on its own.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
The correct fix for -icount is to consider the biggest difference
between iothread and non-iothread modes. In the traditional model,
CPUs run _before_ the iothread calls select (or WaitForMultipleObjects
for Win32). In the iothread model, CPUs run while the iothread
isn't holding the mutex, i.e. _during_ those same calls.
So, the iothread should always block as long as possible to let
the CPUs run smoothly---the timeout might as well be infinite---and
either the OS or the CPU thread itself will let the iothread know
when something happens. At this point, the iothread wakes up and
interrupts the CPU.
This is exactly the approach that this patch takes: when cpu_exec_all
returns in -icount mode, and it is because a vm_clock deadline has
been met, it wakes up the iothread to process the timers. This is
really the "bulk" of fixing icount.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Tested-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Here the int values fds[0], sigfd, s, sock and fd are converted
to void pointers which are later converted back to an int value.
These conversions should always use intptr_t instead of unsigned long.
They are needed for environments where sizeof(long) != sizeof(void *).
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Based on patch by Glauber Costa:
To allow management applications like libvirt to apply CPU affinities to
the VCPU threads, expose their ID via info cpus. This patch provides the
pre-existing and used interface from qemu-kvm.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
With in-kernel irqchip support enabled, the vcpu threads sleep in kernel
space while halted. Account for this difference in cpu_thread_is_idle.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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>
Jan Kiszka