hw/avr: Add limited support for some Arduino boards

Arduino boards are build with AVR chipsets. Add some of these
boards:

  - Arduino Duemilanove
  - Arduino Uno
  - Arduino Mega

For more information:
  https://www.arduino.cc/en/Main/Products
  https://store.arduino.cc/arduino-genuino/most-popular

[AM: Remove word 'Atmel' from filenames and all elements of code]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Joaquin de Andres <me@xcancerberox.com.ar>
[thuth: sysbus_init_child_obj() ==> object_initialize_child()]
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-26-huth@tuxfamily.org>

hw/avr: Add some ATmega microcontrollers

Add some AVR microcontrollers from the ATmega family:

  - middle range: ATmega168 and ATmega328
  - high range: ATmega1280 and ATmega2560

For product comparison:
  https://www.microchip.com/wwwproducts/ProductCompare/ATmega168P/ATmega328P
  https://www.microchip.com/wwwproducts/ProductCompare/ATmega1280/ATmega2560

Datasheets:
  http://ww1.microchip.com/downloads/en/DeviceDoc/ATmega48A-PA-88A-PA-168A-PA-328-P-DS-DS40002061A.pdf
  http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-2549-8-bit-AVR-Microcontroller-ATmega640-1280-1281-2560-2561_datasheet.pdf

[AM: Remove word 'Atmel' from filenames and all elements of code]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
[thuth: Rebased to master, fixed object_initialize_child() calls etc.]
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-25-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

hw/avr: Add support for loading ELF/raw binaries

Add avr_load_firmware() function to load firmware in ELF or
raw binary format.

[AM: Corrected the type of the variable containing e_flags]
[AM: Moved definition of e_flags conversion function to boot.c]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-24-huth@tuxfamily.org>
[PMD: Replace load_image_targphys() by load_image_mr()]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

hw/misc: avr: Add limited support for power reduction device

This is a simple device of just one register, and whenever this
register is written to it calls qemu_set_irq function for each
of 8 bits/IRQs. It is used to implement AVR Power Reduction.

[AM: Remove word 'Atmel' from filenames and all elements of code]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
[rth: Squash include fix and file rename from f4bug]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-22-huth@tuxfamily.org>

hw/timer: avr: Add limited support for 16-bit timer peripheral

These were designed to facilitate testing but should provide enough
function to be useful in other contexts.  Only a subset of the functions
of each peripheral is implemented, mainly due to the lack of a standard
way to handle electrical connections (like GPIO pins).

[AM: Remove word 'Atmel' from filenames and all elements of code]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Ed Robbins <E.J.C.Robbins@kent.ac.uk>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
[rth: Squash info mtree fixes and a file rename from f4bug]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[PMD: Use qemu_log_mask(LOG_UNIMP), replace goto by return]
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-21-huth@tuxfamily.org>
[PMD: Check cpu-frequency-hz property in realize()]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

hw/char: avr: Add limited support for USART peripheral

These were designed to facilitate testing but should provide enough
function to be useful in other contexts.  Only a subset of the functions
of each peripheral is implemented, mainly due to the lack of a standard
way to handle electrical connections (like GPIO pins).

[AM: Remove word 'Atmel' from filenames and all elements of code]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
[rth: Squash I/O size fix and file rename from f4bug]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-20-huth@tuxfamily.org>

tests/machine-none: Add AVR support

Add a single code line that will automatically provide
'machine none' test.

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-28-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Register AVR support with the rest of QEMU

Add AVR related definitions into QEMU, make AVR support buildable.

[AM: Remove word 'Atmel' from filenames and all elements of code]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-23-huth@tuxfamily.org>
[PMD: Fixed @avr tag in qapi/machine.json]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add support for disassembling via option '-d in_asm'

Provide function disassembles executed instruction when '-d in_asm' is
provided.

Example:

$ qemu-system-avr -bios free-rtos/Demo/AVR_ATMega2560_GCC/demo.elf -d in_asm
    ...
    IN:
    0x0000014a:  CALL      0x3808

    IN: main
    0x00003808:  CALL      0x4b4

    IN: vParTestInitialise
    0x000004b4:  LDI       r24, 255
    0x000004b6:  STS       r24, 0
    0x000004b8:  MULS      r16, r20
    0x000004ba:  OUT       $1, r24
    0x000004bc:  LDS       r24, 0
    0x000004be:  MULS      r16, r20
    0x000004c0:  OUT       $2, r24
    0x000004c2:  RET
    ...

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
[rth: Fix spacing and const mnemonic arrays]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-19-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Initialize TCG register variables

Initialize TCG register variables.

Co-developed-by: Richard Henderson <richard.henderson@linaro.org>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-18-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add instruction translation - CPU main translation function

Add the core of translation mechanism.

Co-developed-by: Richard Henderson <richard.henderson@linaro.org>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-17-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add instruction translation - MCU Control Instructions

This includes:
    - BREAK
    - NOP
    - SLEEP
    - WDR

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-16-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add instruction translation - Bit and Bit-test Instructions

This includes:
    - LSR, ROR
    - ASR
    - SWAP
    - SBI, CBI
    - BST, BLD
    - BSET, BCLR

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-15-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add instruction translation - Data Transfer Instructions

This includes:
    - MOV, MOVW
    - LDI, LDS LDX LDY LDZ
    - LDDY, LDDZ
    - STS, STX STY STZ
    - STDY, STDZ
    - LPM, LPMX
    - ELPM, ELPMX
    - SPM, SPMX
    - IN, OUT
    - PUSH, POP
    - XCH
    - LAS, LAC LAT

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-14-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add instruction translation - Branch Instructions

This includes:
    - RJMP, IJMP, EIJMP, JMP
    - RCALL, ICALL, EICALL, CALL
    - RET, RETI
    - CPSE, CP, CPC, CPI
    - SBRC, SBRS, SBIC, SBIS
    - BRBC, BRBS

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-13-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add instruction translation - Arithmetic and Logic Instructions

This includes:
- ADD, ADC, ADIW
- SBIW, SUB, SUBI, SBC, SBCI
- AND, ANDI
- OR, ORI, EOR
- COM, NEG
- INC, DEC
- MUL, MULS, MULSU
- FMUL, FMULS, FMULSU
- DES

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-12-huth@tuxfamily.org>
[PMD: Added qemu_log_mask(LOG_UNIMP) in trans_DES()]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add instruction translation - Register definitions

Start implementation of instructions by adding register definitions.

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-11-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add instruction helpers

Add helpers for instructions that need to interact with QEMU. Also,
add stubs for unimplemented instructions. Instructions SPM and WDR
are left unimplemented because they require emulation of complex
peripherals. The implementation of instruction SLEEP is very limited
due to the lack of peripherals to generate wake interrupts. Memory
access instructions are implemented here because some address ranges
actually refer to CPU registers.

Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-10-huth@tuxfamily.org>
[PMD: Replace cpu_physical_memory() API by address_space_ldst()
      API to fix running on big-endian host,
      reported and suggested by Peter Maydell]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add definitions of AVR core types

AVR core types are:

  - avr5
  - avr51
  - avr6

Each core type covers multiple AVR MCUs, mentioned in the comments
before definition of particular AVR core type (part of this patch).

AVR core type defines shared features that are valid for all AVR
MCUs belonging in that type.

[AM: Split a larger AVR introduction patch into logical units]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Co-developed-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-9-huth@tuxfamily.org>
[PMD: Only include reviewed cores: avr5/avr51/avr6]
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Introduce enumeration AVRFeature

This patch introduces enumeration "AVRFeature" that will be
used for defining various AVR core types.

[AM: Split a larger AVR introduction patch into logical units]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Co-developed-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-8-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: CPU class: Add GDB support

This includes GDB hooks for reading from wnd wrtiting to AVR
registers, and xml register definition file as well.

[AM: Split a larger AVR introduction patch into logical units]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Co-developed-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[thuth: Fixed avr_cpu_gdb_read_register() parameter]
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-7-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: CPU class: Add migration support

Add migration-related functions of AVR CPU class object.

[AM: Split a larger AVR introduction patch into logical units]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Co-developed-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-6-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: CPU class: Add memory management support

This patch introduces three memory-management-related functions
that will become part of AVR CPU class object.

[AM: Split a larger AVR introduction patch into logical units]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Co-developed-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-5-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: CPU class: Add interrupt handling support

This patch introduces functions avr_cpu_do_interrupt() and
avr_cpu_exec_interrupt() that are part of AVR CPU class object.

[AM: Split a larger AVR introduction patch into logical units]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Co-developed-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-4-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Introduce basic CPU class object

This patch introduces AVR CPU class object and its basic elements
and functions.

[AM: Split a larger AVR introduction patch into logical units]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Co-developed-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[thuth: Adjusted reset and parent_reset handling]
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-3-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

target/avr: Add basic parameters of the new platform

This includes definitions of various basic parameters needed
for integration of a new platform into QEMU.

[AM: Split a larger AVR introduction patch into logical units]
Suggested-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Co-developed-by: Michael Rolnik <mrolnik@gmail.com>
Co-developed-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Michael Rolnik <mrolnik@gmail.com>
Signed-off-by: Sarah Harris <S.E.Harris@kent.ac.uk>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Aleksandar Markovic <aleksandar.m.mail@gmail.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[thuth: Simplify MAINTAINERS right from the start]
Signed-off-by: Thomas Huth <huth@tuxfamily.org>
Message-Id: <20200705140315.260514-2-huth@tuxfamily.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2020-07-07-v2' into staging

Error reporting patches patches for 2020-07-07

# gpg: Signature made Fri 10 Jul 2020 14:24:42 BST
# gpg:                using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg:                issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2020-07-07-v2: (53 commits)
  xen: Use ERRP_GUARD()
  nbd: Use ERRP_GUARD()
  virtio-9p: Use ERRP_GUARD()
  fw_cfg: Use ERRP_GUARD()
  pflash: Use ERRP_GUARD()
  sd: Use ERRP_GUARD()
  scripts: Coccinelle script to use ERRP_GUARD()
  error: New macro ERRP_GUARD()
  hmp: Ignore Error objects where the return value suffices
  qdev: Ignore Error objects where the return value suffices
  qemu-img: Ignore Error objects where the return value suffices
  error: Avoid error_propagate() after migrate_add_blocker()
  qapi: Purge error_propagate() from QAPI core
  qapi: Smooth visitor error checking in generated code
  qapi: Smooth another visitor error checking pattern
  block/parallels: Simplify parallels_open() after previous commit
  error: Reduce unnecessary error propagation
  error: Eliminate error_propagate() manually
  error: Eliminate error_propagate() with Coccinelle, part 2
  error: Eliminate error_propagate() with Coccinelle, part 1
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

xen: Use ERRP_GUARD()

If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  No such cases are being fixed here.

This commit is generated by command

    sed -n '/^X86 Xen CPUs$/,/^$/{s/^F: //p}' MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-9-armbru@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]

nbd: Use ERRP_GUARD()

If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix several such cases, e.g. in nbd_read().

This commit is generated by command

    sed -n '/^Network Block Device (NBD)$/,/^$/{s/^F: //p}' \
        MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-8-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]

virtio-9p: Use ERRP_GUARD()

If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix such a case in
v9fs_device_realize_common().

This commit is generated by command

    sed -n '/^virtio-9p$/,/^$/{s/^F: //p}' MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-7-armbru@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]

fw_cfg: Use ERRP_GUARD()

If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  No such cases are being fixed here.

This commit is generated by command

    sed -n '/^Firmware configuration (fw_cfg)$/,/^$/{s/^F: //p}' \
        MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-6-armbru@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.  Coccinelle script rerun for commit 3203148917
"hw/nvram/fw_cfg: Add the FW_CFG_DATA_GENERATOR interface"]

pflash: Use ERRP_GUARD()

If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  No such cases are being fixed here.

This commit is generated by command

    sed -n '/^Parallel NOR Flash devices$/,/^$/{s/^F: //p}' \
        MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-5-armbru@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]

sd: Use ERRP_GUARD()

If we want to check error after errp-function call, we need to
introduce local_err and then propagate it to errp. Instead, use
the ERRP_GUARD() macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_GUARD() leaves errp as is if it's not NULL or
   &error_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_GUARD() macro.
Otherwise, this info will not be added when errp == &error_fatal
(the program will exit prior to the error_append_hint() or
error_prepend() call).  No such cases are being fixed here.

This commit is generated by command

    sed -n '/^SD (Secure Card)$/,/^$/{s/^F: //p}' \
        MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/errp-guard.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[Commit message tweaked]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-4-armbru@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci.  Commit message
tweaked again.]

scripts: Coccinelle script to use ERRP_GUARD()

Script adds ERRP_GUARD() macro invocations where appropriate and
does corresponding changes in code (look for details in
include/qapi/error.h)

Usage example:
spatch --sp-file scripts/coccinelle/errp-guard.cocci \
 --macro-file scripts/cocci-macro-file.h --in-place --no-show-diff \
 --max-width 80 FILES...

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-3-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[ERRP_AUTO_PROPAGATE() renamed to ERRP_GUARD(), and
auto-propagated-errp.cocci to errp-guard.cocci]

error: New macro ERRP_GUARD()

Introduce a new ERRP_GUARD() macro, to be used at start of functions
with an errp OUT parameter.

It has three goals:

1. Fix issue with error_fatal and error_prepend/error_append_hint: the
user can't see this additional information, because exit() happens in
error_setg earlier than information is added. [Reported by Greg Kurz]

2. Fix issue with error_abort and error_propagate: when we wrap
error_abort by local_err+error_propagate, the resulting coredump will
refer to error_propagate and not to the place where error happened.
(the macro itself doesn't fix the issue, but it allows us to [3.] drop
the local_err+error_propagate pattern, which will definitely fix the
issue) [Reported by Kevin Wolf]

3. Drop local_err+error_propagate pattern, which is used to workaround
void functions with errp parameter, when caller wants to know resulting
status. (Note: actually these functions could be merely updated to
return int error code).

To achieve these goals, later patches will add invocations
of this macro at the start of functions with either use
error_prepend/error_append_hint (solving 1) or which use
local_err+error_propagate to check errors, switching those
functions to use *errp instead (solving 2 and 3).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Merge comments properly with recent commit "error: Document Error API
usage rules", and edit for clarity.  Put ERRP_AUTO_PROPAGATE() before
its helpers, and touch up style.  Tweak commit message.]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707165037.1026246-2-armbru@redhat.com>
[Rename ERRP_AUTO_PROPAGATE() to ERRP_GUARD(), tweak commit message
again]

hmp: Ignore Error objects where the return value suffices

qdev_print_props() receives and throws away Error objects just to
check for object_property_get_str() and object_property_print()
failure.  Unnecessary, both return suitable values, so use those
instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-46-armbru@redhat.com>

qdev: Ignore Error objects where the return value suffices

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-45-armbru@redhat.com>

qemu-img: Ignore Error objects where the return value suffices

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-44-armbru@redhat.com>
[One more in img_amend() due to commit 0bc2a50e17 "qemu-option: Use
returned bool to check for failure"]

error: Avoid error_propagate() after migrate_add_blocker()

When migrate_add_blocker(blocker, &errp) is followed by
error_propagate(errp, err), we can often just as well do
migrate_add_blocker(..., errp).

Do that with this Coccinelle script:

    @@
    expression blocker, err, errp;
    expression ret;
    @@
    -    ret = migrate_add_blocker(blocker, &err);
    -    if (err) {
    +    ret = migrate_add_blocker(blocker, errp);
    +    if (ret < 0) {
             ... when != err;
    -        error_propagate(errp, err);
             ...
         }

    @@
    expression blocker, err, errp;
    @@
    -    migrate_add_blocker(blocker, &err);
    -    if (err) {
    +    if (migrate_add_blocker(blocker, errp) < 0) {
             ... when != err;
    -        error_propagate(errp, err);
             ...
         }

Double-check @err is not used afterwards.  Dereferencing it would be
use after free, but checking whether it's null would be legitimate.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-43-armbru@redhat.com>

qapi: Purge error_propagate() from QAPI core

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-42-armbru@redhat.com>

qapi: Smooth visitor error checking in generated code

Use visitor functions' return values to check for failure.  Eliminate
error_propagate() that are now unnecessary.  Delete @err that are now
unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-41-armbru@redhat.com>

qapi: Smooth another visitor error checking pattern

Convert

    visit_type_FOO(v, ..., &ptr, &err);
    ...
    if (err) {
        ...
    }

to

    visit_type_FOO(v, ..., &ptr, errp);
    ...
    if (!ptr) {
        ...
    }

for functions that set @ptr to non-null / null on success / error.

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-40-armbru@redhat.com>

block/parallels: Simplify parallels_open() after previous commit

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-39-armbru@redhat.com>

error: Reduce unnecessary error propagation

When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away, even when we need to keep error_propagate() for other
error paths.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-38-armbru@redhat.com>

error: Eliminate error_propagate() manually

When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous two commits did that for sufficiently simple
cases with Coccinelle.  Do it for several more manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-37-armbru@redhat.com>

error: Eliminate error_propagate() with Coccinelle, part 2

When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous commit did that with a Coccinelle script I
consider fairly trustworthy.  This commit uses the same script with
the matching of return taken out, i.e. we convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
    }

This is unsound: @err could still be read between afterwards.  I don't
know how to express "no read of @err without an intervening write" in
Coccinelle.  Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually.  qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>

error: Eliminate error_propagate() with Coccinelle, part 1

When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  Convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
        return ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
        return ...
    }

where nothing else needs @err.  Coccinelle script:

    @rule1 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
         if (
    (
    -        fun(args, &err, args2)
    +        fun(args, errp, args2)
    |
    -        !fun(args, &err, args2)
    +        !fun(args, errp, args2)
    |
    -        fun(args, &err, args2) op c1
    +        fun(args, errp, args2) op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    )
         }

    @rule2 forall@
    identifier fun, err, errp, lbl;
    expression list args, args2;
    expression var;
    binary operator op;
    constant c1, c2;
    symbol false;
    @@
    -    var = fun(args, &err, args2);
    +    var = fun(args, errp, args2);
         ... when != err
         if (
    (
             var
    |
             !var
    |
             var op c1
    )
            )
         {
             ... when != err
                 when != lbl:
                 when strict
    -        error_propagate(errp, err);
             ... when != err
    (
             return;
    |
             return c2;
    |
             return false;
    |
             return var;
    )
         }

    @depends on rule1 || rule2@
    identifier err;
    @@
    -    Error *err = NULL;
         ... when != err

Not exactly elegant, I'm afraid.

The "when != lbl:" is necessary to avoid transforming

         if (fun(args, &err)) {
             goto out
         }
         ...
     out:
         error_propagate(errp, err);

even though other paths to label out still need the error_propagate().
For an actual example, see sclp_realize().

Without the "when strict", Coccinelle transforms vfio_msix_setup(),
incorrectly.  I don't know what exactly "when strict" does, only that
it helps here.

The match of return is narrower than what I want, but I can't figure
out how to express "return where the operand doesn't use @err".  For
an example where it's too narrow, see vfio_intx_enable().

Silently fails to convert hw/arm/armsse.c, because Coccinelle gets
confused by ARMSSE being used both as typedef and function-like macro
there.  Converted manually.

Line breaks tidied up manually.  One nested declaration of @local_err
deleted manually.  Preexisting unwanted blank line dropped in
hw/riscv/sifive_e.c.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-35-armbru@redhat.com>

error: Avoid unnecessary error_propagate() after error_setg()

Replace

    error_setg(&err, ...);
    error_propagate(errp, err);

by

    error_setg(errp, ...);

Related pattern:

    if (...) {
        error_setg(&err, ...);
        goto out;
    }
    ...
 out:
    error_propagate(errp, err);
    return;

When all paths to label out are that way, replace by

    if (...) {
        error_setg(errp, ...);
        return;
    }

and delete the label along with the error_propagate().

When we have at most one other path that actually needs to propagate,
and maybe one at the end that where propagation is unnecessary, e.g.

    foo(..., &err);
    if (err) {
        goto out;
    }
    ...
    bar(..., &err);
 out:
    error_propagate(errp, err);
    return;

move the error_propagate() to where it's needed, like

    if (...) {
        foo(..., &err);
        error_propagate(errp, err);
        return;
    }
    ...
    bar(..., errp);
    return;

and transform the error_setg() as above.

In some places, the transformation results in obviously unnecessary
error_propagate().  The next few commits will eliminate them.

Bonus: the elimination of gotos will make later patches in this series
easier to review.

Candidates for conversion tracked down with this Coccinelle script:

    @@
    identifier err, errp;
    expression list args;
    @@
    -    error_setg(&err, args);
    +    error_setg(errp, args);
         ... when != err
         error_propagate(errp, err);

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-34-armbru@redhat.com>

qdev: Use returned bool to check for failure, Coccinelle part

The previous commit enables conversion of

    qdev_prop_set_drive_err(..., &err);
    if (err) {
    ...
    }

to

    if (!qdev_prop_set_drive_err(..., errp)) {
    ...
    }

Coccinelle script:

    @@
    identifier fun = qdev_prop_set_drive_err;
    expression list args;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err);
    -    if (err)
    +    if (!fun(args, &err))
         {
             ...
         }

One line break tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-33-armbru@redhat.com>

qdev: Make functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-32-armbru@redhat.com>

qom: Make functions taking Error ** return bool, not 0/-1

Just for consistency.  Also fix the example in object_set_props()'s
documentation.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-31-armbru@redhat.com>

qom: Use returned bool to check for failure, manual part

The previous commit used Coccinelle to convert from checking the Error
object to checking the return value.  Convert a few more manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-30-armbru@redhat.com>

qom: Use returned bool to check for failure, Coccinelle part

The previous commit enables conversion of

    foo(..., &err);
    if (err) {
        ...
    }

to

    if (!foo(..., errp)) {
        ...
    }

for QOM functions that now return true / false on success / error.
Coccinelle script:

    @@
    identifier fun = {
        object_apply_global_props, object_initialize_child_with_props,
        object_initialize_child_with_propsv, object_property_get,
        object_property_get_bool, object_property_parse, object_property_set,
        object_property_set_bool, object_property_set_int,
        object_property_set_link, object_property_set_qobject,
        object_property_set_str, object_property_set_uint, object_set_props,
        object_set_propv, user_creatable_add_dict,
        user_creatable_complete, user_creatable_del
    };
    expression list args, args2;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err, args2);
    -    if (err)
    +    if (!fun(args, &err, args2))
         {
             ...
         }

Fails to convert hw/arm/armsse.c, because Coccinelle gets confused by
ARMSSE being used both as typedef and function-like macro there.
Convert manually.

Line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-29-armbru@redhat.com>

qom: Make functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-28-armbru@redhat.com>

qom: Put name parameter before value / visitor parameter

The object_property_set_FOO() setters take property name and value in
an unusual order:

    void object_property_set_FOO(Object *obj, FOO_TYPE value,
                                 const char *name, Error **errp)

Having to pass value before name feels grating.  Swap them.

Same for object_property_set(), object_property_get(), and
object_property_parse().

Convert callers with this Coccinelle script:

    @@
    identifier fun = {
        object_property_get, object_property_parse, object_property_set_str,
        object_property_set_link, object_property_set_bool,
        object_property_set_int, object_property_set_uint, object_property_set,
        object_property_set_qobject
    };
    expression obj, v, name, errp;
    @@
    -    fun(obj, v, name, errp)
    +    fun(obj, name, v, errp)

Chokes on hw/arm/musicpal.c's lcd_refresh() with the unhelpful error
message "no position information".  Convert that one manually.

Fails to convert hw/arm/armsse.c, because Coccinelle gets confused by
ARMSSE being used both as typedef and function-like macro there.
Convert manually.

Fails to convert hw/rx/rx-gdbsim.c, because Coccinelle gets confused
by RXCPU being used both as typedef and function-like macro there.
Convert manually.  The other files using RXCPU that way don't need
conversion.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-27-armbru@redhat.com>
[Straightforwad conflict with commit 2336172d9b "audio: set default
value for pcspk.iobase property" resolved]

qom: Use return values to check for error where that's simpler

When using the Error object to check for error, we need to receive it
into a local variable, then propagate() it to @errp.

Using the return value permits allows receiving it straight to @errp.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-26-armbru@redhat.com>

qom: Don't handle impossible object_property_get_link() failure

Don't handle object_property_get_link() failure that can't happen
unless the programmer screwed up, pass &error_abort.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200707160613.848843-25-armbru@redhat.com>

qom: Crash more nicely on object_property_get_link() failure

Pass &error_abort instead of NULL where the returned value is
dereferenced or asserted to be non-null.  Drop a now redundant
assertion.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-24-armbru@redhat.com>

qom: Rename qdev_get_type() to object_get_type()

Commit 2f262e06f0 lifted qdev_get_type() from qdev to object without
renaming it accordingly.  Do that now.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-23-armbru@redhat.com>

qom: Use error_reportf_err() instead of g_printerr() in examples

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-22-armbru@redhat.com>

s390x/pci: Fix harmless mistake in zpci's property fid's setter

s390_pci_set_fid() sets zpci->fid_defined to true even when
visit_type_uint32() failed.  Reproducer: "-device zpci,fid=junk".
Harmless in practice, because qdev_device_add() then fails, throwing
away @zpci.  Fix it anyway.

Cc: Matthew Rosato <mjrosato@linux.ibm.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200707160613.848843-21-armbru@redhat.com>

qapi: Use returned bool to check for failure, manual part

The previous commit used Coccinelle to convert from checking the Error
object to checking the return value.  Convert a few more manually.
Also tweak control flow in places to conform to the conventional "if
error bail out" pattern.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-20-armbru@redhat.com>

qapi: Use returned bool to check for failure, Coccinelle part

The previous commit enables conversion of

    visit_foo(..., &err);
    if (err) {
        ...
    }

to

    if (!visit_foo(..., errp)) {
        ...
    }

for visitor functions that now return true / false on success / error.
Coccinelle script:

    @@
    identifier fun =~ "check_list|input_type_enum|lv_start_struct|lv_type_bool|lv_type_int64|lv_type_str|lv_type_uint64|output_type_enum|parse_type_bool|parse_type_int64|parse_type_null|parse_type_number|parse_type_size|parse_type_str|parse_type_uint64|print_type_bool|print_type_int64|print_type_null|print_type_number|print_type_size|print_type_str|print_type_uint64|qapi_clone_start_alternate|qapi_clone_start_list|qapi_clone_start_struct|qapi_clone_type_bool|qapi_clone_type_int64|qapi_clone_type_null|qapi_clone_type_number|qapi_clone_type_str|qapi_clone_type_uint64|qapi_dealloc_start_list|qapi_dealloc_start_struct|qapi_dealloc_type_anything|qapi_dealloc_type_bool|qapi_dealloc_type_int64|qapi_dealloc_type_null|qapi_dealloc_type_number|qapi_dealloc_type_str|qapi_dealloc_type_uint64|qobject_input_check_list|qobject_input_check_struct|qobject_input_start_alternate|qobject_input_start_list|qobject_input_start_struct|qobject_input_type_any|qobject_input_type_bool|qobject_input_type_bool_keyval|qobject_input_type_int64|qobject_input_type_int64_keyval|qobject_input_type_null|qobject_input_type_number|qobject_input_type_number_keyval|qobject_input_type_size_keyval|qobject_input_type_str|qobject_input_type_str_keyval|qobject_input_type_uint64|qobject_input_type_uint64_keyval|qobject_output_start_list|qobject_output_start_struct|qobject_output_type_any|qobject_output_type_bool|qobject_output_type_int64|qobject_output_type_null|qobject_output_type_number|qobject_output_type_str|qobject_output_type_uint64|start_list|visit_check_list|visit_check_struct|visit_start_alternate|visit_start_list|visit_start_struct|visit_type_.*";
    expression list args;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err);
    -    if (err)
    +    if (!fun(args, &err))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-19-armbru@redhat.com>

qapi: Make visitor functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-18-armbru@redhat.com>

hmp: Eliminate a variable in hmp_migrate_set_parameter()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-17-armbru@redhat.com>

block: Avoid error accumulation in bdrv_img_create()

When creating an image fails because the format doesn't support option
"backing_file" or "backing_fmt", bdrv_img_create() first has
qemu_opt_set() put a generic error into @local_err, then puts the real
error into @errp with error_setg(), and then propagates the former to
the latter, which throws away the generic error.  A bit complicated,
but works.

Now that qemu_opt_set() returns a useful value, we can simply ignore
the generic error instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-16-armbru@redhat.com>

qemu-option: Use returned bool to check for failure

The previous commit enables conversion of

    foo(..., &err);
    if (err) {
        ...
    }

to

    if (!foo(..., &err)) {
        ...
    }

for QemuOpts functions that now return true / false on success /
error.  Coccinelle script:

    @@
    identifier fun = {
        opts_do_parse, parse_option_bool, parse_option_number,
        parse_option_size, qemu_opt_parse, qemu_opt_rename, qemu_opt_set,
        qemu_opt_set_bool, qemu_opt_set_number, qemu_opts_absorb_qdict,
        qemu_opts_do_parse, qemu_opts_from_qdict_entry, qemu_opts_set,
        qemu_opts_validate
    };
    expression list args, args2;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err, args2);
    -    if (err)
    +    if (!fun(args, &err, args2))
         {
             ...
         }

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-15-armbru@redhat.com>
[Conflict with commit 0b6786a9c1 "block/amend: refactor qcow2 amend
options" resolved by rerunning Coccinelle on master's version]

qemu-option: Make functions taking Error ** return bool, not void

See recent commit "error: Document Error API usage rules" for
rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-14-armbru@redhat.com>

qemu-option: Replace opt_set() by cleaner opt_validate()

opt_set() frees its argument @value on failure.  Slightly unclean;
functions ideally do nothing on failure.

To tidy this up, move opt_create() from opt_set() into its callers,
along with the cleanup.  Rename opt_set() to opt_validate(), noting
its similarity to qemu_opts_validate().  Drop redundant parameter
@opts; use opt->opts instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-13-armbru@redhat.com>

qemu-option: Factor out helper opt_create()

There is just one use so far.  The next commit will add more.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-12-armbru@redhat.com>

qemu-option: Simplify around find_default_by_name()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-11-armbru@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>

qemu-option: Factor out helper find_default_by_name()

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-10-armbru@redhat.com>

qemu-option: Make uses of find_desc_by_name() more similar

This is to make the next commit easier to review.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-9-armbru@redhat.com>

qemu-option: Check return value instead of @err where convenient

Convert uses like

    opts = qemu_opts_create(..., &err);
    if (err) {
        ...
    }

to

    opts = qemu_opts_create(..., errp);
    if (!opts) {
        ...
    }

Eliminate error_propagate() that are now unnecessary.  Delete @err
that are now unused.

Note that we can't drop parallels_open()'s error_propagate() here.  We
continue to execute it even in the converted case.  It's a no-op then:
local_err is null.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-8-armbru@redhat.com>

virtio-crypto-pci: Tidy up virtio_crypto_pci_realize()

virtio_crypto_pci_realize() continues after realization of its
"virtio-crypto-device" fails.  Only an object_property_set_link()
follows; looks harmless to me.  Tidy up anyway: return after failure,
just like virtio_rng_pci_realize() does.

Cc: "Gonglei (Arei)" <arei.gonglei@huawei.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Gonglei < arei.gonglei@huawei.com>
Message-Id: <20200707160613.848843-7-armbru@redhat.com>

macio: Tidy up error handling in macio_newworld_realize()

macio_newworld_realize() effectively ignores ns->gpio realization
errors, leaking the Error object.  Fortunately, macio_gpio_realize()
can't actually fail.  Tidy up.

Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-6-armbru@redhat.com>

qdev: Use returned bool to check for qdev_realize() etc. failure

Convert

    foo(..., &err);
    if (err) {
        ...
    }

to

    if (!foo(..., &err)) {
        ...
    }

for qdev_realize(), qdev_realize_and_unref(), qbus_realize() and their
wrappers isa_realize_and_unref(), pci_realize_and_unref(),
sysbus_realize(), sysbus_realize_and_unref(), usb_realize_and_unref().
Coccinelle script:

    @@
    identifier fun = {
        isa_realize_and_unref, pci_realize_and_unref, qbus_realize,
        qdev_realize, qdev_realize_and_unref, sysbus_realize,
        sysbus_realize_and_unref, usb_realize_and_unref
    };
    expression list args, args2;
    typedef Error;
    Error *err;
    @@
    -    fun(args, &err, args2);
    -    if (err)
    +    if (!fun(args, &err, args2))
         {
             ...
         }

Chokes on hw/arm/musicpal.c's lcd_refresh() with the unhelpful error
message "no position information".  Nothing to convert there; skipped.

Fails to convert hw/arm/armsse.c, because Coccinelle gets confused by
ARMSSE being used both as typedef and function-like macro there.
Converted manually.

A few line breaks tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-5-armbru@redhat.com>

error: Document Error API usage rules

This merely codifies existing practice, with one exception: the rule
advising against returning void, where existing practice is mixed.

When the Error API was created, we adopted the (unwritten) rule to
return void when the function returns no useful value on success,
unlike GError, which recommends to return true on success and false on
error then.

When a function returns a distinct error value, say false, a checked
call that passes the error up looks like

    if (!frobnicate(..., errp)) {
        handle the error...
    }

When it returns void, we need

    Error *err = NULL;

    frobnicate(..., &err);
    if (err) {
        handle the error...
        error_propagate(errp, err);
    }

Not only is this more verbose, it also creates an Error object even
when @errp is null, &error_abort or &error_fatal.

People got tired of the additional boilerplate, and started to ignore
the unwritten rule.  The result is confusion among developers about
the preferred usage.

Make the rule advising against returning void official by putting it
in writing.  This will hopefully reduce confusion.

Update the examples accordingly.

The remainder of this series will update a substantial amount of code
to honor the rule.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-4-armbru@redhat.com>
[Tweak prose as per advice from Eric]

error: Improve error.h's big comment

Add headlines to the big comment.

Explain examples for NULL, &error_abort and &error_fatal argument
better.

Tweak rationale for error_propagate_prepend().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200707160613.848843-3-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>

error: Fix examples in error.h's big comment

Mark a bad example more clearly.  Fix the error_propagate_prepend()
example.  Add a missing declaration and a second error pileup example.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200707160613.848843-2-armbru@redhat.com>

Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' into staging

Pull request

Fix for a LTTng Userspace Tracer header problem.

# gpg: Signature made Tue 07 Jul 2020 16:10:04 BST
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request:
  tracetool: work around ust <sys/sdt.h> include conflict

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/philmd-gitlab/tags/fw_cfg-20200704' into staging

firmware (and crypto) patches

- add the tls-cipher-suites object,
- add the ability to QOM objects to produce data consumable
  by the fw_cfg device,
- let the tls-cipher-suites object implement the
  FW_CFG_DATA_GENERATOR interface.

This is required by EDK2 'HTTPS Boot' feature of OVMF to tell
the guest which TLS ciphers it can use.

CI jobs results:
  https://travis-ci.org/github/philmd/qemu/builds/704724619
  https://gitlab.com/philmd/qemu/-/pipelines/162938106
  https://cirrus-ci.com/build/4682977303068672

# gpg: Signature made Sat 04 Jul 2020 17:37:08 BST
# gpg:                using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [full]
# Primary key fingerprint: FAAB E75E 1291 7221 DCFD  6BB2 E3E3 2C2C DEAD C0DE

* remotes/philmd-gitlab/tags/fw_cfg-20200704:
  crypto/tls-cipher-suites: Produce fw_cfg consumable blob
  softmmu/vl: Allow -fw_cfg 'gen_id' option to use the 'etc/' namespace
  softmmu/vl: Let -fw_cfg option take a 'gen_id' argument
  hw/nvram/fw_cfg: Add the FW_CFG_DATA_GENERATOR interface
  crypto: Add tls-cipher-suites object

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/kraxel/tags/modules-20200707-pull-request' into staging

qom: add support for qom objects in modules.
build some devices (qxl, virtio-gpu, ccid, usb-redir) as modules.
build braille chardev as module.

v2: more verbose comment for "build: fix device module builds" patch.

note: qemu doesn't rebuild objects on cflags changes (specifically
      -fPIC being added when code is switched from builtin to module).
      Workaround for resulting build errors: "make clean", rebuild.

# gpg: Signature made Tue 07 Jul 2020 14:42:16 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/modules-20200707-pull-request:
  chardev: enable modules, use for braille
  vga: build virtio-gpu as module
  vga: build virtio-gpu only once
  vga: build qxl as module
  usb: build usb-redir as module
  ccid: build smartcard as module
  build: fix device module builds
  qdev: device module support
  object: qom module support
  module: qom module support

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-for-5.1-pull-request' into staging

trivial branch patches 20200707

# gpg: Signature made Tue 07 Jul 2020 11:52:06 BST
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/trivial-branch-for-5.1-pull-request:
  net/tap-solaris.c: Include qemu-common.h for TFR macro
  intel_iommu: "aw-bits" error message still refers to "x-aw-bits"
  util/qemu-option: Document the get_opt_value() function
  MAINTAINERS: Update Radoslaw Biernacki email address
  .mailmap: Update Alexander Graf email address
  trivial: Respect alphabetical order of .o files in Makefile.objs
  fix the prototype of muls64/mulu64

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/vivier/tags/m68k-next-pull-request' into staging

m68k pull-request 20200706

disable floatx80_invalid_encoding() for m68k
fix m68k_cpu_get_phys_page_debug()

# gpg: Signature made Mon 06 Jul 2020 21:05:33 BST
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier/tags/m68k-next-pull-request:
  softfloat,m68k: disable floatx80_invalid_encoding() for m68k
  target/m68k: consolidate physical translation offset into get_physical_address()
  target/m68k: fix physical address translation in m68k_cpu_get_phys_page_debug()

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/kraxel/tags/audio-20200706-pull-request' into staging

audio: deprecate -soundhw

# gpg: Signature made Mon 06 Jul 2020 20:29:07 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/audio-20200706-pull-request:
  audio: set default value for pcspk.iobase property
  pcspk: update docs/system/target-i386-desc.rst.inc
  audio: add soundhw deprecation notice
  audio: deprecate -soundhw pcspk
  audio: create pcspk device early
  audio: rework pcspk_init()
  softmmu: initialize spice and audio earlier
  pc_basic_device_init: drop no_vmport arg
  pc_basic_device_init: drop has_pit arg
  pc_basic_device_init: pass PCMachineState
  audio: deprecate -soundhw hda
  audio: deprecate -soundhw sb16
  audio: deprecate -soundhw gus
  audio: deprecate -soundhw cs4231a
  audio: deprecate -soundhw adlib
  audio: deprecate -soundhw es1370
  audio: deprecate -soundhw ac97
  audio: add deprecated_register_soundhw
  stubs: add pci_create_simple
  stubs: add isa_create_simple

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/rth/tags/pull-tcg-20200706' into staging

Fix for ppc shifts
Fix for non-parallel atomic ops

# gpg: Signature made Mon 06 Jul 2020 19:49:08 BST
# gpg:                using RSA key 7A481E78868B4DB6A85A05C064DF38E8AF7E215F
# gpg:                issuer "richard.henderson@linaro.org"
# gpg: Good signature from "Richard Henderson <richard.henderson@linaro.org>" [full]
# Primary key fingerprint: 7A48 1E78 868B 4DB6 A85A  05C0 64DF 38E8 AF7E 215F

* remotes/rth/tags/pull-tcg-20200706:
  tcg: Fix do_nonatomic_op_* vs signed operations
  tcg/ppc: Sanitize immediate shifts

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2020-07-06' into staging

Block patches for 5.1:
- LUKS keyslot amendment
  (+ patches to make the iotests pass on non-Linux systems, and to keep
     the tests passing for qcow v1, and to skip LUKS tests (including
     qcow2 LUKS) when the built qemu does not support it)
- Refactoring in the block layer: Drop the basically unnecessary
  unallocated_blocks_are_zero field from BlockDriverInfo
- Fix qcow2 preallocation when the image size is not a multiple of the
  cluster size
- Fix in block-copy code

# gpg: Signature made Mon 06 Jul 2020 11:02:53 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2020-07-06: (31 commits)
  qed: Simplify backing reads
  block: drop unallocated_blocks_are_zero
  block/vhdx: drop unallocated_blocks_are_zero
  block/file-posix: drop unallocated_blocks_are_zero
  block/iscsi: drop unallocated_blocks_are_zero
  block/crypto: drop unallocated_blocks_are_zero
  block/vpc: return ZERO block-status when appropriate
  block/vdi: return ZERO block-status when appropriate
  block: inline bdrv_unallocated_blocks_are_zero()
  qemu-img: convert: don't use unallocated_blocks_are_zero
  iotests: add tests for blockdev-amend
  block/qcow2: implement blockdev-amend
  block/crypto: implement blockdev-amend
  block/core: add generic infrastructure for x-blockdev-amend qmp command
  iotests: qemu-img tests for luks key management
  block/qcow2: extend qemu-img amend interface with crypto options
  block/crypto: implement the encryption key management
  block/crypto: rename two functions
  block/amend: refactor qcow2 amend options
  block/amend: separate amend and create options for qemu-img
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

virtio,acpi: features, fixes, cleanups.

vdpa support
virtio-mem support
a handy script for disassembling acpi tables
misc fixes and cleanups

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
# gpg: Signature made Tue 07 Jul 2020 13:00:35 BST
# gpg:                using RSA key 5D09FD0871C8F85B94CA8A0D281F0DB8D28D5469
# gpg:                issuer "mst@redhat.com"
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" [full]
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>" [full]
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream: (41 commits)
  vhost-vdpa: introduce vhost-vdpa net client
  vhost-vdpa: introduce vhost-vdpa backend
  vhost_net: introduce set_config & get_config
  vhost: implement vhost_force_iommu method
  vhost: introduce new VhostOps vhost_force_iommu
  vhost: implement vhost_vq_get_addr method
  vhost: introduce new VhostOps vhost_vq_get_addr
  vhost: implement vhost_dev_start method
  vhost: introduce new VhostOps vhost_dev_start
  vhost: check the existence of vhost_set_iotlb_callback
  virtio-pci: implement queue_enabled method
  virtio-bus: introduce queue_enabled method
  vhost_net: use the function qemu_get_peer
  net: introduce qemu_get_peer
  MAINTAINERS: add VT-d entry
  docs: vhost-user: add Virtio status protocol feature
  tests/acpi: remove stale allowed tables
  numa: Auto-enable NUMA when any memory devices are possible
  virtio-mem: Exclude unplugged memory during migration
  virtio-mem: Add trace events
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
# Conflicts:
# hw/arm/virt.c
# hw/virtio/trace-events

tracetool: work around ust <sys/sdt.h> include conflict

Both the dtrace and ust backends may include <sys/sdt.h> but LTTng
Userspace Tracer 2.11 and later requires SDT_USE_VARIADIC to be defined
before including the header file.

This is a classic problem with C header files included from different
parts of a program. If the same header is included twice within the same
compilation unit then the first inclusion determines the macro
environment.

Work around this by defining SDT_USE_VARIADIC in the dtrace backend too.
It doesn't hurt and fixes a missing STAP_PROBEV() compiler error when
the ust backend is enabled together with the dtrace backend.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20200625140757.237012-1-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

chardev: enable modules, use for braille

Removes brlapi library dependency from core qemu.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-11-kraxel@redhat.com

vga: build virtio-gpu as module

Drops libvirglrenderer.so dependency from core qemu.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-10-kraxel@redhat.com

vga: build virtio-gpu only once

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200624131045.14512-9-kraxel@redhat.com

vga: build qxl as module

First step in making spice support modular.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-8-kraxel@redhat.com

usb: build usb-redir as module

Drops libusbredirparser.so dependency from core qemu.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-7-kraxel@redhat.com

ccid: build smartcard as module

Drops libcacard.so dependency from core qemu.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-6-kraxel@redhat.com

build: fix device module builds

Slightly hackish workaround, works ok as long as we don't
have target-specific modules.  meson will obsolete this.

See comment in the patch for the --verbose description.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-5-kraxel@redhat.com

[ kraxel: updated comment from discussions ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

qdev: device module support

Hook module loading into the places where we
need it when building devices as modules.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-4-kraxel@redhat.com

object: qom module support

Little helper function to load modules on demand.  In most cases adding
module loading support for devices and other objects is just
s/object_class_by_name/module_object_class_by_name/ in the right spot.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-3-kraxel@redhat.com

module: qom module support

Add support for qom types provided by modules.  For starters use a
manually maintained list which maps qom type to module and prefix.

Two load functions are added:  One to load the module for a specific
type, and one to load all modules (needed for object/device lists as
printed by -- for example -- qemu -device help).

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-2-kraxel@redhat.com