diff options
| author | Pavel Butsykin <pbutsykin@virtuozzo.com> | 2017-09-19 15:07:33 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-09-21 11:51:49 +0200 |
| commit | 55289fb036481396466d7825fa01d829c891108c (patch) | |
| tree | 3a3913a0815b31982f08562fd1fefb3a4b01b509 /hw | |
| parent | b62b7ed0fc9c58e373b8946c9bd2e193be98dae6 (diff) | |
| download | qemu-55289fb036481396466d7825fa01d829c891108c.tar.gz | |
virtio-serial: add enable_backend callback
We should guarantee that RAM will not be modified while VM has a stopped
state, otherwise it can lead to negative consequences during post-copy
migration. In RUN_STATE_FINISH_MIGRATE step, it's expected that RAM on
source side will not be modified as this could lead to non-consistent vm state
on the destination side. Also RAM access during postcopy-ram migration with
enabled release-ram capability can lead to sad consequences.
Let's add enable_backend() callback to avoid undesirable virtioqueue changes
in the guest memory.
Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com>
Message-Id: <20170919120733.22020-1-pbutsykin@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/char/virtio-console.c | 21 | ||||
| -rw-r--r-- | hw/char/virtio-serial-bus.c | 7 |
2 files changed, 28 insertions, 0 deletions
diff --git a/hw/char/virtio-console.c b/hw/char/virtio-console.c index 198b2a89c0..172c72d06c 100644 --- a/hw/char/virtio-console.c +++ b/hw/char/virtio-console.c @@ -187,6 +187,26 @@ static int chr_be_change(void *opaque) return 0; } +static void virtconsole_enable_backend(VirtIOSerialPort *port, bool enable) +{ + VirtConsole *vcon = VIRTIO_CONSOLE(port); + + if (!qemu_chr_fe_backend_connected(&vcon->chr)) { + return; + } + + if (enable) { + VirtIOSerialPortClass *k = VIRTIO_SERIAL_PORT_GET_CLASS(port); + + qemu_chr_fe_set_handlers(&vcon->chr, chr_can_read, chr_read, + k->is_console ? NULL : chr_event, + chr_be_change, vcon, NULL, false); + } else { + qemu_chr_fe_set_handlers(&vcon->chr, NULL, NULL, NULL, + NULL, NULL, NULL, false); + } +} + static void virtconsole_realize(DeviceState *dev, Error **errp) { VirtIOSerialPort *port = VIRTIO_SERIAL_PORT(dev); @@ -258,6 +278,7 @@ static void virtserialport_class_init(ObjectClass *klass, void *data) k->unrealize = virtconsole_unrealize; k->have_data = flush_buf; k->set_guest_connected = set_guest_connected; + k->enable_backend = virtconsole_enable_backend; k->guest_writable = guest_writable; dc->props = virtserialport_properties; } diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c index 17a1bb008a..9470bd7be7 100644 --- a/hw/char/virtio-serial-bus.c +++ b/hw/char/virtio-serial-bus.c @@ -637,6 +637,13 @@ static void set_status(VirtIODevice *vdev, uint8_t status) if (!(status & VIRTIO_CONFIG_S_DRIVER_OK)) { guest_reset(vser); } + + QTAILQ_FOREACH(port, &vser->ports, next) { + VirtIOSerialPortClass *vsc = VIRTIO_SERIAL_PORT_GET_CLASS(port); + if (vsc->enable_backend) { + vsc->enable_backend(port, vdev->vm_running); + } + } } static void vser_reset(VirtIODevice *vdev) |