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2018-12-18qmp hmp: Make system_wakeup check wake-up support and run stateDaniel Henrique Barboza
The qmp/hmp command 'system_wakeup' is simply a direct call to 'qemu_system_wakeup_request' from vl.c. This function verifies if runstate is SUSPENDED and if the wake up reason is valid before proceeding. However, no error or warning is thrown if any of those pre-requirements isn't met. There is no way for the caller to differentiate between a successful wakeup or an error state caused when trying to wake up a guest that wasn't suspended. This means that system_wakeup is silently failing, which can be considered a bug. Adding error handling isn't an API break in this case - applications that didn't check the result will remain broken, the ones that check it will have a chance to deal with it. Adding to that, the commit before previous created a new QMP API called query-current-machine, with a new flag called wakeup-suspend-support, that indicates if the guest has the capability of waking up from suspended state. Although such guest will never reach SUSPENDED state and erroring it out in this scenario would suffice, it is more informative for the user to differentiate between a failure because the guest isn't suspended versus a failure because the guest does not have support for wake up at all. All this considered, this patch changes qmp_system_wakeup to check if the guest is capable of waking up from suspend, and if it is suspended. After this patch, this is the output of system_wakeup in a guest that does not have wake-up from suspend support (ppc64): (qemu) system_wakeup wake-up from suspend is not supported by this guest (qemu) And this is the output of system_wakeup in a x86 guest that has the support but isn't suspended: (qemu) system_wakeup Unable to wake up: guest is not in suspended state (qemu) Reported-by: Balamuruhan S <bala24@linux.vnet.ibm.com> Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com> Message-Id: <20181205194701.17836-4-danielhb413@gmail.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Acked-by: Eduardo Habkost <ehabkost@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>
2018-10-02serial: fix DLL writesPaolo Bonzini
Commit 0147883450fe84bb8de2d4a58381881f4262ce9b tries to handle word-sized writes to DLL/DLH, but due to a typo, this patch is causing tracebacks in all Linux kernels running the PXA serial driver, due to an unexpected DLL register value. Here is the surrounding code from drivers/tty/serial/pxa.c: serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */ /* * work around Errata #75 according to Intel(R) PXA27x * Processor Family Specification Update (Nov 2005) */ dll = serial_in(up, UART_DLL); WARN_ON(dll != (quot & 0xff)); // <-- warning Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Fixes: 0147883450fe84bb8de2d4a58381881f4262ce9b Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-16hw/char/serial: retry write if EAGAINMarc-André Lureau
If the chardev returns -1 with EAGAIN errno on write(), it should try to send it again (EINTR is handled by the chardev itself). This fixes commit 019288bf137183bf3407c9824655b753bfafc99f "hw/char/serial: Only retry if qemu_chr_fe_write returns 0" Tested-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180716110755.12499-1-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-07-16PC Chipset: Improve serial divisor calculationCalvin Lee
This fixes several problems I found in the UART serial implementation. Now all divisor values are allowed, while before divisor values of zero and below the base baud rate were rejected. All changes are in reference to http://www.sci.muni.cz/docs/pc/serport.txt Signed-off-by: Calvin Lee <cyrus296@gmail.com> Message-Id: <20180512000545.966-2-cyrus296@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-30Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' ↵Peter Maydell
into staging Pull request * Python 3 support in simpletrace.py * Convert DPRINTF() to trace events # gpg: Signature made Fri 29 Jun 2018 18:53:05 BST # gpg: using RSA key 9CA4ABB381AB73C8 # gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" # gpg: aka "Stefan Hajnoczi <stefanha@gmail.com>" # Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35 775A 9CA4 ABB3 81AB 73C8 * remotes/stefanha/tags/tracing-pull-request: hw/block/pflash_cfi: Convert from DPRINTF() macro to trace events hw/block/fdc: Convert from FLOPPY_DPRINTF() macro to trace events hw/net/etraxfs_eth: Convert printf() calls to trace events hw/net/ne2000: Convert printf() calls to trace events hw/net/ne2000: Add trace events hw/input/tsc2005: Convert a fprintf() call to trace events hw/char/parallel: Convert from pdebug() macro to trace events hw/char/serial: Convert from DPRINTF macro to trace events sdcard: Reduce sdcard_set_blocklen() trace digits trace: Fix format string for the struct timeval members casted to size_t simpletrace: Convert name from mapping record to str Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2018-06-29hw/char/serial: Convert from DPRINTF macro to trace eventsPhilippe Mathieu-Daudé
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-06-28hw/char/serial: Only retry if qemu_chr_fe_write returns 0Sergio Lopez
Only retry on serial_xmit if qemu_chr_fe_write returns 0, as this is the only recoverable error. Retrying with any other scenario, in addition to being a waste of CPU cycles, can compromise the Guest stability if by the vCPU issuing the write and the main loop thread are, by chance or explicit pinning, running on the same pCPU. Previous discussion: https://lists.nongnu.org/archive/html/qemu-devel/2018-05/msg06998.html Signed-off-by: Sergio Lopez <slp@redhat.com> Message-Id: <1528185295-14199-1-git-send-email-slp@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-06-01hw: Do not include "exec/address-spaces.h" if it is not necessaryPhilippe Mathieu-Daudé
Code change produced with: $ git grep '#include "exec/address-spaces.h"' hw include/hw | \ cut -d: -f-1 | \ xargs egrep -L "(get_system_|address_space_)" | \ xargs sed -i.bak '/#include "exec\/address-spaces.h"/d' Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20180528232719.4721-12-f4bug@amsat.org> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-04-26hw/char/serial: Allow disconnected chardevsPeter Maydell
Currently the serial.c realize code has an explicit check that it is not connected to a disconnected backend (ie one with a NULL chardev). This isn't what we want -- you should be able to create a serial device even if it isn't attached to anything. Remove the check. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Acked-by: Thomas Huth <thuth@redhat.com> Message-id: 20180420145249.32435-2-peter.maydell@linaro.org
2017-11-06Enable 8-byte wide MMIO for 16550 serial devicesMike Nawrocki
Some drivers for the PPMC7400 PowerPC evaluation board accesses the serial registers through the floating point unit (stfd/ldfd), which is an 8-byte wide access. This patch enables that behavior. Signed-off-by: Mike Nawrocki <michael.nawrocki@gtri.gatech.edu> Message-Id: <20171106161039.32596-1-michael.nawrocki@gtri.gatech.edu> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-09-27migration: pre_save return intDr. David Alan Gilbert
Modify the pre_save method on VMStateDescription to return an int rather than void so that it potentially can fail. Changed zillions of devices to make them return 0; the only case I've made it return non-0 is hw/intc/s390_flic_kvm.c that already had an error_report/return case. Note: If you add an error exit in your pre_save you must emit an error_report to say why. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Message-Id: <20170925112917.21340-2-dgilbert@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2017-07-14serial: chardev hotswap supportAnton Nefedov
This allows to change the port's backend runtime, e.g. change it from file to a socket making it possible to establish a debug session with WinDbg > qemu-system [..] -chardev file,id=charchannel2,path=/tmp/charchannel2 \ -device isa-serial,chardev=charchannel2,id=channel2 QEMU 2.9.50 monitor - type 'help' for more information (qemu) chardev-change charchannel2 \ socket,host=127.0.0.1,port=4242,server,nowait For a backend change, a number of ioctls has to be replayed to sync the current setup of a frontend to a backend tty. This is hopefully enough so we don't have to track, store and replay the whole original control byte sequence. Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <1499342940-56739-14-git-send-email-anton.nefedov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14serial: move TIOCM update to a separate functionAnton Nefedov
will be used by the following patch Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1499342940-56739-13-git-send-email-anton.nefedov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14char: avoid chardevice direct accessAnton Nefedov
frontends should avoid accessing CharDriver struct where possible Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1499342940-56739-6-git-send-email-anton.nefedov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-07-14char: add backend hotswap handlerAnton Nefedov
Frontends should have an interface to setup the handler of a backend change. The interface will be used in the next commits Signed-off-by: Anton Nefedov <anton.nefedov@virtuozzo.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <1499342940-56739-3-git-send-email-anton.nefedov@virtuozzo.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-02char: make chr_fe_deinit() optionaly delete backendMarc-André Lureau
This simplifies removing a backend for a frontend user (no need to retrieve the associated driver and separate delete call etc). NB: many frontends have questionable handling of ending a chardev. They should probably delete the backend to prevent broken reusage. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-06-02chardev: serial & parallel declaration to own headersMarc-André Lureau
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-06-02chardev: move headers to include/chardevMarc-André Lureau
So they are all in one place. The following patch will move serial & parallel declarations to the respective headers. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
2017-01-27char: rename CharDriverState ChardevMarc-André Lureau
Pick a uniform chardev type name. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-01-16serial: fix memory leak in serial exitLi Qiang
The serial_exit_core function doesn't free some resources. This can lead memory leak when hotplug and unplug. This patch avoid this. Signed-off-by: Li Qiang <liqiang6-s@360.cn> Message-Id: <586cb5ab.f31d9d0a.38ac3.acf2@mx.google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24char: remove explicit_fe_open, use a set_handlers argumentMarc-André Lureau
No need to keep explicit_fe_open around if it affects only a qemu_chr_fe_set_handlers(). Use an additional argument instead. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20161022095318.17775-24-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24char: replace qemu_chr_claim/release with qemu_chr_fe_init/deinitMarc-André Lureau
Now that all front end use qemu_chr_fe_init(), we can move chardev claiming in init(), and add a function deinit() to release the chardev and cleanup handlers. The qemu_chr_fe_claim_no_fail() for property are gone, since the property will raise an error instead. In other cases, where there is already an error path, an error is raised instead. Finally, other cases are handled by &error_abort in qemu_chr_fe_init(). Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20161022095318.17775-19-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24char: use qemu_chr_fe* functions with CharBackend argumentMarc-André Lureau
This also switches from qemu_chr_add_handlers() to qemu_chr_fe_set_handlers(). Note that qemu_chr_fe_set_handlers() now takes the focus when fe_open (qemu_chr_add_handlers() did take the focus) Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20161022095318.17775-16-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24char: rename some frontend functionsMarc-André Lureau
qemu_chr_accept_input() and qemu_chr_disconnect() are only used by frontend, so use qemu_chr_fe prefix. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20161022095318.17775-14-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24char: replace PROP_CHR with CharBackendMarc-André Lureau
Store the property in a CharBackend instead of CharDriverState*. This also replace systematically chr by chr.chr to access the CharDriverState*. The following patches will replace it with calls to qemu_chr_fe CharBackend functions. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20161022095318.17775-12-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-10-24char: serial: check divider value against baud basePrasad J Pandit
16550A UART device uses an oscillator to generate frequencies (baud base), which decide communication speed. This speed could be changed by dividing it by a divider. If the divider is greater than the baud base, speed is set to zero, leading to a divide by zero error. Add check to avoid it. Reported-by: Huawei PSIRT <psirt@huawei.com> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Message-Id: <1476251888-20238-1-git-send-email-ppandit@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-29serial: reinstate watch after migrationPaolo Bonzini
Otherwise, a serial port can get stuck if it is migrated while flow control is in effect. Tested-by: Bret Ketchum <bcketchum@gmail.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-29serial: remove watch on resetPaolo Bonzini
Otherwise, this can cause serial_xmit to be entered with LSR.TEMT=0, which is invalid and causes an assertion failure. Reported-by: Bret Ketchum <bcketchum@gmail.com> Tested-by: Bret Ketchum <bcketchum@gmail.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-29serial: separate serial_xmit and serial_watch_cbPaolo Bonzini
serial_xmit starts transmission of whatever is in the transmitter register, THR or FIFO; serial_watch_cb is a wrapper around it and is only used as a qemu_chr_fe_add_watch callback. Tested-by: Bret Ketchum <bcketchum@gmail.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-29serial: simplify tsr_retry resetPaolo Bonzini
Move common code outside the if, and reset tsr_retry even in loopback mode. Right now it cannot become non-zero, but it will be possible as soon as we start respecting the baud rate. Tested-by: Bret Ketchum <bcketchum@gmail.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-06-29serial: make tsr_retry unsignedPaolo Bonzini
It can never become negative; reflect this in the type of the field and simplify the conditions. Tested-by: Bret Ketchum <bcketchum@gmail.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22Replaced get_tick_per_sec() by NANOSECONDS_PER_SECONDRutuja Shah
This patch replaces get_ticks_per_sec() calls with the macro NANOSECONDS_PER_SECOND. Also, as there are no callers, get_ticks_per_sec() is then removed. This replacement improves the readability and understandability of code. For example, timer_mod(fdctrl->result_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (get_ticks_per_sec() / 50)); NANOSECONDS_PER_SECOND makes it obvious that qemu_clock_get_ns matches the unit of the expression on the right side of the plus. Signed-off-by: Rutuja Shah <rutu.shah.26@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-22include/qemu/osdep.h: Don't include qapi/error.hMarkus Armbruster
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the Error typedef. Since then, we've moved to include qemu/osdep.h everywhere. Its file comment explains: "To avoid getting into possible circular include dependencies, this file should not include any other QEMU headers, with the exceptions of config-host.h, compiler.h, os-posix.h and os-win32.h, all of which are doing a similar job to this file and are under similar constraints." qapi/error.h doesn't do a similar job, and it doesn't adhere to similar constraints: it includes qapi-types.h. That's in excess of 100KiB of crap most .c files don't actually need. Add the typedef to qemu/typedefs.h, and include that instead of qapi/error.h. Include qapi/error.h in .c files that need it and don't get it now. Include qapi-types.h in qom/object.h for uint16List. Update scripts/clean-includes accordingly. Update it further to match reality: replace config.h by config-target.h, add sysemu/os-posix.h, sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h comment quoted above similarly. This reduces the number of objects depending on qapi/error.h from "all of them" to less than a third. Unfortunately, the number depending on qapi-types.h shrinks only a little. More work is needed for that one. Signed-off-by: Markus Armbruster <armbru@redhat.com> [Fix compilation without the spice devel packages. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-01-29x86: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1453832250-766-11-git-send-email-peter.maydell@linaro.org
2016-01-13Use error_fatal to simplify obvious fatal errorsMarkus Armbruster
Done with this Coccinelle semantic patch: @@ type T; identifier FUN, RET; expression list ARGS; expression ERR, EC; @@ ( - T RET = FUN(ARGS, &ERR); + T RET = FUN(ARGS, &error_fatal); | - RET = FUN(ARGS, &ERR); + RET = FUN(ARGS, &error_fatal); | - FUN(ARGS, &ERR); + FUN(ARGS, &error_fatal); ) - if (ERR != NULL) { - error_report_err(ERR); - exit(EC); - } This is actually a more elegant version of my initial semantic patch by courtesy of Eduardo. It leaves dead Error * variables behind, cleaned up manually. Cc: qemu-arm@nongnu.org Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
2015-06-12migration: Use normal VMStateDescriptions for SubsectionsJuan Quintela
We create optional sections with this patch. But we already have optional subsections. Instead of having two mechanism that do the same, we can just generalize it. For subsections we just change: - Add a needed function to VMStateDescription - Remove VMStateSubsection (after removal of the needed function it is just a VMStateDescription) - Adjust the whole tree, moving the needed function to the corresponding VMStateDescription Signed-off-by: Juan Quintela <quintela@redhat.com>
2015-02-18error: Use error_report_err() where appropriateMarkus Armbruster
Coccinelle semantic patch: @@ expression E; @@ - error_report("%s", error_get_pretty(E)); - error_free(E); + error_report_err(E); @@ expression E, S; @@ - error_report("%s", error_get_pretty(E)); + error_report_err(E); ( exit(S); | abort(); ) Trivial manual touch-ups in block/sheepdog.c. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
2015-02-10serial: Fix warnings caused by missing 'static' attributeStefan Weil
Warnings from the Sparse static analysis tool: hw/char/serial.c:630:26: warning: symbol 'vmstate_serial_thr_ipending' was not declared. Should it be static? hw/char/serial.c:646:26: warning: symbol 'vmstate_serial_tsr' was not declared. Should it be static? hw/char/serial.c:665:26: warning: symbol 'vmstate_serial_recv_fifo' was not declared. Should it be static? hw/char/serial.c:681:26: warning: symbol 'vmstate_serial_xmit_fifo' was not declared. Should it be static? hw/char/serial.c:697:26: warning: symbol 'vmstate_serial_fifo_timeout_timer' was not declared. Should it be static? hw/char/serial.c:713:26: warning: symbol 'vmstate_serial_timeout_ipending' was not declared. Should it be static? hw/char/serial.c:729:26: warning: symbol 'vmstate_serial_poll' was not declared. Should it be static? Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2015-01-26vmstate: accept QEMUTimer in VMSTATE_TIMER*, add VMSTATE_TIMER_PTR*Paolo Bonzini
Old users of VMSTATE_TIMER* are mechanically changed to VMSTATE_TIMER_PTR variants. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-01-03serial: refine serial_thr_ipending_neededPaolo Bonzini
If the THR interrupt is disabled, there is no need to migrate thr_ipending because LSR.THRE will be sampled again when the interrupt is enabled. (This is the behavior that is not documented in the datasheet, but relied on by Windows!) Note that in this case IIR will never be 0x2 so, if thr_ipending were to be one, QEMU would produce the subsection. Reported-by: Igor Mammedov <imammedo@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-15serial: only resample THR interrupt on rising edge of IER.THRIPaolo Bonzini
There is disagreement on whether LSR.THRE should be resampled when IER.THRI goes from 1 to 1. Bochs only does it if IER.THRI goes from 0 to 1; PCE does it even if IER.THRI is unchanged. But the Windows driver seems to always go from 1 to 0 and back to 1, so do things in agreement with Bochs, because the handling of thr_ipending was reported in 2010 (https://lists.gnu.org/archive/html/qemu-devel/2010-03/msg01914.html) as breaking DR-DOS Plus. Reported-by: Roy Tam <roytam@gmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-15serial: update LSR on enabling/disabling FIFOsPaolo Bonzini
When the transmit FIFO is emptied or enabled, the transmitter hold register is empty. When it is disabled, it is also emptied and in addition the previous contents of the transmitter hold register are discarded. In either case, the THRE bit in LSR must be set and THRI raised. When the receive FIFO is emptied or enabled, the data ready and break bits must be cleared in LSR. Likewise when the receive FIFO is disabled. Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-15serial: clean up THRE/TEMT handlingPaolo Bonzini
- assert TEMT is cleared before sending a character; we'll get one from TSR if tsr_retry > 0, from the FIFO or THR otherwise - assert THRE cleared and FIFO not empty (if enabled) before fetching a character to send. This effectively reverts dffacd46, but the check makes no sense and commit f702e62 (serial: change retry logic to avoid concurrency, 2014-07-11) must have made it unnecessary. The commit message for f702e62 talks about multiple calls to qemu_chr_fe_add_watch triggering s->tsr_retry >= MAX_XMIT_RETRY, but other failures were possible. For example, if you have multiple calls, the subsequent ones will see s->tsr_retry == 0 and will find THRE and/or TEMT on entry. - for clarity, raise THRI immediately after the code sets THRE - check THRE to see if another character has to be sent. This makes the assertions more obvious and also means TEMT has to be set as soon as the loop ends. It makes the loop send both TSR and THR if flow-control happens in non-FIFO mode. Previously, THR would be lost. - clear TEMT together with THRE even in the non-FIFO case The last two items are bugfixes, but they were just found by inspection and do not squash known bugs. Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-12-15serial: reset thri_pending on IER writes with THRI=0Paolo Bonzini
This is responsible for failure of migration from 2.2 to 2.1, because thr_ipending is always one in practice. serial.c is setting thr_ipending unconditionally. However, thr_ipending is not used at all if THRI=0, and it will be overwritten again the next time THRE or THRI changes. For that reason, we can set thr_ipending to zero every time THRI is reset. There is disagreement on whether LSR.THRE should be resampled when IER.THRI goes from 1 to 1. This patch does not touch the code, leaving that for QEMU 2.3+. This has no semantic change and is enough to fix migration in the common case where the interrupt is not pending or is reported in IIR. It does not change the migration format, so 2.2.0 -> 2.1 will remain broken but we can fix 2.2.1 -> 2.1 without breaking 2.2.1 <-> 2.2.0. The case that remains broken (the one in which the subsection is strictly necessary) is when THRE=1, the THRI interrupt has *not* been acknowledged yet, and a higher-priority interrupt comes. In this case, you need the subsection to tell the source that the lower-priority THRI interrupt is pending. The subsection's breakage of migration, in this case, prevents continuing the VM on the destination with an invalid state. Cc: qemu-stable@nongnu.org Reported-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-19serial: check if backed by a physical serial port at realize timePaolo Bonzini
Right now, s->poll_msl may linger at "0" value for an arbitrarily long time, until serial_update_msl is called for the first time. This is unnecessary, and will lead to the s->poll_msl field being unnecessarily migrated. We can call serial_update_msl immediately at realize time (via serial_reset) and be done with it. The memory-mapped UART was already doing that, but not the ISA and PCI variants. Regarding the delta bits, be consistent with what serial_reset does when the serial port is not backed by a physical serial port, and always clear them at reset time. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-19serial: reset state at startupPaolo Bonzini
When a serial port is started, its initial state is all zero. Make it consistent with reset state instead. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-09-11serial: fixing vmstate for save/restorePavel Dovgalyuk
Some fields were added to VMState by this patch to preserve correct loading of the serial port controller state. Updating FCR value while loading was also modified to disable generating an interrupt by loadvm. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-14serial: change retry logic to avoid concurrencyKirill Batuzov
Whenever serial_xmit fails to transmit a byte it adds a watch that would call it again when the "line" becomes ready. This results in a retry chain: serial_xmit -> add_watch -> serial_xmit Each chain is able to transmit one character, and for every character passed to serial by the guest driver a new chain is spawned. The problem lays with the fact that a new chain is spawned even when there is one already waiting on the watch. So there can be several retry chains waiting concurrently on one "line". Every chain tries to transmit current character, so character order is not messed up. But also every chain increases retry counter (tsr_retry). If there are enough concurrent chains this counter will hit MAX_XMIT_RETRY value and the character will be dropped. To reproduce this bug you need to feed serial output to some program consuming it slowly enough. A python script from bug #1335444 description is an example of such program. This commit changes retry logic in the following way to avoid concurrency: instead of spawning a new chain for each character being transmitted spawn only one and make it transmit characters until FIFO is empty. The change consists of two parts: - add a do {} while () loop in serial_xmit (diff is a bit erratic for this part, diff -w will show actual change), - do not call serial_xmit from serial_ioport_write if there is one waiting on the watch already. This should fix another issue causing bug #1335444. Signed-off-by: Kirill Batuzov <batuzovk@ispras.ru> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-30serial: poll the serial console with G_IO_HUPRoger Pau Monne
On FreeBSD polling a master pty while the other end is not connected with G_IO_OUT only results in an endless wait. This is different from the Linux behaviour, that returns immediately. In order to demonstrate this, I have the following example code: http://xenbits.xen.org/people/royger/test_poll.c When executed on Linux: $ ./test_poll In callback On FreeBSD instead, the callback never gets called: $ ./test_poll So, in order to workaround this, poll the source with G_IO_HUP (which makes the code behave the same way on both Linux and FreeBSD). Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Cc: Peter Crosthwaite <peter.crosthwaite@xilinx.com> Cc: Michael Tokarev <mjt@tls.msk.ru> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: xen-devel@lists.xenproject.org [Add hw/char/cadence_uart.c too. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-06-16savevm: Remove all the unneeded version_minimum_id_old (x86)Juan Quintela
After previous Peter patch, they are redundant. This way we don't assign them except when needed. Once there, there were lots of case where the ".fields" indentation was wrong: .fields = (VMStateField []) { and .fields = (VMStateField []) { Change all the combinations to: .fields = (VMStateField[]){ The biggest problem (appart from aesthetics) was that checkpatch complained when we copy&pasted the code from one place to another. Signed-off-by: Juan Quintela <quintela@redhat.com> Acked-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
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