summaryrefslogtreecommitdiff
path: root/chardev/trace-events
AgeCommit message (Collapse)Author
2021-06-02docs: fix references to docs/devel/tracing.rstStefano Garzarella
Commit e50caf4a5c ("tracing: convert documentation to rST") converted docs/devel/tracing.txt to docs/devel/tracing.rst. We still have several references to the old file, so let's fix them with the following command: sed -i s/tracing.txt/tracing.rst/ $(git grep -l docs/devel/tracing.txt) Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <20210517151702.109066-2-sgarzare@redhat.com> Signed-off-by: Thomas Huth <thuth@redhat.com>
2019-03-22trace-events: Shorten file names in commentsMarkus Armbruster
We spell out sub/dir/ in sub/dir/trace-events' comments pointing to source files. That's because when trace-events got split up, the comments were moved verbatim. Delete the sub/dir/ part from these comments. Gets rid of several misspellings. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-id: 20190314180929.27722-3-armbru@redhat.com Message-Id: <20190314180929.27722-3-armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2019-02-21char/spice: discard write() if backend is disconnectedMarc-André Lureau
Most chardev backend handle write() as discarded data if underlying system is disconnected. For unknown historical reasons, the Spice backend has "reliable" write: it will wait until the client end is reconnected to do further successful write(). To decide whether it make sense to wait until the client is reconnected (or queue the writes), let's review Spice chardev usage and handling of a disconnected client: * spice vdagent The agents reopen the virtio port on disconnect. In qemu side, virtio_serial_close() will also discard pending data. * usb redirection A disconnect creates a device disconnection. * smartcard emulation Data is discarded in passthru_apdu_from_guest(). (Spice doesn't explicitly open the smartcard char device until upcoming 0.14.2, commit 69a5cfc74131ec0459f2eb5a231139f5a69a8037) * spice webdavd The daemon will restart the service, and reopen the virtio port. * spice ports (serial console, qemu monitor..) Depends on the associated device or usage. - serial, may be throttled or discarded on write, depending on device - QMP/HMP monitor have some CLOSED event handling, but want to flush the write, which will finish when a new client connects. On disconnect/reconnect, the client starts with fresh sessions. If it is a seamless migration, the client disconnects after the source migrated. The handling of source disconnect in qemu is thus irrelevant for the Spice session migration. For all these use cases, it is better to discard writes when the client is disconnected, and require the vm-side device/agent to behave correctly on CHR_EVENT_CLOSED, to stop reading and writing from the spice chardev. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Victor Toso <victortoso@redhat.com> Message-id: 20190221110703.5775-3-marcandre.lureau@redhat.com Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
2017-07-31docs: fix broken paths to docs/devel/tracing.txtPhilippe Mathieu-Daudé
With the move of some docs/ to docs/devel/ on ac06724a71, no references were updated. Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2017-06-02char: move char devices to chardev/Marc-André Lureau
Suggested by Paolo Bonzini during series review. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>