After attaching the source, we have to remove the reference we hold
to it, because we do not hold anymore a pointer to the source.
If we do not do this, removing the source will not finalize it and
will not drop the "real" I/O watch source.
This showed up when backporting the new flow control patches to older
versions of QEMU that still used select. The whole select then failed
with EBADF (poll instead will reporting POLLNVAL on a single pollfd)
and QEMU froze.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1365600207-21685-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
I misread the glib manual, g_source_remove does not let you re-attach
the source later. This behavior (called "blocking" the source in glib)
is present in glib's source code, but private and not available outside
glib; hence, we have to resort to re-creating the source every time.
In fact, g_source_remove and g_source_destroy are the same thing,
except g_source_destroy is O(1) while g_source_remove scans a potentially
very long list of GSources in the current main loop. Ugh. Better
use g_source_destroy explicitly, and leave "tags" to those dummies who
cannot track their pointers' lifetimes.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1365426195-12596-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The character backend refactoring introduced an undesirable busy wait.
The busy wait happens if can_read returns zero and there is data available
on the character device's file descriptor. Then, the I/O watch will
fire continuously and, with TCG, the CPU thread will never run.
1) Char backend asks front end if it can write
2) Front end says no
3) poll() finds the char backend's descriptor is available
4) Goto (1)
What we really want is this (note that step 3 avoids the busy wait):
1) Char backend asks front end if it can write
2) Front end says no
3) poll() goes on without char backend's descriptor
4) Goto (1) until qemu_chr_accept_input() called
5) Char backend asks front end if it can write
6) Front end says yes
7) poll() finds the char backend's descriptor is available
8) Backend handler called
After this patch, the IOWatchPoll source and the watch source are
separated. The IOWatchPoll is simply a hook that runs during the prepare
phase on each main loop iteration. The hook adds/removes the actual
source depending on the return value from can_read.
A simple reproducer is
qemu-system-i386 -serial mon:stdio
... followed by banging on the terminal as much as you can. :) Without
this patch, emulation will hang.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1365177573-11817-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
It's not used anymore since the last commit.
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
chardev-frontends need to explictly check, increase and decrement the
avail_connections "property" of the chardev when they are not using a
qdev-chardev-property for the chardev.
This fixes things like:
qemu-kvm -chardev stdio,id=foo -device isa-serial,chardev=foo \
-mon chardev=foo
Working, where they should fail. Most of the changes here are due to
old hardware emulation code which is using serial_hds directly rather then
a qdev-chardev-property.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364412581-3672-3-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Add qemu_chr_fe_claim / _release helper functions for properly dealing with
avail_connections.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364412581-3672-2-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
When we receive a file descriptor over a UNIX domain socket the
O_NONBLOCK flag is preserved. Clear the O_NONBLOCK flag and rely on
QEMU file descriptor users like migration, SPICE, VNC, block layer, and
others to set non-blocking only when necessary.
This change ensures we don't accidentally expose O_NONBLOCK in the QMP
API. QMP clients should not need to get the non-blocking state
"correct".
A recent real-world example was when libvirt passed a non-blocking TCP
socket for migration where we expected a blocking socket. The source
QEMU produced a corrupted migration stream since its code did not cope
with non-blocking sockets.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
The fcntl(fd, F_SETFL, O_NONBLOCK) flag is not specific to sockets.
Rename to qemu_set_nonblock() just like qemu_set_cloexec().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
The current code is oddly written and have equally odd semantics.
Despite the '_all' suffix, upon EAGAIN the result will be a partial
write but instead of returning the partial write, we return EAGAIN.
Change the behavior to write as much as we can until we get an EAGAIN
returning a partial write if we do.
Reported-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Message-id: 1364575190-731-1-git-send-email-aliguori@us.ibm.com
Resending the be_open event only is useful when a frontend is registering, not
when it is unregistering.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-9-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
The decrement of avail_connections is done in qdev-properties-system move
the increment there too for proper balancing of the calls.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-8-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Most frontends can't really determine if the guest actually has the frontend
side open. So lets automatically generate fe_open / fe_close as soon as a
frontend becomes ready (as signalled by calling qemu_chr_add_handlers) /
becomes non ready (as signalled by setting all handlers to NULL).
And allow frontends which can actually determine if the guest is listening to
opt-out of this.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-5-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Add tracking of the fe_open state to struct CharDriverState.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-4-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
To better reflect that it is for handling a backend being opened.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-3-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Rename the opened variable to be_open to reflect that it contains the
opened state of the backend.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Message-id: 1364292483-16564-2-git-send-email-hdegoede@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
qemu_chr_fe_add_watch() can return negative errors, therefore it must
not have an unsigned return type. For consistency with other
qemu_chr_fe_* functions, this uses a standard C int instead of glib
types.
In situations where qemu_chr_fe_add_watch() is falsely assumed to have
succeeded, the serial ports would go into a state where it never becomes
ready for transmitting more data; this is fixed by this patch.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Current colon position in "waiting for telnet connection" message template
produces messages like:
QEMU waiting for connection on: telnet::127.0.0.16666,server
After moving a colon to the right, we will get a correct messages like:
QEMU waiting for connection on: telnet:127.0.0.1:6666,server
Signed-off-by: Igor Mitsyanko <i.mitsyanko@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds 'memory' support to qapi and also switches over
the memory chardev initialization to the new qapi code path.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds 'vc' support to qapi and also switches over the
vc chardev initialization to the new qapi code path.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds 'pipe' support to qapi and also switches over the
pipe chardev initialization to the new qapi code path.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds 'console' support to qapi and also switches over the
console chardev initialization to the new qapi code path.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch switches over the pty chardev initialization
to the new qapi code path.
Bonus: Taking QemuOpts out of the loop allows some nice
cleanups along the way.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds 'stdio' support to qapi and also switches over the
stdio chardev initialization to the new qapi code path.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds 'braille' support to qapi and also switches over
the braille chardev initialization to the new qapi code path.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch adds 'msmouse' support to qapi and also switches over
the msmouse chardev initialization to the new qapi code path.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch add support for a new way to initialize chardev devices.
Instead of calling a initialization function with a QemuOpts we will
now create a (qapi) ChardevBackend, optionally call a function to
fill ChardevBackend from QemuOpts, then go create the chardev using
the new qapi code path which is also used by chardev-add.
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This patch is based of off version 9 of Stefan Berger's patch series
"QEMU Trusted Platform Module (TPM) integration"
and adds a new backend driver for it.
This patch adds a passthrough backend driver for passing commands sent to the
emulated TPM device directly to a TPM device opened on the host machine.
Thus it is possible to use a hardware TPM device in a system running on QEMU,
providing the ability to access a TPM in a special state (e.g. after a Trusted
Boot).
This functionality is being used in the acTvSM Trusted Virtualization Platform
which is available on [1].
Usage example:
qemu-system-x86_64 -tpmdev passthrough,id=tpm0,path=/dev/tpm0 \
-device tpm-tis,tpmdev=tpm0 \
-cdrom test.iso -boot d
Some notes about the host TPM:
The TPM needs to be enabled and activated. If that's not the case one
has to go through the BIOS/UEFI and enable and activate that TPM for TPM
commands to work as expected.
It may be necessary to boot the kernel using tpm_tis.force=1 in the boot
command line or 'modprobe tpm_tis force=1' in case of using it as a module.
Regards,
Andreas Niederl, Stefan Berger
[1] http://trustedjava.sourceforge.net/
Signed-off-by: Andreas Niederl <andreas.niederl@iaik.tugraz.at>
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Corey Bryant <coreyb@linux.vnet.ibm.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Message-id: 1361987275-26289-6-git-send-email-stefanb@linux.vnet.ibm.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This allows a front-end to request for a callback when the backend
is writable again.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Message-id: 96f93c0f741064604bbb6389ce962191120af8b7.1362505276.git.amit.shah@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
I didn't bother switching to g_io_channel_read/write because we need to use
sendmsg on Unix. No problem though since we're using an unbuffered channel.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Message-id: 002f726576dfb51bca4854aa257b74d77c1cd4e8.1362505276.git.amit.shah@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
