The AioContext event loop uses ppoll(2) or epoll_wait(2) to monitor file
descriptors or until a timer expires. In cases like virtqueues, Linux
AIO, and ThreadPool it is technically possible to wait for events via
polling (i.e. continuously checking for events without blocking).
Polling can be faster than blocking syscalls because file descriptors,
the process scheduler, and system calls are bypassed.
The main disadvantage to polling is that it increases CPU utilization.
In classic polling configuration a full host CPU thread might run at
100% to respond to events as quickly as possible. This patch implements
a timeout so we fall back to blocking syscalls if polling detects no
activity. After the timeout no CPU cycles are wasted on polling until
the next event loop iteration.
The run_poll_handlers_begin() and run_poll_handlers_end() trace events
are added to aid performance analysis and troubleshooting. If you need
to know whether polling mode is being used, trace these events to find
out.
Note that the AioContext is now re-acquired before disabling notify_me
in the non-polling case. This makes the code cleaner since notify_me
was enabled outside the non-polling AioContext release region. This
change is correct since it's safe to keep notify_me enabled longer
(disabling is an optimization) but potentially causes unnecessary
event_notifer_set() calls. I think the chance of performance regression
is small here.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20161201192652.9509-4-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
With a vfio assigned device we lay down a base MemoryRegion registered
as an IO region, giving us read & write accessors. If the region
supports mmap, we lay down a higher priority sub-region MemoryRegion
on top of the base layer initialized as a RAM device pointer to the
mmap. Finally, if we have any quirks for the device (ie. address
ranges that need additional virtualization support), we put another IO
sub-region on top of the mmap MemoryRegion. When this is flattened,
we now potentially have sub-page mmap MemoryRegions exposed which
cannot be directly mapped through KVM.
This is as expected, but a subtle detail of this is that we end up
with two different access mechanisms through QEMU. If we disable the
mmap MemoryRegion, we make use of the IO MemoryRegion and service
accesses using pread and pwrite to the vfio device file descriptor.
If the mmap MemoryRegion is enabled and results in one of these
sub-page gaps, QEMU handles the access as RAM, using memcpy to the
mmap. Using either pread/pwrite or the mmap directly should be
correct, but using memcpy causes us problems. I expect that not only
does memcpy not necessarily honor the original width and alignment in
performing a copy, but it potentially also uses processor instructions
not intended for MMIO spaces. It turns out that this has been a
problem for Realtek NIC assignment, which has such a quirk that
creates a sub-page mmap MemoryRegion access.
To resolve this, we disable memory_access_is_direct() for ram_device
regions since QEMU assumes that it can use memcpy for those regions.
Instead we access through MemoryRegionOps, which replaces the memcpy
with simple de-references of standard sizes to the host memory.
With this patch we attempt to provide unrestricted access to the RAM
device, allowing byte through qword access as well as unaligned
access. The assumption here is that accesses initiated by the VM are
driven by a device specific driver, which knows the device
capabilities. If unaligned accesses are not supported by the device,
we don't want them to work in a VM by performing multiple aligned
accesses to compose the unaligned access. A down-side of this
philosophy is that the xp command from the monitor attempts to use
the largest available access weidth, unaware of the underlying
device. Using memcpy had this same restriction, but at least now an
operator can dump individual registers, even if blocks of device
memory may result in access widths beyond the capabilities of a
given device (RTL NICs only support up to dword).
Reported-by: Thorsten Kohfeldt <thorsten.kohfeldt@gmx.de>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
The colo patch series added various trace events to the top
level trace-events file, despite the files using them being
in a sub-dir.
commit 30656b097e
Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Date: Tue Sep 27 10:22:34 2016 +0800
filter-rewriter: rewrite tcp packet to keep secondary connection
commit f4b618360e
Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Date: Tue Sep 27 10:22:31 2016 +0800
colo-compare: add TCP, UDP, ICMP packet comparison
We add TCP,UDP,ICMP packet comparison to replace
IP packet comparison. This can increase the
accuracy of the package comparison.
Less checkpoint more efficiency.
Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
commit 0682e15b19
Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Date: Tue Sep 27 10:22:30 2016 +0800
colo-compare: introduce packet comparison thread
commit 59509ec16b
Author: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Date: Tue Sep 27 10:22:27 2016 +0800
net/colo.c: add colo.c to define and handle packet
This moves all events into net/trace-events where they
were supposed to live.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1475588159-30598-2-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Explicitly state in which execution mode (user, softmmu, all) are guest
events available for tracing.
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 147456962135.11114.6146034359114598596.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The trace points for hw/virtio/virtio-balloon.c were mistakenly put
in the top level trace-events file, instead of util/trace-events in
commit 270ab88f7c
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Thu Jun 16 09:39:57 2016 +0100
trace: split out trace events for hw/virtio/ directory
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1473872624-23285-5-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The trace points for util/qemu-coroutine*.c were mistakenly left
in the top level trace-events file, instead of util/trace-events
in
commit 492bb2dd65
Author: Daniel P. Berrange <berrange@redhat.com>
Date: Thu Jun 16 09:39:48 2016 +0100
trace: split out trace events for util/ directory
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1473872624-23285-3-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
We will rewrite tcp packet secondary received and sent.
When colo guest is a tcp server.
Firstly, client start a tcp handshake. the packet's seq=client_seq,
ack=0,flag=SYN. COLO primary guest get this pkt and mirror(filter-mirror)
to secondary guest, secondary get it use filter-redirector.
Then,primary guest response pkt
(seq=primary_seq,ack=client_seq+1,flag=ACK|SYN).
secondary guest response pkt
(seq=secondary_seq,ack=client_seq+1,flag=ACK|SYN).
In here,we use filter-rewriter save the secondary_seq to it's tcp connection.
Finally handshake,client send pkt
(seq=client_seq+1,ack=primary_seq+1,flag=ACK).
Here,filter-rewriter can get primary_seq, and rewrite ack from primary_seq+1
to secondary_seq+1, recalculate checksum. So the secondary tcp connection
kept good.
When we send/recv packet.
client send pkt(seq=client_seq+1+data_len,ack=primary_seq+1,flag=ACK|PSH).
filter-rewriter rewrite ack and send to secondary guest.
primary guest response pkt
(seq=primary_seq+1,ack=client_seq+1+data_len,flag=ACK)
secondary guest response pkt
(seq=secondary_seq+1,ack=client_seq+1+data_len,flag=ACK)
we rewrite secondary guest seq from secondary_seq+1 to primary_seq+1.
So tcp connection kept good.
In code We use offset( = secondary_seq - primary_seq )
to rewrite seq or ack.
handle_primary_tcp_pkt: tcp_pkt->th_ack += offset;
handle_secondary_tcp_pkt: tcp_pkt->th_seq -= offset;
Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
We add TCP,UDP,ICMP packet comparison to replace
IP packet comparison. This can increase the
accuracy of the package comparison.
Less checkpoint more efficiency.
Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
If primary packet is same with secondary packet,
we will send primary packet and drop secondary
packet, otherwise notify COLO frame to do checkpoint.
If primary packet comes but secondary packet does not,
after REGULAR_PACKET_CHECK_MS milliseconds we set
the primary packet as old_packet,then do a checkpoint.
Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
The net/colo.c is used by colo-compare and filter-rewriter.
this can share common data structure like net packet,
and other functions.
Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Replace the old manual dispatch and validation code by the generic one
provided by qapi common code.
Note that it is now possible to call the following commands that used to
be disabled by compile-time conditionals:
- dump-skeys
- query-spice
- rtc-reset-reinjection
- query-gic-capabilities
Their fallback functions return an appropriate "feature disabled" error.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20160912091913.15831-16-marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
VMs created on older versions on Xen will not have been provisioned with
pages to support creation of non-default ioreq servers. In this case
the ioreq server API is not supported and QEMU's only option is to fall
back to using the default ioreq server pages as it did prior to
commit 3996e85c ("Xen: Use the ioreq-server API when available").
This patch therefore changes the code in xen_common.h to stop considering
a failure of xc_hvm_create_ioreq_server() as a hard failure but simply
as an indication that the guest is too old to support the ioreq server
API. Instead a boolean is set to cause reversion to old behaviour such
that the default ioreq server is then used.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
These will help us monitoring irqchip route activities more easily.
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Adds two events to trace syscalls in syscall emulation mode (*-user):
* guest_user_syscall: Emitted before the syscall is emulated; contains
the syscall number and arguments.
* guest_user_syscall_ret: Emitted after the syscall is emulated;
contains the syscall number and return value.
Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
Message-id: 146651712411.12388.10024905980452504938.stgit@fimbulvetr.bsc.es
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the linux-user/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-id: 1466066426-16657-41-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the qom/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-40-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the target-ppc/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-id: 1466066426-16657-39-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the target-s390x/ directory to
their own file.
[Added missing newline in target-s390x/trace-events as suggested by
Cornelia Huck <cornelia.huck@de.ibm.com>.
--Stefan]
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-id: 1466066426-16657-38-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the target-sparc/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-37-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the net/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-36-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the audio/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-35-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the ui/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-34-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/alpha/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-33-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/arm/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-32-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/acpi/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-31-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/vfio/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-30-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/s390x/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Message-id: 1466066426-16657-29-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/pci/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-28-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/ppc/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-id: 1466066426-16657-27-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/9pfs/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-26-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/i386/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-25-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/isa/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-24-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/sd/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-23-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/sparc/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-22-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/dma/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-21-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/timer/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-20-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/input/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-19-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/display/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-18-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/nvram/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-17-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/scsi/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-16-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/usb/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-15-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/misc/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-14-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/audio/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-13-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/virtio/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-12-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/net/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-11-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/intc/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-10-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Move all trace-events for files in the hw/char/ directory to
their own file.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1466066426-16657-9-git-send-email-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
